Fast attack craft: a fresh start

Black and white image of a German Schnellboote just off land, waving a white flag and with its crew up on deckIn 1956, West Germany was permitted to start rearming as a key component of the Western alliance. Its first surface ships were ex-Allied types, but it was clear from the beginning that Germany’s expertise during World War II in the design and construction of advanced submarines and Schnellboote would soon result in the indigenous production of coastal submarine and fast combat craft. A head-start with the latter had been provided by Lürssen’s design of the Swedish ‘Perseus’ and the company’s part in the construction of the resulting ‘Plejad’ class of FAC(T)s, and this was reflected in Lürssen’s ‘TNC-42’ design for the ‘Jaguar’ FAC(T) type that entered West German service as the ‘Type 141’ class with great similarities to the Swedish ‘Spica I’ class.

Such coastal warfare types were needed for the protection of West Germany’s maritime frontiers on the Baltic and North Seas, east and west respectively of the Schleswig-Holstein isthmus connecting northern Germany with Denmark. The 40 ‘Jaguar’ class units were delivered in the late 1950s and early 1960s as orthodox but effective craft with a full-load displacement of 220 tons on a typical Lürssen non-magnetic hull that had an overall length of 42.6 m (139 ft 9 in) and a beam of 7.0 m (23 ft 0 in) under an aluminium alloy superstructure. The hull was of wooden construction, and revealed its Schnellboot ancestry in the raised turtledeck forecastle with a semi-well for the forward gun. The propulsion arrangement was also typical of its time, with four MTU diesels delivering 8940 kW (11,990 hp) to four shafts for a maximum speed of 35 kt or more, and the armament was a mix of the standard and slightly unusual. The standard part was the gun armament, which comprised a pair of 40-mm Bofors guns located forward and aft in open mountings, while the more unusual part was the torpedo armament, which comprised two aft-facing tubes to launch Seal wire-guided torpedoes over the stern. Fire-control was entrusted to the Dutch WM-20 system, which had the antennae for the search and tracking radars in the spherical glassfibre radome above and behind the bridge. The type has disappeared from service with the German navy, which latterly designated the upgraded survivors as the ‘Type 142’ or ‘Zobel’ class. The type’s relegation from German service was made possible by the advent of more capable craft, but coincided with the need of some of Germany’s NATO allies for improved coastal forces. Thus Greece and Turkey each received seven operational craft as well as three craft to be cannibalised for spares. Another three craft were later transferred to Saudi Arabia.

Additional construction resulted in eight craft for Indonesia and nine revised craft for Turkey. The Indonesian craft were completed as FAC(T)s, four of them with steel hulls and the other four with wooden hulls. The wooden-hulled type proved to have the greater survivability in tropical waters, and the two surviving craft are of this type. The craft built for Turkey comprise the ‘Kartal’ class of FAC(M/T)s, and these in fact preceded the transfer of ex-German ‘Jaguar’ class FAC(T)s. There are a few detail differences from the baseline ‘Jaguar’ class in the hull, but the propulsion arrangement and performance are broadly similar. Where the ‘Kartal’ class is a distinct improvement over the ‘Jaguar’ class, however, is in its impressive armament. This retains the two 40-mm Bofors guns and two 533-mm (21-in) tubes of the ‘Jaguar’ class, and has additional provision either for two more 533-mm tubes for a total of four heavyweight torpedoes in the FAC(T) mode or for four container-launchers for Penguin Mk II anti-ship missiles in the FAC(M/T) mode. In line with its FAC(M) capability, the ‘Kartal’ class also possesses a more sophisticated electronic suite than the ‘Jaguar’ class, its main element being the WM-28 radar fire-control system.

The ‘TNC-42’ design was the first of a family of Lürssen designs that have dominated the market for fast combat craft since the mid-1960s. These craft have been produced with aluminium alloy superstructures on hulls of different construction (steel for the export market and wood over steel frames for the domestic market), and are characterised by a high length/beam ratio, a flush deck without the turtledeck forecastle of the ‘TNC-42’ design, and the bridge structure located just forward of the amidships position with a deckhouse generally located farther aft on the units of the larger classes. This layout allows the installation of guns forward and aft, with the room for torpedo tubes on each side of the deck and/or missiles between the bridge and after deckhouse. The machinery space and after portion of the hull are arranged in such a fashion that different propulsion arrangements are possible, with different numbers of diesel engines powering two, three or four shafts as demanded by the purchaser’s operational needs and financial resources.

The smallest of the Lürssen FAC designs is the ‘FPB-36’ type dating from the early 1960s. Some 19 of the type were delivered to five customers in various forms as comparatively simple FACs with two or three shafts and gun, torpedo and missile armaments. Typical of them is the Spanish ‘Barceló’ class, whose lead unit was built by Lürssen and the other four under licence in Spain by Bazán, which also licence-produced the MTU diesels. These five craft were delivered as straightforward FAC(G)s with an armament of one 40-mm Bofors gun, two 20-mm Oerlikon-Bührle cannon in single mountings and two 0.5-in (12.7-mm) machine guns also in single mountings. The Spanish navy recognised, however, that the basic combination of hull and propulsion arrangement offered the possibility of greater combat capability, and therefore made provision for this in case it was required at a later date. The craft were thus fitted for but not with two 533-mm (21-in) tubes for heavyweight torpedoes in the FAC(T) role, while the omission of tubes and the removal of the 20-mm cannon allow the installation of four container-launchers for anti-ship missiles in the FAC(M) role.

The ‘FPB-38’ class may be regarded as the larger half-brother of the ‘FPB-36’ class with slightly greater size and displacement allowing the installation of heavier armament. Four such craft were built as FAC(G)s for the navies of two Persian Gulf states, their most notable feature being a main armament of two 40-mm Bofors guns built under licence in Italy by Breda and installed in a Breda twin mounting. Malaysia required 18 of the type, but these were used mainly in the high-speed patrol role with armament limited to two 20-mm Oerlikon-Bührle cannon and two 7.62-mm (0.3-in) machine guns.

Next up in size from the ‘FPB-38’ class is the ‘TNC-42’ design with which this important family of fast combat craft started. A general modernisation and slight enlargement of the design, to a length of some 45.0 m (147 ft 8 in) for a full-load displacement of about 260 tons, resulted in the remarkably successful ‘FPB/TNC-45’ type with provision for a two-, three- or four-shaft propulsion arrangement. The country responsible for the design was Israel, which had already turned to the concept of large fast combat craft after a reappraisal of the balance of naval power in the eastern Mediterranean during the first half of the 1960s. The correctness of this change of emphasis from medium-sized surface warships, such as destroyers and frigates, to a mix of small submarines and smaller surface combatants, such as the larger types of fast combat craft, was then confirmed by the shock loss during the October 1967 ‘Six-Day War’ of the Israeli navy’s flagship, the admittedly elderly destroyer Eilat , together with 47 men killed and another 99 wounded from a complement of 199. The loss was attributed to hits by P-15 Termit (SS-N-2A ‘Styx’) anti-ship missiles fired by ‘Komar’ class FAC(M)s of the Egyptian navy, whose most modern equipment had been supplied by the Soviets. Israel now decided to press ahead with all speed toward the creation of a navy based primarily on gun- and missile-armed fast combat craft for both offensive and defensive purposes.

In the late 1940s, Israel had bought at least three and possibly as many as nine Vosper 70-ft (21.3-m) MTBs from the UK, complementing these in 1951/52 with six French-built ‘Ayah’ class MTBs. These latter were delivered with four 850-kW (1,140-hp) Arsenal-Marine Otto petrol engines powering two shafts for a maximum speed of 42 kt, and were armed with two 457-mm (18-in) tubes for medium-weight torpedoes as well as light gun armament. These 62-ton craft were generally operated as MGBs with the torpedo tubes removed, but in the early 1960s they were revised as MTBs with the two 457-mm tubes and a new propulsion arrangement of two 2,500-hp (1865-kW) Napier Deltic lightweight diesels. In 1967 the Vosper MTBs were reported to be unserviceable, but it is estimated that Israel could call on eight MTBs during the ‘Six-Day War’ with its Arab neighbours. At the naval level, the war showed conclusively that such boats were too small to be effective, and that missile-armed fast combat craft offered considerable advantages over torpedo-armed boats.

The tactical importance of the anti-ship missile had been appreciated by Israel as early as the late 1950s, and the development of an all-Israeli missile of this type was put in hand during the early 1960s by MBT, a subsidiary of Israel Aircraft Industries and later known as Israel Military Industries. The resulting weapon is the Gabriel, which proved itself temperamental during its development testing in the late 1960s but soon matured into a highly capable tactical missile by the early 1970s and was then developed in variants up to the Gabriel IV with turbojet propulsion for a range of up to 200 km (124 miles) and the Gabriel V with an advanced active radar seeker optimised for performance in cluttered littoral environments. In its original form, the weapon is based on a cylindrical body containing the electronics, 100-kg (220-lb) high explosive warhead, and solid-propellant booster and sustainer rockets, and is supported in flight by a cruciform of rectangular wings which are located on the missile’s mid-body section and trailed by a cruciform of smaller tail surfaces indexed in line with the wings. The missile is mounted on a launch rail inside a container-launcher that can be located on a turntable on the launch craft’s deck. This allows the missile to be fired on the target’s bearing, launch data being provided by the launch craft’s fire-control system using data provided by search radar. After the boosted launch, the missile cruises on its sustainer motor at about 800 km/h (497 mph) at a height of 10 m (33 ft) above the sea under the control of an inertial system, though course corrections can be made by radio commands or by slaving the missile to an optical director. For the terminal phase of the attack, the missile’s semi-active radar seeker is activated and guides the weapon onto the energy of the launch craft’s radar reflected by the target; alternatively, the slaved optical guidance can be continued right up to missile impact. The Gabriel I missile has a range of only 21 km (13 miles), but the Gabriel II introduced wider-span wings and a longer body for a larger sustainer rocket, and can reach a speed of 850 km/h (528 mph) and a range of 36 km (22.4 miles). Further development yielded the Gabriel III with a larger 150-kg (331-lb) warhead, a longer body for a larger motor producing a range of more than 60 km (37.3 miles), and another seeker option in the form of active radar. The Gabriel III cruises at 100 m (330 ft) and then descends 20 m (66 ft) for the approach to the target before making the final attack at a preset height of 4, 2.5 or 1.5 m (13.1, 8.25 or 4.9 ft) according to the sea state.

The possibility of using the various marks of the Gabriel missile in three differing models (fire-and-forget, fire-and-update, and fire-and-control) allowed the Israelis to develop the concept of a ‘cocktail’ attack by several missiles operating in different modes to confuse the enemy and his electronic countermeasures. This was still in the future, however, as Israel embarked on a large-scale programme to develop its navy along new lines after the 1967 war. For technical and tactical reasons, it made sense for the Israelis to turn to the Western world’s leading designer and producer of fast combat craft, namely the German company Lürssen. For emotional and political reasons it was impossible for Israel to be openly procuring weapons from Germany, so the order was handled through an intermediary, the Constructions Méchaniques de Normandie of Cherbourg in France. The resulting design was that now known as the ‘FPB/TNC-45’ type, and in 1965/66 Israel ordered two batches of six such craft as the ‘Saar’ class. The early history of these craft was chequered in the extreme. An initial four craft had been delivered without armament in 1967 before the outbreak of the ‘Six-Day War’, and were therefore not operational in this conflict. A fifth unit was delivered shortly after this, but France then embargoed the delivery of the remaining craft under pressure from the Arab nations. Israel nonetheless managed to extricate another five craft from Cherbourg in December 1969, under the Panamanian flag and in the guise of Norwegian oilfield supply craft, and these five craft then gave the basic design a classic reputation for seaworthiness and range by reaching Israel in January 1970. The last two craft were later delivered by France. The first six craft were completed in Israel with three 40-mm Bofors guns as FAC(G)s that also possessed a useful anti-submarine capability through the installation of four 12.75-in (324-mm) tubes for lightweight anti-submarine torpedoes launched on the basis of data provided by ELAC search and attack sonar. The second six craft were completed to a more powerful FAC(G) standard with a 76-mm (3-in) OTO Melara Compact gun mounting in place of the single 40-mm weapon located forward of the bridge; for reasons of weight, this installation meant that anti-submarine capability had to be omitted.

Useful though it was, this FAC(G) standard was only an interim step on the way to the creation of a FAC(M) using the Gabriel missile. The first and last six craft were thus developed respectively to ‘Saar 2’ and ‘Saar 3’ missile-armed standards. In the ‘Saar 2’ this involved the installation of two single container-launchers for Gabriel missiles toward the edges of the deck between the bridge and the forecastle-mounted 40-mm gun, and the replacement of the two after 40-mm guns with trainable triple container-launchers for the same missile type. It was possible to omit the triple container-launchers and instead fit over the stern two twin 12.75-in tubes for lightweight anti-submarine torpedoes used in conjunction with EDO 780 variable-depth sonar. The ‘Saar 3’ standard was comparable but limited to six rather than eight Gabriel missiles in two triple container-launchers replacing the two 40-mm guns.

Silver/grey Styx anti-ship missile sitting on a trolleyThe capabilities of the ‘Saar 2’ and ‘Saar 3’ class FAC(M)s were confirmed in Israel’s 1973 ‘Yom Kippur’ with with Egypt and Syria, when 13 Israeli fast combat craft with 63 Gabriel missile launchers were pitted against 27 Arab ‘Komar’ and ‘Osa’ class fast combat craft with 84 launchers for the longer-ranged ‘Styx’. On the first night of the war, five Israeli craft operating off the Syrian port of Latakia, some 200 miles (320 km) from their home base, encountered three Syrian ‘Osa’ class craft in naval history’s first missile-versus-missile surface action. The Israeli craft defeated 12 ‘Styx’ missiles fired in two six-missile salvoes, shooting one of them down with 76-mm gun fire and evading the rest with the use of electronic countermeasures, and then closed the range during the next 18 minutes to fire a salvo of Gabriel missiles that struck all three Syrian craft. Two of these sank immediately, and the Israelis used 40-mm gun fire to finish the crippled third unit.

Two nights later, six Israeli craft were operating off the Egyptian port of Dumyat when they encountered a force of four Egyptian navy ‘Osa’ class craft. The Israeli craft evaded 12 ‘Styx’ missiles fired in four salvoes, and then destroyed three of the Egyptian craft, two of them with Gabriel missiles and the third with gunfire. During actions later in this short war, Arab craft fired another 28 ‘Styx’ missiles at Israeli vessels, again without scoring a single hit, for a 0% hit record during the war. The success rate of the Gabriel, on the other hand, was 85%. The Israelis were able to roam far and wide: typical operations saw patrols off the Syrian coast, where a complete armoured brigade was retained in case these harassments presaged an Israeli landing, and an incursion into the Egyptian anchorage of Ras Ghareb, where 19 armed fishing boats were sunk. In the course of the entire war, the Israeli navy suffered the loss of only three men killed and 24 wounded in the course of operations that resulted in the sinking of 19 warships of the Arabs’ regular navies.

The naval operations of the ‘Yom Kippur War’ saw the fast combat craft come of age in coastal warfare. For the first time the emphasis was placed in operations by FACs rather than larger surface vessels for tasks as diverse as gunfire support of army units operating in coastal regions, and attacks on the enemy’s naval bases. This latter was particularly important, for it denied the enemy the tactical advantages of manoeuvrability while operating on the open sea. In these operations, the Israelis also made extensive use of helicopters for the mid-course guidance of missiles launched from their own FACs, and for the decoying of missiles launched by the enemy’s FACs.

[Second photo by cliff1066™]

Fast attack craft: the origins

A grey fast attack craft of the the German navy, moored next to others,  with German flag at the prowMany of the world’s navies, including a large number without any claim to a long-standing naval or even maritime tradition, operate forces of small but comparatively heavily armed fast combat craft. These can be defined as vessels with a displacement of up to 600 tons and a speed of 25 kt or more, and fall into two basic categories. These are the fast patrol boat (FPB) and the fast attack craft (FAC). The FPB is generally fitted with only light armament (generally machine guns and cannon of up to 40-mm calibre) together with minimal sensor and fire-control suites. The FAC is a considerably more formidable type usually capable of higher speeds and carrying a heavier, longer-ranged armament that can include anti-ship guided missiles, guns of up to 3-in (76-mm) calibre, heavyweight anti-ship torpedoes of up to 21-in (533-mm) calibre, and anti-submarine weapons such as lightweight homing torpedoes, rocket-propelled grenades and depth charges, all controlled with the aid of a considerably more sophisticated sensor and fir-control suites.

The nature of the primary armament is generally indicated by a suffixed letter: thus the FAC(G) carries a medium-calibre gun, the FAC(M) carries anti-ship missiles, the FAC(T) carries anti-ship torpedoes etc.

The FPB is considerably inferior to the FAC in combat capability, but is still worthy of examination. Many countries use such FPBs for patrol and protection of their territorial waters and associated economic zones, which have acquired considerably greater importance in recent years as resources such as oil and gas have been discovered in such areas. In times of peace, therefore, the FPB has an important role as a type of maritime policeman that can also be used for rescue and other humanitarian purposes. Many such FPBs have been designed with upgrading in mind, however, and in times of crisis can be converted into FACs by the addition of items such as heavier armament (usually anti-ship missiles and/or a medium-calibre guns) and a more capable fire-control system.

The most important weapon carried by the FAC is the anti-ship missile, which is now a light and compact weapon carrying a potent warhead over a usefully long range with devastating accuracy. The modern anti-ship missile can destroy a major warship with a single round, as demonstrated during the Falklands war of 1982, when a French-supplied Aérospatiale Exocet (in this instance fired by a warplane though in its basic form it is a surface-launched weapon) devastated the British ‘Type 42’ class destroyer Sheffield. The light weight and compact size of these missiles means that even small FACs can carry four such weapons, conferring virtual capital ship status on what is in effect a highly affordable craft.

A large part of the anti-ship missile’s capability rests with its advanced guidance, self-protection and attack electronics, which have benefited greatly from advances in electronics and electronic miniaturization in the last quarter of a century. Developments in electronics, including the use of digital in place of analog processing and computing techniques, have made the the guidance package considerably more capable, yet miniaturization techniques have allowed this package to be made smaller and lighter so that a missile of the same weight can carry either a greater fuel load or a larger warhead.

These electronic improvements have also transformed the capabilities of the launch vessel’s sensor and fire-control suites. Combined with advances in computing, this has allowed modern surveillance and tracking radars, optronic sensors, sonars, electronic warfare systems, action information systems, and fire-control systems to be fitted in small hulls that nonetheless carry potent long-range armament whose destructive capabilities are maximised by the launch vessel’s electronic systems. In this instance, small most certainly does mean beautiful, for it reduces procurement costs as an initial advantage and then contributes reduced manning and maintenance costs.

A similar advance has been made in propulsion, where the modern diesel engine is powerful yet notably compact and highly reliable, and is often used in conjunction with a gas turbine. The former has been developed in turbocharged form for great power and considerable economy of operation despite its small overall dimensions and comparatively low weight. The latter is also compact and light, yet offers a very high power/weight ratio at the expense of high fuel consumption. A combined propulsion arrangement therefore offers the power of the gas turbine for combat speed, and the economy of the diesel for long cruising endurance.

Recent developments have tended to obscure the fact that the FAC is not a wholly new development, but is a type with more than a century of pedigree behind it. The first small warship may be regarded as John I. Thornycroft’s torpedo boat Lightning built for the Royal Navy in 1876/77. About 10 years earlier Robert Whitehead had demonstrated the capabilities of his new invention, the self-propelled torpedo, and since that time Thornycroft had urged the Admiralty for permission to develop a torpedo-armed launch based on his successful series of fast steam launches. Displacing 32.5 tons and possessing an overall length of 87 ft (26.52 m), Lightning was powered by a compound steam engine delivering 460 ihp (343 kW) to one shaft for a speed of 19 kt, and had a complement of 15. As delivered, Lightning was fitted with two ‘torpedo frames’, which were torpedo-carrying cages that could be lowered into the water on either side of the launch before the torpedo was released for its free-running attack. These frames could not be used when the launch was moving at any speed, and in 1879 they were replaced by a torpedo tube mounted over the bow; two reload torpedoes were carried on trolleys either side amidships.

By the beginning of the 20th century, the Royal Navy alone had operated more than 100 such steam-powered boats. The later units displaced some 200 tons each and could reach 25 kt.

By World War I, there was already a division of torpedo boats into smaller attack craft (the torpedo boat) and slightly larger defensive craft (the torpedo boat destroyer), and this division increased during the war. The small torpedo boat virtually disappeared, and the torpedo boat destroyer emerged as the multi-role destroyer, a larger and far more capable type offering high speed together with a gun and torpedo armament. The original stream of small attack craft did not disappear entirely, however, for as late as 1918 the Germans were producing such craft. The vessels of the ‘A92’ class, for example, displaced 392 tons and had an overall length of 61.2 m (200.75 ft), and their geared steam turbines delivered 6,000 hp (4475 kW) to two shafts for a maximum speed of 26.7 kt; the armament comprised two 88-mm (3.46-in) guns and one 450-mm (17.7-in) torpedo tube.

