Chris Chant's Blog

Operation ‘Postmaster’

Occurring on 13 January 1942, this was a British seizure of Axis shipping in Santa Isabel harbour on the neutral Spanish island of Fernando Pó (now Bioko in Equatorial Guinea) in the Gulf of Guinea off the west coast of Africa. The operation was undertaken by the Special Operations Executive’s ‘Maid Honor’ Force, so-named for its vessel, the ex-Brixham trawler Maid Honor. The force was at this time operating in the Gulf of Guinea with the primary task of searching for clandestine bases which might be used by U-boats preying on Allied merchant shipping plying the routes from South America and South Africa to the UK, but in ‘Postmaster’ the men of Major Gustavus March-Phillipps’s force arrived in two tugs and towed away three Axis merchant vessels.

Military historian, Frank Baldwin, states:

“Henry Gustavus March-Phillips was a Royal Artillery Officer Reservist who served in the BEF in the 1940 battles for France and Belgium, with sufficient distinction to be awarded the MBE.”

In 1941 the British had begun to receive reports that U-boats were using river estuaries in Vichy French Equatorial Africa as refuelling bases. The unit selected to investigate the reports was the Small Scale Raiding Force (otherwise No. 62 Commando), which had been formed in 1941 and currently comprised 55 commando-trained personnel working with the Special Operations Executive. Commanded by March-Phillipps, the SSRF came under the operational control of the Combined Operations Headquarters. Maid Honor, a 65-ton Brixham sailing trawler, departed Poole on the south coast of Dorset on 9 August 1941, bound for West Africa with a five-man crew under March-Phillipps. The rest of the SSRF, under the command of Captain Geoffrey Appleyard, had departed earlier aboard a troop transport ship. On 20 September Maid Honor reached Freetown, Sierra Leone, which Appleyard’s party had reached at the end of August. The search for the U-boat bases now started, but the SSRF found no evidence of U-boat activities in the course of its forays into many of the area’s rivers and deltas.

The SOE maintained a presence in West Africa for the observation of Vichy French, Spanish and Portuguese territories and the detection and subsequent hindering of any activities that might threaten the UK’s colonies in West Africa. While the SSRF searched for U-boat bases, SOE agents had learned that there were three Axis vessels in the port of Santa Isabel on the Spanish island of Fernando Po some 20 miles (32 km) off the coast of Africa near the border of Nigeria and Guinea. These ships were the 8,500-ton Italian Duchessa d’Aosta, large German tug Likomba, and diesel-powered barge Bibundi. Duchessa d’Aosta was equipped with radio, and was therefore perceived as a threat for her potential to provide details of Allied naval movements. Her declared cargo was 1,340 tons of wool, 141.33 tons of hides and skins, 580 tons of tanning materials, 1,786 tons of copra, 243.15 tons of crude asbestos fibre and more than 11 million ingots of electrolytic copper. The first page of the ship’s cargo manifest was not presented to the port authorities and the ship’s captain refused to provide any details, and this led to speculation that the ship was also carrying arms and/or ammunition.

Secret observation

Leonard Guise, an SOE operative, visited the island and kept the ships under observation, and in August 1941 submitted a plan to seize Likomba and disable Duchessa d’Aosta. The Admiralty approved a military operation, despite the fact that it would take place in a neutral port, on 20 November 1941.

To transport the raiders to the island, the tugs Vulcan and Nuneaton were provided by the Nigerian colonial administration. The chosen raiding force was 32 men in the form of four SOE agents, 11 SSRF commandos and 17 men recruited from the local population as crew for the tugs. The mission suffered a blow when General Sir George Giffard, the British military commander in West Africa, refused to support the mission and would not release the 17 men required on the grounds that the undertaking would compromise some unnamed plans he had in mind and that what was in law an act of piracy would have significant repercussions. The Admiralty then suspended the operation, with the initial approval of the Foreign Office. Final approval for the operation, with which the Foreign Office later concurred, was granted on 6 January 1942 with the proviso that there should be no tangible proof of the British involvement. As a safeguard the Admiralty also despatched the corvette Violet to intercept the vessels at sea, thereby opening the possibility of a cover story that the ships had been intercepted while trying to make their way home to Europe.

Richard Lippett, an SOE operative, had meanwhile obtained employment with the shipping company John Holt & Co. of Liverpool, which had business offices on the island. Having taken up the post, Lippett started to make preparations for the raid. He became aware that Duchessa d’Aosta’s crew regularly accepted invitations to parties ashore and had held a party aboard ship on 6 January 1942. Under the guise of a party-goer, Lippett managed to gain information about the readiness of the ship for sea, crew numbers, and the watch arrangements.

The raiding force departed Lagos in Nigeria aboard its two tugs on the morning of 11 January, and while at sea practised lowering Folbots and boarding ships at sea under the command of Captain Graham Hayes.

Opposition distracted

The raiders approached Santa Isabel harbour, and at 23.15 and 23.30 on 14 January 1942 the two tugs were in position 200 yards (180 m) off the harbour entrance. Onshore, Lippett had arranged for Duchessa d’Aosta’s officers to be invited to a dinner party, which was also attended by 12 Italian officers and two German officers from Likomba.

The boarding parties assembled on the decks of the two tugs as they entered the harbour. Vulcan, with March-Phillipps and Appleyard, his second in command, on board, headed for Duchessa d’Aosta. As Vulcan approached, a few men could be seen on the after deck of the merchant vessel, but appeared to take no notice of the tug other than to shine a torch in its direction. At the same time, Folbots under the command of Hayes from Nuneaton, were being paddled toward Likomba and Burundi, which were moored together. Challenged by a watchman on Burundi, they persuaded him with their reply that it was the ship’s captain coming back on board. The men from the canoes boarded Burundi and the two men of the watch crew jumped overboard. After planting explosive charges on the anchor chain, the commandos guided Nuneaton alongside Likomba to take her and Burundi in tow. As soon as they were ready, the charges were blown and Nuneaton began to tow Likomba out of the harbour.

Meanwhile, 11 men from Vulcan had managed to board Duchessa d’Aosta, and while one group planted charges on the anchor chains, another searched below decks and collected prisoners. Once the anchor chains had been severed, Vulcan started to tow Duchessa d’Aosta out of the harbour. The explosions had alerted the population of the town, who started to gather on the pier, but no attempts were made to stop the ships from leaving. Several anti-aircraft emplacements opened fire at imaginary targets, believing the explosions to be the result of an air attack, but the 150-mm (5.9-in) guns protecting the harbour itself remained silent.

Swift completion

From entering the harbour to leaving with the ships under tow, the operation had taken only 30 minutes and the raiding party had suffered no losses while taking 29 prisoners as well as the three vessels. During the evening of the following day the SSRF force began to experience problems with the tugs’ engines and the tow ropes, but one day later Vulcan reached the rendezvous and was ‘captured’ by Violet. Nuneaton managed to contact the Nigerian collier Ilorin by semaphore, which in turn contacted Lagos by radio, and a ship was dispatched to tow them into port.

Maid Honor remained in Lagos and eventually sold to the Sierra Leone government. Duchess d’Aosta was sailed to Greenock and then managed by Canadian Pacific as Empire Yukon for the Ministry of War Transport. Likomba was managed by the Elder Dempster Lines, who renamed the vessel Malakel in 1947 and sold her to Liberia in 1948.

Operation ‘Tracer’ – a British oddity in the defence of Gibraltar

Gibraltar was rightly seen by the British in World War II as one of the three keys to the Mediterranean, and thus the prosecution of the war against Italy after that country had declared war on the UK on 10 June 1940. With the Far East and Australasia vital to British strategic, political and economic thinking, the Mediterranean provided the shortest sea route between the UK and India, the Far East, Australia and New Zealand by ships which passed along the Mediterranean between its western end at the Strait of Gibraltar and eastern access to and from the Red Sea, and thence the Indian Ocean, by means of the Suez Canal. Thus the three keys to the Mediterranean were Gibraltar at one end, the Suez Canal in Egypt at the other, and Malta in the middle.

It was clear that the loss of any of these three keys could close the Mediterranean to the British, forcing maritime communications much farther to the south to make the altogether longer and therefore time- and resources-consuming passage round the southern tip of Africa. The British were well aware of the threats, both real and possible, against the three Mediterranean keys, by the Axis forces of Germany and Italy. Malta and northern Egypt were threatened by Italian naval power, German and Italian air power, and German and Italian land power. Gibraltar was under less immediate threat, for an amphibious assault was highly improbable and any overland assault would first have to cross the Pyrenees mountains from south-western France and then advance across Spain. However, there remained the possibility that Germany might be able to persuade Spain, now ruled by the nationalists of General Francisco Franco y Bahamonde, whose success in the Spanish Civil War (1936/39) had been materially aided by Germany and Italy, to enter the war on the side of the Axis alliance, or at least to remain passive as German forces crossed Spain.

To be buried for the duration

Operation ‘Tracer’ was an unrealised British plan of 1940/43 to seal six men inside the Rock of Gibraltar should this key base fall to the Germans. These volunteers were to have food and water sufficient to survive for seven years. The origins of ‘Tracer’ can be found in the period after the fall of France in June 1940, when British intelligence came to believe that the German forces could and indeed might attempt to advance through Spain to take Gibraltar from the landward side. It was decided to excavate caverns in the rock to hide the men, who would be able to observe subsequent German movements by means of two slits, each measuring 12 by 6 in (305 by 152 mm), looking east and west, and through which an 18-ft (5.5-m) antenna could be lowered to enable the observers to transmit details of German targets for attack by British aircraft. The caverns were to be 45 ft (13.7 m) long by 16 ft (4.9 m) wide by 8 ft (2.4 m) high.

The planning for and possible implementation of ‘Tracer’ were discussed only in the home of Admiral Sir John Godfrey, the Director of Naval Intelligence, and specialist advice was solicited from George Murray Levick, who had been on Captain Robert Scott’s ill-fortuned expedition to the Antarctic in 1910/13 and was now called up, at the age of 64, with the rank of surgeon commander. Levick advised on the selection of suitable volunteers, survival techniques, diet, exercise, recreation, alcohol, tobacco, clothing, ventilation, sanitation, and the disposal of any dead by means of embalming and cementing-up. Levick also suggested a rehearsal, probably in Scotland, to test the temperamental suitability of the personnel. In the end, volunteers were taken to the naval school at Shotley, Suffolk, for training, before being sent to Gibraltar with ‘proper jobs’ as cover for the real purpose of their mission. The MI6 intelligence service provided training in radio techniques and also supplied the radio equipment and a bicycle-operated generator.

