Amphibious Warfare – The DUKW Amphibious Truck

World War II revealed, to an extent hitherto unconsidered and in any event unobtainable by the technology of the period, the very clear advantage of being able to carry men, light weapons and many types of equipment and supplies straight from the landing craft, either beached or lying just offshore, across the assault beach to the forward edge of the beach-head – all without exposing them to small-arms fire and mortar bomb fragments. This need spawned a number of types, both armoured and unarmoured, with tracked propulsion, but there also emerged the desire for an amphibious truck optimised for ferry work. Such a type would provide the great advantage of being able to handle stores without the need for transhipment, especially in the later stages of a landing, when the risks of direct fire from enemy positions were significantly lower and the vehicle could therefore be unarmoured.

The result was the DUKW, generally known as the ‘Duck’, which was an amphibious modification of the 2-ton General Motors CCKW truck used by the US forces. Designed by the naval architecture firm Sparkman & Stephens in partnership with General Motors, the DUKW was used for the movement of men and cargo over land and water and, while providing an unrivalled capability in approaching and crossing beaches during amphibious assaults, it was not created for longevity but rather for hostilities-only service.

The name of the vehicle came from General Motors’ vehicle designation system, in which D indicated the 1942 design year, U the vehicle’s utility nature, K the use of all-wheel drive and W the use of twin rear axles.

Practical validation

The vehicle was designed by Rod Stephens of Sparkman & Stephens, Dennis Puleston, a British deep-water yachtsman living in the USA, and Frank W. Speir, a lieutenant of the Reserve Officers’ Training Corps and graduate of the Massachusetts Institute of Technology. Developed by the National Defense Research Committee and the Office of Scientific Research and Development to provide the capability to resupply units which had just come ashore in an amphibious assault, the resulting type was at first rejected by the armed forces. However, after a US Coast Guard patrol vessel had run aground on a sandbar near Provincetown, Massachusetts, an experimental DUKW happened to be in the area for a demonstration, and was able to rescue the seven men of the patrol vessel’s crew in conditions (60-kt wind, rain and heavy surf) which had prevented conventional craft from achieving the rescue. After this practical validation, military opposition to the DUKW swiftly faded, and further trials confirmed the DUKW’s seaworthiness even on comparatively long passages.

The basis of the DUKW prototype was the AFKWX, a cab-over-engine variant of the CCKW military truck with six-wheel drive. To this basic chassis and propulsion arrangement were added a watertight hull and, in a semi-tunnel under the rear, a propeller and rudder for waterborne propulsion and steering. The final design approved for production in October 1942, after exhaustive trials by the Engineer Special Brigades at Cape Cod, was perfected by a small engineering team of the Yellow Truck & Coach company of Pontiac, Michigan, and the vehicle was built by the GMC division of General Motors, which was still called Yellow Truck and Coach at the beginning of the war.

On land, the topsides of the DUKW were almost 6 ft (1.83 m) above the roadway, but at sea, the freeboard of the laden DUKW could be as little as 1 ft 6 in (0.46 m). These were both deemed drawbacks in the DUKW’s two operating environments, but nonetheless the DUKW was a huge operational success, so the extent that there seemed never to be sufficient DUKW vehicles to satisfy demand despite the production of 21,147 examples by the summer of 1945.

The British ordered 2,000 examples of the DUKW in January 1943, and enough had been delivered by July of the same year for the vehicle to make its operational debut in the ‘Husky’ landings on Sicily. Shepherded by a motor launch, 300 of DUKW vehicles proved very successful later in the campaign when they ferried supplies across the Strait of Messina, and in the ‘Avalanche’ landing at Salerno in September 1943 the US Army’s 105-mm (4.13-in) howitzers were brought ashore in DUKW vehicles so that they could be brought into action far more quickly than would have been the case had they been transhipped from landing craft. The naval commander felt the vehicles’ full value could not be exploited at Salerno to maximum effect because they had been diverted to US Army rather than US Navy service at so early a stage, however, and thinking of this type may have delayed the DUKW’s use in the US Navy-led commands of the Pacific theatre.

Pacific service

The DUKW did not come into full service in this theatre before February 1944, when 60 of the vehicles were first used to land army howitzers and another 40 to land supplies. In this ‘Flintlock’ operation at Roi and Namur in the Marshall islands group, the DUKW vehicles were carried on the vehicle (upper) decks tank landing ships and driven down the interior ramp to the tank (lower) deck for launching over the bow ramp while the tank landing ships were still offshore. The DUKW vehicles landed their cargoes of guns, hoisting these out with A-frames and lifting tackles fitted to some vehicles which backed against others for unloading. These then returned for stores (two cargo nets or preloaded pallets per vehicle) to be delivered in bulk from the tank landing ships. On other occasions, DUKW vehicles yoked in pairs by a removable platform were used to carry light vehicles ashore.

The cargo area, which could be covered by bows and a canvas tilt, measured 12 ft 6 in (3.81 m) in length and 6 ft 9.75 in (2.08 m) in width.

The marshalling of DUKW groups, which was undertaken in the British forces by the Royal Army Service Corps using motor boats and in the US forces by LCVPs (Landing Craft, Vehicle Personnel), was difficult in rough weather – when many of these unwieldy craft foundered. Once ashore its large wheels allowed the DUKW to negotiate rough terrain. Like many other vehicles, however, the DUKW required bulldozer aid in the volcanic sand of Iwo Jima in the ‘Detachment’ of February 1945.

Supply vehicle

The DUKW was not designed as a fighting vehicle, but a pair of the first DUKW trucks in the Pacific theatre were adapted by US Army engineers to carry 120 4-in (102-mm) rockets with a range of 1,100 yards (1005 m). These were then fired to cover troops as their assault craft carried them to within a distance of 150 yards (140 m) of the beaches at Arawe on New Britain island during the ‘Director’ landing of December 1943.

DUKW companies of the British army, US Army and US Marine Corps were involved in all the major Allied landings after 1943, and also in a host of river crossings.

The DUKW was complicated to maintain, and the two US Army and one US Marine Corps DUKW companies in ‘Detachment’ had to have 200 spare shafts and propellers urgently flown from Hawaii before that operation. Although some DUKW vehicles were carried in the davits of transport vessels in the course of a few operations, it was the close link between tank landing ships and all Allied amphibious vehicles which made possible the vehicles’ use in great numbers.

The DUKW was powered by a 269-cu in (4408 cm³) General Motors water-cooled six-cylinder inline engine delivering 94 hp (70 kW). The vehicle weighed 6.5 tons 13,000 lb (5895 kg) empty and 18,600 lb (8435 kg) loaded, and its performance included a speed of 50 mph (80 km/h) on roads and 5.5 kt on water, and a range of 400 miles (645 km) on roads at 35 mph (56 km/h) and 50 nm on water. The vehicle was 31 ft (9.45 m) long, 8 ft 2.875 in (2.51 m) wide, 7 ft 1.375 in (2.17 m) high with the folding canvas top down and 8 ft 9.5 in (2.68 m) with the folding canvas top up. A ring mount was fitted on all DUKW vehicles during manufacture, but only about 25% of the vehicles were equipped with a 0.5-in (12.7-mm) Browning heavy machine gun. Operated by a one- or two-man crew, the DUKW could carry 25 troops, or 12 litters, or 5,000 lb (2268 kg) of cargo.

The DUKW was not created as an armoured vehicle, being plated with steel sheet between 1/16 and 1/8 in (1.59 and 3.175 mm) thick to keep the weight to a minimum and thereby maximize buoyancy. A high-capacity bilge pump system kept the vehicle from sinking if the thin hull was breached by holes up to 2 ins (51 mm) in diameter. The DUKW was the first vehicle to provide the driver with the capability to vary the tyre pressure from inside the cab with the use of a device created by Speir: the tyres were fully inflated to run on hard surfaces such as roads, and were less inflated to run on softer surfaces, especially beach sand. This added to the DUKW’s great versatility as an amphibious vehicle.