The trouble with such torpedo boats, however, was that they were too small and vulnerable for fleet operations, and at the same time too large and unhandy for coastal operations against convoys escorted by destroyers. Thus the mantle of coastal operations, now firmly established as the metier of such torpedo boats, shifted onto the shoulders of the type of smaller craft made possible by the replacement of the steam powerplant by the internal combustion engine.

The main thrusting force in the development of such torpedo boats was the German navy. The ‘LM’ class units of 1917/18 each displaced between 15 and 17 tons and possessed an overall length of between 14.6 and 17.1 m (48 and 56 ft). Each unit was powered by three Maybach petrol engines delivering a total of between 630 and 720 hp (470 and 535 kW) to three shafts for a maximum speed of between 28 and 32 kt. The armament was a single 450-mm (17.7-mm) torpedo tube.

On the other side of the maritime front line, the British developed a similar though smaller type as the coastal motor boat (CMB) that entered service in 1916. The CMB was evolved from pre-war racing boats with a stepped hydroplaning hull that allowed speeds in excess of 40 kt. The type was too small and light to carry a torpedo tube, so the boats were armed with a single torpedo that was launched tail-first over a stern chute, the boat then having the agility to swerve out of the torpedo’s path as the latter accelerated along the boat’s original course. The boats were built in 40-, 55- and 70-ft (12.2-, 16.8- and 21.3-m) lengths, the most numerous being the 55-ft (16.8-m) type that was built in several forms with different engines and armaments. The typical 55-ft CMB had a displacement of 11 tons and an overall length of 60 ft (18.3 m) over the torpedo-launching chute. Two petrol engines delivered between 750 and 900 hp (560 and 670 kW) to two shafts for a maximum speed of between 34 and 42 kt. The armament comprised one or two 18-in (457-mm) torpedoes, four 0.303-in (7.7-mm) Lewis machine guns, and up to four depth charges.

The World War I combatant that made the greatest use of torpedo craft was Italy, which developed as built 422 craft of several MAS types. Though completed after the war, a class that typifies such Italian craft was the ‘D’ group of the SVAN Veloce type. Each unit displaced 28.9 tons and had an overall length of 22.0 m (72.2 ft). The propulsion arrangement comprised four Isotta-Fraschini petrol engines delivering 1,600 hp (1195 kW) to four shafts or two Rognini electric motors delivering 10 hp (7.5 kW) to two shafts for silent approach, and the maximum speeds of these two arrangements were 30 kt and 4 kt respectively. The armament comprised two 450-mm (17.7-in) torpedoes, two 6.5-mm (0.26-in) machine guns and up to 20 depth charges. Two of these MAS boats showed the potential of small attack craft by torpedoing and sinking Wien, a pre-dreadnought battleship of the Austro-Hungarian navy.

During the 1920s, the concept of such coastal torpedo craft fell into disfavour, and it was only during the later 1930s that there was something of a revival. It was Germany that effectively pioneered the renaissance with S 1 of 1929, designed and built by Lürssen of Vegesack as the prototype of the new Schnellboote (fast boats) that came to be called E-boats by the Allies. The boats were based on a round-bilge rather than hard-chine hull for improved seaworthiness. S 1 displaced 51.5 tons and had an overall length of 27.0 m (88.5 ft). The propulsion arrangement comprised three Daimler-Benz petrol engines delivering 3,300 hp (2460 kW) to three shafts for a maximum speed of 34 kt, and the armament included one 20-mm cannon and two tubes for 500-mm (19.7-mm) torpedoes. S 1 proved seaworthy and effective, but serious doubts were raised about its propulsion arrangement, whose petrol engines provided shorter range than diesel units and whose fuel was known to be dangerously flammable. This last became of particular concern, for the boat lacked armour protection and would therefore be highly vulnerable to the fire that might follow hits from conventional rounds, let alone incendiary projectiles.

S 6 therefore introduced the diesel-engined powerplant that remained standard in all Schnellboote up to the end of World War II. S 7 introduced the distinctive knuckled hull form, and S 18 introduced the Daimler-Benz diesel that was used in all later boats. Later boats had a raised forecastle over the torpedo tubes, and reload torpedoes were carried aft. During World War II, gun armament was increased significantly, and the Schnellboote matured as exceptional fast combat craft. Lürssen built 162 Schnellboote during World War II, and other yards produced about the same number to the basic Lürssen design. The craft were extensively used in the North Sea and Baltic Sea, but their undoubted technical merits were not matched by aggressive leadership, so their effect was less than that of the smaller and less capable British craft, which were handled with considerably greater flair.

During the war, the displacement of the ‘average’ Schnellboot increased from 35 to 105 tons, the length from 28.0 to 34.9 m (91.9 to 114.5 ft), and the speed from 37 to 42 kt. Typical of the Schnellboot in its fully fledged form was the ‘S 186’ type built in 1944/45. This had a displacement of 105.5 tons and an overall length of 35.1 m (114.75 ft), and its propulsion arrangement was based on three Daimler-Benz diesels delivering 7,500 hp (5590 kW) to three shafts for a maximum speed of 41 kt. The armament included two 533-mm (21-in) tubes for four torpedoes, and two 30-mm cannon (fore and aft) often supplemented by numbers of lighter weapons.

The British returned to the concept of torpedo-armed coastal craft in 1935, when the Admiralty placed orders for motor torpedo boat (MTB) prototypes with the British Power Boat Company. These became the precursors of several important types, most notably the British motor gun boat (MGB) and American PT (pursuit torpedo) boat, but in the event most British MTBs were built to a baseline Vosper design of hard-chine form. This was enlarged during World War II and fitted with greater power and armament, but remained essentially unchanged. A notable feature of British MTB design in World War II was the frequent replacement of the 21-in (533-mm) heavyweight torpedo, of which only two could be shipped, by the 18-in (457-mm) medium-weight torpedo, of which four could be carried. In common with their German foes, the British crews added whatever gun armament they could to their fast combat craft as wartime experience revealed the need for additional cannon and machine gun armament for use against enemy surface craft and aircraft.

For lack of a suitable British engine, the Italian Isotta-Fraschini petrol engine was used in early craft until Italy’s June 1940 entry into the war on the Axis side cut off supplies. After a problem with the final drive had been eliminated, Packard engines from the USA then became the standard type for British craft. It was notable throughout the war, however, that the petrol-engined British craft were considerably more prone to fires than their diesel-engined German opponents.

Typical of the British MTB late in World War II was the Vosper 73-ft (22.25-m) type, which was authorised and built in 1944. This had a displacement of 46.7 tons and an overall length of 72 ft (22.3 m). The propulsion arrangement was three Packard petrol engines delivering 4,050 hp (3020 kW) to three shafts for a maximum speed of 39.5 kt, and the armament comprised four 18-in tubes for four torpedoes, two 20-mm cannon and four 0.303-in (7.7-mm) machine guns.

The ‘Fairmile D’ class also produced late in World War II was a larger and more capable design that could be completed as an MTB or MGB. The type had a displacement of 105 tons and an overall length of 115 ft (35.1 m). The propulsion arrangement comprised four Packard petrol engines delivering 5,000 hp (3730 kW) to four shafts for a maximum speed of 29 kt. The basic armament included one 2-pdr (40-mm) gun, two 20-mm cannon in a twin mounting, four 0.5-in (12.7-mm) machine guns in two twin mountings, and four 0.303-in machine guns in two twin mountings; later in the war, the 2-pdr gun was replaced by a 6-pdr (57-mm) weapon, a second weapon of the same type being located aft in place of the 20-mm twin mounting, which was moved farther forward. To this could be added two 21-in tubes for two torpedoes, though later in the war it was more common to see four 18-in tubes for four torpedoes.

The British also developed dedicated MGBs that complemented the MTBs in providing a balanced offensive capability. Here the primary designer and builder was the British Power Boat Company, which produced five basic classes. The largest of these classes was the ‘MGB-107’ type, of which 60 were built from 1942. This type had a displacement of 37 tons and an overall length of 71.75 ft (21.9 m). The propulsion arrangement comprised three Packard petrol engines delivering 4,050 hp (3020 kW) to three shafts for a maximum speed of 42 kt, and the armament included one 2-pdr gun, two 20-mm cannon in a twin mounting and four 0.303-in machine guns in two twin mountings. In 1943 some of the craft were converted into hybrid MTB/MGB types with two 18-in tubes for two torpedoes, and some of the craft were completed to this standard.

Early experience with the MTB and MGB showed the British that a large measure of the tactical surprise could be secured by the types’ high speed and small silhouette, but that this element of surprise was often lost because of the two types’ great noise, which resulted from the use of unsilenced engines. In the longer term, the answer was found to lie in an effective silencing system. In the shorter term, however, the British tried to develop a quieter type with steam propulsion. The resulting steel-hulled steam gun boat (SGB) was a large round-bilge type that was both fast and quiet. On the other side of the coin, however, its machinery was also extremely vulnerable to damage from even the lightest of gunfire and its production could only be undertaken at the expense of the construction of larger warships such as destroyers, frigates, corvettes and sloops.

Plans were laid for 60 SGBs, but in the event only nine were ordered and seven actually built. To provide protection for their vulnerable machinery, the boats were fitted with 0.75-in (19-mm) armour over their machinery spaces, and the weight of this metal reduced speed dramatically. The SGB displaced 165 tons and had an overall length of 145.25 ft (44.3 m). The propulsion arrangement comprised geared steam turbines delivering 8,000 hp (5965 kW) to two shafts for a maximum speed of 35 kt, and the armament included two 2-pdr guns in single mountings, four 0.5-in machine guns in two twin mountings, and two 21-in tubes for two torpedoes. The gun armament was later strengthened to one 3-in (76-mm) gun, two 6-pdr guns in single mountings and six 20-mm cannon in three twin mountings, which required the complement to be increased from 27 to 34. Together with the armour, this raised displacement to 260 tons and reduced speed to 30 kt.

The US Navy showed very little interest in fast combat craft of such coastal types until 1939, when contracts were placed with six yards, including the British Power Boat Company, for prototype craft varying in length between 54 and 80 ft (16.5 and 24.4 m). The type that found greatest technical favour was that of the British Power Boats Company, and salient features of this design were incorporated in later American designs. Like the British craft, these US boats were of the hard-chine type, and more than 800 such craft were ordered before the end of World War II. The three main types were the ‘PT 71’ class ordered from Higgins Industries of New Orleans, Louisiana, the ‘PT 103’ class ordered from Elco (Electric Boat Company) of Bayonne, New Jersey, and the ‘PT 368’ class ordered from a number of smaller yards such as R. Jacobs, Herreshoff, the Annapolis Yacht Company, and Canadian Power Boats.

The ‘PT 71’ class displaced 46 tons and had an overall length of 78 ft (23.8 m). The propulsion arrangement comprised three Packard 4M2500 petrol engines delivering 4,050 hp (3020 kW) to three shafts for a maximum speed of 40+ kt, and the armament comprised two or four 21-in tubes for two or four torpedoes, one 40-mm gun, two 20-mm cannon, varying numbers of 0.5-in machine guns and, in two-tube craft, 12 depth charges or four mine racks. The ‘PT 103’ class displaced 45 tons and had an overall length of 80.3 ft (24.5 m). The propulsion arrangement again comprised three Packard 4M2500 petrol engines delivering 4,050 hp (3020 kW) to three shafts for a maximum speed of 40+ kt, and the armament comprised four 21-in tubes for four torpedoes, two 20-mm cannon and varying numbers of 0.5-in machine guns. The ‘PT 368’ class displaced 43 tons and had an overall length of 70 ft (21.3 m). The propulsion arrangement comprised the standard three Packard 4M2500 petrol engines delivering 4,050 hp (3020 kW) to three shafts for a maximum speed of 40+ kt, and the armament comprised two 21-in tubes for two torpedoes as well as varying numbers of 20-mm cannon and 0.5-in machine guns.

Like the Americans, the Japanese were late into the development of coastal craft. All Japanese craft of this type were developed from two British craft, Thornycroft-built CMBs including one captured at Canton in 1938. Examination of these two types resulted in a Japanese-designed experimental type built in 1940. This led to the construction of at least 248 MTBs before Japan’s defeat in 1945. Typical of these was the ‘Type T-14’ class, which had a displacement of 15 tons, a length of 15.0 m (49.2 ft), a propulsion arrangement of one Type 91 petrol engine delivering 920 hp (685 kW) for a maximum speed of 28 kt, and an armament of two 457-mm (18-in) tubes for two torpedoes as well as one 25-mm cannon or 13-mm (0.51-in) machine gun. In parallel with these small and highly limited MTBs, the Japanese also developed some MGBs. Typical of these was the ‘Type H-2’ class with a displacement of 24.5 tons, length of 18.0 m (59.1 ft), propulsion arrangement of two Type 11 petrol engines delivering 2,100 hp (1565 kW) to two shafts for a maximum speed of 33.5 kt, and armament of two 20-mm cannon, two 7.7-mm (0.303-in) machine guns and two depth charges. In overall terms, however, the Japanese MTBs and MGBs were a technical dead end.

After World War II, development of these fast combat craft came to a virtual end in the navies of the victorious western Allies. The UK and USA decided that their fast combat craft had played on a comparatively ineffective part on the naval effort of World War II, and that their navies should therefore return to the pre-war concept whose large surface combatants had dominated operations in the Atlantic and Pacific Oceans. Large numbers of fast combat craft were therefore deleted or transferred to smaller navies. These latter used the craft mainly for the patrol role, but the navies of some middle-rank nations used them as a sort of stepping stone toward the re-creation of conventional navies out of the ashes of World War II.

It is worth noting, however, that there were a number of interesting experimental developments in fast combat craft. The most important, one can now say with hindsight, was the re-engining of a British SGB with two Rolls-Royce RM.60 engines to create the world’s first vessel powered only by gas turbines.

[Photo by yetdark]

Castles of the Iberian Peninsula

Picture of Bragança Castle, Portugal, with blue sky in the background, and a small white car in the foregroundThe castle-building period in the Iberian peninsula was roughly that in which the Moors occupied much of the country. Arriving in 711 and finally ejected in 1492, the Moors left as part of their legacy to Spain a number of alcazaba garrison fortresses whose design influences were slowly melded with the tower keep type of feudal castle that was first built in the north of the region, moving slowly south as the Moors were progressively eliminated from the peninsula. Portugal is fairly evenly dotted with castles, such as Alter do Chao, Beja, Elvas, Leiris and Silves, but possibly the most important castle in the country is that at Bragança, on the north-eastern frontier with Spain.

The present castle was built by Sancho I in 1187 on the site of an earlier fortification. The castle is typical of the northern Iberian tradition with a blocky rectangular keep of considerable height and provided with two watchtowers. The keep is surrounded by a truly formidable curtain wall of granite, the same stone having been used for the keep. Further additions were made in the 14th and 15th centuries. Bragança is somewhat unusual, for a Portuguese castle, in having its keep built into the enceinte wall.

At Guimarães, by contrast, the 10th century keep is distinct from the enceinte wall. The construction of the first castle was ordered by Dona Mumadona Dias in the 10th century to defend the town’s monastery from Moorish and Norman attacks. The castle was then built up from its earlier basis by Henri of Burgundy after his elevation, as Dom Henrique, to the position of count of Portugal by Alfonso VI of Castile in 1095. Dom Henrique selected Guimarães as the site of his court, and decided that the castle, by then more than 100 years old, was in urgent need of improvement rather than merely renovation. Dom Henrique opted to demolish what remained of Mumadona’s castle, and extended the area of the new castle, which had two entrances. The castle continued to be the official royal residence through much of the 11th and 12th centuries. The castle was further rebuilt on a major scale during the 15th century along current notions of geometric defence, the revised castle having a trapezoidal plan with towers in the angles. In 1836, a member of the Sociedade Patriótica Vimaranense recommended the demolition of the castle, and suggested the use of its stones to pave the streets of Guimarães, as the fortress had been used as a political prison during the reign of King Miguel. The notion was not accepted, and 45 years later, in 1881, the Diário do Governo (state journal) listed the castle of Guimarães as the most unusual historic monument in the entire Minho region. In 1910 the castle became a national monument, and in 1937 a major restoration was begun, this ending with the inauguration of the castle’s present symbolic status in 1940.

Situated to the north of Lisbon close to the coast, the castle at Leiria was built in the second quarter of the 12th century as a border fortification on the southern border of what became Portugal in 1137. The site had already seen Roman fortifications, and wherever possible these were included in the first Portuguese castle produced by Alfonso Enriques just before his elevation as king of Portugal. With the conquest of territory farther to the south Leiria ceased to be a border castle, and fell into disarray before a revival in the first quarter of the 14th century, when King Dinis rebuilt the castle with a small but powerful citadel above a royal palace. The keep was surrounded by a curtain wall, and further additions were made in the late 14th and early 15th centuries. Almost immediately after the reconquest of Segovia from the Moors by the Christian forces of King Alfonso VI of Segovia in the 11th century, the Spanish began the construction of the Alcázar de Segovia right in the middle of the city as a stone fortification rising above a rocky crag above the confluence of the Eresma and Clamores river near the Guadarrama mountains, it is one of the most distinctive castle-palaces in Spain by virtue of its shape, which resembles that of a ship’s bow. The Alcázar was originally built as a fortress but steadily became a royal palace, a state prison, an artillery college and finally a military academy before being restored to public viewing. Like many fortifications in Spain, the Alcázar started life as a Moorish fortress. The first reference to this particular Alcázar is to be found in a record of 1120, around 32 years after the city of Segovia returned to Christian hands during the time in which King Alfonso VI of Castile reconquered the territory to the south of the Duero river down to Toledo and beyond. However, archaeological evidence suggests that the site of this Alcázar was once used in Roman times as a fortification. This theory is further substantiated by the presence of Segovia’s famous Roman aqueduct.

The Alcázar de Segovia in the Iberian Peninsula, against the background of a blue sky with cloud, trees in the foreground.The current shape and form of the Alcázar was not known until the reign of King Alfonso VIII in the late 12th and early 13th centuries, although early documentation mentioned a wooden stockade fence. It seems likely, therefore, that before Alfonso VIII’s reign, the fortification was no more than a wooden fort built over the old Roman foundations. Alfonso VIII and his wife, the Plantagenet Eleanor of England, made this Alcázar their principal residence and much work was carried out to erect the beginnings of the stone fortification. Throughout the mediaeval period, the Alcázar remained one of the favourite residences of the kings of Castile and a key fortress in the defence of their kingdom. It was during this period that most of the construction still visible was undertaken, and the palace was extended on a large scale by the monarchs of the Trastámara dynasty. In 1258 parts of the Alcázar had to be rebuilt by King Alfonso X after a collapse, and soon after this the Hall of Kings was built to house the Castilian parliament. However, the single largest contributor to the continuing construction of the Alcázar was King Juan II, under whose auspices was built the New Tower, now known as the Juan II Tower. The castle was steadily transformed into a beautiful royal palace by King Juan II, who built a tower keep alongside the original keep. The Alcázar was most notable for its exquisite plasterwork that revealed the long-lasting cultural impression made on Spain by the Moors, transforming the original fortress into a courtier residence and prolonging the construction of the castle until the 16th century.

In 1474, the Alcázar played a major role in the rise of Queen Isabella I of Castile. In December news of the death of King Henrique IV, her older half-brother, reached Segovia, and Isabella immediately took refuge within the walls of the Alcázar, and it was here that she received the support of Andres Cabrera and Segovia’s council. She was crowned on the next day as Queen of Castile and Leon. It was in the Alcázar that she married Fernando II. The next major renovation at the Alcázar was conducted by King Felipe II after his marriage to Anna of Austria. He added the sharp slate spires to reflect the castles of central Europe. In 1587, architect Francisco de Morar completed the main garden and the School of Honour areas of the castle.

The royal court eventually moved to Madrid, and the Alcázar then served as a state prison for almost two centuries before King Carlos III established the Royal Artillery School in the Alcázar during 1762. It served this function for almost a hundred years until March 1862, where a fire badly damaged the roofs and much of the castle’s structure. It was only in 1882 that the building was slowly restored to its original state, and in 1896 King Alfonso XIII instructed that the Alcázar to be transferred to the war ministry for use as a military college. Actually of Moorish origins are the Alhambra and Alcazaba in Granada. The Alhambra is a combined fortress and palace, and was built in the 13th century as an enceinte structure with powerful towers built into the walls. The castle is now most notable for its cool but masterly interior, a long-term decoration process completed only in 1408, and for the massive strength of the Justice Gate, built in 1348 with an entrance tunnel of vaulted construction and three right-angle corners for maximum defensive strength.

Toward the other end of the ridge accommodating the Alhambra is the Alcazaba, the garrison fortress that afforded traditional protection for the Alhambra. This Alcazaba is largely of mud-brick construction and was rebuilt in the 13th century on the basis of a 9th century original structure. The basic layout of the Alcazaba is reinforced by powerful towers of square configuration. The surrender of the Alhambra and Alcazaba in 1492 finally ended the Moors’ hold in Spain.