The scheme was deemed to be so full of potential that similar operations were planned for Colombo and Trincomalee in Ceylon, Malta and Aden.

In August 1943, however, the decline of any real German threat to Gibraltar led to the termination of ‘Tracer’, whose personnel were stood down and their caves sealed.

Warships that never were – the Soviet ‘Sovetsky Soyuz’ class battleship (II)

The main armament of the ‘Sovetsky Soyuz’ class battleships was based on a trio of electrically powered MK-1 turrets, each with three 16-in (406-mm) B-37 L/50 guns. These guns could be depressed to -2° and elevated to +45°, had a fixed loading angle of 6° and their rate of fire varied with the time required to re-aim the guns. The rate therefore varied 2.0 to 2.6 rounds per minute depending on the elevation. The turrets could elevate at a rate of 6.2° per second and traverse at 4.55° per second. For reach gun 100 2,443-lb (1108-kg) projectiles were carried. The guns fired these projectiles at a muzzle velocity of 2,723 ft (830 m) per second to a maximum range of 49,870 yards (45600 m).

The secondary armament consisted of 12 6-in (152-mm) B-38 L/57 guns mounted in six MK-4 twin turrets. These guns could be elevated in an arc between -5° and +45°, had a fixed loading angle of 8°, and their rate of fire also varied with elevation between 4.8 and 7.5 rounds per minute. Each gun was provided with 170 rounds of ammunition. The guns could be elevated at a rate of 13° per second and the turrets could be traversed at 6° per second. The guns had a maximum range of about 32,810 yards (30000 m), their 121-lb (55-kg) shell being fired at a muzzle velocity of 3,117 ft (950 m) per second.

Major anti-aircraft fire was provided by 12 3.94-in (100-mm) B-34 L/56 dual-purpose guns in six twin MZ-14 turrets with 400 rounds per gun. As their construction began, the ships had only four turrets, but two additional turrets were restored to the quarterdeck in January 1941. The guns could be elevated to a maximum of +85° and possessed a maximum depression angle of -8°, elevation being achieved at a rate of 10° per second and the turrets traversing at a rate of 12° per second. The 3.94-in (100-mm) guns fired a 34-lb (15.6-kg) HE shells at a muzzle velocity of 2,936 ft (895 m) per second for a maximum range of 24,320 yards (22240 m) against surface targets, but their maximum range against air targets was 32,465 ft (9895 m) as dictated by the limit of their time fuse.

Minor anti-aircraft defence was the responsibility of 10 46-K mounts each carrying four 37-mm water-cooled 70-K guns with 1,800 rounds per gun. Only eight mounts were planned when construction of the ships began, but two more mounted were added, probably in January 1941, one on each side of the forward superstructure. Each mount was fully enclosed to protect the crew from the muzzle blast of the larger guns and against splinters. The 70-K gun fired a 1.61-lb (0.732-kg) projectile at a muzzle velocity of 2,887 ft (880 m) per second, and its effective anti-aircraft range was 13,125 ft (4000 m).

Fire control

Each main turret had a 39.3-ft (12-m) DM-12 rangefinder for use in local control, but the main armament was generally controlled by one of three KDP-8 fire-control directors. These each possessed had two 26.25-ft (8.0-m) stereoscopic rangefinders, one to track the target and the other to range the splashes of the ship’s own shells. Two of these directors were protected by 20 mm (0.79 in) of armour and were mounted above the rear superstructure and the tower mast, and the other on top of the conning tower, where it was protected by 50 mm (2 in) of armour. Four KDP-4t-II directors, each with two 13.1-ft (4.0-m) rangefinders, controlled the secondary armament: one pair was on either side of the tower mast and the other pair was located on each side of the after funnel. Three SPN-300 stabilised directors, each with a 13.1-ft (4.0-m) rangefinder, controlled the heavy anti-aircraft guns: there was one on each side of the forward funnel while the other was mounted above the rear superstructure.

As noted before, Soviet industry could not produce plates of cemented armour thicker than 230 mm (9.1 in), and this forced the November 1940 decision to replace cemented plates thicker than 200 mm (7.9 in) with less effective face-hardened plates. The factories tended to compensate by making the thicker plates harder, but this often made them more brittle and large numbers failed to pass acceptance tests. This would have significantly reduced the level of protection enjoyed by the ‘Sovetsky Soyuz’ class ships in combat.

Protective elements

The ‘Sovetsky Soyuz’ class ships had 22,938 tons of armour protection, a slightly greater weight than that of the larger Japanese ‘Yamato’ class, which had 22,895 tons). The armour of the Soviet ships was designed to provide protection against 16-in (406-mm) shells and 1,102-lb (500-kg) bombs, specifically shells fired from forward bearings between 35° and 50° off the centreline. This led to the very uncommon situation in which the armour belt thickened toward the bow to compensate for the narrowing of the ship near the forward magazines, which had to be offset by the incorporation of thicker armour. The belt was 486 ft 11 in (148.4 m) long and extended over 57% of the total waterline length, and was inclined at 5° to increase its resistance to flat-trajectory shells.

Over the machinery spaces, the armour had a thickness of 375 mm (14.8 in) and increased in steps until it was 17 in (420 mm) thick over the forward magazines. It was 15 in (380 mm) thick over the rear magazine. The belt extended forward of the magazines at a thickness of 8.7 in (220 mm) and terminated in a 11.1-in (285-mm) bulkhead inclined at 30°: this bulkhead was reduced to a thickness of 9.8 in (250 mm) at the lower deck, from which it was continued downward to the inner bottom by a 3-in (75-mm) bulkhead. Forward of this, the bulkhead was a 0.79-in (20-mm) splinter belt which extended all the way to the bow. The main belt dropped down to the main deck from the upper deck abreast the aft turret to reduce weight. This downward step was protected by 7.1-in (180-mm) plates. A transverse bulkhead, 14.4 in (365 mm) thick, separated the rear turret and the ship’s sides. The main part of the armoured citadel was closed off by a 9.05-in (230-mm) forward bulkhead and a 7.1-in (180-mm) rear bulkhead, both of homogeneous armour, and 1-in (25-mm) splinter armour covered the upper portion of the citadel.

The forecastle deck was 1 in (25 mm) thick and the upper deck 6.1 in (155 mm) thick over the citadel. Below it, the 2-in (50-mm) middle deck served as a splinter deck. The upper deck was 3.9 in (100 mm) thick above the 8.7-in (220-mm) waterline belt extension. The bottom edge of the forward splinter belt met with a 2.6-on (65-mm) arched deck. Another arched deck of the same thickness covered the stern abaft of the rear transverse bulkhead.

The main gun turrets had faces 19.5 in (495 mm) thick, with sides and roofs 9.1 in (230 mm) thick. Plates with a thickness of 7.1 in (180 mm) protected the gun ports and 2.4-in (60-mm) bulkheads separated each gun. The turrets sat on barbettes which were 16.7 in (425 mm) thick above the upper deck. The turrets of the secondary armament had 3.9-in (100-mm) faces and 2.6-in (65-mm) sides, and sat on barbettes with a thickness of 3.9 in (100 mm) reducing to 2.6 in (65 mm) on their inboard sides. Some 3.9 in (100 mm) of armour protected the faces, sides and backs of the heavy anti-aircraft turrets, whose roofs and barbettes were also of 3.9-in (100-mm) thickness. The forward conning tower had walls 16.7 in (425 mm) thick, while those of the rear conning tower were only 8.7 in (220 mm) thick. The flag bridge in the tower mast had 3 in (75 mm) of protection.

The defensive system against torpedoes was designed to withstand weapons with a warhead filled with 1,653 lb (750 kg) of TNT, and it was intended that the ships should be capable of remaining afloat with any five adjacent compartments flooded or with three torpedo hits and the destruction of the unarmored above-water side. The Pugliese system of voids containing liquid-carrying drums protected 403 ft 7 in (123 m) of the ships’ central section. At the aft end was a multi-bulkhead protection system that extended another 108 ft 3 in (33 m) to the rear. The system’s depth was 26 ft 11 in (8.2 m) amidships reducing to 23 ft 0 in (7.0 m) fore and aft. The outer plating ranged from 11 to 14 mm (0.43 to 0.55 in) in thickness while the inner bottom was 7 mm (0.28 in) thick.

Overambitious and impractical

The Soviet shipbuilding plan of August 1938 envisaged a total of 15 ‘Projekt 23’ class battleships, and this grandiose scheme was only slightly trimmed to 14 ships in the plan of August 1939. Of these, eight were to be laid down before 1942 and the other six by 1947. However, only four were actually laid down before the outbreak of World War II persuaded the Soviets to reconsider their scheme. On 19 October 1940 it was ordered that no new battleships were to be laid down so that greater resources would be available for the construction of smaller warships and the strengthening of the army that one ship was to be scrapped, and priority was to be given to only one of the three remaining battleships.

Soviet industry proved to be incapable of supporting the construction of so many large ships at the same time. Historian Mark Harrison states: “The Soviet economy produced weapons on a larger scale than Germany, and more of Soviet war production came earlier in the war.”

The largest warships built in the USSR up to 1938 were the 7,875-ton ‘Kirov’ class cruisers, and even they had suffered from a number of production problems, but the Soviet leadership wilfully ignored the difficulties encountered in the ‘Kirov’ class ships’ construction when ordering 14 much more ambitious ships. Construction of two more ships planned for Leningrad and Nikolayev had to move to the new Shipyard 402 in Molotovsk (now Severodvinsk) because the existing yards could not be expanded to handle so many large ships. Components for these two ships had to be manufactured at Leningrad and shipped via the Baltic Canal and White Sea to Molotovsk. Moreover, the turret-making facility at Nikolaev was inadequately equipped to assemble the 16-in (406-mm) mountings, and the propeller shafts had to be ordered in 1940 from Germany and the Netherlands as Soviet factories were already overburdened. Shipbuilding steel proved to be in short supply in 1940, and a number of batches were rejected because they did not come up to specification. The manufacture of armour plate was still more troublesome as only 1,772 of the planned 9,842 tons were delivered in 1939, and more than half of that was then rejected.