Of the 21,147 DUKW vehicles to emerge from the production line, 2,000 were supplied to the UK, 535 to Australia, and 586 to the USSR, which built its own version as the BAV-485 after World War II.

Amphibious Warfare – The Tank Landing Ship (III)

For a transoceanic passage, the LST Mk 2 could carry one landing landing craft (LCT Mk 5 or LCT Mk 6) for side-launching, and this was a feature which was sometimes also used for the carriage of LCTs to the vicinity of an amphibious assault.

In LST beaching operations, a satisfactory manner to bridge the gap between the forward edge of the ramp and the beach was not evolved until the ‘Husky’ landing on Sicily in July 1943; an operation which saw the introduction of pontoon causeways designed by a US naval officer, Captain John N. Laycock. Carried in sections on each side of the LST, these ‘roadways’, measuring between 75 and 140 ft (22.9 and 42.7 m) in length, were dropped just off the assault beach and then floated inshore to overlap, forming a shallow-water causeway of adjustable length and with the ability to ride the shore-line waves. When first used, these causeways had been towed in astern of LSTs, as indeed were LCT Mks 5 and 6 and other equipment when the situation dictated it, but as far as possible such cargoes were carried rather than towed because of the difficulties caused to the towing ship’s handling. The causeways were used in all the Allied theatres where amphibious operations were undertaken, although experiments with coconut log causeways were made in the early phases of the US Navy’s amphibious assaults in the Pacific theatre. It is worth noting that in that theatre, such as Operation Galvanic against Japanese-held islands in the Gilberts group (including Tarawa), LSTs carried multi-pontoon sections for floating jetties which were designed for assembly by US construction battalions into a pier alongside a reef. Two months later, at the ‘Shingle’ landing at Anzio in western Italy during January 1944, follow-on LSTs beached at the seaward edge of bulldozer-prepared mounds to supply the landed force with tonnages so great that for a short time Anzio could be rated as one of the largest ‘ports’ in the world: one of the problems which had to be overcome here was the fact that the disturbances caused by the LSTs’ propellers raised sandbanks which all types of landing craft and ships had to cross on the surge.

Complex offloading process

The LST carried so much more cargo than the LCT that the process of unloading it took considerable time, even when the causeway was used. In the ‘Cherryblossom’ landing in Empress Augusta Bay on Bougainville island in the Solomons group during November 1943, for example, the LST was in the early stages of its use in the Pacific and South-West Pacific campaigns, loads of vehicles and cargo were as much as 1,400 tons, which was 200 tons more than the designed beaching load and double the average load: once the vehicles had been driven out of the LST onto the beach, the bulk cargo was offloaded by trucks, which had to be backed into the cargo space and then loaded by hand. This was a process which could consume as much as eight hours even with an average cargo. Many vehicles, and most especially the two-wheel drive British trucks used in operations such as the ‘Avalanche’ landing at Salerno on the west coast of Italy in September 1943, could not be driven quickly over the 1-ft (0.3-m) drop off an LST ramp even when plank extension ramps were used, so an unloading time of eight hours was deemed not to be unreasonable. Faster times were achieved by manhandling the stores ashore, and in the course of the ‘Postern’ landing of September 1943 at Finschhafen on the north-east coast of New Guinea, 100 men were carried to clear LSTs of an hourly average of 20 vehicles and 50 tons of bulk cargo.

Experiments with other offloading concepts were undertaken: in one, a 50-ft (15.2-m) gap was left on the tank deck between cargo stowed aft and the other bulk cargo so that once the vehicles had landed from the tank deck, seven trucks at a time might be used for offloading in a process coordinated with the offloading of light vehicles from the vehicle deck. This allowed the process of cargo-handling to continue as these were driven ashore.

A method of accelerating the cargo-landing process in order to meet the desired one-hour limit for discharging as LST was to preload trucks or trailers. This was trialled at Cape Torokina in Empress Augusta Bay but deemed to be only partially successful as the space taken by the vehicles seriously reduced the overall load capacity of LSTs of the second echelon.

Palleted cargo loads

By 1945 the bulk cargo loads were often carried on pallets, with the LSTs each carrying specific stores and materials for amphibian vehicles (such as LVT tractors and DUKW trucks) to collect as though they were proceeding from bay to bay of a floating warehouse. Other LSTs were employed to carry the amphibian vehicles to the dropping zone, although as these exceeded the 10-ton vehicle weight limit for which the vehicle deck was stressed they had to be carried on weight-spreading chocks or in the tank hold. Vehicles of this type could be driven down the inboard ramp to offload through the tank deck, which was a process simpler than the use of the lift of early LSTs, which needed special maintenance and could simply become jammed. This latter required the LST with the jammed lift to proceed alongside another ship to drive vehicle-deck cargoes across to the other LST’s vehicle deck and thence its lift.

During the ‘Detachment’ amphibious descent on Iwo Jima in 1945, in addition to their primary load of amphibian tractors, the LSTs carried the stores which would be required as soon as the assault waves of US Marines had gone ashore: these immediate-use stores included drinking water in vehicle-towed trailers, two ‘units of fire’ (ammunition) for each battalion, concertina wire; 2,000 C and K rations of pre-cooked wet and survival food, 1,200 D rations of alternative survival food, and petrol and lubricating oil.

LSTs were also used to deliver a host of other equipment items needed as soon as the assault troops had a toehold on a beach: Marston perforated steel matting (8.5 miles [13.67 km] at Iwo Jima), four- and six-wheel drive trucks, vehicle service trailers, mobile cranes, bulldozers, and anti-aircraft guns. The amphibian tractors were the first vehicles to come ashore, and then trucks were loaded from the cargo hold in a sequence carefully pre-planned to ensure that the traffic was sent to different dumps and this caused no traffic jams of the type that were inevitably subjected to artillery attack. The entire scheme to offload the LSTs had to be created and finalised before the start of the operation so that the bulk cargo could be loaded and stowed in the right sequence to ensure the speediest possible tactical offloading.

A typical LST load was 26 six-wheel drive trucks, six four-wheel drive trucks, four Jeeps, one four-wheel machine shop trailer, one 5-ton crane, two prime movers, two 40-mm Bofors anti-aircraft guns on their carriages, and ‘dead’ cargo in the forms of 115 tons of rations, 200 tons of fuel in drums, 40 tons of ammunition and 12 tons of  ‘organic’ gear. This entire load had, of course, to be fully secured, as for any sea passage with chocks and chains to ensure that nothing could shift as the LST rolled and pitched.

It is also worth noting that several LSTS were fitted with a short flight deck and Brodie landing gear to allow them to operate Stinson OY-1 light artillery spotter aircraft.

The general practice in many Pacific amphibious operations was for a specified number of LSTs, once unloaded, to remain off the assault beach for use as casualty clearing stations for wounded lifted from the assault beach before being passed farther offshore to hospital ships. In the North-West European theatre, moreover, several LSTs were outfitted with railway tracks so that they could deliver rolling stock to France, where a very large proportion of the national equipment had been destroyed by Allied air attacks to prevent its use by the Germans to reinforce their forces facing the Allied ‘Overlord’ invasion of June 1944.

Amphibious Warfare – The Tank Landing Ship (II)

When the LST Mk I was being designed, the concept of distant raiding still featured strongly in British minds and thus influenced the design, but by the winter of 1941 the distant raiding concept had been largely replaced by a fear of invasion. At their first meeting at the Atlantic conference in Argentia, Newfoundland, during August 1941, President Franklin D. Roosevelt and Prime Minister Winston Churchill confirmed the British Admiralty’s initial concept, and it was decided that US yards were to build seven LST Mk I vessels. In November 1941, however, a small Admiralty team reached the USA to pool ideas with the US Navy’s Bureau of Ships about the development of ships and the possibility of building further LST Mk I vessels in the USA. The meeting decided that the Bureau of Ships would design these vessels, and US yards would construct them so that British yards could concentrate on building and repairing ships for the Royal Navy and British merchant marine.