Though now in Spain, the great castle at Albuquerque was in fact of Portuguese origins, for it was built in 1354 by a son of King Dinis of Portugal to cover the approaches to central Portugal just north of Badajoz. The castle occupies a monumentally impressive hilltop site of very considerable natural strength. The town itself is enclosed by the outer ring of defensive flanking walls, and access to the hilltop enceinte fortification with a great tower and extra-mural tower is gained by a fortified passage covered by a number of other flanking walls. Certainly one of the most impressive castles in the whole of Europe is La Mota, located on the eastern side of Valladolid. The origins of the castle are Moorish, and earlier fortification having been augmented in the 12th century to produce a massive brick-built enceinte castle, in the 15th century the Moors employed Christian builders to modernise the fortress, which acquired an immense bartizaned tower keep and an outer curtain wall, only a short way in front of the enceinte structure and designed for the artillery defence of the castle. The whole castle as it still stands is the most remarkable tour de force in construction and design in brick, rivalled only by Coca near Segovia, which was built at about the same time (the middle of the 15th century) for the archbishop of Seville. In the same general area as La Mota is Penafiel, which is built on a narrow ridge commanding the valley of the Duero river. This castle is of the type known in Spain as gran buque (great ship), for it is only 75 ft (23 m) wide despite its length of 690 ft (210 m). Built in the later half of the 15th century, Penafiel has at its heart a massive and rectangular keep, some 110 ft (33.5 m) tall with cylindrical bartizans along its upper sides. This core is protected by an enceinte fortification whose two sides have 12 towers apiece, with another at each end and two more defending the gatehouse, which can be approached only by means of a bridge over a deep ditch.

Other classic Spanish castles are El Real de Manzanares, an extraordinary palace-castle close to Madrid in the foothills of the Guadarrama mountains and built in the last quarter of the 15th century; Banos de la Encina, a Moorish castle built in 967/68 by the Caliph Hakam II as the main defence of the Guadalquivir river near Jaen, and a good example of the Moorish expertise in enceinte fortifications well before the northern Europeans; and Montalban, a fine Moorish castle built on a Visigothic base close to Toledo.

[Photos by hashashin and james.gordon6108]

Nexter/Thales (GIAT/Thomson-CSF) Shahine SP surface-to-air missile system

Land-based forces face a threat of air-launched attack comparable to that faced by sea-based forces, and have historically responded in a similar fashion with towed and self-propelled cannon equipments to tackle lower-grade threats against infantry and logistical troops, and a judicious blend of man-portable and self-propelled surface-to-air missile systems to tackle higher-grade threats against mechanised and armoured forces.

In 1975 Saudi Arabia ordered a gun-armed AA vehicle, the AMX-30 SA, based on the chassis of the AMX-30 main battle tank. At the same time the Saudis ordered a missile-armed counterpart, now designated as the Nexter/Thales Shahine self-propelled surface-to-air missile system. This is based on the same Nexter (originally GIAT) AMX-30 chassis but, given the importance of the missile and radar systems, the prime contractor is the electronics giant Thales (originally Thomson-CSF). Matra (now EADS) was subcontracted for the R.460 missile, which is essentially an upgraded version of the R.440 used in the Crotale systems. The standard Shahine firing battery comprises one acquisition vehicle and four missile vehicles, all using a modified AMX-30S chassis to ensure commonality of parts and combat mobility with Saudi Arabia’s fleet of AMX-30S main battle tanks. The acquisition unit weighs 32700 kg (72,090 lb) and is tasked with surveillance, target detection and interrogation using a pulse-Doppler radar operating in E-band for the detection of targets out to a range of 18500 m (20,230 yards). The system possesses a moving target indication facility plus an SN1050 digital information-processing and threat-evaluation subsystem, allowing the simultaneous registration of 40 targets. The computer system handles threat prioritisation on an automatic basis, and the 18 highest-threat targets are handled simultaneously. The acquisition unit also possesses a turret-mounted TV system, independent of but concentric with the radar. This allows the acquisition unit to monitor the position of the battery’s firing units, and also to fall back on an optronic system in the event that the radar fails or is jammed. Data are passed to the firing units by the inter-vehicle and positioning data-link, a J-band microwave system with minimum and maximum ranges of 500 and 4000 m (545 and 4,375 yards).

The missile firing unit is similar to that of the Crotale system. There is a vertical bank of three missile container/launchers on an elevating mounting on each side of the central pedestal, which can turn through 360°. The pedestal accommodates the drum-like antennae of the J-band monopulse target-acquisition and missile-guidance radar. Initial target data are received by the appropriate firing unit over the microwave data-link, allowing the firing unit’s target-acquisition radar to pick up the target as soon as it enters the radar’s 17000-m (18,590-yard) search range. The firing unit’s onboard fire-control system uses radar data to generate a fire-control solution, and automatically fires one or two missiles as soon as the target is within range. The missiles are automatically gathered by means of an infra-red system, and are thereafter fully guided to the target. The firing unit also possesses a back-up TV system for use in the event of radar failure or jamming. The system is fully integrated into the firing unit’s fire-control system, and provides target- and missile-tracking capabilities. Missiles are replaced from the battery’s stocks by means of a crane-equipped reload vehicle.

The Shahine can also be installed on the P6R 6×6 wheeled vehicle, and was further developed as a mobile shelter-mounted installation, the Shahine ATTS (Air-Transportable Towed System) using a three-axle semi-trailer.

In recent years the system has been upgraded to Shahine 2 standard with modest but useful improvements. The range of the main search radar is increased by 1000 m (1,095 yards) to 19500 m (21,325 yards); the missile has been provided with alternative radar and IR proximity fuses; and a revised SHADL (SHAhine Data-Link) has been introduced to allow the system to be linked with higher-level command structures. This last is generally the Litton TSQ-73 command and control centre, which is used by the United States, other NATO countries and some favoured export customers. The complete unit is accommodated in an S-280 shelter, transportable by aircraft, helicopter or truck. The system is linked to locally-available 2D or 3D radars, and the use of a GYK-12 digital computer provides real-time threat analysis and decision-making for a number of interlinked firing units. Shahine was also used as the basis of the Thomson-CSF/Vought Liberty self-propelled surface-to-air missile/twin 25-mm AA gun system proposed to meet the LOS-FH (Line of Sight – Forward Heavy) component of the US Army’s FAAD requirement, won late in 1987 by the Oerlikon-Bührle/Martin Marietta ADATS package. Initial development of the Liberty system centred on a revised sensor and fire-control package, adding an optronic unit (FLIR and TV) for simultaneous tracking of the target and intercepting missile(s). The capability of this system was validated in trials that witnessed the successful nocturnal tracking and interception, at a range of more than 6000 m (6,560 yards), of a drone flying at low level and at a speed of more than 900 km/h (559 mph). Plans called for the use of an M1 Abrams main battle tank chassis as the basis for the installation of a new armoured turret accommodating the electronics and armament, the latter increased to 12 R.460 missiles in the proposed initial production version. The turret would have been fitted with the new Griffon search radar, the Shahine/Liberty upgraded tracking system, two McDonnell Douglas M242 Bushmaster 25-mm cannon and, ultimately, two pods each containing six Vought/Thomson-CSF VT-1 SAMs.

The TRS 2630 Griffon radar is capable of detecting a fixed-wing aircraft at 18000 m (19,685 yards) and a hovering helicopter at 8000 m (8,750 yards). The antenna is a rectangular unit located above the rear of the turret for 360° search coverage, and can be lowered to the horizontal position to reduce the vehicle’s travelling height. The M242 is a powerful cannon already in large-scale use, and fires ammunition of the standard M790 series (M791 APDS, M792 HEI and M793 TP). The M791 round is 8.7 in (221 mm) long and weighs 16.12 oz (457 g), firing its 4.7-oz (133-g) projectile with a muzzle velocity of 4,415 ft (1346 m) per second; the M792 and M793 rounds are each 8.58 in (218 mm) long and weigh 17.35 oz (493 g), firing their 6.53-oz (185-g) projectiles (the former containing 1.06 oz/30 g of PBXN-5/aluminium explosive, and the latter solid shot) with a muzzle velocity of 3,610 ft (1100 m) per second. Like the search radar antenna, the two cannon on the turret top were intended to hinge down to reduce the vehicle’s travelling height. The VT-1 missiles were to be carried in elevating launchers on the turret sides, each launcher unit accommodating two vertical rows of three missiles. The missile was a combined development by Vought and Thomson-CSF with a length of 2290 m (7.51 ft) and a diameter of 165 mm (6.5 in), a warhead detonated by radar proximity fuse, a cruciform of fold-out rear fins and a maximum speed of Mach 3.5. A typical maximum engagement range of 10000 m (10,935 yards) was envisaged, a range of 8000 m being attained in 10 seconds. Reload rounds were to have been carried in six-round packs for rapid resupply by a special crane vehicle. As befitted a vehicle designed for continued capability in the front line of an advanced-technology battlefield, the Liberty’s armoured hull and turret would have been complemented by armour protection for the tracking radar and missiles.

Employment

Finland (Liberty variant chosen in 1988) & Saudi Arabia (Shahine and Shahine ATTS)

Specification

Shahine

Type: tracked self-propelled point defence tactical SAM system

Crew: 3 (driver, commander and operator)

Combat weight: 38800 kg (85,538 lb)

Dimensions: length 6.59 m (21.62 ft)

Armament system: six ready-to-fire R.460 SAMs mounted three on each side of the electrically powered turret/radar unit

Armour: welded steel

Powerplant: one 462-kW (620-hp) Hispano-Suiza HS 110 multi-fuel engine with 970 litres (213.4 Imp gal) of fuel

Performance: speed, road 65 km/h (40.4 mph); range, road 600 km (373 miles); fording 2.2 m (7.2 ft) with preparation; gradient 60%; side slope 30%; vertical obstacle 0.93 m (36.6 in); trench 2.9 m (9.5 ft); ground clearance 0.45 m (17.7 in)

Otobreda 76/62 Compact 76-mm single DP gun mounting

OTO Melara 76mm Super Rapid gun aboard a ship, blue sea and coast in the backgroundIn modern naval warfare, one of the major threats posed to surface vessels of all sizes is the high-speed attack warplane armed with anything between air-to-surface unguided rockets and cannon projectiles at the lower end of the technology spectrum to air-to-surface guided bombs and guided missiles at the upper end. In the middle of the spectrum fall unguided bombs, which are unsophisticated weapons that can nonetheless be deadly when delivered with the aid of a high-quality fire control system. It is the lower- and middle-spectrum weapons that are seen as the greatest threat to smaller warships whose destruction possibly does not warrant the expenditure of a guided weapon.

The Otobreda (originally OTO Melara) 76/62 Compact naval 76-mm (3-in) dual-purpose single gun mounting is one of the most widely used and important equipments of its type in service anywhere in the world, and is a highly effective lightweight weapon designed for minimum volume and operation as a fully automated system against aircraft (fixed- and rotary-wing) and smaller surface attackers such as fast attack craft and corvettes. The origins of the gun lie with the OTO Melara 76/62 MMI Allargato dual-purpose gun produced for the Italian navy. This was designed to use standard US Navy 3-in (76-mm) ammunition, then considered the smallest that could be fitted with a proximity fuse, and was planned as the main armament of corvettes and frigates, and as the secondary armament of destroyers and cruisers. The mounting weighs 12000 kg (26,455 lb) complete with ammunition and associated systems, and is powered by an electro-hydraulic system. This provides traverse through 360° at the rate of 70° per second, and elevation in an arc from -15° to +85° at the rate of 40° per second, both with an acceleration of 70° per second². The magazine accommodates 59 rounds and is located under the splinterproof turret. Rounds are fed automatically to the loading tray, from which they are power-rammed into the gun. This can fire between 55 and 65 rounds per minute under remote or single-man local control.

The MMI was very sophisticated for its time, but by 1963 it was clear that much improvement could be effected to the basic design. This led to the OTO Melara 76/62 Compact, which entered service in 1969 in response to a NATO requirement for an MMI successor with light weight and compact dimensions (so that the weapon could be installed in vessels as small as fast attack craft), a rate of fire of at least 80 rounds per minute; a large ready-use ammunition capacity to allow sustained engagements without the need to replenish the system, high rates of traverse and elevation to enable high-speed targets to be tracked under all weather conditions, and rapid reaction time made possible by an entirely unmanned mounting controlled by a gun captain at a remote monitoring station, and a below-deck ammunition replenishment crew.

The 76/62 Compact thus emerged as a single unit with an under-deck trunk accommodating the 80-round rotating drum magazine and ammunition hoist, and an above-deck gunhouse accommodating the elevating mass, the loading system, the loading tray, the feed drum and the two rocking arms that take ammunition from the hoist and insert them in the feed drum. Rounds are hoisted and loaded in a series of short movements that reduce accelerations to the moving parts and ammunition, and rounds are power-rammed with the ordnance at any angle of elevation and the mounting at any angle of traverse. The mounting is driven by three identical servo motors (one for traverse and two for elevation); of these any one can drive the mounting at reduced speed. Standard traverse and elevation rates are 60° per second and 35° per second, both with an acceleration of 72° per second². Cooling is undertaken with salt water during firing, followed by fresh water flushing after the engagement, and the ordnance has a muzzle brake and a bore extractor.

The key to the 76/62 Compact’s performance is the loading system. As the magazine turns, each round is drawn into the screw feeder hoist that lifts it to a point below the left trunnion, where it is seized by the two rocking arms and carried to the loading drum on the cradle. The drum transfers the round to the vertically-oscillating loading tray operated by the gun’s recoil. As the ordnance recoils the tray is moved up to accept the spent case and the fresh round, and as the ordnance runs out the tray drops down to allow the fresh round to be rammed and the spent case to be ejected forward through the gun shield. The standard 76x900R round fires a 6.3-kg (13.89-lb) projectile with a muzzle velocity of 925 m (3,035 ft) per second. The ammunition types are HE with proximity or point detonating fuses, TP, TP-T and Flash Non-Fragmentation.

The 76/62 is also built under licence in Spain by Bazan. This mounting is essentially similar to the baseline Italian mounting, and its specification includes an ordnance weight of 8520 kg (18,783 lb) firing a 12.358-kg (27.24-lb) round whose projectile leaves the muzzle with a velocity of 925 m (3,035 ft) per second to attain a horizontal range of 16300 m (17,825 yards). The mounting can be traversed through 360° at the rate of 70° per second, with an acceleration of 100° per second²; while the ordnance can be elevated in an arc from -15° to +85° at the rate of 40° per second, with an acceleration of 60° per second². The 76/62 Compact has also been licence-built in the USA by FMC Corporation for the US Navy’s Mk 75 DP gun mounting. This US version is identical in all important respects with the Italian original.

In 1984 the company announced the OTO Melara 76/62 Super Rapid, essentially the 76/62 Compact (modified to incorporate mechanical and structural features of the Otomatic land ordnance, which includes titanium rather than steel for many components, and strengthening of the rocker arms and buffering system) and fitted with a local stabilisation system to secure a higher rate of more accurate fire. In the 76/62 Compact the rate can be varied between 10 and 85 rounds per minute by the gun captain, and in the 76/62 Super Rapid the maximum rate is boosted to 120+ rounds per minute, giving this medium-calibre gun almost the fire rate capability of large-calibre cannon, though in this instance with very considerably more devastating projectiles. To match the capabilities of the 76/62 Super Rapid OTO Melara has produced the MOM (Multi-role OTO Munition) round, a multi-role type optimised for the destruction of missiles. The projectile of this round has a body of high-quality steel filled with cubes of tungsten alloy. The projectile is detonated by the FB371 proximity fuse, the powerful bursting charge ensuring that the tungsten alloy cubes are dispersed in a spherical pattern at a high velocity to ensure maximum penetration of the target. The projectile can also be fired with the proximity fuse paralysed, thus operating with its point detonation fuse in a fashion similar to that of the SAPOM (Semi-Armour-Piercing OTO Munition) type with a delay-action fuse. The 76/62 Super Rapid will also be able to fire two new rounds currently under development. The first is a guided projectile designed jointly by OTO Melara and British Aerospace for use against both aircraft and missiles; and the second is an extended-range projectile for use against surface targets.

The mounting has local stabilisation for improved accuracy, and is also fitted with a secondary feed system that permits swift change from automatic fire against aerial targets to semi-automatic fire against surfaces targets and vice versa. Reliability has also been upgraded through the addition of BITE using small computers, and extra safety has been provided by features such as a pointing accuracy check and provision of safety firing arcs.

Features of the 76/62 Super Rapid can be retrofitted to the 76/62 Compact to boost the rate of fire to about 100 rounds per minute. The 76/62 Super Rapid has provision for the incorporation of a stabilised line-of-sight local fire-control system such as the OTO Melara Local Control Unit, a TV-based system with its stabilized tracking head on top of the 76/62’s gunshield; but the types are designed for use primarily with the parent vessel’s main fire-control system, most notably Dutch and Italian systems. The former are mostly variants of the Hollandse Signaalapparaten WM20 series, and the latter the series produced by Elsag, Officine Galileo, OTO Melara and Selenia using a variety of radar and optronic sensors.

The 76/62 Super Rapid has recently been favoured over the French 100-mm (3.93-in) naval gun for the new ‘Horizon’ Franco-Italian class of frigates, and on 27 September 2006 Iran announced that it had started mass production the Fajr-27, which is a reverse-engineered Otobreda 76/62 gun.

Employment (past and present)

Algeria, Argentina, Australia, Bangladesh, Belgium, Brazil, Burma, Canada, Chile, Colombia, Denmark, Ecuador, Egypt, France, Germany, Greece, India, Indonesia, Iran, Ireland, Israel, Italy, Japan, Kenya, Kuwait, Libya, Malaysia, Mexico, Morocco, Netherlands, Nigeria, Norway, Oman, Peru, Philippines, Poland, Portugal, Qatar, Romania, Saudi Arabia, Senegambia, Singapore, South Africa, South Korea, Spain, Sri Lanka, Taiwan, Thailand, Tunisia, Turkey, UK, USA and Venezuela

Specification

Otobreda 76/62 Compact

Type: naval single point-defence tactical DP gun mounting

Calibre: 76 mm (3 in)

Barrel length: 62 calibres

Mounting: powered turntable with glass-fibre turret

Weight: 7350 kg (16,204 lb)

Dimensions: swept radius 5.286 m (17.34 ft); length 7.3595 m (24.15 ft); width 4.146 m (13.60 ft); height above deck 2.187 m (7.18 ft)

Traverse/elevation: 360°/-15° to +85°

Rate of fire: 85 rounds per minute

Horizontal range: 8000 m (8,750 yards) effective

Slant range: 5000 m (5,470 yards) effective

Crew: 0

Rheinmetall GDF

Picture of the twin cannon Rheinmetall GDF at some kind of outdoor exhibition, surrounded by people, with steps in the background leading up to domed and colonnaded white buildingsAlthough the defence of ground and naval forces is generally considered to be the province of the surface-to-air missile, there is still an important place on the land and sea battlefields for the anti-aircraft gun in its modern form as a powered mounting for one or more cannon in the calibre range between 20 and 40 mm firing an explosive projectile and often with provision for command and control from a higher-level fire-control system.

One of the most impressive of such equipment is the Rheinmetall GDF with two 35-mm cannon. The design and manufacture of this long-lived weapon have gone through several changes of nomenclature and ownership. Introduced in the early 1960s by the Swiss company Oerlikon-Bührle (later Oerlikon Contraves, and now Rheinmetall Air Defence AG since the merger of the companies in 2009), the 2 ZLA/353 MK became known as the GDF-001 or as the K-63, and was the first production variant of the heavyweight member of the manufacturer’s series of land-mobile AA mountings. It was designed from the late 1950s primarily for use in the surface-to-air role but has a significant surface-to-surface capability. The range of HEI, HEI-T and SAPHEI-T ammunition is fired at the muzzle velocity of 1175 m (3,855 ft) per second from the two KDB (formerly 353 MK) cannon. The system has an on-mounting optical sight, but is best used as a battery of two such equipments supported by a radar-directed fire-control system. The GDF-001’s weights are 6300 kg (13,889 1b) in travelling order without ammunition or accessories, rising to 6700 kg (14,771 lb) complete with ammunition and accessories. The GDF mounting is supported on a two-axle carriage towed by any suitable 6×6 5-ton truck. In firing position the carriage is stabilised by an arrangement of three jacks, comprising one at the rear of the carriage and one on each of two lateral outriggers located towards the front of the carriage. The wheels are then lifted to rest well clear of the ground with their upper portions and mudguards inclined inward over the carriage. An electro-hydraulic system is used for jack and wheel actuation, allowing the equipment to be brought into action in 1.5 minutes by three men or in 2.5 minutes by one man. The system also possesses a manually pumped system for emergency use, which brings the equipment into action in 5 minutes. The same type of electro-hydraulic actuation is used for mounting traverse at the rate of 114.5° per second, with an acceleration of 145.25° per second²; and gun elevation at the rate of 57.3° per second, with an acceleration of 114.5° per second². In the basic system electrical power for all carriage and mounting functions is supplied by an off-carriage generator.

The KDB cannon weighs 430 kg (948 lb) complete with its 120-kg (264.55-lb) barrel and is a gas-operated weapon. In this application it is carried on a cradle fitted with a hydro-mechanical recoil system. The GDF’s two weapons are cradle-mounted comparatively close to each other in the centre of the mounting, just in front of the gunner, and can be fitted with devices for measurement of muzzle velocity, which improves considerably the continuously computed fire-control solution provided by an off-carriage fire-control system. The cannon are automatically fed, by means of electrically or manually tensioned springs driving a conveyor system, with ammunition from seven-round clips located in horizontal layers in the 56-round containers placed outside each breech. The containers are themselves replenished manually with clips drawn from the 126-round reserve supply carried on the mounting.