Machinery problems were also likely to delay the ships well past their intended delivery dates of 1943/44. Three turbines were delivered to Arkhangelsk by Brown, Boveri in 1939 for Sovetskaya Rossiya, but the Kharkov works had not completed even one turbine before the German invasion of June 1941. A prototype boiler was supposed to have been built ashore for evaluation, but it was not completed until early 1941, which further complicated the production plan.

Construction of all three ships was ordered halted on 10 July 1941, and Sovetsky Soyuz was placed into long-term conservation, but this ship, Sovetskaya Ukraina and Sovetskaya Rossiya were stricken on 10 September 1941.

Warships that never were – the Soviet ‘Sovetsky Soyuz’ class battleship (I)

The ‘Sovetsky Soyuz’ class comprised four battleships which were started in the late 1930s but not completed. Designed in response to the battleships being built by Germany, the class was to have totalled 16 ships, but in the event only four had been laid down by 1940, it was decided to curtail the programme to three ships so that greater resources could be diverted to an expanded army rearmament programme.

The ‘Sovetsky Soyuz’ class ships would have rivalled the Japanese ‘Yamato’ class and US ‘Montana’ class in size had any been completed, although only with significantly less firepower in the form of nine 16-in (406-mm) guns by comparison with the nine 18.1-in (460-mm) guns of the Japanese ships and the 12 16-in (406-mm) guns of the US ships. However, they would have been theoretically superior to their German rivals, the ‘Bismarck’ class, though the inability of Soviet industry to create cemented armour in thicknesses greater than 9.1 in (230 mm) would have significantly offset the notional advantage of the ‘Sovetsky Soyuz’ class ships’ thicker armour.

Construction of the first four ships was beset by many problems as the Soviet shipbuilding and related industries were inadequate to the task of constructing ships as large as these and indeed one of the ships, Sovetskaya Belorussiya, was cancelled on 19 October 1940 after major constructional failings had been discovered. Construction of the other three ships was suspended shortly after the start of Germany’s ‘Barbarossa’ invasion of the USSR in June 1941, and never resumed.

Work on the design of the new battleship type began in 1935 in response to the existing and planned German battleships, and the Soviets tried to buy either drawings or ships from Italy and the USA in the late 1930s. The Italian Ansaldo company proposed a 42,000-ton ship with nine 16-in (406-mm) guns and similar in overall concept and size to the battleship Littorio it then had under construction for the Italian navy. The US company Gibbs & Cox provided four designs: one conventional battleship, and three hybrid designs combining battleship main armament with a raised flightdeck on the central superstructure capable of operating up to 30 aircraft. The USSR decided finally to press forward with its own design.

Start in 1936

The first tactical/technical requirement was issued on 21 February 1936 but proved too ambitious, specifying nine 18.1-in (460-mm) guns and a speed of 36 kt on a displacement of 55,000 tons. The requirement was revised in May 1936, the speed being trimmed to 30 kt and the secondary and anti-aircraft batteries being reduced. A few months later the displacement was further reduced to 45,000 tons and the main armament calibre changed to 16 in (406 mm). Soon after this, the USSR signed the Anglo-Soviet Quantitative Naval Agreement agreeing to follow the terms of the 2nd London Naval Treaty limiting battleship displacement to 35,000 tons), although the agreement included a proviso allowing the Soviets to build ships of unlimited size to face the Japanese navy if they notified the British. Yet another requirement, approved on 3 August, called for ships of 41,500 tons with an armament of nine 16-in (406-mm), 12 6-on (152-mm), 12 3.94-in (100-mm) and 40 37-mm) guns, a maximum armour thickness of 15 in (380 mm) and a speed of 30 kt.

The design of KB-4, the surface ship design bureau of the Baltic Shipyard, was selected for further development. Its designers were sure that only a larger ship could satisfy the full requirement, and on 22 November 1936 secured approval for a thickening of the deck armour, thereby increasing the displacement to about 47,000 tons. Design work continued on this basis and technical work was completed for a ship of 47,700 tons in April 1937, but the designers continued to press their case for larger ships. The issue was resolved by Premier Iosif Stalin at a meeting on 4 July, when he agreed to increase displacement to about 56,000 tons. This forced a restart of the entire project at what was the worst possible time as the ‘great purge’ was decimating the Soviet armed forces and the industries on which they depended. The original deadline for completion of design work by 15 October was missed, and only an incomplete version could be presented to the navy in the following month. Among the details still to be completed were the final propulsion plant design, the 16-in (152-mm) guns and the 3.94-in (100-mm) gun mounts.

Model testing

Extensive testing was undertaken on the hull form, deck armour and torpedo protection. More than 100 hull models were tested in a ship model basin to find the optimum hull form and two 1/10th scale launches were built for evaluation of the hull’s manoeuvrability. An old ship was fitted with a replica of the design’s armour decks and tested against 1,102-ob (500-kg) bombs, and revealed that such weapons would generally penetrate both the 1.6-in (40-mm) upper and 2-in (50-mm) middle decks before exploding on the armoured deck. As a result the main armour deck was raised one deck and a splinter deck added underneath it to stop bomb or shell fragments which did manage to penetrate the armour deck. The underwater protection system was tested on 15 1/5th scale models and two full-sized experimental barges. These tests proved that the torpedo belt system of multiple bulkheads was superior to the system of a large tube filled with smaller sealed tubes, but it was too late to incorporate these test results as construction was already well under way by the time they had been completed.

A revised design was approved on 28 February 1938 and the first ship was to be laid down on 15 July, but even this design was incomplete and had later to be revised. Trials with similarly shaped motor launches suggested that speed would be 1 kt less than planned, and this was accepted in the November 1938 revision as a maximum speed of 27.5 kt, but then a new propeller design proved to be more efficient and was predicted to increase speed to 28 kt. Another change was the elimination of the central rudder after tests revealed that the two outer rudders would not be able to counteract its effects should it jam. The weight toward the stern was calculated to be too great, producing a substantial stern-down trim, and the two 3.94-in (100-mm) quarterdeck turrets were therefore deleted and the height of the armour belt abreast the rear turret was reduced, but this decision was then reversed. This forced a revision of the aircraft arrangements as the catapult had to be removed from the quarterdeck’s centreline, and two catapults were therefore added to the sides of the quarterdeck.

Massive vessels

As designed, the ‘Projekt 23’ class ships, as Sovetsky Soyuz and her sisters were designated, had an overall length of 883 ft 10 in (269.4 m). beam of 127 ft 7 in (38.9 m) and full-load draught of 34 ft 1 in (10.4 m). They displaced 58,220 tons at standard load and 64,121 tons) at full load, although weight estimates made in 1940 show that they would in fact have exceeded 59,052 tons standard and 65,942 tons full load.

There were facilities for two to four KOR-2 flying boats. Two hangars were built into the after end of the forecastle deck to house two of the ‘boats, and cranes were provided at the forward end of the quarterdeck to hoist them out of the water.

The propulsion machinery arrangement provided tactically good dispersal of these vital spaces, but required wing shaft lengths of about 344 ft 6 in (105 m). The turbine compartments for the wing shafts were located forward of boiler room No. 1 and aft of the No. 2 turret magazines. The engine room for the central shaft’s turbine was between boiler room Nos 2 and 3, and this meant that the wing propeller shafts had to extend below the boilers.

The steam turbines, and a license to build them, were originally to have been ordered from Cammell Laird of the UK, but the cost was greater than the Soviets were prepared to pay, so they were instead purchased from Brown, Boveri of Switzerland, using the technical information acquired from Cammell Laird. Four single-reduction geared turbines were ordered from the Swiss firm, three to equip Sovetskaya Rossiya and one to serve as a pattern for the Kharkov factory which was to build the remainder. The three produced a total of 201,000 shp (149866 kW), and steam was provided by six boilers (two on each of the three boiler rooms). The standard bunkerage was 5,197 tons, giving an estimated endurance of 6,300 nm (7,200 miles; 11700 km) at 14.5 kt and 1,890 nm (2,170 miles; 3500 km) at full speed. The maximum fuel capacity was 6,338 tons).

Robert Farley, writing for The National Interest, describes the Sovetsky Soyuz as one of the 5 most lethal battleships to never set sail. He discusses the battleship’s cancellation, saying: “The demands of the civil war and the relentlessly hostile international environment meant that Moscow had to delay in favor of other priorities. Moreover, the Soviet economy lacked the strength to withstand a major program of naval construction.”

[Photo by Korabli]

Warships that never were – the US ‘Montana’ class battleship (II)

The secondary armament of the ‘Montana’ class battleships was planned as 20 5-in (127-mm) L/54 guns in 10 turrets located as five on each side of the ships’ central superstructure ‘island’. Designed specifically for the ‘Montana’ class ships, these guns were to replace the 5-in (127-mm) L/38 guns of the secondary batteries then in widespread use on the larger ships of the US Navy. The 5-in (127-mm) L/54 turrets were similar to the 5-in (127-mm) L/38 mounts in that they were intended for the dual anti-ship and anti-aircraft roles, but differed in that they were somewhat heavier, fired heavier rounds of ammunition, and as a result caused the onset of crew fatigue sooner than the 5-in (127-mm) L/38 guns. The magazine capacity for the 5-in (127-mm) L/54 gun was 500 rounds per turret, and at an elevation of +45°the guns could engage targets nearly 26,000 yards (23775 m) distant. At an elevation of +85°, the guns could fire on air targets flying as high as 50,000 ft (15240 m).

The cancellation of the ‘Montana’ class battleships in 1943 pushed back the combat debut of the 5-in (127-mm) L/54 gun to 1945, when it was introduced on the US Navy’s ‘Midway’ class aircraft carriers, which each carried 18 such gun in single mounts. The gun proved adequate for carrier air defence, but was gradually phased out of carrier use as a result of its weight: the gun defence of carriers then passed wholly to the other ships within the carrier battle group.