The specification called for vessels capable of crossing the Atlantic on their own bottoms, and the original title given to them was Atlantic Tank Landing Craft, but then the idea of calling a vessel 300 ft (91 m) long a craft was seen as inappropriate and the type was reclassified as the Landing Ship, Tank Mk II, or LST Mk II (later LST Mk 2), able to make long ocean passages but still provide the ability to land heavy tanks directly onto an assault beach. The details of the design were worked out by the British Department of Naval Construction and US Bureau of Ships in the winter of 1941/42, and the first ships were ordered in February 1942. Roosevelt authorised the construction of 200 LST Mk 2 vessels (only a little more than half of these entered British service) for delivery under Lend-Lease arrangements, together with 200 examples of the LCT Mk 5, and the same numbers for the US Navy. Roosevelt also approved the construction of 14 dock landing ships, seven of them for the British in replacement for the seven cancelled LST Mk I vessels.

The LST Mk 2 design incorporated elements of the first British LCTs from their designer, Sir Rowland Baker, who was part of the British delegation. These elements included sufficient buoyancy in the ships’ sidewalls that they would float even with the tank deck flooded. And while the LST Mk 2 had only a slightly greater speed than the LST Mk I, it possessed a similar load capability while drawing only 3 ft (0.9 m) forward when beaching.

First draft

Within a few days, the Bureau of Ships’ John C. Niedermair had drafted a ship of awkward appearance but which nonetheless became the basic design for the more than 1,000 LST Mk 2 ships built in World War II. To meet the conflicting requirements of deep draught for ocean travel and shallow draught for beaching, the design included a ballast system which could be filled for ocean passage and pumped out for beaching operations. The incorporation of an anchor and variable-power mechanical winch system also enabled the ship to kedge itself off the beach. Other features were a vehicle lift between the vehicle and tank decks and fan-trunk ventilation to allow vehicle engines to be run on the enclosed tank deck.

The rough draft was sent to the UK on 5 November 1941 and was immediately accepted. It then became the subject of the first British Lend-Lease order for 200 ships. The initial draft was for a ship 280 ft (85.34 m) long, but in January 1942 the Bureau of Ships discarded this draft for that of a ship 290 ft (88.39 m) long, and within a month there emerged the definitive plan for a type 328 ft (99.97 m) long with a beam of 50 ft (15.24 m) and minimum draught of 3 ft 9 in (1.14 m). This helped to distribute the ship’s weight over a larger area, and thereby made possible a shallower draught in landing trim.

The LST Mk 2 was optimised for the carriage of a 2,100-ton load of tanks and vehicles, and the enlargement of its dimensions made it possible for the design team to widen the bow door opening and ramp from 12 to 14 ft (3.66 to 4.27 m) and thus allow a larger number of vehicles type to be accommodated.

As the dimensions and weight of the LST increased, the thickness of the steel plating was increased from 0.25 in (6.4 mm) to 0.375 inch (9.5 mm) on the deck and sides, with 1-in (25-mm) plating under the bow. By January 1942, the first LST Mk 2 scale model was being tested at the David Taylor Model Basin in Washington, DC. The trials were completed in three months.

Revised tank deck

In the LST Mk 2, the tanks were carried just above the water-line level and parallel to it along the ship’s length. This arrangement provided convenient machinery space aft for the two locomotive-type Diesel engines below the tank deck. At the bow was a ramp of the LCT type behind two outward-opening vertical doors. Major modifications were made from LST-513, and in all but one of the subsequent ships there was a ramp rather than a lift between the vehicle and tank decks. From LST-542 the payload was reduced to allow for increased armament, a seawater distillation plant with a capacity of 4,000 US gal (15140 litres) per day, and other added weight. Thus the draught of both basic variants was kept within the same parameters. The loading of these ships was varied to suit either an ocean passage or the shallower draught needed for beaching. With 33.3 tons per inch immersion, the ships carried 1,875 tons (1,695 tons in the ‘LST-542’ class) for an oceangoing draught of 8 ft (2.44 m) forward, and with 500 tons for landing they drew 3 ft 1 in (0.94 m) at the bow. When light, they drew only 1 ft 6 in (0.46 m). A causeway carried outboard of the sides allowed vehicles to land in shallow water on a beach after it had been floated into position.

The main feature of the LST Mk 2 was the large tank deck, which was 288 ft (87.78 m) long, 30 ft (9.14 m) wide and 11 ft 3 in (3.43 m) in clear height from the deck to the underside of the electric lights, giving a volume of 92,765 cu ft (2627 m³) after allowing for ship’s equipment. The size of the deck made the handling of any vehicle type, including the bulldozer, comparatively straightforward. There were, of course, considerable fire hazards as petrol- and ammunition-laden vehicles were moved through an assault area swept by all manner of projectiles, but there were sprinklers in the hold and fire mains on the upper deck, and later US Navy ships were outfitted with water curtains and drenching equipment.

Troop accommodation was spacious by the standards of major landing craft. The troops had multiple two- and three-tier bunks with heads and a seawater shower in each accommodation area in the sidewalls. The crew was accommodated on the vehicle deck level abaft the superstructure.

The invasion of Europe and the defeat of Japanese forces were entirely dependent on the rapid building of the Allied armadas in which the LST played a key role. The date of the Normandy landings was not fixed until the supply of such vessels had been assured, and Pacific operations could not have been mounted so rapidly and on so large a scale without LSTs. More than 1,000 LST Mk 2 ships had been built before the end of the war, many of them built in very short times even by comparison with the records set for all manner of armament manufacture at that period. The first 30 completed at the Baltimore, Maryland, yards of Bethlehem Steel were delivered in 10 months, only 19 days outside the contract schedule, yet the LST took more man-hours to build than a ‘Liberty’ ship which was about five times larger.

Massive production effort

The construction programme rapidly gained great momentum. So high a priority was assigned to LST construction, for instance, that the previously laid keel of an aircraft carrier was hastily removed to make room for several LSTs to be built in her place. The keel of the first LST was laid down on 10 June 1942 at Newport News, Virginia, the first standard LSTs were floated out of their building dock in October, and 23 were in commission by the end of 1942.

The LST programme had several unique aspects. As soon as the basic design had been developed, contracts were let and mass production started even before the completion of a test vessel. Preliminary orders were rushed out verbally or by telegram, telephone and air mail letter. The ordering of certain materials actually preceded the completion of the design work. While many heavy equipment items such as main propulsion machinery were furnished directly by the US Navy, other procurement was centralised in the Material Coordinating Agency so that the programme’s several builders would not have to bid against each other.

The need for LSTs was so urgent that the programme enjoyed a high priority throughout the war. Since most shipyards were located on the USA’s coast, and used primarily for the construction of large, deep-draught ships, new construction facilities for LSTs were established on inland waterways, some of them converted from heavy industry plants such as steel fabrication yards. The movement of the completed vessels from yard to sea was complicated by the presence of many bridges across waterways, but large numbers of these were modified by the US Navy to permit passage, and a special command controlled the movement of newly constructed ships to coastal ports for fitting out.

Of the 1,051 LSTs built during the war, 670 were supplied by five Midwest ‘cornfield shipyards’. The Dravo Corporation’s facility at Neville Island, Pennsylvania, was the lead shipyard for the project, building 145 vessel and developing fabrication techniques which significantly reduced construction time and cost across all the LST shipyards. The Missouri Valley Bridge & Iron Co. built the more LSTs than any other yard, with 171 constructed at Evansville, Indiana. Chicago Bridge and Iron’s yard at Seneca, Illinois, launched 156 ships after being selected for its reputation and skills, especially in welding. The American Bridge Company of Ambridge, Pennsylvania, built 119.