In its basic form, the mounting is a clear-weather daylight system, but can be linked into a higher-level fire-control system. The system thus has three operating modes: remote electric control from the Super-Fledermaus or Skyguard fire-control radar, providing all-weather capability with an on-mounting crew of two; local electric control with the Xaba optical sight, for normal daylight operation with an on-mounting crew of three including the gunner with a control column; and local manual control with handwheels in emergency daylight operation with an on-mounting crew of three.

The GDF-002 is an updated version available from 1980, which can handle target data in digital rather than analog form, and has a Ferranti Type GSA Mk 3 optical sight. The only factor that requires manual insertion with the GSA Mk 3 is estimated target range. This comparatively simple evolution of the basic mounting provides faster and more accurate laying of the cannon in both bearing and elevation. Both the GDF-001 and GDF-002 can also be enhanced with any of three optional packages, known to Oerlikon-Bührle as the NDF-A, NDF-B and NDF-C Combat Improvement Kits.

The most complete of these is the NDF-C kit, which offers optimisation of the weapons’ automatic functions, to stabilise the rate of fire at a combined total of 680 rounds per minute as a means of reducing wear and preventing highly stressed components from becoming overtaxed; a weapon cover with an integral and fully automatic weapon-lubrication system that also enhances protection against sand, rain etc; a weapon camouflage facility; automatic reloaders, with the cannon elevated to the vertical position so that a hydraulic-mechanical device can ram the clips forward into the on-mounting containers from a manually-replenished ready-use supply that increases the ready-use supply to 280 rounds; an integral power supply; and, perhaps most important of all, a Contraves Gun-King sight system. Compared with this upgraded standard, the NDF-A kit offers weapon lubrication, weapon optimisation, camouflage and automatic reloading; and the NDF-B kit provides weapon lubrication, weapon optimisation, camouflage, automatic reloading and a gunner’s cab.

The NDF-A and NDF-B kits retain the GSA Mk 3 sight and cannot be fitted with a power unit. GDF-002 weapons built with the NDF-A package are designated GDF-003. Gun-King is a self-contained system providing 3D optronic tracking once the gunner has brought the sight crosshairs onto the target and started to track it. The sight provides the system’s digital computer with angular tracking data and an inbuilt laser rangefinder provides range data for processing with pre-loaded details about the ambient air and ammunition to provide an optimised fire-control solution, whose automatic insertion into the fire-control system is reported to the gunner by an audible signal. The gunner has then only to use his trigger, and the continuously updated fire-control solution is further enhanced by the muzzle velocity measurement system attached to the cannon muzzles.

The system allows extremely fast reaction to a pop-up target, and also provides great flexibility in the engagement of successive targets. The x8 magnification optics of the Gun-King sight, which has an 8° field of vision, are sufficiently sensitive to make possible night engagements in good conditions.

For reloading purposes the barrels automatically move into the 90° elevation position, and the automatic reloading process is started by pressure on the relevant button on the gunner’s console. Replenishment of the horizontally configured automatic reloaders is manual, each reloader being fed with a maximum 12 seven-round clips. The current GDF-005 was introduced in May 1985. It is, in essence, the basic mounting with two KDC cannon and a breech recoil brake and other modern features, plus the full range of NDF-C Combat Improvement Kit modifications. This includes the Gun-King sight to increase effective slant range to 4000 m (4,375 yards). The mounting is fitted with an automatic reloader, reducing the crew from three to one, for the ready-use supply of 280 rounds per gun. This on-mounting supply of 560 rounds, compared with 224 in earlier versions, is considered sufficient for 10 bursts under typical combat conditions. The GDF-005 has a permanently attached power unit, and this drives the electro-hydraulic unit which carries out the outrigger extension, jack activation, wheel pivoting and push-button levelling when mounting or dismounting the weapon; for gun functions; and for the weapon lubrication systems.

The ammunition is available in the following types; APDS-T, SAPHEI-T, HEI-T, two types of HEI, FAPDS, AHEAD, and two practice rounds (TP and TP-T). The APDS-T round is 370 mm (14.57 in) long and weighs 1.46 kg (3.22 lb), firing its 380-g (13.4-oz) projectile (containing a 294-g/10.37-oz subcalibre penetrator) with a muzzle velocity of 1390 m (4,560 ft) per second. This produces flight times to 1000, 2000 and 3000 m (1,095, 2,185 and 3,280 yards) of 0.75, 1.58 and 2.51 seconds respectively, and gives a 40-mm (1.57-in) penetration of 60° angled armour at 1000 m (1,095 yards). With the exception of the FAPDS and AHEAD, the other ammunition types are all 387 mm (15.24 in) long and have a muzzle velocity of 1175 m (3,855 ft) per second. The SAPHEI-T round weighs 1.552 kg (3.42 lb) and fires a 550-g (19.4-oz) projectile containing 22 g (0.78 oz) of Hexal P30 explosive, the flight times to 1000, 2000 and 3000 m (1,095, 2,185 and 3,280 yards) being identical with those of the HEI and HEI-T projectiles. The SAPHEI-T projectile can penetrate 15 mm (0.59 in) of armour inclined at 60° at a range of 1000 m (1,095 yards). The HEI-T round weighs 1.565 kg (3.45 lb) and fires a 535-g (18.87-oz) projectile with 98 g (3.46 oz) of Hexal P30 explosive. The flight times to 1000, 2000 and 3000 m (1,095, 2,185 and 3,280 yards) are identical with those of the HEI projectiles. The two HEI types each weigh 1.58 kg (3.48 lb) and fire a 550-g (19.4-oz) projectile with flight times to 1000, 2000 and 3000 m (1,095, 2,195 and 3,280 yards) or 0.96, 2.18 and 3.78 seconds respectively. The difference between the projectiles lies in their explosive content, the older HEI type having 112 g (3.95 oz) of Hexal P30 and the newer HEI(BT) type 67 g (2.36 oz) of the same explosive plus 20 g (0.71 oz) of zirconium. The HEI type is thus optimised for blast effect, with good fragmentation and incendiary effect, and only limited penetration capability (5-mm/0.197-in) against steel plate, while the HEI(BT) type is optimised for fragmentation, with good blast, incendiary and penetration capabilities. The last two include 3- rather than 1-second incendiary effect, and penetration of 20-mm (0.79-in) steel plate at 1000 m (1,095 yards). The FAPDS (Frangible Armour-Piercing Discarding Sabot) type weighs 1440 g (50.79 oz) and fires a 375-g (13.23-oz) projectile with a notably high muzzle velocity of 1440 m (4,724 ft) per second for the sub-calibre penetrator. The AHEAD type weighs 1780 g (62.79 oz) and fires a special 750-g (26.46-oz) projectile at 1050 m (3,445 ft) per second) to explode at a pre-calculated point in front of the target to despatch a spinning cone of 152 tungsten sub-projectiles at the target. The AHEAD ammunition is used by Canada, Greece, Oman, Spain and, possibly, Chile.

The GDF series is basically a clear-weather system with limited night capability in some models. The defensive requirement is best met by linking the mountings to a radar-directed fire-control system, initially the Contraves Super-Fledermaus and more recently the Contraves Skyguard. One Super-Fledermaus fire-control system can generally co-ordinate two or four GDF mountings. An increasingly more common arrangement pairs two GDF mountings with two quadruple launchers for RIM-7 Sparrow or Aspide medium-range SAMs under the control of a Skyguard fire-control system. This creates a layered defence system for high-value installations or sites. The Contraves Skyguard fire-control system was designed for the control of AA batteries equipped with guns or missiles, as well as a mixed defence using heavy cannon and short-range missiles. The system, based on the same towed two-axle chassis as the GDF gun mounting, is essentially a container-mounted system with an overhead arrangement of sensor heads, and entered production in 1975 as successor to the Super-Fledermaus equipment, providing more modern hardware, separate search and tracking radars, and digital rather than analog computing. The radar is provided by Ericsson of Sweden, and comprises a UAR 1021 I/J-band coherent pulse-Doppler search and tracking equipment with its antennae on a mounting about the mobile housing to provide search capability to a range of 20000 m (21,875 yards). The separate monopulse-Doppler tracking element provides tracking from a range of 11200 m (12,250 yards) down to 300 m (330 yards). The system offers high rejection of clutter and ECM, together with moving target indication of multiple targets. The radar is backed by automatic closed-circuit TV tracking. Data are fed into a Contraves Cora II M computer, a real-time unit that undertakes the functions of system check, threat evaluation, and fire-control solution for guns and missiles.

Working on the basis of the Skyguard system the Brazilian company Avibras has developed a new fire-control system designed for 35- and 40-mm guns with growth potential for SAMs. This system is designated EDT-FILA (Fighting Intruders at Low Altitude), and is carried on a two-axle towed trailer with a body of reinforced fibre-glass. Though modelled on Skyguard with its I/J-band search and tracking radars and its TC tracker, the EDT-FILA adds features such as an extra K/L-band tracking radar with fully integrated laser rangefinder, and an advanced C-2001 digital computer with comprehensive self-test, diagnosis and operational software.

Super-Fledermaus is also a towed system, again based on a two-axle chassis with accommodation for the tactical crew inside an extending shelter at the rear of the trailer. The system weighs some 5000 kg (11,023 lb) and was designed for the control of three heavy-calibre guns or three SAM launchers. This system has a combined head for the visual tracker and Siemens-Albis search/tracking radar, allowing target detection by helical or sector scanning at ranges up to 50000 m (54,680 yards), followed by target tracking at ranges inwards from 40000 m (43,745 yards). The computer allows for ambient air conditions and gun parallax, and delivers a continuously updated fire-control solution, improved further during firing by three integral muzzle-velocity measurement sets. The equipment can be operated in manual, semi-automatic and automatic modes. Additional features are the possibility of linkage into a higher-level detection system, and the use of a putting-on capability to allow rapid re-direction of the system should the spotting number detect an unexpected target.

Further developments of the GDF towed AA cannon system series are the GDF-006 (GDF-001/002/003 upgraded with AHEAD ammunition) and the GDF-007 (GDF-005 upgraded with AHEAD ammunition). The Type 90 is the Chinese licence-manufactured copy of GDF-002, the Samavat is the Iranian model with a night vision sight and used with Skyguard and Super-Fledermaus fire-control systems, and the Amoun is the Egyptian version with the Skyguard fire-control system linking with a Sparrow SAM launcher. Other equipments using the same pair of GDF cannon are self-propelled guns such as the German Gepard using the chassis of the Leopard 1 main battle tank; British Marksman based around the Marksman turret that could be installed on numerous tank chassis (the only model that went into production was a version based on the T-55 chassis for Finland); Type 87 Japanese SPAAG; PZA Loara Polish SPAAG based on the PT-91 tank; Type 87 Japanese SPAAG; and ItPsv 90 Finnish SPAAG.

Operators of the GDF towed systems include Argentina (50+ GDF-002 units with the Xaba sight), Austria (74 GDF-005 in army service and 18 GDF-005 in air force service), Bahrain (12 GDF-005 units), Brazil (38 GDF-001 with updated Super-Fledermaus and Brazilian-made Skyguard fire-control systems, Cambodia, Canada (20 AHEAD-modified GDF-005 and 10 Skyguard fire-control systems in the process of being phased out of service), Chile (24 GDF-005), China (licensed copy of GDF-002 as the Type 90 totalling more than 150 units with Skyguard fire-control system), Cyprus (30 GDF-005 with Skyguard fire-control system and Aspide SAM), Ecuador (30 GDF-003), Egypt (50 Amoun with Skyguard fire-control system and Sparrow SAM), Finland (16 known locally as 35 ITK 88), Greece (44 GDF-002 with Skyguard fire-control system and Aspide SAM), Iran (92 GDF-002 perhaps being upgraded and/or supplemented by new manufacture, with Skyguard and Super-Fledermaus fire-control systems), Indonesia, Japan (about 70 GDF-001 used with updated Super-Fledermaus fire-control radars; made under a joint venture with Japan Steel Works for the cannon and Mitsubishi Electric Corporation for the rest of the system), Kuwait (12 Amoun with Skyguard fire-control system and Sparrow SAM), Malaysia (28 GDF-003), Oman (10 AHEAD-modified GDF-005), Pakistan (about 200 GDF-005, 60 of them AHEAD-modified), Romania (72 GDF-003), Saudi Arabia (128 updated GDF-005 with Skyguard fire-control system), Singapore (34 GDF-002), South Africa (about 100 GDF-002 and 48 modified GDF-005), South Korea (more than 18 GDF-003), Spain (92 GDF-005 being upgraded to GDF-007 standard and with Skydor and Skyguard fire-control systems), Switzerland (45 GDF-007 modified units from 264 GDF-001 and GDF-002), Taiwan (24 GDF-003 with Skyguard fire-control system), Turkey (about 120 GDF-002), United Arab Emirates (30 GDF-005), and UK (15 GDF-002 captured from Argentina during the Falklands War along with six Skyguard and one Super Fledermaus fire-control systems; four Skyguard systems are used to catch UK military aircraft exceeding flight restrictions over residential areas, and the GDF-002 guns are now in storage).

Specification

GDF-005

Type: towed twin point defence tactical AA gun mounting

Calibre: 35 mm

Barrel length: 3.15 m (124.02 in), or 90 calibres

Carriage: four-wheel platform with outriggers and shield

Weights: 7250 kg (15,983 1b) without ammunition and 7700 kg (16,975 1b) with ammunition

Dimensions: length, travelling 7.80 m (25 ft 7 in) and in firing position 8.83 m (28 ft 11 in); width, travelling 2.26 m (7 ft 5 in) and in firing position 4.49 m (14 ft 8¾ in); height, travelling 2.60 m (8 ft 6 in) and in firing position 1.72 m (5 ft 7¾ in)

Traverse/elevation: 360°/-5° to +92°

Rate of fire (per barrel): 550 rounds per minute (cyclic)

Horizontal range: 9500 m (10,390 yards) maximum

Slant range: 4000 m (4,375 yards) effective

Crew: 3

[Photo by MoRsE]

Western Electric MIM-14B Nike Hercules

1:1 scale model of a Nike Hercules missile, outdoors, with mountains and blue sky in the background, and a man in jeans and T-shirt standing at its base, demonstrating its sizeIntroduced in 1958 as successor to the first-generation SAM-A-7 (then called M1 and from October 1962 MIM-3) Nike Ajax long-range surface-to-air missile, the Western Electric MIM-14 Nike Hercules SAM was still in limited service during the late 1980s, but by this time was generally obsolescent. The Nike Hercules was replaced in the US inventory by the MIM-104 Patriot, most of the units being retired in 1983.

The Nike Hercules was a solid-propellant two-stage surface-to-air missile for the high- and medium-altitude air-defence role, and also possessed a limited surface-to-surface role capability. A Cold War development, the Nike Hercules was intended for the destruction of Soviet bombers (both individually and entire formations) and to a more limited extent ballistic missiles. Western Electric, Bell Laboratories and the Douglas Aircraft Company were chief contractors for the system. Nuclear-armed Nike Hercules missiles were deployed in the USA, Greece, Italy and Turkey, and with the Belgian, Dutch and US forces in West Germany. Conventionally armed Nike Hercules missiles also served in the USA, Denmark, Japan, Norway, Taiwan and West Germany. The deployment of the Nike Hercules to Europe began in 1959, and the last nuclear-armed Nike Hercules missiles in Europe were deactivated in 1988. The Nike Hercules missile systems built in Japan were later retrofitted with upgraded guidance systems in which the original vacuum tube systems were replaced by transistorised systems.

Key features of the Nike Hercules’s design were its range and altitude capabilities, the powerful General Electric HIPAR radar associated with the system, and the potent warhead. Where this last was concerned, only the USA fielded the initial W7 Mod 2E 2.5- or 28-kiloton nuclear warhead or, from 1961, the W31 nuclear warhead. The latter was fielded in two basic variants: the W31 Model 0 with yields of 2.5 kilotons (Y1) or 30 kilotons (Y2), and the W31 Mod 2 with yields of 2 or 20 kilotons. The latter weighed 1,123 lb (509.4 kg) and used an enriched uranium known as oralloy (plus tritium) as the fissile material with Cyclotrol as the explosive to produce the implosion which resulted in the fission reaction. The W31 warhead was developed at the Los Alamos National Laboratory from 1954, and entered service in 1958.

The origins of the Nike Hercules system went back to Project ‘Nike’ (the Greek word for victory) in the years immediately after the end of World War II. Throughout that war the continental USA had remained largely untroubled by the possibility of strategic air attack by Germany and Japan (though both countries were developing weapons for that purpose as their wars ended), but the concept of hemispheric defence was still strong in the minds of the US services. World War II had demonstrated what could be achieved by massed bombers carrying conventional bombs, or a single bomber carrying a nuclear bomb, and defence against such a threat was already a high priority when the USSR exploded its first nuclear device in September 1949. By this time the Tupolev Tu-4 ‘Bull’, a reverse-engineered and therefore wholly unlicensed copy of the Boeing B-29 Superfortress strategic bomber, was already beginning to enter service. Other indications of the USSR’s plans were readily forthcoming in Berlin and Korea, and the SAM-A-7 programme was pressed ahead with all priority.

The team selected for the programme was centred on Western Electric as prime contractor and Bell Telephone Laboratories as main subcontractor. This was the team which had been responsible for the M9 radar fire-control system evolved in World War II for the USA’s M117 and M118 90-mm (3.54-in) high-altitude anti-aircraft guns, and from this it was simple to deduce that the new surface-to-air missile system was designed to operate in a comparable fashion within the context (from 1956) of the Semi-Automatic Ground Environment (SAGE) network of radars and computers tasked with the defence of the continental USA. The large thermionic valve computers allocated specific weapons, such as AA guns, fighters or missiles to each potential target detected by the radar systems. After detection and acquisition by a SAGE radar, the target was passed to a Western Electric target-tracking radar, which in turn provided a continuous stream of data to the fire-control computer that selected the appropriate missile and fired it at the optimum moment into the beam of the missile-tracking radar; thereafter the computer commanded the two radars to intersect their beams at the predicted position of the target, and commanded warhead detonation when the climbing missile was just below the target aircraft. Given the complexity of the system, as well as the size and power requirements of the associated radars and computers, the Nike system was necessarily fixed, with launch sites, complete with radars, computers and traversing/elevating single-arm launchers, located on strategic approach routes to targets in the continental USA.

The system became operational with the US Army in December 1953 as the world’s first fully guided SAM system. The missile was produced in North Carolina by Douglas Aircraft as the Nike Ajax. This was 34 ft 10 in (10.617 m) long complete with its slim tandem-mounted booster, which weighed 1,245 lb (565 kg). The booster had three cropped triangular fins set 120° apart, and had a Hercules Powder Company solid-propellant rocket delivering 59,000-lb (262.45-kN) thrust for 2.5 seconds. Thereafter propulsion was entrusted to the missile’s Bell Aircraft liquid-propellant sustainer, delivering 2,600-lb (12.73-kN) thrust for 21 seconds to give the 1,210-lb (549-kg) missile a burn-out speed of Mach 2.3 and a maximum range of 44,000 yards (40235 m). The missile proper had a diameter of only 12 in (0.305 m), and was excellently streamlined towards its pointed nose. The cruciform of low-aspect-ratio delta wings was fixed, control being effected via the cruciform of smaller delta canards nearer the nose and indexed in line with the wings, which were located just aft of the body’s mid-point. Between the canards and the wings was another cruciform of swept surfaces, these small projections housing the antennae for the guidance system.

The missile had an unusual warhead arrangement, with separate charges of 12, 122 and 179 lb (5.44, 55.3 and 81.2 kg) surrounded by 0.25-in (6.35-mm) metal cubes for optimum shrapnel effect against a heavy bomber. Production of the Nike Ajax continued up to 1958, by which time 15,000 missiles had been delivered. From 1957 the type was supplied to a number of the USA’s main allies both within and outside NATO, but even by this time it was clear that the missile was obsolescent. Yet, given the fact that there were well over 3,000 launchers in service, the US Army alone having 40 battalions each operating 36 or 48 launchers, there was considerable economic and logistical pressure to upgrade rather than replace the whole system.

This led to the development, still under the overall leadership of Western Electric, of the Nike Hercules initially as the SAM-A-25, adopted for service as the M6 and in 1962 redesignated MIM-14. This new missile’s performance was impressively superior to that of the Nike Ajax, largely as a result of its more powerful booster. Developed by Radford Arsenal and Borg-Warner, this tandem-mounted M42 arrangement incorporated four Hercules M5E1 solid-propellant rockets of the same type used singly as the booster for the Nike Ajax, strapped together by a circular tapering nose band containing the attachments to the Nike Hercules proper, and by a square-section tail band whose four curved corners each supported a swept fin. The M42 booster package produced a thrust of 220,000 lb (978.61 kN). After booster burn-out, the missile proper used a Thiokol M30 solid-fuel sustainer motor delivering a thrust of 10,000 lb (44.48 kN) to give the missile a burn-out velocity, in later models, of about 2,750 mph (4425 km/h) or Mach 3.65, a range of 90 miles (145 km) and a ceiling of 150,000 ft (45720 m).