For the first time since the construction of the ‘Iowa’ class, the US Navy was not building a fast battleship class solely for the purpose of escorting aircraft carriers operating in the Pacific, so the ‘Montana’ class ships were not designed for the primary task of escorting fast carrier task forces. Even so, they were schemed with a strong array of dedicated light anti-aircraft guns to protect themselves and other ships (principally the US aircraft carriers) from Japanese fighters and dive-bombers.

The 20-mm Oerlikon cannon was produced in very large numbers during World War II for aircraft and anti-aircraft use: the USA alone manufactured 124,735 such cannon. When brought into service during 1941, these cannon replaced the 0.5-in (12.7-mm) Browning M2 machine gun on a one-for-one basis. The Oerlikon cannon remained the primary light anti-aircraft weapon of the US Navy until the introduction of the 40-mm Bofors gun in 1943. The Oerlikon cannon was an air-cooled weapon based on the blowback recoil system so, unlike other automatic guns employed during World War II, the Oerlikon cannon’s barrel did not recoil, and the breechblock was never locked against the breech and is moving forward as the cannon fired. The weapon lacked a counter-recoil brake, as the force of the counter-recoil was checked by recoil from the firing of the next round.

Between December 1941 and September 1944, 32% of all Japanese aircraft downed were credited to this weapon, which reached its greatest success level in the second half of 1942, when it was credited with 48.3% of all the Japanese aircraft shot down. The revolutionary Mk 14 sight was introduced in 1943, and made these cannon still more effective. The 20-mm cannon were found to be ineffective against the Japanese kamikaze attacks used during the latter half of World War II, however, and were then phased out of service in favour of the heavier 40-mm Bofors guns.

Blogger Karl Smallwood states the following about kamikaze pilots:

“While there certainly were those who were willing to volunteer to die for emperor and country, and many more willing to die in this way simply because they felt, somewhat correctly, that they were the last line of defense to protect their families and friends at home, in truth many seem to have simply been pressured into it.”

The battery of 20-mm Oerlikon cannon which was to have been carried by the ‘Montana’ class battleships was to have been 10 and 56 single weapons of this type.

The 40-mm Bofors gun was used on almost every major warship in the US and UK fleet from 1943. Though a descendant of German, Dutch and Swedish designs, the Bofors mounts used by the US Navy during World War II had been significantly Americanised to bring the guns up to US Navy standards. This resulted in a guns system fixed to British standards with interchangeable ammunition to simplify logistics. When coupled with hydraulic drives and the Mk 51 director for improved accuracy, the 40-mm Bofors gun was devastating against shorter range air targets, and was credited with about half of all Japanese aircraft shot down between 1 October 1944 and 1 February 1945.

The battery of 40-mm Bofors gun which was to have been carried by the ‘Montana’ class battleships was to have been between 10 and 32 such weapons, the latter in eight quadruple mounts.

Aside from its firepower, a battleship’s defining characteristic is its protection. The exact design and placement of the armour constitute a complex science. A battleship was usually armoured to withstand an attack from guns of the calibre it itself carries, but the armour scheme of the ‘North Carolina’ class of 1937 was proof only against 14-in (356-mm) shells as the ships were originally to have been armed with weapons of this calibre, while the ‘South Dakota’ class of 1939 and the ‘Iowa’ class of 1040 were designed to resist only their original 2,240-lb (1016-kg) Mk V shells, not the new 2,700-lb (1225-kg) Mk 8 Armor Piercing, Capped shell actually fired by their Mk 7 guns. The ‘Montana’ class ships were the only US battleships designed to resist the Mk 8 shell, providing a ‘zone of immunity’ against the 2,700-lb (1225-kg) Mk 8 shell between 18,000 and 31,000 yards (16460 and 28345 m), and against the 2,240-lb (1016-kg) shell of the same 16-in (406-mm) calibre between 16,500 and 34,500 yards (15090 and 31545 m).

Thus the armour thickness of the ‘Montana’ class battleship included a 7.2- to 16.1-in (183- to 409-mm) belt and lower belt, 9.3-in (236-mm) armoured deck, 1.5-in (38-mm) weather deck, 0.625-in (16-mm) splinter deck, 15.25- to 18-in (387- to 457-mm) bulkheads, 18- to 21.3-in (457- to 541-mm) barbettes, 16-in (406-mm) conning tower, and turrets with 22.5-in (572-mm) faces, 12-in (305-mm) rears, 10-in (254-mm) sides and 9.15-in (232-mm) roofs.

Until the authorisation of the ‘Montana’ class, all US battleships were built within the size limits imposed by the ability to transit the Panama Canal. The main reason for this was logistical: the largest US shipyards were located on the USA’s eastern seaboard, but the nation had territorial interests in both the Atlantic and Pacific oceans, and the ability of battleships to transit the Panama Canal obviated the need for such ships to make a lengthy passage round Cape Horn. By the time of the Two Ocean Navy act, the US Navy had come to appreciate that ship designs could no longer be limited by the Panama Canal, and so approved the ‘Montana’ class knowing that the ships could not transit the canal. This shift in policy meant that the ‘Montana’ class would have been the only US battleships of the World War II period to be armoured adequately against guns of the same power as their own.

Like other major US warships of the period, the ‘Montana’ class ships were designed to use floatplanes for reconnaissance and gunnery spotting, with a secondary task of recovering downed aircrew. The type of aircraft used would have depended on when the battleships were commissioned, but in all probability the aircraft would have been either the Vought OS2U Kingfisher or Curtiss SC Seahawk. Three or four such aircraft were to have been carried for launch by two catapults and recovery by crane after alighting on the water.

The standard complement was to have been in the order of 2,355 men rising to 2,789 men as a flagship.

Warships that never were – the US ‘Montana’ class battleship (I)

The ‘Montana’ class of battleships planned by the United States Navy were schemed as successors to the ‘Iowa’ class ships, but reverted to a more traditional concept inasmuch as they were slower but larger, better armoured and more heavily armed. Five such ships were approved for construction in World War II, but a major change in priorities meant their cancellation in favour of the ‘Essex’ class aircraft carriers and ‘Iowa’ class battleships before any had been laid down. With a beam of 121 ft 2 in (36.93 m), the ships would have been the first US battleships too wide to transit the Panama Canal, whose locks could accommodate a beam of 110 ft 0 in (33.53 m). The main armament was planned as 12 16-in (406-mm) Mk 7 guns in four triple turrets, representing a 33.3% increase over the ‘Iowa’ class ships. With increased anti-aircraft firepower and thicker belt armour, the ‘Montana’ class would have been the largest, best-protected and most heavily armed US battleships ever conceived.

Preliminary design work for the ‘Montana’ class began before the US entry into World War II: the first two vessels were approved by the Congress in 1939 following the enactment of the 2nd Vinson Act in the previous year, and though another three units were later authorised, the Japanese ‘Ai’ attack on Pearl Harbor delayed construction, and the success of carriers in the Battles of the Coral Sea and Midway in 1942 greater decreased the value of the battleship.

Bruce Danforth, writing for Pearl Harbour Oahu, states:

“The Japanese felt that as an axis power that they would eventually go to war with the United States in the Pacific Ocean. By attacking and disabling the Pacific Fleet of the United States, which was stationed at Pearl Harbor, they hoped to cripple the pacific fleet and the moral of the United States bringing her into submission and a peace treaty favorable to Japan.”

The US Navy therefore opted to cancel the ‘Montana’ class in favour of more urgently needed aircraft carriers as well as amphibious and anti-submarine ships. The orders for the ‘Iowa’ class ships were retained as these battleships were fast enough to escort the new ‘Essex’ class aircraft carriers.

As the political situation in Europe and Asia worsened and made World War II all but inevitable, Carl Vinson, the chairman of the House Committee on Naval Affairs, instituted the Vinson Naval Plan to upgrade the US Navy after the cutbacks imposed by the ‘Great Depression’ and the two London naval treaties of the 1930s. Within this context the US Congress passed the 2nd Vinson Act, which opened the way for construction of the four ‘South Dakota’ class fast battleships and the first two of four ‘Iowa’ class fast battleships. Four more battleships were approved in 1940 as another two ‘Iowa’ class and first two ‘Montana’ class ships. By 1942, it was apparent to the US Navy that it needed as many fast battleships as possible, and another two ‘Iowa’ class ships were approved.

Knowing of the Japanese construction of two ‘Yamato’ class super-battleships, the US Navy had been working on a 58,000-ton super-battleship concept since 1938. With a primary armament of 12 16-in (406-mm) guns, this was given the name Montana and authorised for construction by the US Congress under the Two-Ocean Navy Act of 1940, with funding approved in 1941. The ‘Montana’ class ships were the last battleships ordered by the US Navy, and were at first to be designated BB-65 to BB-69: BB-65 and BB-66 were subsequently re-ordered as the ‘Iowa’ class Illinois and Kentucky, so the ‘Montana’ class ships were redesignated as BB-67 to BB-71. The completion of the ‘Montana’ class and the last two ‘Iowa’ class battleships was intended to give the US Navy a considerable advantage over any other nation, or probable combination of nations, with a total of 17 new battleships by the late 1940s.

Preliminary planning of the ‘Montana’ class battleships took place in 1939 at a time when the aircraft carrier was still considered strategically less significant than the battleship. The US Navy began designing a 65,000-ton battleship to counter the threat posed by the ‘Yamato’ class battleships in the Pacific Ocean. Although the US Navy knew little about the two new Japanese battleships, these were believed to have a primary armament of 18-in (457-mm) guns. US plans were at first drawn for a 45,000-ton battleship, but the Battleship Design Advisory Board later increased the displacement to 58,000 tons.

At the time, the design board issued a basic outline for the ‘Montana’ class calling for it not to be limited to the beam restrictions imposed by the Panama Canal, but to be 25% stronger offensively and defensively than any other battleship completed or under construction, and be capable of withstanding the 2,700-lb (1225-kg) shells used by US battleships equipped with either the 16-in (406-mm) L/45 Mk 6 or L/50 Mk 7 guns. However, the length and height of the ‘Montana’ class ships were limited by one of the shipyards at which they were to be built: the New York Navy Yard could not handle the construction of a 58,000-ton ship, and vessels built there had to be low enough to pass under the Brooklyn Bridge at low tide.