Modest improvements

By 1943, the time needed to build an LST had been reduced to four months, and by the end of the war to two months. Considerable effort was expended to hold the ship’s design constant in order to streamline production, but by mid-1943 operational experience demanded the incorporation of changes in new ships.

The ‘LST-491’ class replaced the elevator with a ramp hinged on the vehicle deck, and this made it possible for vehicles to be driven directly from the vehicle deck to the tank deck, and then across the bow ramp to the beach or causeway, thereby speeding disembarkation. Changes in the ‘LST-542’ class included the addition of a navigation bridge, the installation of a water distillation plant, the elimination of the tank deck ventilator tubes from the central section of the vehicle deck, the strengthening of the vehicle deck to carry the smaller tank landing craft, and improved armour and armament, the latter by the addition of a 3-in (76.2-mm) gun.

The data for the LST Mk 2 included included a displacement of 1,780 tons light and 3,880 tons full load, length of 327 ft 9 in (99.90 m), beam of 50 ft 0 in (15.24 m), draught of 14 ft 1 in (4.29 m) aft and 8 ft 2 in (2.49 m) forward when loaded, and 7ft 6 in (2.29 m) aft and 3 ft 4 in (1.02 m) forward when unloaded, propulsion by two General Motors 12-567 water-cooled Diesel engines delivering 1,800 hp (1340 kW) to two shafts for a speed of 12 kt, range of 27,620 miles (44450 km) at 9 kt, capacity of 25 tanks on the tank deck, trucks or other vehicles on the vehicle deck, between two and six LCVPs  and about 140 army personnel, complement of 125 men, and armament of one 3-in (76.2-mm) gun, six 40-mm Bofors guns, six 20-mm Oerlikon cannon, two 0.5-in (12.7-mm) machine guns and four 0.3-in (7.62-mm) machine guns.

Amphibious Warfare – The Tank Landing Ship

The Tank Landing Ship, or more properly, the Landing Ship, Tank (LST), is the type of vessel created in World War II to support amphibious operations with the carriage of vehicles (most especially armoured vehicles), cargo and troops to be landed directly onto an unimproved shore.

The British ‘Dynamo’ evacuation from Dunkirk in June 1940 forcefully demonstrated to the Admiralty, although in a reverse of the demand which then emerged, that the British needed ocean-going and therefore comparatively large ships able to handle the shore-to-shore delivery of tanks and other vehicles in amphibious assaults upon the continent of Europe.

Although tank landing craft (LCT) designs and a prototype were completed during the winter of 1940/41, Prime Minister Winston Churchill demanded ships that could land the heavy tanks which were to be built during 1941 and put them ashore anywhere in the world. This last meant that the new vessels had to be fast enough to allow them to steam in convoy, which demanded that the new vessels would need a ship’s bow. This also meant that there would also be a gap between the beached ship’s bow ramp and water shallow enough for the embarked tanks to wade ashore. In addition to these design problems was the difficulty of finding British yards with the capacity to build such ships, and the problem of providing for the ship’s survival on a fire-swept assault beach. This was the most taxing aspect of the entire concept, for ships of the size envisaged would take several hours to discharge bulk cargoes, and would need at least 45 minutes to land a full load of vehicles. During this time the ship might be savaged by enemy fire, or merely be left standard as a result of missing the tide. Ultimately these fears were not realised, largely as a result of the Allies’ overwhelming air superiority, but some LSTs did remain fast on a beach longer than had been intended despite the adoption of many means to speed the unloading process.

Interim measure

As a stop-gap measure to meet Churchill’s demands, pending the design and construction of dedicated LSTs, the Admiralty found that there were three shallow-draught oilers, Misoa, Tasajero and Bachequero, built to cross the shallow bar of the harbour of Maracaibo in Venezuela. The Greenwell yard of Sunderland undertook the task of effecting a conversion of the 4,890-ton Misoa,  completed in July 1941 as the world’s first LST. The ship had a double ramp arrangement designed by the Department of Naval Construction and developed by the Clarke Chapman company: this ramp had an effective length of 100 ft (30.48 m) and extended through double-flap bow doors hinged at their base. On a beach with a 1/35 gradient and a forward draught of 4 ft (1.22 m), the converted ship could land a 40-ton tank across the retractable causeway, which was 8 ft (2.44 m) wide. The ship carried a maximum load of 18 Churchill infantry tanks, or between 22 and 25 smaller tanks or 33 trucks in rows on the turret deck above the oil tank spaces, which had been adapted for accommodation and the installation of large ballast water tanks. The ship’s sides were extended above the turret deck and a new deck was added to protect the tank cargo, which was carried in an enclosed volume which featured special ventilation.

Trials confirmed that ships of Misoa’s size could be kedged off a beach, and although the ship was more a proof-of-concept vessel rather than a prototype for purpose-built LSTs, the Department of Naval Construction gained invaluable experience in several aspects of landing tanks and other vehicles on beaches.

The Bachequero was a sister ship of Misoa, both having a length of 382 ft 6 in (116.59 m) and beam of 64 ft 0 in (19.51 m). The 3,952-ton Tasajero was slightly smaller, with a length of 365 ft 0 in (111.25 m) and beam of 60 ft 2 in (18.34 m), but could carry almost the same cargo.

Each of the three ships carried two mechanised landing craft (LCMs), had two 50-ton derricks and carried an armament of three 2-pdr ‘pom-pom’ guns, six 20-mm Oerlikon cannon (later increased in number to between 11 and 26), two 4-in (102-mm) smoke mortars and two 0.303-in (7.7-mm) Lewis guns. There was accommodation for tank crews or other army drivers (between 192 and 207 men), or 98 combined operations personnel, as well as the ship’s complement of 83.

The speed of between 8.25 kt and 10 kt on the 3,000 shp (2237 kW) provided to two shafts by reciprocating steam engines was deemed too slow for the ships to make passage with transport convoys but the limitation had to be accepted in these first LST attempts, though the three ships of the ‘Boxer’ class, which was the first purpose-built British LST type, were designed for 18.5 kt at beaching draught on the 7,000 shp (5219 kW) delivered to two shafts by steam turbines.

Revised ramp

The ‘Boxer’ class ships benefited from the DNC’s careful consideration about the design of a ramp capable of extending across a 100-ft (30.48-m) gap to very shallow water from a bow drawing 5 ft 6 in (1.68 m) on a 1/35 beach. Though mechanically complex, the solution finally developed by Stothert & Pitt of Bath was a double-cantilever ramp with a 71-ft (21.64-m) main section and a 54-ft (16.46-m) forward extension. The folding ramp occupied a considerable part of the tank deck’s forward area on these vessels. The vehicle deck was retained for later LST designs, and extended along almost the full length of the ship. Vehicles could also be carried on the upper deck, from which they were lowered to the tank deck by lift, and along either side of the upper deck were the accommodation spaces for 193 army personnel and the ship’s complement of 169. The two sets of boilers and turbines were installed just abaft the centre section, and the funnel offset to starboard to provide the deck area for a 40-ton crane. The design also included side ports which permitted the offloading of vehicles into LCMs, ventilation of the type used on the Maracaibo conversions with exhaust trunks joined by flexible connections to the embarked vehicles’ exhausts and, most far-sightedly, features to facilitate the carriage of crated aircraft. There was one 40-ton crane.

The three ‘Boxer’ class LSTs were Boxer, Bruizer and Thruster, of which the first was ordered in January 1941 from Harland & Wolff of Belfast, which in fact built all three vessels. Harland & Wolff had been involved in the project from an early stage, and it was this company’s suggestion to use a pair of vertical bow doors. The teething problems of the ramp/causeway in the shallow-draught hull, other design innovations and the damage caused by German air raids resulted in the first ship being launched early in 1943. The design was not suitable for mass production and had too great a draught to beach in shallow water, however, the dedicated LST role was assumed by the LST Mk 2. The three vessels were converted to other uses, Boxer being adapted in 1944 as a fighter direction ship with a longer ship’s bow and extending radar antennae.