The Nike Hercules was a radically different missile to its predecessor, with a considerably wider-diameter body (again beautifully tapered along its forward portion), and a cruciform of very long-chord low-aspect-ratio wings indexed in line with the fins of the booster. Projecting guidance-system antennae at the forward end of the wings looked like small canards, and aerodynamic control was entrusted to servo-actuated elevons on the trailing edge of each wing. The missile’s propulsion was also radically improved, the low-power liquid-propellant sustainer of the Nike Ajax being replaced by a powerful solid-propellant unit giving early Nike Hercules missiles a velocity of Mach 3.35 at burn-out.

The warhead (either nuclear or 1,106-lb/502-kg HE) warhead was located just aft of the guidance system bay. The T45 blast/fragmentation HE warhead contained 600 lb (272 kg) of HBX-6 explosive. General Electric was responsible for the improved guidance and warhead fusing systems.

The Nike Hercules entered full-scale service in 1958 as the M6 (from 1962 the MIM-14A), and was produced eventually to the extent of some 25,000 missiles including licensed production by Mitsubishi in Japan (Nike-J). During the early 1960s this initial service model was superseded in production by the M6A1 (MIM-14B Nike Hercules) with the Thiokol M30A1 sustainer and a number of electronic improvements. The system was initially deployed in direct replacement of the Nike Ajax, using the same radar, fire-control and launcher systems. This was again too cumbersome for anything by operational- and strategic-level use, but here the Nike Hercules soon proved itself a formidable weapon, especially when the new General Electric HIPAR (High-Power Acquisition Radar) was tied into the system. Early in 1969 a Nike Hercules intercepted and destroyed a Corporal ballistic missile, and later in the same year a Nike Hercules successfully tackled another Nike Hercules at a combined closing speed of Mach 7+, at an altitude of 161,500 ft (49225 m) and range of 52,800 yards (48280 m). These trials proved conclusively that the Nike Hercules was effective against some ballistic missiles and all high-altitude aircraft.

Comparable developments were taking place in the USSR, and the death of the ‘high-flier’ age was signalled by the shooting down of Gary Powers’s Lockheed U-2 spyplane over the USSR during 1960. Henceforward combat air operations rapidly switched to low altitude, and here the Nike Hercules was largely ineffective. Efforts were made to reduce this limitation, and to improve the system’s mobility, resulting in the introduction from 1962 of a semi-mobile Nike Hercules launcher unit and associated electronic systems. The Nike Hercules thus became a more effective operational- and tactical-level weapon, being able to operate independently yet still retaining the capacity for integration into a higher-level command structure.

The most important electronic development associated with the mobile version of the Nike Hercules system was the MPQ-43 mobile version of the HIPAR, requiring only three vans and two trailers instead of the semi-mobile HIPAR’s 20 vehicles. The HIPAR/MPQ-43 system operated in the D-band, and provided long-range target detection of high accuracy even in conditions of severe electronic countermeasures. Indeed, it was claimed that the system offered high-elevation and moving-target indication capabilities unequalled in modern, but smaller, radars right into the early 1990s.

Once a possible target had been acquired, it was interrogated by a TPX-46 IFF system and, if judged positively non-friendly, the data were passed to the missile battery’s target-tracking radar and fire-control system. This generated a solution to the fire-control problem as the launcher was trained to the right bearing. At the appropriate moment the missile was launched automatically at an elevation of 85°, its guidance system being activated only after the separation of the booster. At this point the missile was rolled onto the correct course for interception and warhead detonation.

The Nike Hercules network reached its peak in 1963, when there were 134 US Army batteries equipped with the type. Even at this time it was appreciated that the shifting balance of air operations required the rapid adoption of a more mobile system optimised for defence at lower altitudes, and the SAM-D requirement was issued. This led eventually to the MIM-104 Patriot, which entered service in 1981, and to maintain the Nike Hercules’s capabilities as an interim weapon a series of improvements was put in hand from the early 1960s. The missile itself was upgraded to MIM-14C Nike Hercules standard with improved electronic counter-countermeasures and the Thiokol M30A2 motor. As late as 1981 it was decided to upgrade surviving systems still further with a new fire-control/fault diagnosis system based on a Norden digital micro-computer. The US Army started to deactivate its operational Nike Hercules batteries in the USA during 1974, but retained a number of training batteries and also maintained batteries in Alaska, Florida and Europe up to 1983. The MIM-14B system was also employed by Belgium, Denmark, Greece, Italy, Japan (Nike J to MIM-14C standard), Netherlands, Norway, South Korea, Taiwan, Turkey and West Germany. with the collapse of the USSR from the late 1980s, the last of these missiles were retired.

Specification

MIM-14B Nike Hercules

Type: ground-based two-stage long-range operational/tactical-level SAM

Dimensions: diameter 31.5 in (0.80 m) for booster and 21 in (0.53 m) for the missile; length 41 ft 6 in (12.649 m) overall and 26 ft 10 in (8.18 m) for the missile; span 11 ft 6 in (3.51 m) for the booster and 6 ft 2 in (1.88 m) for the missile

Weight: total round 29,000 lb (13154 kg) and missile 10,415 or 10,710 lb (4720 or 4858 kg); warhead 900/945-lb (408/429-kg) W31 Mod 2 nuclear with a yield of 2, 20 or 40 kilotons, or alternatively 1,106-lb (502-kg) M17 proximity-fused FRAG-HE

Propulsion: four jettisonable Hercules solid-propellant booster rockets packaged as the M42 booster rated at 220,000-lb (978.61-kN) thrust for 2.5 seconds, and one Thiokol M30A1 solid-propellant sustainer rocket rated as 10,000-lb (44.48-kN) thrust

Performance: speed Mach 3.65; range 90+ miles (145+ km); altitude limit 150,000 ft (45720 m) Guidance: radar command

[Photo by jurvetson]

The tank – France enters the lists

Black and white photo of J. E. Estienne, in white shirt and black suit and tieAt much the same time that Colonel Swinton was first pleading his case to the War Office for armoured fighting vehicles, the same pattern of events was emerging in France. Here Colonel J. E. Estienne had also seen the cross-country capability of the Holt tractor and, working from this conceptual basis, advocated the development of what he called a cuirassé terrestre (land battleship) to unlock the static nature of trench warfare. Estienne’s ideas found a ready acceptance in the mind of General Joseph Joffre, the French field commander, who saw great tactical utility for Estienne’s original concept for a 4000-kg (8,818-lb) armoured tractor with a crew of four and able to drag a 7000-kg (15,432-lb) armoured sled carrying 20 infantrymen. The similarity to Swinton’s original thinking is strong, and Estienne’s tactical notion was that such an armoured force could ‘sandwich’ the occupants of the desired trench by pushing half its strength across the trench to isolate it and keep it under machine-gun fire.

While he saw the advantages of such a combination, Joffre was sufficiently astute to realise its technical impracticality. Ultimately the French army reached the same conclusions as the British about the need for a tracked armoured vehicle that could cross barbed-wire and knock out the German machine-gun posts, and so open the way for the attacking infantry. Joffre therefore ordered Estienne to Paris, there to liaise in the development of France’s first tank with Eugene Brillie of the Schneider-Creusot company. This was the French licensee of the American Holt company, which had supplied one 45-hp (33.6-kW) and one 75-hp (55.9-kW) machine for trials purposes in May 1915. The basic design made extensive use of Holt components and practices, and was completed towards the end of 1915: on 31 January 1916 an order was placed for 400 of these tanks, to be designated Char d’Assaut 1 (CA 1) Schneider and to be delivered by November 1916. August 1916 saw the creation of the Artillerie d’Assaut, as the French tank arm was named, and in September the first CA 1 Schneider tanks were delivered just before Estienne was appointed commander of the tank arm at the end of the month.

The CA 1 Schneider was based on the Holt track system, which in this application was notable for the fact that it was sprung by vertical coil springs, but equally notable for its short overall length and very limited forward rise. The all-important trench-crossing and parapet-climbing capabilities were therefore an indifferent 1.75 and 0.8 m (5 ft 9 in and 2 ft 7 in) respectively, and ground clearance was also too small to give the tank useful performance under adverse conditions. The hull was basically rectangular, with a boat-hull nose section to aid parapet-climbing and reduce the tank’s chances of embedding its nose in mud, and terminated at its front in a large serrated wire cutter. At the rear were a pair of upward-curving projections designed to increase trench-crossing capability by increasing the tank’s effective length. The CA 1 Schneider was armoured to a maximum thickness of 11.5 mm (0.45 in).

The vehicle massed 13500 kg (29,762 lb) under combat conditions, and was powered by a 55-hp (41-kW) Schneider petrol engine located at the front left of the vehicle (with the driver to its right), driving the tracks via a crash gearbox: steering was effected by clutches and brakes on the half shafts. As in the British Mk I, the petrol tank was located internally, to feed the engine by gravity. The CA 1 Schneider had a crew of six (an officer as commander/driver, an NCO as second-in-command, and four enlisted men in the form of a gunner, a loader and two machine-gunners), who entered and left the tank via large double doors in the rear. The armament was planned originally as one 37-mm gun and machine-guns, but the definitive fit comprised one short-barrel 75-mm (2.95-in) Schneider gun with 90 rounds and two 8-mm (0.315-in) Hotchkiss machine-guns with a total of 4,000 rounds. The gun was located in a narrow embrasure on the right towards the front of the vehicle, and this allowed traverse of only 60° and elevation in an arc between -10° and +30°, severely limiting the capabilities of this otherwise useful main armament. The machine-guns were located in substantial ball-and-socket mountings on the hull sides, each mounting allowing traverse of 106° and elevation in an arc between -45° and +20°.

The CA 1 Schneider first saw action at Berry-au-Bac near the Chemin des Dames on 16 April 1917: of the 132 tanks committed no fewer than 57 were destroyed and many others damaged beyond economical repair. The primary culprit for this disaster was a combination of poor design and the Germans’ special ‘K’ bullet with its tungsten carbide core, which could penetrate the French armour without undue difficulty. The poor design concerned mainly the dismal ventilation and the location of the fuel tankage right next to the machine-guns, and after several tanks had blown up the CA 1 Schneider was dubbed the ‘mobile crematorium’, an epithet that was slow to disappear even after the internal tankage had been replaced by two armoured external tanks each holding 100 litres (22 Imp gal); ventilation was also improved, but remained problematical under certain conditions. Protection was enhanced by the addition over the most vulnerable areas of rudimentary spaced armour 5.5 mm (0.22 in) thick and located some 40 mm (1.57 in) from the base armour: this added about 500 kg (1,102 lb) to the tank’s combat weight.

Black and white photograph of a CA 1 Schneider tank, manned by three soldiers who appear in the photo, one very prominently standing up out of the rearThe CA 1 Schneider remained in service up to the Armistice of November 1918, but was neither popular nor successful. Developments were planned as the CA 2 (with the 75-mm/2.95-in embrasure gun replaced by a 47-mm gun in a rotating roof turret) and the CA 3 (with twin roof turrets in a longer hull and powered by a 100-hp/76-kW engine): the CA 2 attained prototype form, but the CA 3 did not reach even this stage. Later in the war the CA 1 Schneider found additional employment as a supply tank, the embrasure gun being removed and another door fitted in its place to create the Schneider Char de Ravitaillement.

Development and production of the CA 1 Schneider had bypassed the French army’s normal vehicle procurement executive, the Service Technique Automobile, which was sufficiently piqued to instigate the design and construction of another battle tank. This was the Char d’Assaut Saint Chamond, designed by Colonel Rimailho and ordered from the Compagnie des Forges et Acieries de la Marine et Homecourt (FAMH) at Saint Chamond. The first prototype was completed in February 1916, and two months later the STA ordered 400 of the type. Like the CA 1 Schneider, the CA Saint Chamond was based on the Holt sprung tractor system, though in this application with the track length increased by about 0.3 m (11¾ in). This was clearly a basic improvement over the trackwork of the CA 1 Schneider, but was totally offset by the superimposition of an extraordinarily long hull, increasing overall length from the 6.32 m (20 ft 9 in) of the CA 1 to 8.69 m (28 ft 6 in): the result was cross-country performance still worse than that of the CA 1, with the tendency to ditch on only slightly undulating ground: in terms of performance in front-line conditions this translated into trench-crossing and parapet-climbing capabilities of only 2.4 and 0.38 m (7 ft 10 in and 1 ft 3 in) respectively.

Two unusual features of the CA Saint Chamond were its provision for a rear driving position (the only time this has been featured in a tracked fighting vehicle) and its use of electric drive for the tracks. The Crochat-Collardeau electric generator was driven by a 90-hp (67.1-kW) Panhard petrol engine, and current was supplied to the electric motor attached to each track’s drive sprocket. Differential powering of the tracks provided considerable agility within the limitations imposed by the hull, and despite a combat weight of 22000 kg (48,501 lb) the CA Saint Chamond had useful performance including a maximum speed of 8 km/h (4.9 mph) but a range of only 60 km (37 miles). The primary disadvantage of the electric drive system was its weight, which added to the mobility problems engendered by the long hull. This was armoured to a maximum thickness of 11.5 mm (0.45 in), and terminated at its forward end in a well-sloped glacis plate above an angled-back V-shaped lower surface designed to help the tank ride over earth banks and the like.

The CA Saint Chamond possessed a crew of eight including the driver and commander, who each had a small cupola at the front of the vehicle, and access to the vehicle was provided by a door in each side plus a third in the tail plate. The armament comprised one 75-mm (2.95-in) Saint Chamond TR commercial gun (first 165 vehicles) or one 75-mm (2.95-in) modèle 1897 gun (last 235 vehicles) with 106 rounds, and four 8-mm (0.315-mm) Hotchkiss machine-guns with a total of 7,488 rounds. The TR main gun was located in a limited-traverse mounting in the glacis plate, and the machine-guns were placed one in the bow (on the lower right-hand side), one in the tail plate, and one on each side of the hull.

Deliveries of the CA Saint Chamond began late in 1916, and the type was first used in action on 5 May 1917 at Moule de Laffaux. In this first engagement the limitations of the design became all too apparent: of 16 CA Saint Chamond tanks committed, 15 ditched in the first line of German trenches. Further action confirmed the need for modification, successive efforts increasing the armour to a maximum thickness of 17 mm (0.67 in) against the effect of the ‘K’ anti-tank bullet, a raised forward section of the hull, the elimination of the commander’s cupola, the replacement of the original flat roof with a pitched roof so that grenades would roll off, and the use of wider tracks. These improved the CA Saint Chamond’s capabilities, but nothing could be done about the basic design flaw in the vehicle’s configuration, and from May 1918, when the final deliveries were made, the type was increasingly stripped of its main gun and used for supply tasks as the Char Saint Chamond de Ravitaillement.

The French St Chamond tank driving over hilly grass, showing the overhanging front hullBoth the French chars d’assaut were perhaps ahead of their British contemporaries in gun calibre and the location of this single weapon in a central mounting, but the French designers had been too impressed with the cross-country capabilities of the Holt tractor to realize that a long track length combined with a large forward rise were essential to adequate trench performance. The two French tanks were thus little more than incidentals to the French army’s war effort, though they did play an important part in the development of ‘tank consciousness’ and in the evolution of tank tactics and organization. However, the most important French tank of World War I was an altogether different machine, the Renault FT light tank, the designation indicating Faible Tonnage (light weight). The concept stemmed from Estienne’s desire for a lightweight partner to his CA 1: the heavy tank would crush barbed wire and deal with the German strongpoints, and the lightweight machine would accompany the attacking infantry to suppress any surviving pockets of German resistance and develop the exploitation phase of any breakthrough.

Estienne’s first choice as partner in the design and development of the CA 1 had been the company headed by Louis Renault, but Renault had declined Estienne’s invitation on the grounds that the company lacked any experience in heavy tracked vehicles and was, in any case, heavily committed to other efforts. However, by 1916 Renault had become involved in production of tracked vehicles (mainly tractors for the French artillery), and was more receptive when Estienne proposed a collaborative venture to produce the desired light tank. There remains some doubt as to the exact design parentage of the resulting FT, though Renault and a subordinate (Serre) were certainly involved, and it seems likely that Estienne exercised more than a watching brief over the project. Yet again Estienne bypassed the normal channels of procurement, and in October 1917 went straight to Joffre with his scheme for 1,000 examples of a 4000-kg (8,818-lb) light tank carrying one 8-mm (0.315-in) machine-gun or, in a small number, one 37-mm gun in a 360° traverse turret, possessing a maximum height of 1.75 m (5 ft 9 in), armoured against small arms fire and possessing a maximum speed of 12 km/h (7.5 mph). Estienne also proposed, in a very far-sighted manner, that a number of the machines should be completed with wireless equipment to allow communication between commanders and their mobile forces. Though there was considerable resistance from some parts of the French war ministry apparatus, Estienne’s notion found sufficient favour to secure authorization of prototype production after a mock-up had been completed at the end of 1916. The first prototypes appeared in February and March 1917, and immediately displayed excellent qualities in trials at the Champlieu camp. An initial order for 150 FT tanks was placed on 22 February 1917, but at the insistence of General Henri Pétain, the French commander-in-chief, the total was upped to 3,500 vehicles for delivery by the end of 1918, and additional orders then increased the planned production run to more than double this figure. It was clear that Renault could not handle the orders on its own, and this important programme soon involved Belleville, Berliet, Delaunay, Renault and SOMUA (Société d’Outillage Mécanique et d’Usinage d’Artillerie) as manufacturers with a large number of other companies (including some in the UK) as subcontractors.

The FT was an unusual but interesting and successful tank in its technical and tactical features. Technically, the tank lacked a conventional chassis but was rather a monocoque of riveted armour plate between 6 and 16 mm (0.24 and 0.63 in) thick, a boxlike structure to which were attached the major internal and external components terminating at the tail in an upswept plate that increased the effective length of the vehicle as an aid to trench crossing, which was 1.35 m (4 ft 5 in) without and 1.8 m (5 ft 11 in) with the tailplate. The hull accommodated the driver at the front, the turret in the centre, and the combined engine and transmission assembly at the rear. The driver gained access to his position via twin frontal doors, and the other crew member, the commander/gunner, used rear doors to enter the turret, which had a maximum thickness of 22 mm (0.87 in). The turret, surmounted at its rear by a mushroom-shaped observation cupola, was the world’s first to offer 360° traverse and rested on a ball race for ease of manual movement until a neat handbrake was used to lock the turret on the desired bearing. The armament in the first machines to enter service was an 8-mm (0.315-in) Hotchkiss machine-gun capable of elevation in an arc between -20° and +35°. Some 4,800 rounds of ammunition were carried. The engine was a 35-hp (26.1-kW) Renault petrol unit, and drove the tracks by means of a crash gearbox, with a clutch-and-brake system used for steering. Suspension of the tracks was achieved by coil and leaf springs for the four bogies (nine road wheels), and at the front of each track was a large idler to provide sufficient track rise for the FT to climb a 0.6-m (2-ft) parapet. The idlers comprised a steel rim over laminated wood centres, and there were six track-return rollers.

The first production tanks were completed in September 1917, but the whole programme was hampered by shortages of the special cast steel turret and by arguments within the army about the precise nature of the armament to be fitted. By the end of the year Renault had delivered only 83 examples of the initial variant, which was designated the Char Mitrailleuse Renault FT 17 and first used in combat on 31 May 1918 in the Forêt de Retz. The turret problem proved impossible of solution in the short term, and after the delivery of some pre-production vehicles with cast turret the producers designed their own eight-sided turrets of riveted plate construction, allowing larger-scale production from about the middle of 1918 for the delivery of 3,177 tanks before the Armistice against orders that currently totalled 7,820 including 3,940 from Renault. When the cast turret began to arrive in useful numbers it was installed on a version generally designated FT 18. In 1921 the French army still deployed the FT in substantial quantities: of the total of 3,728 such vehicles 2,100 were armed with a machine-gun, 1,246 with a 37-mm gun and 39 with a 75-mm (2.95-in) gun, while 188 were fitted with wireless equipment and 155 were training tanks.

The French Char Canon Renault FT17, two driving along a dusty road in procession, manned by American soldiersThe second FT version to appear was the Char Canon Renault FT 17, in which the turret accommodated a 37-mm Puteaux gun capable of elevation in an arc between -20° and +35°. Ammunition stowage was provided for 200 HE, 25 armour-piercing and 12 shrapnel rounds (237 rounds in all). Production orders for the gun-armed version totalled 1,830 units, and together with the standard model with a machine-gun it was used by countries including Belgium, Brazil, Canada, China, Czechoslovakia, Finland, Greece, Italy (with modification the Fiat 3000), Japan (Type 79 Ko-Gata Sensha), Manchuria, the Netherlands, Poland, Spain, the UK, the USA (6-Ton Tank M1917), the USSR (KS, and with modification MS-1 and MS-2) and Yugoslavia.

The other two initial variants were the Char Canon Renault 75S with a short-barrel 75-mm (2.95-in) gun in a riveted heptagonal turret with a bustle to accommodate the gun recoil, and the three-man Char Renault Télégraphie Sans Fil with a boxlike superstructure and tall aerial for the wireless equipment needed in the command role. The variant with the 75-mm (2.95-in) gun was really a self-propelled gun, and though orders were placed for 970 units the type was so delayed that it did not appear until after the Armistice, thereafter being produced only in very small numbers mainly for service in North Africa.