After debate about whether the ‘Montana’ class should be fast, equalling the 33 kt of the ‘Iowa’ class, or be more powerfully armed and protected, firepower was preferred to speed. By fixing the speed of the ‘Montana’ class at the 28 kt figure of the ‘North Carolina’ and ‘South Dakota’ class ships, the design team was able to increase the ‘Montana’ class’s protection to the level at which they could withstand fire equivalent to their own guns’ ammunition. This limited the ‘Montana’ class’s ability to escort and defend the aircraft carriers used in the Pacific campaign as the ships were to be powered by eight Babcock & Wilcox boilers delivering steam to four sets of geared turbines for a speed of 27 to 28 kt.

By January 1941, the design limit for the new battleship class had been reached, and most of those responsible for the design wished to increase the displacement to support the ships’ weapons and protection. At the same time, planners decided to adopt a slightly greater length and reduce power for a better machinery arrangement, as well as improving internal subdivisions, and selecting as the secondary armament several 5-in (127-mm) L/54 dual-role twin mounts in place of the 5-in (127-mm) L/38 guns used on the ‘Iowa’ class. Thus the basic scheme for the ‘Montana’ class was not dissimilar to that of the ‘Iowa’ class inasmuch as the ships of both classes would have the same main gun calibre and similar secondary gun calibre: however, the ‘Montana’ class had more armour, mounted three more main guns in one more turret, and were 22 ft (6.7 m) longer and 13 ft (4.0 m) wider than the ‘Iowa’ class.

By April 1942, the ‘Montana’ class design had been approved, and the projected date of completion was estimated to be somewhere between 1 July and 1 November 1945. The US Navy ordered the ships in May 1942, but the class was then postponed as the ‘Iowa’ class battleships and ‘Essex’ class aircraft carriers were under construction in the yards in which the ‘Montana’ class was to be built. Both the ‘Iowa’ and ‘Essex’ classes had by now been allocated a greater priority, the ‘Iowa’ class as it was fast enough to keep up with and defend the ‘Essex’ class carriers with 40- and 20-mm guns, and the ‘Essex class for its ability to launch aircraft to gain and maintain air supremacy over the islands in the Pacific and to intercept and destroy Japanese warships. The whole of the ‘Montana’ class was suspended in May 1942, before any of the keels had been laid, and on 21 July 1942, the construction of the ‘Montana’ class was terminated after the Battle of Midway and the corresponding shift in naval warfare from surface engagements to air supremacy and a corresponding shift from battleships to aircraft carriers.

The five ‘Montana’ class ships (Montana, Ohio, Maine, New Hampshire and Louisiana) were to have been built at the New York Navy Yard, Philadelphia Navy Yard and Norfolk Navy Yard.

Thew ‘Montana’ class’s armament was to have been similar to that of the ‘Iowa’ class, but with an increase in the number of primary and secondary guns for use against surface ships and aircraft. In the event that they had been completed, the ‘Montana’ class ships would have been the most powerful battleships the USA had constructed, and the only US battleship class that would have come close to matching the Japanese ‘Yamato’ class in displacement, armament and protection.

The primary armament schemed for the ‘Montana’ class was 12 16-in (406-mm) L/50 Mk 7 guns carried in four three-gun turrets installed as two forward and two aft. The guns were the same as those of the ‘Iowa’ class battleships, with a length of 66 ft (20.12 m) from breech face to the muzzle. Each gun weighed about 267,900 lb (121519 kg) with its breech. The gun fired projectiles weighing up to 2,700 lb (1225 kg) at a muzzle velocity of 2,690 ft (820 m) per second for a range of up to 48,600 yards (44440 m) at a flight time of almost 90 seconds. The presence of the No. 4 turret would have given the ‘Montana’ class the accolade of carrying the heaviest broadside: 32.400 lb (14697 lg) as opposed to the ‘Yamato’ class’s 28,800 lb (13064 kg). Each gun would have rested within an armoured barbette, but only the top of this would have protruded above the main deck: the barbettes would have extended to a depth of four decks (turrets nos 1 and 4) or five decks (turrets nos 2 and 3). The lower spaces would have contained rooms for storing and handling the projectiles and the bagged powder charges used to fire them. Each turret would have needed a 94-man crew, and would not have been attached to the ship instead rested on rollers.

The turrets would have been of the three-gun rather than triple type as each barrel would have elevated and fired independently. The ships could fire any combination of their guns, including a broadside of all 12. The guns would have been elevated through an arc of 50° (−5° to +45°) at the rate of 12° per second. The turrets would have rotated about 300° at the rate of about 4° per second.

Like most World War II battleships, the Montana class would have been equipped with a fire-control computer, in this case the Ford Mk 1A Ballistic Computer, a 3,150-lb (1429-kg) rangekeeper designed to direct gunfire on land, sea, and in the air. This computer was of the analogue type and used to direct the fire from the battleship’s larger-calibre guns, taking into account factors such as the bearing and speed of the target, the time it took for the projectiles to travel to the target, and the effects of aerodynamic drag on the shells during their flight. At the time the ‘Montana’ class was about to enter construction, the rangekeepers could accept radar data to help target enemy ships and land-based targets. The results of this advance were telling: the rangekeeper was able to track and fire at targets at a greater range and with increased accuracy. This provided the US Navy a major tactical advantage as the Japanese did not develop radar or automated fire control to the level of the US Navy.

The 16-in (406-mm) could fire either of two different types of shell: an armour-piercing round for anti-ship and anti-structure work, and a high-explosive round designed for use against unarmored targets and shore bombardment. The Mk 8 APC (Armour-Piercing, Capped) shell weighed 2,700 lb (1225 kg) and was designed to penetrate the hardened steel armour protecting target ships: at a range of 20,000 yards (18288 m), the Mk 8 shell could penetrate 20 in (508 mm) of armour plate or, at the same range, 21 ft (6.40 m) of reinforced concrete. For use against unarmored targets and for shore bombardment, the 1,900-lb (862-kg) Mk 13 HC (High-Capacity) shell was available: this could blast a crater 50 ft (15.2 m) wide and 20 ft (6.1 m) deep upon impact and detonation, and could defoliate trees 400 yards (365 m) from the point of impact.

Warships that never were – the British ‘Lion’ class

The ‘Lion’ class was to have comprised six battleships, and was designed for the Royal Navy in the late 1930s as what was in essence a larger and improved version of the ‘King George V’ class battleship with 16-in (406-mm) guns. The class design changed several times in response to the removal of treaty restrictions on size and in reflection of war experience.

The choice of 14-in (356-mm) guns in a mix of quadruple and twin turrets for the main battery of the ‘King George V’ class had been dictated by the Second London Naval Treaty, which limited battleships to a standard displacement of 35,000 tons and a main calibre of 14 in (356 mm). When Japan refused to agree to the treaty terms, however, the maximum calibre permitted reverted to 16 in (406 mm) in April 1937.

Robert Farley, writing for Nationalinterest.org, states:

“A Second London Naval Treaty, taking force in 1936, essentially gave up on the project of arms limitation because of the defection of Japan. The treaty didn’t prevent World War II, and the decision of the Japanese and Italians to defect in the 1930s certainly gave them a leg up on the next war.”

The Admiralty then began preliminary design work on a 35,000-ton ship armed with 16-in (406-mm) guns, and this was sufficiently promising for the Director of Naval Construction to be instructed to investigate such designs further, and at the same time provide for several aircraft to be carried. To save design time, many ‘King George V’ class features were incorporated, but the limited displacement proved a major design challenge, and the greater weight of the main armament was offset by a slight reduction in the overall weight of armour and the elimination of two twin 5.25-in (133-mm) turrets.

The design task was eased in March 1938, when the treaty signatories invoked its escalation clause because the Japanese refused to provide any information about their battleship construction programme and the signatories feared that their new ships could be outclassed by the new Japanese construction. The new displacement limit was 45,000 tons, but the Admiralty opted for 40,000 tons and nine 16-in (406-mm) guns on the grounds of cost and the need for the ships to dock at Rosyth and Portsmouth. A new design included more armour, more powerful propulsion machinery, the restoration of the two twin 5.25-in (133-mm) turrets, and four aircraft added. On 15 December 1938, the Admiralty approved this design, which posited a ship with an overall length of 785 ft (239.3 m), beam of 105 ft (32.0 m) and maximum draught of 33 ft 6 in (10.2 m). The standard displacement was 40,550 tons increasing to 46,400 tons at deep load.

Unaltered machinery

To save time, the four-shaft machinery design of the ‘King George V’ class was duplicated with alternating boiler and engine rooms. The ‘Lion’ class ships had four sets of single-reduction geared Parsons steam turbines housed in separate engine rooms. Each set consisted of one high-pressure and one low-pressure turbine driving one propeller shaft, and the combined total of 130,000 shp (96928 kW) was designed to provide a speed of 30 kt. The turbines were powered by eight Admiralty-type three-drum boilers in four boiler rooms. The turbines and boilers could be cross-connected in an emergency. The ships were designed to carry 3,720 tons of fuel oil for a maximum range of 14,000 nm (26000 km) at 10 kt.

The main armament was to comprise nine 16-in (406-mm) L/45 guns of a new Mk II design in the hydraulically powered A, B and Y centreline turrets. The maximum gun elevation was increased to +40°, though the guns were loaded at +5°, and the guns fired a 2,375-lb (1077-kg) shell at a muzzle velocity of 2,483 ft (757 m) per second to a maximum range of 40,560 yards (37090 m). Each gun’s rate of fire was two rounds per minute, and each gun was provided with 100 shells per gun. The secondary armament comprised 16 5.25-in (133-mm) L/45 Mk I dual purpose guns in eight twin mounts: these guns had a maximum depression of −5° and a maximum elevation of +70°, and fired an 80-lb (36.3-kg) HE shell at a muzzle velocity of 2,672 ft (814 m) per second. The normal rate of fire was some seven to eight rounds per minute. The guns had a maximum range of 24,070 yards (22010 m), and 400 rounds were provided for each gun. Short-range air defence was provided by 48 2-pdr guns in six octuple mountings: this weapon fired a 40-mm shell weighting 1.684 lb (0.764 kg) at a muzzle velocity of 2,400 ft (730 m) per second to a range of 6,800 yards (6220 m) at a rate of 96 to 98 rounds per minute. Some 1,800 rounds were provided for each gun.