The data for the LST Mk 1 included a displacement of 3,620 tons standard and 5,410 tons full load, length of 400 ft 0 in (121.92 m), beam of 49 ft 0 in (14.94 m), draught of 14 ft 6 in (4.42 m) standard and 18 ft 5 in (5.61 m) deep load, declining to 5 ft 0 in (1.52 m) forward and 13 ft 0 in (3.96 m) aft for beaching, propulsion by two Foster Wheeler boilers supplying steam to two Parsons geared turbines, 1,728 tons of fuel oil, range of 10,355 miles (16665 km) at 14 kt, capacity of 13 Churchill tanks or 25 medium tanks on the tank deck, 27 3-ton trucks on the upper deck and 193 army personnel, complement of 169 men, and armament of four 2-pdr ‘pom-pom’ guns, eight 20-mm Oerlikon cannon, and two 4-in (102-mm) smoke mortars.

Amphibious Warfare – The Dock Landing Ship

A dock landing ship (often formally designated as a landing ship, dock, or LSD) is an amphibious warfare ship incorporating a docking well into the stern for the accommodation, transport, and launch/recovery of landing craft and amphibious vehicles. Some ships with docking wells, such as those of the Soviet/Russian ‘Ivan Rogov’ class, also have bow doors akin to those of the tank landing ship (LST), enabling them to deliver vehicles directly onto a beach.

Modern LSDs can also carry and operate helicopters. A ship with a docking well is better suited to the loading of landing craft with infantry and/or equipment in rough seas than a amphibious warfare ship, which has to depend on cranes or a stern ramp. Based on US Navy practice, the modern standard nomenclature for a ship with a well deck depends on its aircraft facilities. The modern LSD has a helicopter deck, the LPD also has a hangar, and the LHD or LHA has a full-length flight deck.

A Japanese pioneer

Though it remains a little-known fact, and bears no long-term significance, it was Japan which was the world’s first nation to design and build vessels specifically for the amphibious warfare role. The pioneer LSD was Shinshu Maru, which was designed to an army specification of 1932 to support operations in China, built by Harima between 8 April 1933 and 14 March 1934 for commissioning on 15 November 1934. Built on the lines of a whaling factory ship, Shinshu Maru marked a significant advance in amphibious warfare as she incorporated a number of innovative features, and as such she was shrouded in secrecy throughout her existence. In the lower part of her hull she could carry 29 ‘Daihatsu’ class landing craft, or 25 ‘Shohatsu’ class landing craft and four armoured gunboats, to be launched from a floodable docking well and sloping rear ramp otherwise closed to the sea by a pair of large doors. The provision of large ports in the sides of the ship made it possible for stores and equipment to be trans-loaded into landing craft waiting alongside, and a heavy crane and derricks were also fitted to assist with the handling of heavier items. The ship was sunk, possibly by the ‘friendly fire’ of the destroyer Fubuki in the Battle of the Sunda Strait on 1 March 1942, but was raised in 1943 and received a major upgrade as she was refitted. This upgrade revised the superstructure into a hangar large enough to accommodate six Mitsubishi Ki-30 light bombers and six Nakajima Type 91 fighters. There was no flight deck, but the the crane on the foredeck was replaced by a catapult to launch the aircraft, which had perforce to alight on land, preferably on a captured airfield. The ship was used for landing operations until 5 January 1945, when she was sunk by US air attack.

Shinshu Maru’s data included standard and full-load displacements of 9,000 and 11,800 tons, length of 492 ft 1.5 in (150.0 m), beam of 72 ft 2 in (22.0 m), draught of 26 ft 9 in (8.16 m), propulsion by geared steam turbines delivering 8,000 shp (2440 kW) to two shafts for a speed of 19 kt, and armament of four to eight 75-mm (2.95-in) Type 88 anti-aircraft guns and eight to 12 20-mm cannon.

Evolutionary ideas

The modern concept of the LSD was spurred by the British, who needed a fully optimised vessel for the carriage and launch of large landing craft across the seas at speed on longer-range commando operations. Originating in 1941, the first LSD came from a design by Sir Roland Baker who had designed the British tank landing craft (LCT), and provided a solution to the problem of launching small craft rapidly. The initial results were the single Landing Ship, Stern Chute, which was a converted train ferry with accommodation for 105 troops and 50 vehicles, and fitted with a stern chute down which mechanised landing craft (13 LCM Mk 1 or nine LCM Mk 3) could be launched; the three Landing Ships, Gantry, which were converted tankers each with accommodation for about 260 troops and fitted with a crane to transfer its cargo of landing craft (15 LCMs ) from deck to sea in a little more than 30 minutes; and two Landing Ships, Carrier (LSC), which were heavy cargo ships with accommodation for 323 troops and fitted with large derricks to handle as many as 21 LCMs carried as deck cargo.

These interim designs paved the way to the first thoughts leading directly to the LSD. These were originated from the winter of 1941 by the Admiralty Construction Department as a vessel to be used as a mobile floating dock ship which could take a single LCT on longer passages for possible raids beyond the LCT’s range. This requirement had been outlined in September 1941, and the Admiralty design for this LSD was sent to the USA, where the Bureau of Ships and subsequently the naval architect Gibbs & Cox of New York developed the type for construction in US yards.

The principle of flooding the LSD’s cargo spaces to float off smaller craft and the use of specially trained civilian floating dock crews was thought too complex for general service personnel of the Royal Navy to attempt. There were many problems to be overcome, but the Department of Naval Construction overcame these with an arrangement of machinery that worked satisfactorily, although the buoyancy of engine room and other machinery spaces meant that tanks above the waterline as well as those below it had to be filled when the ship was being lowered so that the doors could be opened and the docking well flooded. Flooding-down took only 90 minutes and could be undertaken even with the ship steaming at slow speed, and the pumping out of the docking well and closure of the doors took 150 minutes to restore the ship to normal cruising trim.

Docking well

The docking well measured 394 ft (120.1 m) in length and 44 ft (13.4 m) in width, and was flooded to allow amphibious craft and vehicles as large as LCTs and Infantry Landing Craft, Large (LCI[L]s) to motor out when the stern doors were opened. The dangers from seas washing around this area, making the half-submerged ship unmanageable, were prevented by lock-gates fitted amidships, but these were taken out after some months.

The first LSDs went into service in 1943: 27 were built for the US Navy as the ‘Ashland’ class and seven were ordered for the Royal Navy, although the latter received only four (Eastway, Highway, Northway and Oceanway). In addition to accommodation for landing craft crews and cargo-handling personnel, the LSD had workshops for the repair of the metalwork and woodwork of minor craft, and could be used to repair LCI(L)s, PT-boats and similar craft.

When flooded, the dock had a depth of 8 ft (2.4 m) forward sloping to 10 ft (3.05 m) aft. Two temporary decks could be installed above the dock pontoon, and LVTs or DUKWs could be loaded onto these by the ship’s pair of 35-ton cranes. The additional decks had a ramp extending to the stern, and on the US Navy’s later ships an inboard travelling crane was fitted to facilitate the installation of these removable decks.