The FT was also developed after World War I in a number of largely experimental forms as the Char Fascine (trench-filler with up to three fascines), Char Demineur (mineclearer with two ploughs on hinged forward arms), Char Projecteur (internal-security searchlight vehicle with a tall mast supporting twin searchlights), a smokelaying vehicle, an amphibious vehicle, a bridgelayer, a bulldozer, and a cargo carrier with a largely redesigned hull. The FT was also used as the basis for experimental work with the Citroen-Kegresse suspension and rubber-band track system for higher speeds and quieter running. Trials with these continuous rubber tracks were undertaken in 1924 and 1925, and though much interesting data was collected, nothing came of the system. From 1931 remaining FT 17 and FT 18 vehicles were refitted with the new 7.5-mm (0.295-in) Hotchkiss modèle 31 machine-gun and redesignated Char Mitrailleuse Renault FT 31: this variant’s ammunition stowage was 4,050 rounds including 400 armour-piercing rounds.

The FT remained in widespread service between the two world wars, seeing service in Morocco, Syria and Tunisia before meeting its end in the German invasion of France during May and June 1940. Machines captured by the Germans were used for internal security duties with the designation PzKpfw 18R 730(f).

It is worth noting that even in the 1920s the French sought to capitalise on the capabilities of the basic FT design by producing an upgraded model as the Char NC 1, otherwise designated the Char NC 27 and intended as an infantry support tank. This was considerably up-armoured from the standard of the FT, with a maximum of 34 mm (1.34 in) on the turret front and 30 mm (1.18 in) on the hull front for a combat weight of 8500 kg (18,730 lb). Power was provided by a 60-hp (44.7-kW) Renault petrol engine for a maximum speed of 18 km/h (11.2 mph), and on each side the suspension comprised three coil-spring columns combined with six hydro-pneumatic shock absorbers for three four-wheel bogies; there was also an independent wheel at the front. Armament was either one machine-gun or one 37-mm gun, and though the type was not adopted by the French army it was exported to Japan as the Otsu-Gata Sensha, and to Yugoslavia.

The Char NC 1 was followed by the Char NC 2, otherwise designated the Char NC 31. This was similar to the NC 1 (NC27), but weighed 9500 kg (20,944 lb), was fitted with heavier tracks, was powered by a 75-hp (55.9-kW) Renault petrol engine, and carried an armament of two 7.5-mm (0.295-in) machine-guns. Small sales were made to the Greek army.

This was the mainstream of French tank development in World War I, and though a few experimental types were developed these generally failed to lead anywhere. The exception was the Char 1, developed in two forms as a char de rupture (breakthrough tank) for the planned 1919 offensives and most important as the precursor of the Char 2C.

Specifications

Schneider Char d’Assaut 1

Type: assault tank

Crew: 6

Combat weight: 14600 kg (32,187 lb)

Dimensions: length overall 6.32 m (20 ft 8¾ in); width 2.05 m (6 ft 8¾ in); height 2.30 m (7 ft 6 in)

Armament system: one 75-mm (2.95-in) gun with 90 rounds and two 8-mm (0.315-in) machine-guns with 4,000 rounds

Armour: 11.5 mm (0.45 in) maximum

Powerplant: one 41-kW (55-hp) Schneider petrol engine

Performance: speed, road 7.5 km/h (4.6 mph); range, road 48 km (30 miles); gradient 57%; vertical obstacle 0.787 m (2 ft 7 in); trench 1.75 m (5 ft 9 in)

Char d’Assaut St Chamond

Type: assault tank

Crew: 8

Combat weight: 22000 kg (48,501 lb)

Dimensions: length overall 8.687 m (21 ft 11¼ in); width 2.667 m (8 ft 9 in); height overall 2.362 m (7 ft 9 in)

Armament system: one 75-mm (2.95-in) Canon de 75 modèle 1897 L/36 rifled gun with 106 rounds and four 8-mm (0.315-in) Hotchkiss machine-guns (one bow, one rear and two beam) with 7,488 rounds; the main gun was stabilised in neither elevation nor azimuth, and simple optical sights were fitted

Armour: riveted steel varying in thickness from 5.5 to 17 mm (0.22 and 0.67 in)

Powerplant: one 67.1-kW (90-hp) Panhard petrol engine with 250 litres (55 Imp gal) of fuel driving one Crochat-Collardeau electrical generator powering one motor attached to each drive sprocket Performance: speed, road 8 km/h (4.9 mph); range, road 60 km (37.3 miles); gradient 57%; vertical obstacle 0.381 m (1 ft 3 in); trench 2.45 m (8 ft 0 in); ground clearance 0.33 m (13 in)

Char Canon Renault FT17

Type: light tank

Crew: 2

Combat weight: 6800 kg (14,991 lb)

Dimensions: length overall 4.10 m (13 ft 5½ in) or 5.00 m (16 ft 5 in) with optional tail; width 1.74 m (5 ft 8½ in); height overall 2.14 m (7 ft 0¼ in)

Armament system: one 37-mm SA Canon rifled gun with 200 rounds; the turret was manually operated, the gun was stabilised in neither elevation (-20º to +35º) nor azimuth (360º), and simple optical sights were fitted

Armour: riveted steel varying in thickness between 6 and 16 mm (0.24 and 0.63)

Powerplant: one 26-kW (35-hp) Renault petrol engine with 100 litres (22 Imp gal) of fuel Performance: speed, road 7.7 km/h (4.8 mph); range, road 35 km (21.75 miles); fording 0.7 m (2 ft 3½ in); gradient 50%; vertical obstacle 0.6 m (2 ft 0 in); trench 1.35 m (4 ft 5 in) or 1.8 m (5 ft 11 in) with optional tail; ground clearance 0.435 m (17 in)

The tank – development gathers pace

Tank Mk IV, deploying its unditching beamAlthough the Tank Mk I had made its debut in the Battle of Flers-Courcelette in September 1916, this could not be regarded as a real technical or tactical success. However, the combat debut of the tank did finally persuade sceptical British army officers in France that here was a potentially decisive weapon. Thus orders for the tank were increased as the fledgling tank arm was increased in personnel size to 9,000 by February 1917 and 20,000 by the time of the Armistice in November 1918. After Flers-Courcelette Field Marshal Sir Douglas Haig, commanding the British forces in France, requested the production of another 1,000 tanks. Stern moved swiftly to order the required armour and powerplants, though the limited power of the Foster-Daimler petrol engine led this astute pioneer to consider alternatives to this weakest feature of the Tank Mk I. That the army as a whole was still uncommitted to the tank found expression in the Army Council’s 10 October cancellation of Haig’s order, which was reinstated when Stern went straight to Lloyd George, who was now a keen advocate of any device that could reduce the horrific toll of head-on infantry battles. Lloyd George was to become prime minister on 6 December, and Stern persuaded him of the need not only for more tanks but for better tanks.

An improved machine was now under development as the Tank Mk IV, and to keep the production line open until this was ready Lloyd George allowed production of 100 examples of the Tank Mk II and Tank Mk III, essentially the Tank Mk I with detail modifications: the Tank Mk II (50 built) had a revised roof hatch with raised coaming and wider track shoes at every sixth link for greater traction, while the Tank Mk III (50 built) was the Tank Mk II up-armoured to the standard of the Tank Mk IV. The Tank Mk II and Tank Mk III complemented the Tank Mk I in the trench battles of 1917 at Arras (9/15 April), Messines (7 June) and 3rd Ypres (31 July/10 November), but these first three models were rapidly superseded by the Tank Mk IV during the second half of 1917. Once discarded at first-line tanks, the Mks I, II and III were used as training tanks or as wireless tanks (one sponson fitted out as a ‘wireless office’ and the other carrying the wireless equipment) or, with their sponsons removed and the resultant openings plated over, as supply tanks, known at the time as tank tenders fitted with sponson-like side panniers each 3 ft (0.91 m) wide and made of mild steel: like the standard sponsons, these panniers were rectangular and all too prone to embedding themselves in the mud when the tank tipped sideways or forward. The Tank Mk IV introduced sponsons with upward-swept lower sides, but this more practical design was not carried forward to the supply tenders’ panniers. Each supply tank could also tow three sleds each carrying 22,400 lb (10160 kg) of stores, and in the case of Tank Mk IV conversions an uprated 125-hp (93.2-kW) engine was often fitted to provide greater tractive power. These supply tanks were generally used to ferry forward ammunition and fuel, and to carry back the most seriously wounded.

By February 1917 the Tank Mk IV was ready for production. The type still relied on the indifferent Foster-Daimler engine and its associated gear system, but was otherwise a much improved vehicle incorporating the lessons of Flers-Courcelette and, as they were fought, the 1917 battles. Several of the earlier tanks had suffered because of the gravity feed from their 50-Imp gal (227-litre) internal fuel tanks, which also leaked highly inflammable petrol over the inside of the tank if it was punctured, and failed to work if the tank was trying to climb up to or down from a steep parapet: in the Tank Mk IV, therefore, the tank was moved to the outside of the vehicle between the rear horns, increased in capacity to 70 Imp gal (318 litres), provided with armour and fitted with a pump to ensure an uninterrupted flow of petrol. Other major improvements were the use of thicker armour (16 mm/0.63 in at the front and 12 mm/0.47 in declining to 8 mm/0.315 in elsewhere) to defeat the Germans’ new anti-tank rifle bullets; steel ‘spuds’ bolted to every third, fifth or ninth track shoe to increase traction in heavy going; smaller sponsons that could be shifted inboard rather than removed for transport; an exhaust and external silencer for the engine; improved internal stowage, ventilation and cooling; shorter 6-pdr (57-mm) L/23 guns to prevent the muzzles digging into the ground; an unditching beam carried above the vehicle on special rails; and 0.303-in (7.7-mm) Lewis machine-guns in place of the original 8-mm (0.312-in) Hotchkiss weapons in ball-and-socket mountings that allowed 90° movement in elevation and traverse. Experience soon confirmed that the Lewis gun was unsuitable for tank use as its air-cooling system filled the tank with fumes, the gun itself was vulnerable to enemy fire, and the need for a large opening in the sponson to accommodate the Lewis gun’s air-cooling jacket increased the problem of splash: a revised Hotchkiss was then substituted, though without the original form of very limited-movement trunnion mounting. After development from October 1916, the Tank Mk IV was delivered from April 1917, and the production of 1,015 vehicles was undertaken in the ratio of three female to two male tanks. The Tank Mk IV Female was somewhat different to the earlier females, for the sponsons were shallower (allowing the incorporation of a pair of hatches on each side in the area previously covered by the sponson) and narrower at only 1 ft 3 in (0.381 m). The reduced weight of these sponsons contributed significantly to the reduction in combat weight to 58,240 lb (26418 kg).

The growing sophistication of the tank is attested by the development of several Tank Mk IV variants as dictated by the nature of combat experience. There had been some criticism of the November 1916 decision to eliminate the rear steering wheels as this also reduced trench-crossing capability, and in an effort to improve this capability once more, Tritton in 1917 suggested the lengthening of the tank by 9 ft (2.74 m) through the extension of the rear horns. These extensions were of mild steel, strapped and riveted to the original structure, and braced diagonally by stays to provide a rigid frame for tracks each lengthened by the insertion of 28 extra shoes and driven by a lengthened drive. Trials were also conducted with a 6-in (152-mm) Newton and Stokes mortars on a platform inserted between the rear horns to fire forward over the hull. Some interesting results were achieved with the ‘tadpole tail’ and mortars, but the lengthened horns lacked rigidity and were not put into production.

British Tank Mk IV with tadpole tail, standing in a churned-up muddy field, with trees and a house in the backgroundEven the tadpole tail could not offer much hope for the crossing of the extra wide trenches built by the Germans in their so-called ‘Hindenburg Line’ defences, and to overcome this problem there was evolved the Tank Mk IV Fascine. In its original form this could carry wooden fascines on its unditching beam rails, these chain-bound bundles of brushwood, each 10 ft (3.05 m) in length and 4 ft 6 in (1.37 m) in diameter, being dropped over the nose under control of the driver; later versions carried hexagonal wood or steel cribs for the same purpose of filling the trench and providing a roadway for the tank’s further progress.

Ditching was always a problem with the British tanks of World War I, and several experimental unditching systems were evaluated as alternatives to the standard beam. Some of these were promising, but none got past the evaluation phase. There were also salvage tanks of several patterns, developed in the field for recovery and maintenance work: these were generally fitted with a manually-operated jib crane for tasks such as engine changes.

When the Germans first began to put tanks into action in the field during April 1918, the British realised that their blend of male and female tanks was perhaps not the optimum solution, for the female tank was distinctly vulnerable to the efforts of the German tanks. The result was the Tank Mk IV Hermaphrodite, essentially a standard Tank Mk IV Female with one of its sponsons replaced by the gun-armed sponson of a Tank Mk IV Male to provide a blend of male and female firepower.

The key moment for the Tank Mk IV, and indeed for the tank in general, came on 20 November 1917 with the beginning of the Battle of Cambrai. This was the first occasion on which tanks were used in a homogeneous mass, and the practice nearly proved decisive. The British 3rd Army was entrusted with a surprise offensive against the German 2nd Army: in ideal terrain conditions to the south of Cambrai, the army was to attack without the protracted artillery bombardment that had previously been standard, this novel concept being designed to give the Germans no forewarning of the offensive, and to prevent the ground from being churned up. This latter ensured excellent going for the 400 tanks that spearheaded the offensive behind a sharp creeping barrage that forced the Germans to keep their heads down. Tactical surprise was achieved by the new tactics, and the tanks were instrumental in opening a 6-mile (9.7-km) gap in the German line, through which the British advanced to a depth of 5 miles (8 km). Two cavalry divisions were poised to exploit any advantage, but the extent of this success caught the British so unexpectedly that there were insufficient infantry and tanks in reserve to allow any rational exploitation. The Germans recovered with remarkable speed, and their counterattacks of 30 November forced the British to fall back most of the way to their start line by 3 December. The Battle of Cambrai was thus a draw, but this fact cannot disguise the fact that the first mass use of tanks had in general secured unprecedented results.

As usual, however, the tanks had suffered large numbers of mechanical breakdowns, and many of these non-runners were captured by the Germans as they pushed back the British. Impressed with the capabilities of the tanks, and lacking their own counterparts, the Germans rushed the captured machines to their depot at Charleroi for refurbishment and rearming: in this latter aspect the 6-pdr (57-mm) guns were replaced by Sokol 57-mm guns captured from the Russians, and the 0.303-in (7.7-mm) machine-guns by 7.92-mm (0.31-in) MG08 weapons. The vehicles were then issued to the Germans’ fledgling tank arm with the designation Beutepanzerwagen IV, the comparative extent of British and German tank production at this time being indicated by the fact that captured tanks equipped four of the Germans’ seven tank companies in December 1917.

As noted above, Stern appreciated from the early days of the Tank Mk I that the weakest point of the tank was its transmission/gearing and associated Foster-Daimler petrol engine. To meet operational requirements the Tank Mk IV was rushed into production and service even as Stern was investigating alternative powerplants, so from October 1917 the Tank Supply Department had a modest breathing space in which to consider other tank automotive systems. These included a Westinghouse petrol-electric drive with one-man control via a separate petrol-electric generator on each track for infinitely variable speed control; a Daimler petrol-electric drive with similar capabilities; a Williams-Janney petrol-hydraulic drive similar in concept to the petrol-electric drives though using hydraulic rather than electric motors; a Wilkins multiple clutch drive of extraordinary complexity; and a Wilson mechanical system using epicyclic gears and brakes instead of the standard change-speed gearing. The petrol-electric drives offered superior capabilities, but were sufficiently complex and expensive to urge on Stern the advantages of the Wilson system, which offered the possibility of one-man control without the potential problems of the petrol-electric systems.

Wilson was entrusted with the overall design of the tank to use his epicyclic gearbox, and this emerged as the Tank Mk V with hull and armament based on those of the Tank Mk IV but fitted with the Wilson gearbox and a new 150-hp (112-kW) Ricardo petrol engine commissioned by Stern. The Tank Mk V Male weighed 64,960 lb (29466 kg) and the Tank Mk V Female 62,720 lb (28450 kg), but the use of a more powerful engine boosted maximum speed to 4.6 mph (7.4 km/h) and combat radius was 45 miles (72 km) on 93 Imp gal (423 litres) of fuel in armoured external tanks. The Tank Mk V entered production at the Birmingham works of the Metropolitan Carriage, Wagon and Finance Company during December 1917, and began to reach service units in May 1918 in equal numbers of male and female tanks, of which a proportion were converted in the field to Tank Mk V Hermaphrodite standard. The initial 200 machines had tracks 20.5 in (521 mm) wide, but later examples had tracks 26.5 in (673 mm) wide for better performance in poor going. One-man control of the Mk V’s automotive system made for considerable improvement in control and manoeuvrability, and the more powerful engine made useful contribution to performance, but the Mk V was also a considerable advance over its predecessors in its better engine cooling and ventilation system; the provision of a cupola above the roof at the rear for the commander, who thus had far better fields of vision than in earlier tanks; and facility for the unditching beam to be connected and disconnected from inside the vehicle, thereby obviating the need for at least two crew members to leave the vehicle in the fashion that had at times cost earlier tanks considerable casualties.

British Tank Mk V (male), spattered with mud, muddy field meeting the sky in the backgroundThe Tank Mk V first went into action at Hamel in July 1918, and thereafter partnered the more numerous Tank Mk IV for the rest of World War I. The new type was dimensionally similar to the Tank Mk IV, and thus suffered the same limitations when faced with a wide trench. Not surprisingly, therefore, the Tank Mk V was evaluated with a ‘tadpole tail’, but a better expedient was adopted after development by the Tank Corps Central Workshops in France from February 1918. This resulted in the Tank Mk V*, in which the vehicle was cut in half to allow the insertion of a 6-ft (1.83-m) armour section, comprising three 2-ft (0.61-m) panels, between the rear of the sponsons and the epicyclic gearbox, increasing ground length and so providing a 13-ft (3.96-m) trench-crossing capability at an increase in weight of 8,960 lb (4064 kg). The additional section carried two machine-gun positions to complement the standard fit based on that of the Mk IV but already boosted by the provision of two positions in the new commander’s cupola. The extra weight inevitably reduced performance slightly and manoeuvrability considerably, but the additional length had the incidental advantage of increasing internal volume to the extent that the Mk V* could be used to carry 25 troops, who suffered badly from the heat and the poor ventilation, or more usefully a substantial load of supplies. Production was undertaken by Metropolitan from May 1918, production reaching 579 examples by the time of the Armistice.

The Tank Mk V** was similar to the Tank Mk V*, but designed as such and built in small numbers by Foster for post-war service. The forward rise was increased to provide better parapet-climbing capability, an uprated 225-hp (168-kW) Ricardo engine was located farther to the rear, and the commander’s cupola was therefore moved forward to a position just behind the driver’s cupola. It is interesting to note that post-war development gave evidence of the tank’s multiple uses: the Tank Mk V** was developed as a Royal Engineer Tank in two forms as a carrier and launch vehicle for a 20-ft (6.1-m) bridge capable of supporting a tank, and as a mineclearing vehicle fitted with a forward roller to detonate pressure-activated mines.

The Tank Mk V* was the ultimate version of British mainstream battle tank development to see service in World War I, no fewer than 324 Tank Mk V and Tank Mk V* machines spearheading the decisive breakthrough offensive of 8 August 1918 in the Battle of Amiens, which the German commander, General Erich Ludendorff, characterised as ‘the black day of the German army’. In this offensive the Tank Mk IV and Tank Mk V variants were partnered by a number of light tanks, but before turning to these it is perhaps sensible to complete a summary of British battle tank development in World War I. Next in sequence came the Tank Mk VI, which was designed in from December 1916 and reached mock-up form in February 1917. The type was designed to provide better cross-country performance than the Tank Mk IV and Tank Mk V, and the armament was centred on a 6-pdr (57-mm) gun located in a limited-traverse mounting between the front horns, backed by six machine-guns carried in a substantial cupola above the hull roof (four guns) and in two small hull-side sponsons (one gun each). Work was cancelled in favour of addition Tank Mk V production to meet the German offensives in France from 21 March 1918.

The Tank Mk VII was built by Brown Bros of Edinburgh, the sole prototype completing successful trials between October and November 1917. The Tank Mk VII was based on the Tank Mk V but with a tail lengthened by 3 ft (0.91 m) for improved trench-crossing capability, and the electrically started 150-hp (112-kW) Ricardo petrol engine was used to power twin Williams-Janney hydraulic motors. The cross-country performance and agility of the type were most encouraging, and early in 1918 an order was placed for 75 production vehicles. Production of the Williams-Janney hydraulic motors proved troublesome, however, and only one production machine was completed before the Armistice and the wholesale cancellation of production orders.

Up to the Tank Mk VII, British tank design followed a linear line of descent from the Tank Mk I. But with the Tank Mk VIII all the lessons of earlier development and combat use were melded into a completely new design by the army’s Mechanical Warfare Department for joint Anglo-US manufacture of an initial 1,500 machines whose hulls and armament were to have been provided from the UK to be assembled with American-supplied engines, transmission systems and controls on a special assembly line in France. The tank was variously known as the Anglo-American Tank, the Liberty, the International and the Allied, and the hopes vested in the machine are evidenced by the fact that the 1,500 joint-venture tanks were to be supplemented by 1,450 purely British examples and 1,500 purely American examples for a grand total of 4,450 Mk VIII vehicles.