Unchanged protection

The armour scheme was virtually identical to that of the ‘King George V’ class ships, and based on a 433-ft (132-m) waterline belt of Krupp cemented armour 15 in (381 mm) thick: the belt’s main portion was 15 ft (4.6 m) high, but a lower strake, 8 ft 3 in (2.5 m) high, extended an additional 40 ft (12.2 m) past the ends of the armoured citadel. It tapered vertically from 15 in (381 mm) in thickness to 5.5 in (140 mm) at the bottom edge of the belt, while the plates at the end of the belt were only 11 in (279 mm) thick at the top. Transverse bulkheads 10/12 in (254/305 mm) thick closed off each end of the central citadel. The KCA face-plates of the main gun turrets were 15 in (381 mm) thick and their roofs were 6-in (152-mm) non-cemented armour plates, and their sides remained 7 to 10 in (180 to 250 mm) thick. The main armament barbettes were 15 in (381 mm) thick on the sides, but tapered to 12–13.5 in (305/343 mm) closer to the ship’s centreline.

Intended to resist the impact of a 1,000-lb (454-kg) armour-piercing bomb dropped from 14,000 ft (4265 m), the deck protection was identical to that of the ‘King George V’ class and comprised 6-in (152-mm) non-cemented armour over the magazines, a thickness reduced to 5 in (127 mm) over the machinery spaces. The armour continued forward and aft of the citadel at the lower-deck level. Forward, it tapered in steps from 5 in (127 mm) to 2.5 in (64 mm) near the bow. Aft, it protected the steering gear and propeller shafts with 4.5 to 5 in (114 to 127 mm) of armour. Unlike the Germans, French and Americans, the British no longer believed that heavy armour for the conning tower served any real purpose given that the chance of the conning tower being hit was very small, so the forward conning tower had only 3 to 4.5 in (76 to 114 mm) of armour.

The underwater protection, also virtually identical to that of the ‘King George V’ class, comprised of a three-layer system of voids and liquid-filled compartments designed to absorb the energy of an underwater explosion. It was bounded on the inside by the 1.75-in (44-mm) torpedo bulkhead. Both of the inner and outer voids were fitted with pumps to flood them with water to level the ship (counter-flood) in case she began to list. The ‘Lion’ class design had a double bottom with a depth of 4 ft (1.2 m).

Design changes

Construction of the two ships which had been laid down was suspended shortly after the World War II began in September 1939, and the Admiralty took advantage of the time to refine the design in light of war experience in late 1941. The beam was increased to the maximum width of the locks of the Panama Canal to increase the depth and effectiveness of torpedo protection system, and bunkers for almost 1,100 more tons of fuel oil were added to increase endurance. In partial compensation for the additional weight, the thickness of the belt armour was reduced by 1 in (25 mm) except over the magazines, and the aircraft and their facilities were removed. The space in the superstructure freed up by these changes was used to increase the light anti-aircraft armament to nine octuple and one quadruple 2-pdr mounts.

The overall length increased to 793 ft (241.7 m) and beam to 108 ft (32.9 m). The displacement grew to 42,550 tons standard and 47,650 tons deep load. No changes were made to the propulsion machinery, but the speed decreased to 28.25 kt because of the greater displacement. The 4,800 tons of fuel increased endurance to 16,500 nm (30560 km) at 10 kt. The freeboard forward was increased by almost 9 ft (2.7 m), and the radar suite was increased to match that of the battleship Vanguard, then under construction. The additional beam was used to increase the depth of the torpedo protection system amidships from 13.25 ft (4.0 m) to 15 ft (4.6 m). The ship’s crew was estimated at 1,750 officers and men.

Another attempt was started in February 1944 by the DNC to incorporate wartime lessons. Among the proposed changes was the use of an improved 16-in (406-mm) Mk IV gun in a new Mk III turret to fire a heavier shell at a slightly lower velocity, and 12 4.5-in (114-mm) dual-purpose guns in twin mounts as well as nine sextuple Bofors 40-mm guns plus an undetermined number of 20-mm Oerlikon cannon for anti-aircraft protection.

With this ‘Design A’ of 1944 pushing to if not past the edge of what was technically feasible for the time, it was largely abandoned in favour of a simpler ‘Design B’ modification of the 1942 scheme with reduced underwater protection, speed and citadel size in concert with greatly increased freeboard and much of the armour and firepower of ‘Design A’. Two further iterations (‘Design C’ and ‘Design D’) considered alternative ways of saving weight via a reduction of armament or belt thickness, but these were quickly deemed unsatisfactory. ‘Design B’ became the primary focus and seven proposed versions were produced between March 1944 and February 1945, and though design work continued on a spasmodic basis, the British economic situation after World War II meant that work was called to a halt in 1949, so bringing to an end all British battleship design and construction.

Hybrid battleship/carrier?

On 8 January 1941, Rear Admiral Bruce Fraser, Third Sea Lord and Controller of the Navy, asked the DNC to work up a hybrid aircraft carrier based on the ‘Lion’ class hull. Two months later, a sketch design was presented for consideration, but was not approved as while it retained all three main gun turrets, the flight deck was deemed too short to be useful. A revised version with only the two forward turrets was requested, and this was ready by July. At a displacement ranging from 44,750 tons standard to 51,000 tons deep load, the design’s dimensions included a waterline length of 800 ft (243.8 m), beam of 115 ft (35.1 m) and a draught of 29 ft 6 in (9.0 m). The flight deck was 500 ft (152.4 m) long and had a width of 73 ft (22.3 m). The machinery was unchanged, but enlarged bunkerage increased endurance. The armament comprised six 16-in (406-mm) guns in two triple turrets, 16 5.25-in (1330mm) guns and eight octuple 2-pdr mounts. Twelve fighters and two torpedo bombers could be carried. The design was rejected.

Pairs of ‘Lion’ class ships had been planned to be ordered in the 1938, 1939 and 1940 naval programmes. The first pair, Lion and Temeraire, were ordered on 28 February 1939 from Vickers Armstrongs and Cammell Laird respectively. Lion was laid down at Vickers’ Walker, Newcastle upon Tyne shipyard on 4 July while Temeraire preceded her at Birkenhead on 1 June. Contracts for Conqueror and Thunderer were awarded on 15 August to John Brown and Fairfield, but neither were laid down.

After the start of World War II in September 1939, construction continued desultorily until October when it was suspended by the Admiralty for one year to release labour and material for escorts needed to protect merchant convoys. Construction of the 16-in (406-mm) guns and their turrets was continued. The question of construction was raised again on 12 November 1940 and the decision to suspend construction was reaffirmed, and all three ships which had been ordered were cancelled in 1942, though Lion’s keel was not scrapped until after the war. Only four 16-in (406-mm) guns were completed, and no turrets were completed.

The German ‘P’ class pocket battleship

The ‘P’ class was planned as a group of no fewer than 12 heavy cruisers to succeed the three ‘Deutschland’ class cruisers, known to the British as pocket battleships, in the long-endurance commerce raiding role. Work on the type began in 1937 and continued until 1939, and in this time no fewer than nine designs were considered. The final design was was for a type to be armed with six 11-in (280-mm) fast-firing guns in two triple turrets, as in the preceding ‘Deutschland class. In the German nomenclature of the time, the ships were designated as Panzerschiffe (armoured ships), and given the preliminary names P1 to P12. The core design was in essence an improved version of that developed for the preceding ‘D’ class cruisers, which had been cancelled in 1934. Although the ships were assigned to yards, construction never started as the design was superseded by that of the ‘O’ class battlecruiser.

During the early 1930s, Adolf Hitler launched a major rearmament effort in Germany while also signing the Anglo-German Naval Agreement of June 1935, which allowed Germany to enlarge its navy to 35% of the strength of the Royal Navy, and thereby effectively overcame the strictures imposed of the German navy by the Treaty of Versailles in 1919.

Regarding the German rearmament, historian Adam Tooze states:

“The original programme from 1933 onwards is still framed within the fairly conventional parameters of German armaments thinking in the 1920s. So they have a staggered programme under which the first phase is to build a defensive fighting force, and they set a timeframe of about four years for that, and then in the second phase they want to build defensive capacity which then, over the course of 1933-34, gets defined as Panzer divisions. These are then incorporated into the armaments build up programme.”

This led to a decision, taken in 1937, to construct ships of an improved ‘Deutschland’ class type. This led, in the same year, to the start of work on the new type. After consideration of many basic designs, that selected for full development was the ‘P’ class with a 19,685-ton displacement, maximum speed of 34 to 35 kt, and armament of six 11-in (280-mm) guns in a pair of triple turrets.

By 1938 it had become clear to Admiral Erich Raeder, commander-in-chief of the German navy, that the aggressive nature of Hitler’s foreign policy would inevitably bring Germany into conflict with the UK, and accordingly came to the conclusion that a significantly larger force of armoured ships would be necessary to undertake a successful commerce-raiding campaign against the British merchant marine. Raeder’s intention to fight a commerce war against the UK lay at the heart of the ‘Z-Plan’ finalised early in 1939, and which included 12 ‘P’ class ships. The design work on the new ships was undertaken in parallel with that on the planned ‘O’ class battlecruiser. Experiments were conducted on at least nine different design proposals between March 1938 and December 1939, and these proposals varied somewhat in terms of dimensions as well as armament, and some of the designs featured nine 11-in (280-mm) guns in three triple turrets.