These ‘Ashland’ class LSDs were built by five yards in two basic forms, the first 12 with two Skinner Uni-Flow reciprocating engines delivering 7,400 ihp (5517 kW) and the last 15 with geared steam turbines delivering 9,000 shp (6710 kW), each in each two two shafts for speeds of 15.4 and 15.6 kt respectively. The other data included light and loaded displacements of 4,032 and 7,930 tons respectively, length of 457 ft 9 in (139.5 m), beam of 72 ft 2 in (22.0 m), draught of 15 ft 5.5 in (4.7 m) forward and 16 ft 2 in (4.9 m) aft when loaded, endurance of 9,200 miles (14805 km) 15 kt, armament of one 5-in (127-mm) gun, two quadruple 40-mm anti-aircraft guns, two twin 40-mm anti-aircraft guns, and 16 20-mm anti-aircraft cannon, crew of 290 men, and capacity of 240 men, and payload of three LCT Mk 5s or Mk 6s, or two LCT Mk 3s or Mk 4s, or 14 LCM Mk 3s, or 1,500 tons of cargo, or 41 LVT amphibious tractors or 47 DUKW amphibious trucks.

 

US riverine monitors

The comparatively small type of monitor intended for use on rivers and larger wetlands is well protected and, in general, carried the largest-calibre guns of any riverine warship. On 18 December 1965, as its major commitment to the Vietnam War was in its early stages, the US Navy decided to create a ‘brown-water navy’ for deployment on the extensive waterways characteristic of the southern region of South Vietnam, and in July 1966, authorisation was granted for the establishment of a Mobile Riverine Force, which would re-create the heavily armoured river monitor fitted with a single gun turret and closely related in conceptual terms to the river gunboat.

River monitors are intended for service on inland waters such as rivers, river estuaries and deltas, canal networks and lakes. In general such vessels are characterised by the shallow draught which allows them to operate effectively in enclosed waters, but the displacement, size and draught of such craft varies quite considerably depending on the precise nature of their operational theatre. In Asia, large river monitors had first been employed on the Amur river by the USSR and Japan, and were of a displacement of as much as 1,000 tons and armed with 130-mm (5.12-in) guns. However, over the course of the Vietnam War, the US Navy commissioned riverine craft of several types, generally based on the ‘LCM-6’ class of landing craft. These included 24 Monitors, of which 10 carried one 40-mm Bofors cannon in a Mk 52 turret, eight carried one 105-mm (4.13-in) M49 or M101 howitzer in a T172 turret, and six carried two M10-8 flamethrowers in a pair of M8 turrets located on each side of the vessel’s 40-mm cannon.

For Vietnamese operations, the US Navy’s ‘brown-water navy’ deployed its monitors as part of the River Assault Flotilla One, which at first comprised four River Assault Divisions: RAD 91 had three monitors, RAD 92 two monitors, RAD 111 three monitors, and RAD 112 two monitors.

Old and new

The riverine monitors used in South Vietnam were divided into two groups of steel-built craft: Program 4 comprised the 40-mm gun monitors converted from ‘LCM-6’ class landing craft built in World War II and therefore fitted with a ramp bow intended for lowering, and Program 5 comprised the eight 105-mm (4.13-in) howitzer monitors and the eight flamethrower monitors based on new-build hulls derived from that of the ‘LCM6’ class with a rounded rather than ramp bow. All of the monitors were powered by two Gray Marine Model 64NH9 water-cooled Diesel engines delivering 330 hp (246 kW) to two shafts for a speed of 8 kt in the ramp-bowed Monitor Mk IV and 8.5 kt in the round-bowed Monitor Mk V. With a full-load displacement of 75 or 75.5 tons, the craft of the two monitor classes each carried about 10 tons of armour protection, including screen and bar armour designed to defeat the hollow-charge warheads of the rockets fired by recoilless rifles and rocket-propelled grenade launchers, and were manned by 11 men.

The Monitor Mks IV and V had a beam of 17 ft 6 in (5.33 m) and draught of 3 ft 6 in (1.07 m), but at a length of 60 ft 6 in (18.44 m) the Monitor Mk V was 6 in (0.15 m) short than the Monitor Mk IV. The Monitor Mk IV was armed with one 81-mm (3.2-in) mortar or two M10-8 flamethrowers in a well between the conning position and the 40-mm cannon turret, one 40-mm cannon in a forward turret, one 20-mm cannon in a small turret on the rear of the conning position, two Mk 18 grenade launchers, three M79 grenade launchers, two 0.5-in (12.7-mm) Browning heavy machine guns in port and starboard positions just forward of the 20-mm cannon, and four 7.62-mm (0.3-in) M240 medium machine guns. As noted above, the Monitor Mk V was developed in two forms. That carrying a howitzer as its primary armament for the direct-fire engagement of communist bunker complexes on the banks of the waterway had one 105-mm (4.13-in) howitzer in the main turret, two 20-mm cannon in a bow turret, three M79 grenade launchers, two 0.5-in (12.7-mm) Browning machine guns as in the Monitor Mk IV and one 7.62-mm (0.3-in) M240 machine gun, while that equipped for flamethrowing had two 20-mm cannon, two flamethrowers each with a range of 220 yards (200 m), three M79 grenade launchers and two 0.5-in (12.7-mm) Browning machine guns.

Soviet armoured river and coastal gunboats – the BKA and MBK types

Given its huge size and enormously varied geography, the USSR – like the Imperial Russia it succeeded in 1917 – found that there was considerable scope for the use of gunboats on the country’s many large rivers, major lakes, and even its shallow coastal waters (such as the Sea of Azov and the Gulf of Finland). This was as true in Eastern Siberia, where the Amur river Flotilla was created as part of the Soviet defence against Japanese territorial ambitions, as it was in European Russia – where there were river and lake flotillas on many of the larger rivers (inc. the Volga, Dniepr, and Pripyet) and lakes (such as Ladoga).

Many of the areas in which these lakes rested and rivers flowed lacked much in the way of overland communications by road or rail, but were often desired in their own right by adversaries for their agricultural or material wealth – and the fact that they offered axes of advance toward major cities. Thus, there was considerable advantage to the Soviets possessing river and lake flotillas, where their vessels’ guns could serve as mobile artillery for intervention in land warfare, and could prevent a European use of Russian coastal and inland waters for logistics.

The USSR therefore built and operated large numbers of BKs (bronekater, or armoured motor boat) craft. Initially produced in modest numbers during the 1930s as prototypes, production of the ships escalated in WWII for operational use. The type was pioneered by the 18-ton Type N and 20-ton Type K boats, each built only in small numbers. The first carried one 16-mm machine gun and several lighter machine guns, had a maximum speed of 19 kt on 90 bhp (67.1 kW) and was crewed by eight men, while the latter carried two 76.2-mm (3-in) guns and several machine guns, had a maximum speed of 21 kt on 800 bhp (596 kW) and was crewed by an unspecified number of men.

Production ordered

Experience with these prototypes helped to finalise Soviet decision-making, and by January 1940 orders had been placed for 85 such craft – the majority of them for service on the rivers. Designed during the period of the 2nd Five-Year Plan, the craft were built by the many smaller yards on Soviet rivers and lakes, and protection was provided by the addition of comparatively thin armour plating over the conning position and machinery spaces.

The two first riverine gunboat classes to emerge from this process were the Type 1124BKA and Type 1125BKA. Production of the Type 1124BKA and the Type 1125BKA boats began in about 1935, primarily in small inland yards. The early craft were armed with the turret of the T-28 medium and T-35 heavy tanks: this turret was armoured to a maximum of 20 mm and fitted with a 76.2-mm (3-in) L/20 gun, but with the advent of the classic T-34 medium tank from 1939, the turret of this tank was made available for riverine gunboats: the turret was initially fitted with a 76.2-mm (3-in) F-34 L/30.5 gun, upgraded in 1940 to the 76.2-mm (3-in) L/41.2 gun and had a maximum frontal armour thickness of 50 mm (2 in). Some of the Type 1124BKA craft were also revised in the course of the war to carry a ROFS-82 multiple rocket launcher in place of the turret.