The design was modelled on the standard rhomboidal shape that had proved generally successful in previous British tanks, but provided with lower contours that allowed 7 ft 6 in (2.29 m) of contact length with the ground by comparison to the Mk V’s 4 ft 6 in (1.37 m), and ground clearance of 1ft 9 in (0.533 m) by comparison to the earlier tanks’ 1 ft 4 in (0.406 m). The result was a considerably heavier machine, with a combat weight of 82,880 lb (37594 kg). The Tank Mk VIII was also a generally larger machine, with an overall length of 34 ft 2.5 in (10.43 m) to the Mk V’s 26 ft 5 in (8.05 m), width of 12 ft 4 in (3.76 m) to the Mk V Male’s 12 ft 10 in (3.91 m), and height of 10 ft 3 in (3.12 m) to the Mk V’s 8 ft 8 in (2.64 m). In terms of battlefield capabilities, the additional length reduced manoeuvrability, but provided an impressive trench-crossing capability of 15 ft (4.57 m). The crew remained the standard eight men, and the armour thicknesses were the same as those on the Tank Mk V. The larger dimensions of the Tank Mk VIII allowed a useful compartmentalisation of the interior, with the engine and transmission in the rear section cut off from the rest of the tank by a bulkhead for considerable improvement in terms of noise and fumes. The main armament comprised two 6-pdr (57-mm) Hotchkiss L/23 guns in the side sponsons with 104 rounds each, and the secondary armament was seven machine-guns with a total of 13,484 rounds: the machine-guns were located as one in the bow, one in each of the doors behind the sponsons, and four in the centrally-mounted main fighting turret (one in each side, one on the front left and one on the rear right). The sponsons were hinged and fitted on roller bearings so that they could be hand-pulled into the main fighting compartment for transport, and each machine-gun was carried in a ball-and-socket mounting (itself carried in a spherical mounting) to allow 130° movement. The main fighting turret was also fitted with a commander’s rotating sub-turret offering a 360° field of vision.

Grey graphic representation of a British Tank Mk VIII standing on grassConsiderable difficulties were encountered with the design and final development of the Tank Mk VIII, the most troublesome individual component being the 300-hp (224-kW) engine. In the joint and American versions this was a Liberty unit adapted from the standard V-12 aeroplane engine by lowering the compression ratio and using cast iron rather than steel cylinders. In the British version the engine was a V-12 Ricardo, produced by mounting two 150-hp (112-kW) Ricardo V-6 engines on a common crankcase. Under good conditions the Ricardo unit provided a maximum speed of 7 mph (11.25 km/h) in a lightly-loaded Mk VIII. Some 200 Imp gal (909 litres) of fuel were carried in three armoured tanks at the rear, and pump-fed to a gravity tank above the end, surplus fuel being vented back into the main tankage by an overflow pipe. This fuel tankage provided a 55-mile (88.5-km) combat radius. Considerable thought was given to engine cooling, and the location of the engine in its own compartment greatly aided the designers, who opted for a system in which air was drawn in through a roof louver to pass round the engine and through the rear-mounted radiator before being expelled by a fan through a rear louver. Compartmentalization also allowed proper ventilation of the fighting section by an electrically powered fan that created a slight internal overpressure that was vented through any available opening to take with it any gun fumes.

Mild steel prototypes had been successfully trialled by the end of the war, and a large number of components had been produced for assembly in the unfinished French factory at Nervy-Pailloux. The programme was cancelled at the end of the war, but in 1919 and 1920 the Americans used existing components to build 100 tanks at the Rock Island Arsenal: these differed from the wartime standard only in having 0.3-in (7.62-mm) Browning machine-guns instead of Hotchkiss machine-guns, and formed the mainstay of the US tank arm up to 1932, when they were placed in storage and finally used by Canada as training machines in the early days of World War II.

The final designations in the mainstream of British battle tanks during World War I were the Tank Mk IX and Tank Mk X. The Tank Mk IX was really a supply tank based mechanically on the Tank Mk V, and at a combat weight of 60,480 lb (27434 kg) could carry 50 troops or 22,400 lb (10161 kg) of supplies with access through four large side hatches; only three prototypes were completed. In 1919 one of these was modified for amphibious trials, being fitted with a raised cab, high exhausts and ex-naval ‘camel’ flotation chambers. The Tank Mk X was schemed as a revised Tank Mk V with modifications intended to increase habitability, reliability and manoeuvrability. If the war had continued into 1919 some 2,000 Tank Mk X vehicles would have been ordered as the backbone of the tank army round which the assault into Germany was being planned.

The Allied concept of military operations after November 1914 had been posited without significant deviation on a breakthrough of the German line and exploitation into the enemy rear. Even before the battle tank had begun to prove itself as a weapon for the breakthrough phase, tank advocates had begun to work on a lighter and more mobile tank suitable for the exploitation phase, for the battle tank was clearly too slow and too short-ranged for any but the most direct battlefield tasks. In 1916 Tritton designed a high speed tank with light armour for the task of co-operating with the cavalry, and this initial ‘Whippet’ scheme was revised from December 1916 as the Tritton Chaser or, more prosaically, the Tritton No. 2 Light Machine. The type first ran in February 1917, and trials were generally successful. Various changes were required before a firm order was placed in June 1917. The definitive version became the Medium Tank Mk A, generally named the Whippet, and deliveries from the Foster works in Lincoln began in October 1917 to meet the initial requirement for 200 machines. This order was subsequently increased to 385 machines, and then reduced once more to 200 when it became clear that the double automotive system of the Medium Tank Mk A was both expensive to produce and difficult to maintain at a reasonable standard of reliability. The overall design of the Whippet was totally different from that of the battle tanks, with long low-set unsprung tracks whose shoes were based on those of battle tanks but of lighter construction and fitted with provision for spuds: the tracks were long enough to provide a 7-ft (2.13-m) trench-crossing capability. The track units were fitted on each side with four chutes along much of the length of the top run to keep the tracks clear of mud and thus lighter. The long forward section of the hull above the upper run of the tracks accommodated two 45-hp (33.6-kW) Tyler four-cylinder inline engines (as developed for truck use), located side by side and each provided with its own clutch and gearbox to drive one track. Twin throttles were located on the steering wheel, their movement together controlling acceleration to a maximum speed of 8.3 mph (13.4 km/h) in this 31,360-lb (14225-kg) vehicle. Steering was effected by the driver’s steering wheel, whose movement worked on the throttles to increase the power of one engine and decrease that of the other (to a maximum variation of 12 hp/8.95 kW) and so provide additional power to one track or the other: the system was complex and extremely demanding on the driver, who often stalled one engine in a tight turn and then shed a track, thus immobilizing his vehicle. An armoured tank in the extreme nose held 70 Imp gal (318 litres) of petrol fed to the engines by a pump, and this capacity was sufficient for a combat radius of 80 miles (129 km).

The crew of three or four was located in the fighting compartment at the rear of the vehicle. This compartment was essentially a fixed barbette (the original notion of a rotating turret having been abandoned to simplify production), and in addition to the driver was occupied by the commander and one or two gunners, with between them three or four Hotchkiss machine-guns (with 5,400 rounds) for all-round fire. The second gunner and the Hotchkiss in the rear of the barbette were generally omitted by operational units to mitigate the appalling conditions inside the barbette. Armour varied from a minimum of 6 mm (0.24 in) to a maximum of 12 mm (0.47 in).

The type first saw action in March 1918 near Herbertune in northern France, and was used up to the end of the war. The type’s greatest moment came in the Battle of Amiens on 8 August 1918, when the 3rd Tank Brigade’s two battalions were fully equipped with 96 Medium Tank Mk A machines. The brigade was tasked with support of the Cavalry Corps, and though liaison was poor some useful results were gained. The major tactical problem was that in good conditions the cavalry was faster than the tank brigade, but had to wait for the tanks to catch up and deal with opposition armed with anything but small arms. The result was that the tanks were not employed in a homogeneous mass that might have completely destroyed the German rear areas to a depth of 10 miles (16 km) or more. The Medium Tank Mk A machines were used in small numbers attached to specific cavalry units, but nonetheless achieved the successes that fully vindicated their overall capabilities.

Obviously the type was limited by its use of two low-powered engines and unsprung tracks, and in an effort to overcome this limitation Major Philip Johnson, an Army Service Corps officer serving at the Tank Corps Central Workshops in France, reworked the design with sprung tracks and a 360-hp (268-kW) Rolls-Royce Eagle aero engine working through the transmission of a Mk V battle tank: speeds well over 20 mph (32 km/h) were achieved, but this important advance failed to find favour.

As noted above, production of the Medium Tank Mk A was limited to just 200 machines, a fact ensured by the development of the Medium Tank Mk B, whose arrival in service was anticipated in good time for the grand tank offensive designed to finish off Germany in 1919. The Medium Tank Mk B was also called Whippet, but in this instance was designed by Wilson and bore closer conceptual affinities to current battle tanks than to the Medium Tank Mk A, despite being intended for the same cavalry or exploitation role.

The Medium Tank Mk B was based on a new automotive system using a 100-hp (76-kW) four-cylinder version of Harry Ricardo’s 150-hp (112-kW) six-cylinder battle tank engine located at the rear of the hull in the first instance of a tank engine in its own compartment. The fan-cooled engine drove the twin tracks via epicyclic gearing, and provided greater levels of manoeuvrability with much improved reliability and reduced production cost. The rest of the vehicle was also different from the Medium Tank Mk A, being based on the rhomboidal shape of contemporary battle tanks with the tracks running right round the hull and its projecting front and rear horns. On each side of the Mk B were three large chutes to clear mud from the upper run of the tracks.

At 7 ft 0 in and 2 ft 6 in (2.13 and 0.76 m) respectively, the Medium Tank Mk A’s trench-crossing and parapet-climbing capabilities were notably poor: the shape of the Medium Tank Mk B improved these figures considerably, the trench-crossing figure to 8 ft 6 in (2.59 m). Inevitably the Medium Tank Mk B was a larger and, at a combat weight of 40,320 lb (18289 kg), a heavier tank. The crew of four comprised the driver, commander and two gunners, all accommodated in a large barbette at the front of the tank. The Medium Tank Mk B was proposed in two forms, a female with the standard armament of four Hotchkiss machine-guns with 7,500 rounds, and a male with a revolving turret carrying a 2-pdr (40-mm) gun: only the female type was produced. Armour was comparable to that of the Medium Tank Mk A, though the thinnest plates were to a 6- rather than 5-mm (0.24- rather than 0.2-in) basis.

Other features of the Medium Tank Mk B were removable rear decking to provide access to the engine compartment, a crude smoke-generation system whereby sulphonic acid was dripped onto the hot exhaust from a special tank, and provision for electric or hand starting. Design work was completed late in 1917, but it was mid-1918 before the first production order was placed with the Metropolitan Carriage, Wagon and Finance Company for 450 vehicles: this delay was occasioned in part by the need for modifications to the original design, and in part to the caution of the army, which wished to assess the capabilities of the first medium tank (the Medium Tank Mk A) before committing scarce production facilities to a successor. The first vehicle appeared in September 1918, and only 45 had been completed by the time of the Armistice, when all further production was cancelled. The Medium Tank Mk B displayed a maximum speed of only 6.1 mph (9.8 km/h) and a combat radius of 65 miles (105 km) on 85 Imp gal (386 litres) of fuel, so outright performance was well down on that of the Medium Tank Mk A. Other criticism of the Medium Tank Mk B centred on the engine installation: all appreciated the fact that its separation from the rest of the tank by a bulkhead reduced the problem of engine noise and fumes in the fighting compartment, but the compact nature of the engine compartment meant that the entire engine had often to be lifted out for even the most minor of maintenance tasks.

As Wilson worked on development of the Medium Tank Mk B, Tritton was involved on his own successor to the Mk A in the form of the Medium Tank Mk C, generally known as the Hornet and judged to have been the best medium tank design evolved in World War I. The Medium Tank Mk C bore a strong conceptual similarity to the Medium Tank Mk B (a rear engine, all-round tracks and a forward fighting compartment complete with a rotating cupola for the commander), and the basic design was completed at about the same time in December 1917. Again like the Medium Tank Mk B, the Medium Tank Mk C was offered in male and female forms, the male with a 6-pdr (57-mm) gun located in the hull front and the female with four Hotchkiss machine-guns and 7,200 rounds. The engine was the 150-hp (112-kW) six-cylinder version of the Ricardo tank engine, driving the tracks by means of epicyclic gears. Tritton gave considerable attention to the engine and transmission installation to ensure easy access for maintenance, and planned the whole design for rapid manufacture making maximum use of subassemblies.

The Medium Tank Mk C prototype was completed in the summer of 1918 and underwent a highly successful evaluation programme before a production order for 200 Medium Tank Mk C Female machines was placed at the beginning of October. Faith in the type was considerable, and longer-term plans called for production of 6,000 Medium Tank Mk C machines (4,000 females and 2,000 males) for the proposed ‘Plan 1919’. Building of the Medium Tank Mk C was drastically curtailed at the time of the Armistice, and only 48 such tanks were completed, serving with considerable distinction up to 1925.

Weighing 44,800 lb (20321 kg), the Medium Tank Mk C had a length of 26 ft (7.92 m) in comparison with the Medium Tank Mk B’s 22 ft 9 in (6.93 m), width of 8 ft 4 in (2.54 m) in comparison with 8 ft 10 in (2.69 m) and height of 9 ft 6 in (2.90 m) in comparison with 8.5 ft (2.59 m). The Medium Tank Mk C’s additional length contributed to a trench-crossing capability of 10 ft (3.05 m), and the type’s other main performance figures included a maximum speed of 7.9 mph (12.7 km/h) and a combat radius of 140 miles (225 km) on 150 Imp gal (682 litres) of fuel.

Mock up of a British Medium Tank Mk D, standing in an empty warehouse, bright light coming in through the windows in the backgroundThe ultimate British tank design of World War I was the Medium Tank Mk D, which was designed by the same Johnson responsible for development of the Medium Tank Mk A with leaf-spring suspension and (from February 1918) a modified Eagle aero engine. It was not thought practical to modify in-service Medium Tank Mk A machines in this fashion, but the capabilities of the single experimental vehicle did not go unremarked. With the support of the corps’ chief engineer, the Tank Corps’ chief-of-staff, Colonel J. F. C. Fuller, in May 1918 produced his now-classic Tactics of the Attack as Affected by the Speed and Circuit of the Medium D Tank. This was the direct inspiration for ‘Plan 1919’, which envisaged a breakthrough on a 90-mile (145-km) front by concentrated masses of battle tanks (mostly Tank Mk V** and Tank Mk VIII types) to allow an exploitation by Medium Tank Mk C and Medium Tank Mk D machines supported by lorried infantry and close-support aircraft.

The core of the concept was the Medium Tank Mk D whose development was entrusted to Johnson, who capitalised on his Whippet experimental programme to suggest a machine capable of high cross-country speed as a result of its automotive system, which was to comprise a converted aero engine and sprung tracks that had two-axis freedom of movement. In basic shape the Medium Tank Mk D was similar to the Medium Tank Mk A, but convention was flouted in the fact that Johnson’s layout was exactly opposite to the Medium Tank Mk A, with the lower end of the track at the front to provide good fields of vision and fire for the four men in the front-mounted barbette, which was well shaped and fitted for an armament of perhaps three Hotchkiss machine-guns in the female version that was later to be supplemented by a male version with a short 6-pdr (57-mm) gun. Development was protracted, and four prototypes (the first appearing in May 1919) were followed by only two production machines before the programme was cancelled in 1921. Powered by a 240-hp (179-kW) Armstrong Siddeley Puma aero engine driving through epicyclic gears, the Medium Tank Mk D weighed 44,800 lb (20321 kg) and was 30 ft (9.14 m) long. Maximum speed was 25 mph (40 km/h), and the tank’s combat radius was about 200 km (322 km).

Specification

Tank Mk IV (Male)

Type: battle tank

Crew: 8 (commander, driver/brakesman, two gearsmen, and four gunners)

Combat weight: 62,720 lb (28450 kg)

Dimensions: length overall 26 ft 5 in (8.05 m); width 13 ft 6 in (4.115 m); height 8 ft 2 in (2.49 m)

Armament: two 6-pdr (57-mm) Hotchkiss L/23 guns with 332 rounds and four 0.3303-in (7.7-mm) Lewis machine-guns with 6,272 rounds; the main guns were stabilised in neither elevation nor azimuth (120º out from the forward centreline), and simple optical sights were fitted

Armour: riveted steel between 6.35 and 12.7 mm (0.25 and 0.5 in)

Powerplant: one 105-hp (78.3-kW) Foster-Daimler water-cooled six-cylinder inline petrol engine with 70 Imp gal (318 litres) of fuel

Performance: road speed 3.7 mph (5.95 km/h); road range 35 miles (56.3 km); fording 4 ft 6 in (1.37 m) without preparation; gradient 47%; vertical obstacle 4 ft 6 in (1.37 m); trench 10 ft 0 in (3.05 m); ground clearance 16 in (0.406 m)

The tank MK I – an infant giant

Tank MK IWhatever its theoretical and technical antecedents, the tank first appeared as a practical weapon in World War I, and in its initial forms was a true child of that grim conflict. In the first weeks of their war against the Western Allies, the Germans had carried all before them in a huge sweeping offensive into north-eastern France. But then their reliance on horse transport, and the sheer exhaustion of so great and so rapid an advance told on the German infantry: the all-important right wing found by the German 1st Army over the Marne river to the east of Paris rather than over the Seine river to the west of the French capital. The Germans had been forced to deviate from Generalfeldmarschall Alfred Graf von Schlieffen’s master plan, and in the 1st Battle of the Marne (5/10 September 1914) the Allies inflicted a first major reverse on the Germans, who recoiled to the line of the Aisne river slightly to the north. The exhausted Allies were slow to pursue their initial advantage, and failed to dislodge the Germans from their extemporised positions along the Aisne river (15/18 September 1914). Thereafter each side sought to find the other’s exposed northern flank in a northward extension of the front generally known as the Race to the Sea. By 24 November 1914 both sides had reached the southern coast of the English Channel in the vicinity of Nieuport, and after a furious 10-day general offensive by the Allies between Verdun and Nieuport it became clear that operations of a fluid nature were now impossible on the Western Front, at least in the short term. The opposing sides were located in entrenched positions between the English Channel and the Swiss frontier, busy digging themselves in and shielding their positions with barbed-wire entanglements covered by machine-gun posts and field artillery.

The generals could see no alternative but to enter into a slugging match in which increasingly huge artillery bombardments were used to destroy the barbed wire and the machine-gun posts so that the infantry could storm forward as soon as the barrage lifted. The fallacy of this concept became abundantly clear as 1915 progressed. The artillery barrage revealed the location of an impending offensive, allowing the enemy to muster his reserves behind the front in the relevant sector; at the same time the barrage inevitably failed to cut more than a slight proportion of the wire, and churned up the area so badly that infantry advances were slow and fragmented; the barrages generally failed to achieve more than superficial destruction of the enemy’s system of interlocking trenches and machine-gun posts; and finally the lifting of the barrage provided the enemy with the tactical warning that allowed his men to emerge from their bunkers, man their firing positions and, perhaps most importantly, crew the machine-guns posts sited to pour enfilading and then defilading fire on the attacking infantry. Battle after ghastly battle proved during 1915 that the technology of the period could, on the one hand, rapidly strengthen trench systems but, on the other hand, provide no easy means to defeat the combination of barbed wire and machine-gun. And the poverty of the period’s military leadership could see no alternative to these head-first offensives designed to puncture the enemy’s front line and allow the cavalry to stream through into the enemy’s rear areas and exploit the breakthrough in preparation for the following infantry.

The roll call of disastrous failures in 1915 makes sorry reading: Artois, Champagne, Woevre, 2nd Ypres, 2nd Artois (Festubert, Souchez and Vimy Ridge), 2nd Champagne, and 3rd Artois (2nd Vimy Ridge and Loos) were grisly battles in which the Allies lost hundreds of thousands of men in battering ram efforts to break through the steadily solidifying German line. Gains were indeed made, but these gains were measured in hundreds of yards only, and never once was there any chance of a genuine breakthrough and the unleashing of the cavalry. As the year progressed the chance of the anticipated breakthrough became increasingly remote, but in the absence of any alternative the generals still pinned their faith in its occurrence. Another problem that they failed to consider was the nature of any breakthrough: even if the cavalry had been introduced through a rupture in the enemy’s line, it is hard to see what success it could have achieved even with the unlikely support of the plodding infantry.