Length/beam ratio

The design team had to overcome many problems in the design of these ships, the most taxing of them pertained to the armour protection. The required maximum speed of 34 kt meant that the minimum length had to be increased from 711 ft 11 in (217.0 m) to 752 ft 11 in (229.5 m). It also meant that the beam could be a minimum of 82 ft 0 in (25.0 m) unless a Diesel propulsion arrangement, like that of the ‘Deutschland’ class ships, was desired: this would add 6 ft 7 in (2.0 m) to the beam. Unfortunately for the designers,, the widening of the beam meant that a still longer hull was needed to maintain hydrodynamic efficiency by the provision of the designed length/beam ratio. All of this complicated the protection arrangements, as more armour was needed to cover the longer length and widened beam. Eventually it was deemed impossible to include a Diesel propulsion arrangement on the 19,685-ton displacement.

Initially, 12 ships of the ‘P’ class were ordered from a number of German yards including Deutsche Werke in Kiel, Blohm & Voss in Hamburg, and the KM yard in Wilhelmshaven. However, the ‘Z Plan’ was then trimmed in ambition and the number of Panzerschiffe was reduced to eight. This caused several of the contracts to be redeployed among the various yards, and the keel of P1 was to be laid on 1 February 1940. The revised version of the ‘Z Plan’, approved on 27 July 1939, then removed the ‘P’ class ships from the construction queue, and instead it was decided to build only the ‘O’ class battlecruisers.

The design of the ‘P’ class ships included a waterline length of 731 ft 8 in (223.0 m) and overall length of 754 ft 7 in (230.0 m). The beam was 85 ft 4 in (26.0 m) and the designed draft was 23 ft 7 in (7.2 m) increasing to 26 ft 3 in (8.0 m) at full load. The ships were to have been fabricated using the longitudinal frame/stringer method, largely in welded steel. The hull was to have incorporated 13 watertight compartments and a transom stern. The ships were to have been equipped with two catapults and two Arado Ar 196 floatplanes. The protection scheme was to have been based on the used of KCA (Krupp cemented steel), but its details were never finalised. Known figures include a main armoured deck 2.75 in (70 mm) thick with 3.93-in (100-mm) sloping deck armour and 0.7-in 20-mm) thick upper deck armour. The two main barbettes were of armour between 3.15 and 3.93 in (80 and 100 mm) thick. The belt was 4.72 in (120 mm)) thick over vital areas and tapered to 1,575 in (40 mm) in less critical areas.

The propulsion arrangement was based on 12 MAN 9-cylinder double-acting two-stroke Diesel engines together providing 165,000 shp (123075 kW): these engines were grouped in four sets of three, and each drove one of the four shafts. The ships were designed to carry 3,545 tons of fuel oil, but were capable of storing up to 4,920 tons. At a cruising speed of 13 kt, this provided a maximum range of 25,000 nm (46300 km) declining to 15,000 nm (27780 km) at 19 kt.

The Main armament was to have been six 11-in (280-mm) guns in two triple turrets, one fore and one aft, but it is not known whether these guns were to have been the same SK C/28 guns as carried by the ‘Deutschland’ class ships. The armament scheme also included four 5.91-in (150-mm) guns in two twin turrets, also mounted on the centreline fore and aft. The forward 11-in (28-mm) turret was to have been superfiring over the forward 5.91-in (150-mm) turret, and this arrangement was to have been reversed for the after pair of turrets. The 5.91-in (150-mm) twin turrets were Drh L. C/34 mounts of the type also used in the ‘Bismarck’ class battleships and ‘Scharnhorst’ class battlecruisers. The turrets provided an elevation arc between -10° and +40°; the latter providing a maximum range of 24,060 yards (22000 m).

The proposed anti-aircraft armament was decidedly light: four 4.13-in (105-mm) and four 37-mm guns. Each ships was also to have been fitted with six 21-in (533-mm) submerged torpedo tubes.

The German ‘H-39’ Class Battleship

When the ‘Z-Plan’ was authorised by Adolf Hitler on 18 January 1939 for the upgrade of the German Navy on the basis that World War II would not be triggered until 1942, its heavyweight core was six ‘H’ class battleships. In its initial form, the new type of battleship was to be of the ‘H-39’ variant: in essence, an enlarged ‘Bismarck’ class battleships with 406-mm (16-in) guns. Then, given Hitler’s belief that ‘bigger is better’, the ‘H-39’ design was upgraded to the ‘H-42’ class with eight 42-mm (16.54-in) weapons, and then there followed two more grandiose variants as the ‘H-42’ and ‘H-43’ classes with eight 480-mm (18.9-in) guns, and finally the preposterous ‘H-44’ class with eight 508-mm (20-in) guns to create a ship of 129,000 tons with a length of 1,131 ft 11 in (345.0 m). Most of the designs had a maximum speed of greater than 30 kt.

As a result of the outbreak of World War II in September 1939, however, none of the ships were built, and only first two ‘H-39’ class ships were even laid down, on 15 July and 1 September 1939 at the Hamburg yard of Blohm und Voss and Bremen yard of Deschimag (A. G. Weser) respectively. The little work which had been completed by that time was then brought to a halt, and the incomplete keel structures remained on their slips until November 1941, when the Oberkommando der Marine ordered diversion to other purposes. Contracts for the other four ‘H-39’ class ships had been awarded, but no work on them had been undertaken before they were cancelled.

The earliest design studies for the Schlachtschiff ‘H’ (battleship ‘H’) were undertaken in 1935, and were near-repeats of the early designs for the ‘Bismarck’ class ships, armed with 13.78-in (350-mm) guns. Then intelligence reports that the Soviets were planning the ‘Sovetsky Soyuz’ class with 14.96-in (380-mm) guns prompted the Germans to increase the calibre of the main armament to the same calibre on 5 October 1936. At the end of this month, the Oberkommando der Marine issued a requirement for a 35,000-ton ship armed with eight 380-mm guns, capable of 30 kt and possessing a radius of action at least equal that of the ‘Deutschland’ class pocket battleships.

Work on the design which was designated as the ‘H-39’ class began in 1937. The design team were ordered to create a new battleship altogether superior to that of the ‘Bismarck’ class and with a larger-calibre main armament to match that of any battleship built by a potential adversary. It appeared that Japan would not ratify the 2nd London Naval Treaty, which would permit the treaty’s signatories to increase main armament calibre to 16 in (406 mm) and, as a result of the Anglo-German Naval Agreement of 1935, Germany was considered to be party to the other international naval arms limitation treaties. Japan refused to sign the 2nd London Naval Treaty in April 1937, and soon after this the US Navy announced that it planned to arm its new ‘North Carolina’ class battleships with 16-in guns.

Hitler demanded guns larger in calibre than those of any possible adversary, but guns of such a calibre would required displacements of more than 80,000 tons and drafts too great to allow the ships to use Germany’s ports unless these latter be significantly dredged. Admiral Werner Fuchs, responsible for the OKM staff section in the OKM was tasked with fixing the operating requirements for the ship. He managed to persuade Hitler that the 16-in gun was the right for the ‘H-39’ design. In 1938 the OKM developed the ‘Plan Z’ programme of construction, and in this, six ‘H-39’ class battleships constituted the core.

Jack, a historian and author at War History Online, states:

“In 1938 Hitler decided to build a fleet capable of challenging the Royal Navy, in the event of war with Great Britain. He asked the Kriegsmarine to provide plans for such a fleet. Subsequently, it was decided to embark on a large-scale re-building of the German Navy.”

Limited construction options

Only four German yards possessed slip large enough to build the new battleships. The OKM issued orders for construction of the first two ships as ‘H’ and ‘J’ on 14 April 1939. The contracts for the other four ships (‘K’, ‘L’, ‘M’ and ‘N’) were issued on 25 May. The ships received no names, and no official name proposals were made.

The final ‘H-39’ class design was for a ship 911 ft 5 in (277.80 m) long overall with a waterline length of 872 ft 8 in (266.00 m), beam of 121 ft 5 in (37.00 m) and typical draft of 32 ft 10 in (10.00 m) increasing at a full-load displacement of 62,600 tons, to 36 ft 9 in (11.20 m). The hull was to be based on transverse and longitudinal steel frames, and was to be almost wholly welded rather than riveted. The hull comprised 21 large watertight compartments and a double bottom extending over 89% of the keel’s length, and four bilge keels were to be fitted for enhanced stability. The estimated complement was 2,600 officers and men.

Propulsion was to be provided by 12 MAN nine-cylinder two-stroke Diesel engines. These were disposed in groups of four on three shafts to drive three-blade propellers with a diameter of 15 ft 9 in (4.80 m). Back-up was provided by four auxiliary boilers: two of these were to be oil-fired and were located between the central transmission rooms, and the other two were a pair of exhaust gas boilers, and these were placed above them. The propulsion plant was to deliver 165,000 shp (123024 kW) for a designed speed of 30 kt. A fuel capacity of 8,600 tons of Diesel oil would provide for a range of 7,000 nm (8,100 miles; 13000 km) at 28 kt, or 19,200 nm (22,100 miles; 35600 km) at 19 kt.

Orthodox armament layout

The main armament was to comprise eight 406-mm SK C/34 guns in four twin turrets disposed in fore and aft pairs, and for these, 960 rounds of ammunition were to be carried. The turrets provided for a gun elevation of 30° to fire the 2,271-lb (1030-kg) at a muzzle velocity of 2,657 ft (810 m) per second for a maximum range in the order of 39,810 yards (36,400 m). The rate of fire was expected to be two rounds per minute per gun.

The secondary armament was to comprise 12 4.92-in (150-mm) SK C/28 guns mounted in six twin turrets. The turrets provided for a gun elevation of 40° to fire the 99.9-lb (45.3-kg) shell at a muzzle velocity of 2,871 ft (875 m) per second for a maximum range in the order of 25,155 yards (23000 m). The secondary armament was intended primarily for defence against surface threats.

The tertiary armament was to comprise 16 4.13-in (105-mm) SK C/33 Flak guns in twin mountings for long-range defence against aircraft. Unlike those mounted on the ‘Bismarck’ class battleships and ‘Scharnhorst’ class battle-cruisers, these guns were to be in armoured mountings to provide their crews with protection against shell fragments, debris and strafing attacks. The new turrets also provided faster rates of training and elevation than the earlier open mountings. Close-range air defence was the task of a battery of 16 37-mm SK C/33 and 24 20-mm SK C/38 cannon. The 37-mm weapons were to be located in eight twin mounting, and the 20-mm cannon in six Flakvierling quadruple mountings. The 37-mm cannon were closely grouped amidships and shared one ammunition hoist.