The 42-ton Type 1124BKA had a length of 25.00 m (), beam of 3.80 m () and draught of 0.80 m), propulsion by two petrol engines delivering 1,600 hp (1193 kW) to two shafts for a speed of 28 kt, protection by 12.7-mm (0.5-in) armour for the belt and conning position, a crew of 17 men, and an armament of two turrets, each fitted with one 76.2-mm (3-in) gun and two 12.7-mm (0.5-in) machine guns.

The 29-ton Type 1145BKA had a length of 22.60 m, beam of 3.50 m and draught of 0.50 m, propulsion by one petrol engine delivering 720 hp (537 kW) to one shaft for a maximum speed of 20 kt, protection by light plate on the sides and conning position, a crew of 10 men, and armament of one turret fitted with a 76.2-mm (3-in) gun, one 12.7-mm (0.5-in) machine gun and two 7.62-mm (0.3-in) machine guns.

By the time of the German invasion of June 1941, 85 boats of these two types had been ordered and 68 were under construction, and on 18 January 1941 another 110 units had been ordered. All of this occured before the end of the war in May 1945.

Enlarged development

A third type of gunboat, better suited to estuarine and also coastal operations, was developed during the war as the MBK. Its design was developed shortly before the outbreak of war as an enlarged version of the Type 1124. Construction of the prototype was started in Leningrad in 1941, and this was completed in 1943. Other examples were delivered in 1944, and though initially intended for use in the shallow waters of the Baltic, they were instead employed for a wide range of duties. Whereas the Type 1124BKA and Type 1125BKA had been designed to carry the turret of the T-34/76 tank, the BKM was conceived round the turret of the later T-34/85 armed with the longer 85-mm (3.35-in) ZiS-53 gun and finally a 100-mm (3.94-in) gun.

The data for the 150-ton MBK included a length of 36.00 m, beam of 5.40 m and draught of 1.50 m, propulsion by two Diesel engines delivering 1,000 hp (746 kW) to two shafts for a maximum speed of 18 kt, protection by 50-mm (2-in) plate on the sides and conning position, a crew of 38 to 42 men, and armament of two turrets each fitted with one 85- or 100-mm (3.35- or 3.94-in) gun, one 37-mm L/67 cannon and four 12.7-mm (0.5-in) machine guns.

All three types were very successful. At least 270 were built between 1935 and 1945, and of these some 90 were lost.

[Photos by wio.ru]

US Chinese river gunboats

A number of European powers, the USA and Japan maintained flotillas of these shallow-draft river gunboats to patrol the larger rivers with which China abounds, enforcing these nations’ concessionary rights under the terms of treaties which China had been compelled to sign in the period after her defeat during the 1st Opium War (1840/42) with the UK. The combination of steam power, shallow draft and comparatively powerful armament in these vessels meant that the new European vessels totally outclassed anything which the Chinese could operate at the time.

 In their desire to extort advantageous trading positions vis-à-vis China, the foreign powers had in effect coerced from China concessions such as extraterritoriality for their citizens in China, and the gunboats were used to police these rights.

The first non-European nation to gain treaty rights was the USA, which gained concessions in Shanghai on the Yangtze River Delta and Tianjin and the northern end of the Grand Canal, which links with the Yellow and Yangtze rivers. Over a period of some 80 years, the US Navy then operated gunboats of varying age, design, size and overall utility. The earliest such craft made brief forays up some of the larger rivers between 1861 and 1901, but were rarely allocated to any permanent patrol structure. In 1901 two large gunboats, the 1,290-ton Helena with a crew of 170 men and the 1,570-ton Wilmington with a crew of 212 men, were assigned to the Asiatic Squadron’s so-called 2nd Division as permanent river patrol vessels. The two were too large to be able to patrol deep inland, but remained in service until 1932 and 1923 respectively. In 1903 Spanish gunboats, captured in the Philippine islands group during the US/Spanish War of 1898, were adapted for the riverine role in US service and placed in service for patrols which took them farther up the Yangtze River toward Chungking: the 620-ton Elcano with a crew of 103 men and the 350-ton Villalobos with a crew of 50 men served until 1928, when they were decommissioned and sunk. The 240-ton Callao and 350-ton Quiros, which was a sister ship of Villalobos, served until 1916 and 1923 respectively.

New construction

In 1914 a pair of 204-ton patrol craft of British design were built at Mare Island Naval Shipyard, then disassembled and shipped to China for reassembly in Shanghai. These vessels were Palos, which patrolled until 1934 before being relegated to become the station vessel at Chungking, and Monocacy, which patrolled until 1939. Each manned by 47 men, the two vessels carried an armament of two 6-pdr guns and six machine guns, and possessed a maximum speed of 13.25 kt on the 800 shp (596.5 kW) provided by their vertical triple-expansion steam engines to two shafts.

The Yangtze Patrol was established in 1922 as a element of the US Asiatic Fleet, and the new patrol was allocated six new vessels designed and built in Shanghai during 1928. The new vessels were of three different sizes. The 380-ton Guam and Tutuila, each with a crew of 60, were able to steam up and down the whole navigable length of the Yangtze River at any time of the year. The 450-ton Panay and Oahu, each with a crew of 65, and the 560-ton Luzon, with a crew of 82 men, were too large for such a round-the-year capability, and were deemed ‘May–September’ gunboats as they could patrol completely upriver only during these high-water months. (Luzon’s sister ship, Mindanao, served on the China coast but not in the river patrol.) Except for Panay, which was sunk by Japanese aircraft on 12 December 1937, the newer ships served in China until a time late in 1941.

Riverine stalwart

The best known of the vessels as a consequence of her loss as a neutral during the 2nd Sino/Japanese War, Panay was built by the Kiangnan Dockyard and Engineering Works in Shanghai and launched on 10 November 1927 for commissioning on 10 September 1928.

Designed and built for service on the Yangtze River, Panay was tasked primarily with the protection of US lives and property, which were frequently threatened in the disturbances that ripped through China during the 1920s and 1930s as this Asiatic giant struggled to modernise, create a strong central government and finally attempt to fight Japanese aggression. Throughout Panay’s service, movement up and down the Yangtze river was constantly menaced by bandits and outlaws (the latter were mostly disaffected soldiers who had deserted), and Panay and the other US gunboats helped to provide protection for US shipping and nationals.

Detachments from Panay were often used as armed guards on US steamers plying the Yangtze River. In 1931 Panay’s commanding officer reported that being fired on from the banks was to be expected as a matter of routine by US shipping and gunboats, but also that the Chinese seemed to be so indifferent in their marksmanship that his vessel had not yet suffered any casualties.

As the Japanese moved through southern China, US gunboats evacuated most of the embassy personnel from Nanking during November 1937. Panay was assigned as station ship to guard the remaining Americans and take them off at the last moment, which she did on 11 December, bringing the number of persons on board the gunboat to five officers, 54 enlisted men, four US embassy staff and 10 civilians, including six news men. In an effort to avoid involvement in the fighting around the doomed Chinese Nationalist capital, Panay and three US merchant tankers steamed up the river, and the senior Japanese naval commander in Shanghai was informed of the four ships’ movement both before and after the fact.

The Panay Incident

On 12 December warplanes of the Imperial Japanese Navy’s air arm were ordered to attack any and all ships on the Yangtze River above Nanking. Knowing of the presence of Panay and the merchant vessels, the Japanese navy requested verification of the order, which had been issued by the Japanese army, and received the verification before beginning the attack at about 13.27 on the same day. Panay was flying several large US flags and had another painted above the superstructure, but the Japanese warplanes pressed home their attacks regardless. Panay was hit by two of the 18 132-lb (60-kg) bombs dropped by three Yokosuka B4Y bombers and was also strafed by nine Nakajima A4N fighters. The bombing continued until Panay sank at 15.54. One man of the US Navy and two civilians were killed, and another man of the US Navy died of his wounds during the night which followed. Some 43 sailors and five civilians were wounded.