E. SwintonThe concept of a caterpillar-tracked ‘landship’ had enjoyed a considerable currency in the period leading up to World War I, but failed to find any measure of acceptance among military leaders with little or no knowledge or even appreciation of science and technology: indeed, many of the combatant nations’ senior generals were still trying to come to grips with the nature and effect of established technology as epitomised by modern artillery and the machine-gun. One British convert of singular importance, however, was Lieutenant Colonel E. W. Swinton, assistant secretary of the Committee of Imperial Defence. Serving in France as a reporter during 1914, Swinton soon appreciated that his existing fears about the machine-gun’s role in defensive warfare had been more than fully realised. However, he also saw the Holt caterpillar tractors being used as tow vehicles for heavy artillery, and envisaged the possibility of fitting such tractors with armoured bodies for the transport of assault parties (or light artillery) through no-man’s land and over the barbed wire for direct assaults on the machine-guns that tore apart every infantry assault. Swinton reported back to his immediate superior, Lieutenant Colonel Maurice Hankey, the secretary of the Committee of Imperial Defence, who passed on Swinton’s notions to the Imperial General Staff and to Lord Kitchener. The IGS and Kitchener rebuffed the concept immediately, mostly on the grounds that any such ‘Trojan horse’ would be catastrophically vulnerable to artillery fire. To a certain extent the authorities were correct, for Swinton’s concept envisaged a massive machine able to transport some 50 men. What the pundits ignored, however, was the difficulty for the artillery of the period in engaging a moving target at all except the closest direct-fire ranges, which would themselves leave the artillery hopelessly exposed to counter-battery fire.

The problem faced by Swinton and other advocates of the embryonic tank concept was how to convince their sceptical superiors about the technical feasibility and tactical advantages of their novel concept. The decisive moment was perhaps the Christmas period of 1914 when, in a memorandum on the progress of the war to date, Hankey included amongst his recommendations the desirability of some sort of armoured protection for infantry assaults. The memorandum was circulated within the Committee of Imperial Defence, which numbered amongst its members the First Lord of the Admiralty, Mr Winston Churchill. Ambitious for himself and for the service whose political fortunes he controlled, Churchill was an unorthodox thinker ready to accept and develop apparently impossible ideas. Hankey’s interim recommendation therefore found a ready home with Churchill, who was already aware of the limited progress being made by the Royal Naval Air Service in the development and procurement of armoured vehicles for use in northern France and Belgium by the Naval Armoured Car Division.

Churchill responded to the Hankey memorandum with a note of his own to Prime Minister Herbert Asquith criticising the army’s apparent antipathy towards the notion of trench assault by the use of special cross-country vehicles carrying armour protection. Churchill warned, in typical fashion, that the Germans might already be working along the lines eschewed by the War Office, and urged the creation of a committee ‘of engineer officers and other experts’ to consider the concept of cross-country armoured vehicles. Asquith was impressed by Churchill’s arguments (and indeed deliberately raised fear that the Germans might already be at work on the suggested lines, when there was no evidence either direct or indirect for this fear) and induced Kitchener to order such a committee into existence.

The committee comprised the War Office’s directors of fortification, artillery and transport, and was tasked with a thorough evaluation of the suggestions made by Swinton and others. On 17 February 1915 the committee witnessed trials with a Holt tractor towing a trailer ballasted to simulate the weight of men, guns and armour: Swinton had never proposed so unwieldy an arrangement, and in extremely wet conditions the trial was judged a failure. The committee therefore reported negatively, on the grounds that the trialled system was too unwieldy and thus vulnerable, going on to claim that in any event the war would have ended before a practical system could be evolved. Having fulfilled the wishes of the politicians, the army allowed any current interest in the concept to lapse.

The torch now passed to the Royal Navy in the form of the RNAS, which was already using powerful touring cars fitted with armour and machine-guns for the mobile defence of its air bases at Calais and Dunkirk. These vehicles were very limited by their origins, but the value of armour protection was sufficiently impressive for the RNAS commander, Captain Murray Sueter, to urge upon Churchill the potential armoured vehicles based on the Diplock Pedrail crawler chassis for greater cross-country mobility. The RNAS was alive with interesting concepts at this time: one of the most ambitious was proposed by Flight Commander Thomas Hetherington, transport officer of the RNAS Armoured Car Division, as a ‘land battleship’ based on a tricycle chassis whose 800-hp (596.5-kW) diesel powerplant was to drive three 40-ft (12.2-m) diameter wheels to allow this massive machine to cross German trenches, which were 2.75 m (9 ft) wide. The ‘land battleship’ was to carry prodigious armament in the form of three turrets each fitted with two 4-in (102-mm) naval guns.

Such a machine was clearly impractical, but on 15 February 1915 Hetherington was called to describe his concept to a receptive Churchill. Full of enthusiasm, the First Lord of the Admiralty ordered the establishment on 20 February of a Landship Committee under the chairmanship of Mr Eustace Tennyson d’Eyncourt, the Director of Naval Construction. The committee included Hetherington and a number of engineer and transport specialists, with Lieutenant Albert Stern as its secretary, and its initial brief was the assessment of the two different ‘landship’ concepts embodied in Sueter’s tracked and Hetherington’s big-wheel notions. While the committee was still assessing the two options the impetuous Churchill on 26 March ordered prototypes of the two types in the form of 12 tracked and six wheeled machines, the latter sensibly scaled down with 15-ft (4.57-m) diameter wheels. The development of the tracked type was entrusted to Colonel Crompton, a highly capable though elderly engineer with a wealth of transport experience, aided by Lieutenant W. G. Wilson of the RNAS armoured car force and a pre-war automotive engineer of great repute. The big-wheel type was contracted to a Lincoln firm, William Foster and Co. Ltd under the managing directorship of Mr William Tritton: the company’s Foster-Daimler petrol-engined tractors were already in service with the Royal Marine Artillery as heavy gun tractors, and it was thought that the mechanical system and other components of these vehicles could be adapted for the proposed big-wheel machine.

One of the initial conclusions of the Crompton team was that the Diplock Pedrail could not be used as the basis of a machine for service in France as its length of more than 40 ft (12.2 m) made it too unwieldy to negotiate the types of bend commonly encountered on French roads and, perhaps more importantly, country lanes. At the same time it was also appreciated that the Diplock Pedrail was mechanically complex and considerably underpowered. Work on adaptation of the first chassis was abandoned in May 1915, and the chassis was handed over to the army, which also abandoned the type.

The Crompton team deemed that an articulated chassis would be needed for a machine able to operate in France, and after trials with an ex-agricultural machine on Greenhithe marshes an order was placed in the USA for two Bullock Creeping Grip Caterpillar tractors. It was appreciated that the Bullock machine was too small to provide the 5-ft (1.52-m) trench-crossing and 2.5-ft (0.76-m) parapet-climbing capabilities fixed as minima by the Landship Committee, so at the same time additional track and suspension components were ordered so that larger machines could be developed. The two Bullocks were delivered in June 1915 to the new RNAS testing ground at Burton-on-Trent, where Wilson was in command of the test programme.

Meanwhile the Foster company had completed its mock-up of the big-wheel proposal. It was abundantly clear that the machine was too big and ponderous to have any real tactical value, and would moreover be a considerable target for artillery. In May 1915 the big-wheel concept was formally abandoned, and all development effort was henceforward devoted to the tracked machine. Early trials with the Bullock machine were essentially encouraging, but realistic assessment indicated that the vehicle was still too unhandy for France and, moreover, that the coupling between the two major units was too weak for service use, especially for tasks such as trench crossing.

No. 1 Lincoln MachineMeanwhile Swinton had been working to overcome the army’s inertia so far as armoured vehicles was concerned. Although at first his efforts met the wall of refusal engendered by the field army’s chief adviser on military engineering, dividends were finally paid by his close links with the head of the newly created Inventions Department of the Ministry of Munitions (headed by Mr David Lloyd George, who was becomingly increasingly distraught with the level of casualties in France): renewed army interest was finally evinced. At the same time a GHQ officer in France, Major Glyn, had been sufficiently impressed with Swinton’s initial approach to press for army liaison with the Landship Committee. The ball was tossed backwards and forwards in typical fashion before it was decided at the end of June to invite four army representatives onto the Landship Committee, which thus became a joint-service body with the army’s Director of Fortifications as chairman. A number of RNAS personnel were transferred to the army to ease the task of bringing the new type of weapon to fruition. Additional impetus was given to the work by an about-turn in the attitude of GHQ in France, which now saw the new machine as offering a sensible alternative to the head-on artillery and infantry assaults that were continuously proving themselves such costly failures.

In this time Swinton had been evolving his particular concept, formalised in a series of memoranda reflecting the demands of a front-line machine. These thoughts were combined into a specification issued on 9 June for a machine with the following characteristics: a 4-mph (6.4-km/h) maximum speed on flat ground, a 20-mile (32-km) radius of action, the ability to make a sharp turn at maximum speed, a reversing capability, the ability to climb a 5-ft (1.52-m) parapet with a 1-in-1 slope, the ability to cross an 8-ft (2.44-m) trench), a crew of 10, and an armament of one light quick-firing gun and two machine-guns. Swinton also called for armour up to 12 mm (0.47 in) thick, and ultimately a 6-pdr (57-mm) naval gun rather than the 2-pdr (40-mm) pom-pom originally envisaged as the main armament.

The Landship Committee had now decided to end further exploration of the articulated chassis in favour of a new vehicle roughly equivalent to one half of the articulated machine, but engineered for the specific military demands of service on the Western Front. On 22 July (confirmed on 24 July) the work was entrusted to the Foster company, under the design leadership of Tritton with Wilson as his deputy and the Landship Committee’s representative. This vehicle was to use the lengthened Bullock tracks and additional suspension units ordered during May in combination with the standard 105-hp (78.3-kW) Foster-Daimler petrol engine.

At last real progress could be made and the new prototype, variously known as the Tritton Machine or No.1 Lincoln Machine, was soon taking shape after the start of construction on 11 August. The vehicle emerged as a boxlike hull of boiler plate, the standard Foster’s powerplant and transmission driving the lengthened Bullock tracks low-mounted at the base of the hull on each side. Provision was made in the hull roof for a centrally mounted turret accommodating a 2-pdr (40-mm) naval gun (only a dummy turret was ever fitted), and steering was effected by a combination of differential braking and/or movement of the two 4.5-ft (1.37-m) diameter wheels projecting from the rear of the hull on a bogie frame for an overall length of 26 ft 6 in (8.08 ft) and a height of 10 ft 2 in (3.10 m). The fully laden machine turned the scales at some 32,480 lb (14733 kg), and with a crew of between four and six men could attain 3.5 mph (5.6 km/h) under favourable conditions. The No. 1 Lincoln Machine was first run on 10 September 1915, and immediately encountered problems as a result of the inadequate Bullock tracks, which were easily shed and had poor grip even in good going.

Tritton and Wilson realised that the tracks would have to be completely revised, and launched a high-priority effort to produce an effective type. Considerable experimental work was undertaken before the two men evolved a new and mechanically simpler type of track based on lengthened track frames with rollers carrying the tracks proper, each comprising cast steel shoes riveted to links fitted with guides that engaged the inside of the track frames. Fitted with this radically improved type of track the No. 1 Lincoln Machine became Little Willie, which emerged in December 1915 and immediately showed itself superior to the original: the tracks were more reliable, and allowed Little Willie to cross a 5-ft (1.52-m) trench and to climb a 4.5-ft (1.37-m) parapet: the comparable figures for the machine in its original form had been 4 ft (1.22 m) and 2 ft (0.61 m). In other respects Little Willie was similar to the No. 1 Lincoln Machine.

Little WillieLittle Willie was obsolescent even as it appeared, however, for even before the No.1 Lincoln Machine had started its trials the ingenious Wilson had come up with a notion to overcome the basic design’s lack of stability when surmounting an obstacle. Wilson’s inspired thought was to combine the parapet-climbing capability of the original big-wheel notion with the other advantages of the tracked concept: a new machine was planned on the basis of the existing hull, but with the tracks running round the full height of the hull and over ‘horns’ (projecting forward and aft from the hull on each side) to provide over the lower forward section an arc approximately equivalent to that of a 60-ft (18.3-ft) diameter wheel.

The result was the rhomboidal- or lozenge-shaped tank that became standard in World War I, combining the parapet-climbing superiority of the big-wheel concept with the trench-crossing, stability and silhouette advantages of the tracked chassis. The Landship Committee was shown a wooden mock-up of Wilson’s design at the time of the No. 1 Lincoln Machine’s trials in September. As a further aid to stability in the revised concept, the roof-mounted turret was abandoned in favour of a heavier armament located in two hull-side sponsons. The specification for the vehicle, to be called Big Willie, was settled on 29 September: frontal armour 10 mm (0.39 in) thick, side armour 8 mm (0.315 in) thick, a crew of eight (including four men for steering and gear changing), a speed of 4 mph (6.4 km/h), and a main armament of two 6-pdr (57-mm) guns backed by four 0.303-in (7.7-mm) machine-guns.

The building of the new machine was seriously hampered by labour problems at the Foster company, where the secrecy of the work was such that the men could not be given war worker badges and began to leave when they were accused of cowardice for not having volunteered for the services. During construction the machine was variously called the Wilson Machine, the Centipede and Big Willie, but finally emerged at the end of 1915 as Mother, which weighed 62,720 lb (28450 kg) and was capable of 3.7 mph (5.95 mph) on its 105-hp (78.3-kW) Foster-Daimler engine. Built of boiler plate rather than the lightweight pressed steel proposed for the production version, the machine was 32 ft 6 in (9.91 m) long including the twin steering wheels at the rear, 13 ft 9 in (4.19 m) wide over the sponsons, and 8 ft (2.44 m) high. In the front of each sponson was a naval 6-pdr (57-mm) quick-firing gun, the four machine-guns being disposed one in the rear of each sponson, one in the bow and one at the rear. Naval guns were used as the army’s Master General of the Ordnance was opposed to the tank concept and therefore refused to release any weapons for use in the new machines.

Mother first ran on 3 December 1915, at about the time that the cover name ‘water carrier’ (soon amended to ‘tank’) was ordained at Swinton’s instigation in preference to the revealing ‘landship’. After initial and successful running trials, Mother was fully completed on 26 January 1916 and moved, together with Little Willie, to Hatfield Park for two official trials and demonstrations. The first was attended only by those intimately involved in tank development, but four days later on 2 February the main demonstration was attended by such dignitaries as the Secretary of State for War (Field Marshal Lord Kitchener), the Minister of Munitions (Mr D. Lloyd George) and the Chancellor of the Exchequer (Mr R. McKenna). Both tanks were put through trials in terrain very similar to that of the Western Front (complete with British and German trench layouts), and Mother was judged worthy of production. As the Ministry of Munitions had in December refused to allow tank production, Kitchener ordered Stern to the War Office to oversee production on a direct basis, and this had the desired effect of forcing the ministry’s hand: on 12 February the ministry ordered the production of 100 tanks based on Mother (25 by Foster and the other 75 by the Metropolitan Carriage, Wagon and Finance Co.) in a programme to be overseen by the Landships Committee, now renamed the Tank Supply Committee headed by Stern and including Swinton as a member.

Churchill was now in France, having been forced to resign in May 1915 when a coalition government took over from the Liberal administration after the failure of the Dardanelles campaign, but had tried to keep up with developments. Though now ‘only’ a regimental officer, Churchill sent to Field Marshal Sir Douglas Haig, the British commander-in-chief in France, a paper entitled Variants of the Offensive which, among other items, exaggerated the state of tank development but persuaded Haig to despatch Major Hugh Elles to report personally on the new weapon. It was Elles’s approval that persuaded Haig to think in terms of an order for 40 tanks that led to the initial plan for 100 vehicles, later increased to 150 vehicles.

In March 1916 the new tank arm was formed under Swinton, initially as the Armoured Car Section, Motor Machine Gun Service and then from May as the less revealing Heavy Section, Machine Gun Corps. (After the tank had been used in action the name was changed in November 1916 to the Heavy Branch, Machine Gun Corps and finally in July 1917 to the Tank Corps.) As the men for the new branch were being found and trained, production of the service version of Mother, the Tank Mk I, was being undertaken for the first deliveries to be made in June. At first it was planned that the production model should be all but identical with Mother other than construction in mild steel rather than boiler plate and the installation of a frame of wood and chicken wire over the roof to prevent ‘bombs’ (grenades) from lodging and detonating on it. The armament sponsons projected about 3 ft (0.91 m) from each side of the tank, and were therefore designed to be removed for separate (or towed) carriage to ease transport problems. Each sponson weighed some 3,920 lb (1778 kg), and required about eight hours to remove or replace in the field with skids and levers, assuming that the hull had not been ‘wrung’ in transit and thereby moved out of alignment the bolt holes that had to be matched by those in the sponsons.

However, in April 1916 Swinton decided that a proportion of the tanks (ultimately fixed at half of the production run) should be completed with the Hotchkiss 6-pdr (57-mm) guns replaced by two machine-guns. The more powerfully armed variant was designated Tank Mk I Male, and at a combat weight of 62,720 lb (28450 kg) carried an armament of two Hotchkiss L/40 guns (each with 166 rounds) in limited-movement mountings allowing traverse out to an angle of 120° from the centreline, plus three or four Hotchkiss machine-guns (with a total of 6,272 rounds of ammunition): the role of this variant was to tackle guns, emplacements and other fixed defences. The lighter variant, turning the scales at a combat weight of 60,480 lb (27434 kg), was designated Tank Mk I Female and carried an armament of one or two Hotchkiss air-cooled machine-guns and four water-cooled Vickers machine-guns (in place of the Male’s guns and sponson-mounted machine-guns) with a total of 30,080 rounds of ammunition: the role of this variant was protection of the heavier Males from infantry attack, and pursuit of enemy infantry.

The men of the new army branch were soon coming to grips with their extraordinary new machines, which offered great things but were extremely uncomfortable: the Tank Mk I lacked any form of sprung suspension, vision of the outside world was limited by the small size of the few vision slits, the engine was unsilenced (meaning that internal communication had to be undertaken largely by hand signalling) and ventilation was virtually nonexistent. And as operations were shortly to confirm, while the tank’s construction (soft steel that was cut and drilled and then hardened before being bolted together over the primary structure of riveted girders and angle irons) may have provided protection from smalls arms fire it was totally prone to spall and splash when struck on the outside: this last meant that the crew had to wear thick clothing and face protection to avoid being pierced and cut by the shards sent flying off the inside of the armour when it was struck on the outside (spall) or hit by the molten metal that penetrated the tank’s ill-fitting plates when bullets melted on hitting the tank (splash).

The Tank Mk I had a crew of eight comprising the commander/brakesman and driver in the front with their heads in the central cupola, four gunners in the central portion, and two gearsmen in the rear section. Modest steering capability was provided by the tail in good conditions, but major course corrections required a four-man effort in which the gear driving the track on the inside of the turn was put into neutral while that on the outside was operated in first or second until the turn had been accomplished, whereupon the same drive was applied to both tracks. The steering tail increased trench-crossing capability from 10 to 11 ft 6 in (3.05 to 3.51 m), but proved a great hindrance in operations (being easily damaged or clogged with mud), and from November 1916 was abandoned. Most of the vehicles so modified were then fitted with a substantial shelf between the rear horns for the carriage of equipment such as a towing hawser.

The tank went into action for the first time on 15 September 1916 in one of the subsidiary components of the Battle of the Somme, namely the Battle of Flers-Courcelette: here the British Reserve and 4th Armies were to punch a 4-mile (6.4-km) hole in the German line at Flers and Courcelette in the sector between Thiepval and Combles, the 10 assault divisions being supported by a proposed 50 tanks. Yet such was the technical infancy of the new weapon that some 18 Tanks Mk I had broken down before the assault started, and the surviving 32 machines were allocated in penny packets (the largest mass being seven tanks) as what were in effect mobile pillboxes that could crush wire and lead the infantry into what would clearly be totally dumbfounded German positions. In the event the tanks did well, but their role was hopelessly wrong and their effect was thus small when the Battle of Flers-Courcelette fizzled out at the end of the day.

Yet the technical seed had been sown, and ideas for the appropriate tactical use of the tank soon started to sprout in the soil of north-eastern France.

Specification

Tank Mk I

Type: battle tank

Crew: 8 (commander, driver/brakesman, two gearsmen, and four gunners)

Combat weight: 62,720 lb (28450 kg) for Male and 60,480 lb (27434 kg) for Female

Dimensions: length overall with steering tail 32 ft 6 in (9.91 m) and 25 ft 5 in (7.75 m) without tail; width 8 ft 8.5 in (2.65 m) for the hull, 13 ft 9 in (4.19 m) over the sponsons for the Male and 14 ft 4 in (4.37 m) over sponsons for the Female; height 8 ft 0 in (2.44 m)

Armament: two 6-pdr (57-mm) Hotchkiss L/40 guns with 332 rounds and three/four 8-mm (0.315-in) Hotchkiss machine-guns with 6,272 rounds for Male, and four 0.303-in (7.7-mm) Vickers machine-guns and one/two 8-mm (0.312-in) Hotchkiss machine-guns with 30,080 rounds for the Female

Armour: between 6 and 12 mm (0.24 and 0.47 in)

Powerplant: one 105-hp (78.3-kW) Foster-Daimler water-cooled six-cylinder inline petrol engine with 50 Imp gal (227 litres) of fuel in two gravity-feed tanks; power was transmitted by one two-speed main gearbox and two auxiliary gearboxes to two unsprung tracks each of 90 shoes passing over 26 rollers

Performance: road speed 3.7 mph (5.95 km/h); road range 24 miles (38.6 km); fording 4 ft 6 in (1.37 m) without preparation; gradient 24%; vertical obstacle 4 ft 6 in (1.37 m); trench 11 ft 6 in (3.51 m) with steering tail; ground clearance 16 in (0.406 m)