The design also included six 533-mm (21-in) torpedo tubes, all submerged in the bow and angled off the centreline by 10°.

Uninspired protection

The designers envisaged that the ‘H-39’ class ships would engage in combat at comparatively short ranges, and therefore opted for a basic armour scheme of the type which had been used on German battleships since the ‘Nassau’ class dreadnought battleships of 1907. The main belt was vertical and attached directly to the side of the hull, and was of KCA (Krupp cemented steel armour) 11.8 in (300 mm) thick over its central section covering the ammunition magazines and machinery spaces, declining to 8.66 in (220 mm) thick fore and aft of this; the bow and stern had no main-belt protection. The upper side belt was 5.71 in (145 mm) thick. It has been estimated that the main belt would have provided protection against 16-in projectiles from ranges between 12,030 and 22,965 yards (11000 and 21000 m), but that the upper belt could have been penetrated by 16-in projectiles at any range, which would have left the ships vulnerable above the waterline.

The underwater protection was essentially similar to that of the ‘Bismarck’ class. A 1.77-in (45-mm) torpedo bulkhead of Wotan Weich steel backed the side armour and provided protection against underwater weapons. The bulkhead was placed some 18 ft (5.5 m) from the side of the hull, though in the area abreast the turrets and further toward the bow and stern, this spacing could not be maintained, the distance between the bulkhead and the side of the ship there being 10 ft 8 in (3.25 m) in these areas: the reduction of the spacing was offset in these area by a thickening of the armour to 2.36 in (60 mm).

Two armoured decks of Wotan Hart steel protected the ships from plunging fire and bombs. The upper deck was 3.12 in (80 mm) thick above the magazines and 1.98 in (50 mm) thick over the machinery spaces. The main armoured deck was 4.72 in (120 mm) and 3.93 in (100 mm) thick respectively, although across its outboard sloped sections, the thickness was increased to improve the protection over the ship’s vital spaces. Over the magazines and machinery spaces the sloped armour was 4.92 and 4.72 in (150 and 120 mm) respectively.

The main turrets each had 15.16 in (385 mm) fronts, 9.45 in (385 mm) sides, 5.12 in (130 mm) tops (5.1 in) and 12.8 in (325 mm) backs. It is worth noting that the relatively considerably thickness of the turrets’ backs helped to move the turrets’ centre of gravity farther to the rear, thereby helping to balance the turrets and improve their operation. The barbettes on which the turrets were mounted were armoured with 14.37 in (365 mm) face-hardened steel above the upper armour deck and 9.45 in (240 mm) non-cemented steel below that deck. The 150-mm gun turrets had 3.94 in (100 mm) thick faces, 1.575 in (40 mm sides and 1.38 in (35 mm) tops, and their barbettes had 3.12 in (80 mm) protection. The 105-mm mountings were protected by 0.79 in (20 mm) gun shields. The forward conning tower had 13.78 in (350 mm) KCA sides and a 7.97 in (200 mm) roof composed of non-cemented steel. The rear conning tower had 3.93 in (100 mm) sides and roof, the former of KCA and the latter of non-cemented steel.

Tinkering with the concept

Early in July 1940 Hitler ordered the navy to examine new battleship designs and the manner in which wartime experience might be incorporated. A study completed on 15 July contained several recommendations for the ‘H’ class ships, including an increase in freeboard and a strengthening the horizontal protection. In order to maintain displacement and speed, and also to accommodate the increased weight of the additional armour protection, the design staff drew up an informal design which removed one of the main battery turrets to save weight; increased the power of the propulsion machinery to maintain speed at the original figure, and replaced the original Diesel propulsion arrangement with a hybrid Diesel and steam turbine arrangement. The design staff also prepared a second design which retained the fourth turret and accepted a much higher displacement, but incorporated the hybrid propulsion arrangement. These studies were abandoned in 1941 after Hitler had come to the decision to halt further battleship construction until after the end of the war. The design staff therefore attempted to improve the protection of the ‘H’ class ships.

The 1940 designs did not form part of the design chain that resulted in the ‘H-41’ to ‘H-44’ designs.

Fighters which did not make the cut – the Lockheed F-90

With its P-80 Shooting Star firmly established in production during 1945, in July of that year Lockheed was able to commit its development team to the start of work on a more advanced fighter. The first step in this process was the creation of a number of conceptual designs, and these eventually totalled more than 65. The concept designs drew heavily on German research data captured by the US forces in the closing stages of World War II. There was a particular emphasis placed on the use of swept wings for improvement of transonic performance, and covered a large part of the configuration spectrum including W-planform or conventionally swept wings, butterfly or conventional tails, and a powerplant of up to three engines (this last detail comprised one turbojet unit in the fuselage and one turbojet unit at each wing tip).

This basic programme started to bear fruit in 1946 when the US Army Air Forces, which became the US Air Force during the following year, issued a requirement for a penetration fighter with the primary task of escorting bombers and the secondary task of flying ground-attack missions. The task of creating a turbojet-powered escort fighter was formidable enough in itself, for the provision of adequate range was difficult given the thirst typical of current turbojet engines, but this basic problem was compounded by the USAAF’s failure to issue a definitive specification. As a result, the range requirement was extended from 782 nm (900 miles; 1448 km) to 1,303 nm (1,500 miles; 2414 km) and was then reduced to 521 nm (600 miles; 965.5 km), while the time-to-height requirement was increased drastically from 35,000 ft (10670 m) in 10 minutes to 50,000 ft (15240 m) in 5 minutes.

Revised concept

Lockheed pressed ahead regardless, and in June 1946 received a contract for two XP-90 prototypes which were redesignated XF-90 in June 1948. The company’s initial thinking was directed toward a delta-wing layout in its initial Model 090-32-01 proposal, but wind-tunnel testing of this layout led to a change of heart by Willis Hawkins’s design team, which was supervised by Clarence L. ‘Kelly’ Johnson. Thus the already completed components were scrapped as the design team reworked the XP-90 to the Model 90 standard with conventional but swept flying surfaces including a low-set wing swept at 35° and accommodating the two main units of the tricycle landing gear, a fuselage with a sharply pointed nose, and the powerplant of two Westinghouse J34 turbojet engines. These were axial-flow units whose slenderness permitted a side-by-side installation in the fuselage, where they were aspirated via lateral inlets and exhausted under the tailplane, itself located about one-quarter of the way up the vertical tail surface. The design team was particularly concerned about the high stresses that would be imposed on the airframe during ground-attack missions, and therefore planned the airframe on the basis of the new 75ST high-strength aluminium alloy rather than the more normal 24ST aluminium alloy, and also made extensive use of machined and forged parts. The result was an extremely strong but heavy airframe whose empty weight was 50% higher than that of the competing McDonnell XF-88.

Featuring the powerplant of two XJ34-WE-11 engines, each rated at 3,000 lb st (13.34 kN) dry, the first XF-90 was completed some seven months later than the XF-88, which was therefore already well embarked on its flight test programme before the first XF-90 recorded its maiden flight on 3 June 1949 at Edwards Air Force Base in California, in the hand of Tony LeVier.

Historian, Robert Smith, states in his blog: “Tony LeVier (February 14, 1913 – February 6, 1998) was an air racer and test pilot for the Lockheed Corporation from the 1940s to the 1970s”.

Flight trials revealed that the XF-90 had no major vices but also possessed disappointing flight performance, the latter resulting from the low power/weight ratio due to the combination of a weighty airframe and an indifferent powerplant.

Greater power

To improve the power/weight ratio of the basic XF-90 and thereby enhance its overall performance, Lockheed decided to complete the second aeroplane and also revise the first machine to the XF-90A standard with the afterburning powerplant of two XJ34-WE-15 engines. The more potent powerplant boosted performance to a useful degree (a speed of Mach 1.12 being achieved in a dive), but the XF-90A was still slower than the North American F-86A Sabre that was already in service as the USAF’s primary air combat fighter. In June 1950 the USAF decided that further development should be concentrated on the XF-88, and work on the XF-90A was ended three months later.

The first airframe ended its life as a structural test item, and the second airframe was expended in A-bomb tests. Nothing came of plans to develop an improved version with the powerplant of one Allison J33-A-29, one General Electric J47-GE-21, or two Westinghouse J46-WE-2 turbojet engines.

Specification

Lockheed XF-90A

Type: penetration fighter

Accommodation: pilot on a Lockheed ejection seat in the enclosed cockpit

Armament: six 20-mm M24 fixed forward-firing cannon under the engine air inlets, and up to 2,000 lb (907 kg) of disposable stores carried on two hardpoints (both under the wing with each unit rated at 1,000 lb/454 kg), and generally comprising two 1,000-lb (454-kg) weight free-fall bombs or 5-in (127-mm) HVAR air-to-surface unguided rockets

Equipment: standard communication and navigation equipment, plus a gyro weapons sight

Powerplant: two Westinghouse XJ34-WE-15 axial-flow turbojet engines each rated at 3,600 lb st (16.01 kN) dry and 4,200 lb st (18.68 kN) with afterburning

Fuel: internal 1,225 US gal (1,020.0 Imp gal; 4637.1 litres); external 440 US gal (366.4 Imp gal; 1665.6 litres) in two jettisonable tip tanks; external fuel none; no provision for inflight refuelling

Wing: span 40 ft 0 in (12.19 m); area 345.00 sq ft (32.05 m²)

Fuselage: length 56 ft 2 in (17.12 m); height 15 ft 9 in (4.80 m)

Weights: empty 18,520 lb (8401 kg); normal take-off 27,200 lb (12338 kg); maximum take-off 31,060 lb (14089 kg)

Performance: maximum level speed 580 kt (668 mph; 1075 km/h) at 1,000 ft (305 m); cruising speed 411 kt (473 mph; 761 km/h) at optimum altitude; initial climb rate not available; climb to 25,000 (7620 m) in 4 minutes 30 seconds; service ceiling 39,000 ft (11890 m); maximum range 1,997 nm (2,300 miles; 3701 km) with tip tanks; typical range 912 nm (1,050 miles; 1690 km) with standard fuel