The US ambassador immediately lodged a formal protest, and while it accepted responsibility, the Japanese government insisted that the attack had not been made deliberately, claiming that the pilots could not distinguish between Chinese and US flags from the distance from which the warplanes attacked, which was in fact only some 300 yards (275 m). An indemnity of about US$2 million was paid, and this officially settled the incident on 22 April 1938, though the entire episode rankled deeply in the minds of the US government and people, and marked another step in the worsening relationship between the USA and Japan.

The data for the river gunboat Panay included a displacement of 474 long tons, length of 191 ft 1 in (58.24 m), beam of 28 ft 1 in (8.56 m), draft of 5 ft 3 in (1.60 m), propulsion two Vosper Thornycroft boilers supplying steam to two vertical triple-expansion steam engines supplying 2,250 ihp (1864 kW) to two shafts for a maximum speed of 15 kt, armament of two 3-in (76.2-in) L/50 guns in single mountings and six 0.3-in (7.62-mm) machine guns, and crew of 70.

The British ‘Insect’ class river gunboat

Despite its different designation, the river gunboat was in reality the riverine counterpart of the sea-going monitor, but because of its supposed limitation to more confined waters was a far smaller vessel with a correspondingly lighter armament optimised for the bombardment of river bank targets.

In February 1915 the British ordered 12 ‘Fly’ class river gunboats of a 98-ton normal displacement and with a primary armament of one 4-in (101.6-mm) gun, and followed in December of the same year with an order for another four of the class, which were all built by Yarrow. These useful little vessels were intended for operations on the Tigris and Euphrates river of Mesopotamia against the Turks, and in an effort to disguise the fact were generally called China gunboats.

In February 1915 the Admiralty also ordered the 12 larger units of the ‘Insect’ class of river gunboats. These were intended for projected operations on the Danube river against the Austro-Hungarians, and to conceal their intended operational theatre were generally know as large China gunboats. The Danubian operation did not materialise, and the first four of the vessels were in fact used in Mesopotamia alongside the ‘Fly’ class vessels. Small but well armed, the ‘Insect’ class vessel was designed by Yarrow, which also provided the propulsion, and was created to operate in shallow fast-flowing rivers, with a shallow draught and a good turn of speed to ensure useful progress against the current. The propulsion arrangement was basically an enlarged version of the single-shaft arrangement of the ‘Fly’ class, with two mixed-firing Yarrow boilers delivering steam to triple-expansion engines driving two propellers accommodated in tunnels to minimise the operating draught and also to provide a measure of protection against typical river debris passing beneath the hull.

The 12 vessels of the class comprised Aphis and Bee built by Ailsa Shipbuilding, Cicala, Cockchafer, Cricket and Glowworm built by Barclay Currie, Gnat and Ladybird built by Lobnitz, Mantis and Moth built by Sunderland Shipbuilding, and Scarab and Tarantula built by Wood Skinner. All 12 of the vessels were launched in 1915/16.

Though the primary armament was two 6-in (152-mm) QF L/40 Mk VII guns in single mountings, in 1916/17 Cicala, Cockchafer, Cricket and Glowworm received a temporary rearmament of two 6-in (152-mm) QF Mk II on CP II anti-aircraft mountings, providing an elevation of 53.5°, for use against Zeppelin airships.

Varied service

None of the class fought on the Danube river, as by the time the craft were completed, Serb resistance had collapsed and there was therefore no Danube theatre, so the vessels were operated in other theatres where their shallow draught and firepower were useful for the support of land operations. Aphis, Bee, Ladybird and Scarab were sent to Port Said from November 1915 to April 1916 for possible service on the Suez Canal, and Gnat, Mantis, Moth and Tarantula were towed to the Persian Gulf early in 1916 for service in Mesopotamia. Cicala, Cockchafer, Cricket and Glowworm were despatched to the east coast of England (Cicala and Cricket in the Humber estuary, Cockchafer at Brightlingsea, and Glowworm at Lowestoft) to use their revised armament in the effort to deter Zeppelin raids on the British mainland, and then in September 1918 were redeployed to Arkhangyel’sk in northern Russia for operations on the Dvina river as part of the British response to the Bolshevik revolution and to aid the White forces in the Russian Civil War against the Red forces. Glowworm was severely damaged at Bereznik on 24 August 1919 when ammunition barge exploded alongside, killing her captain and several other members of the crew. Aphis and Ladybird patrolled the Danube river between November 1918, after Austria-Hungary’s surrender, and March 1922, Aphis being replaced by Glowworm in 1920. Bee and Scarab were despatched to Hong Kong in March 1918, followed by Gnat and Tarantula. Cicala, Cockchafer, Cricket, Mantis and Moth were towed out from England to the Far East in 1920, leaving Glowworm on the Danube river as Aphis and Ladybird laid up at Malta. Cicala was sunk by Japanese aircraft at Hong Kong on 21 December 1941. Cricket was crippled by bombing in the Mediterranean on 29 June 1941 and laid up at Port Said, her hull being stripped and sold for breaking up in 1942. Gnat was torpedoed in the Mediterranean by U-79 on 21 October 1941, laid up at Suez and sold for breaking up in 1945 after being stripped for spares. Ladybird was sunk by air attack off Tobruk on 12 May 1944. Moth was scuttled at Hong Kong on 21 December 1941, but was raised by the Japanese and recommissioned as Suma, which was mined and sank in the Yangtze river on 19 March 1945. Tarantula was sunk as target off Trincomalee on 1 May 1946. Finally, Aphis, Cockchafer and Scarab were sold for breaking up between 1947 and 1949.

In northern Russia the crew of Cicala mutinied, as part of a wider wave of unrest in the Royal Navy about pay, conditions and demobilisation, and five ringleaders were sentenced to death, later commuted to imprisonment for five years.

Far Eastern service

Between the two world wars, the class was used primarily in the Far East, and saw some service after the Japanese invasion of China. As noted above, in 1937 the Japanese attacked Ladybird, firing on her from a battery on the bank of the Yangtze river. Panay, a US gun boat, was also attacked, in this instance by Japanese aircraft, and sunk. Ladybird sailed the 20 miles (32 km) to the scene of the attack, took on board some of Panay’s survivors and steamed down the river to deliver them to Shanghai. Scarab and Cricket were off Nanking in 1937 as the Japanese started to bomb the city.

In 1939, the original two 6-in (152-mm) Mk VII L/45 guns on Aphis and Ladybird were replaced by more modern 6-in (152-mm) Mk XIII L/50 guns from the decommissioned battleship Agincourt: 30 in (76.2 cm) longer than the Mk VII weapons, the Mk XIII guns provided greater range and accuracy.

At the start of World War II, Cricket, Gnat and Ladybird were transferred to the Inshore Squadron of the Mediterranean Fleet to supplement the monitor Terror in the provision of bombardment support for the 8th Army. Their shallow draught also allowed them to act also as supply and landing vessels.

The data for the ‘Insect’ class gunboats as built included a normal displacement of 645 tons, length of 237 ft 6 in (72.39 m) overall, beam of 36 ft 0 in (10.97 m), draught of 4 ft 0 in (1.22 m), propulsion by triple-expansion steam engines delivering 2,000 ihp (1491 kW) to two shafts for a maximum speed of 14 kt, fuel capacity of 89 tons (54 tons of oil and 35 tons of coal), armament of two 6-in (152-mm) QF Mk VII guns, two 12-pdr guns and 6 0.3-3in (7.7-mm) machine guns, and crew of 53. Later armament variations included one 3-in (76.2-mm) QF anti-aircraft guns, one 2-pdr pom-pom anti-aircraft gun, 20-mm cannon and 0.303-in (7.7-mm) Lewis machine guns.

‘Roberts’ class British monitor

The designation ‘monitor’ is used for the type of comparatively small warship which was not fast or strongly protected, but carried a small number of guns characterised by their disproportionately large calibre. Monitors were operated by several navies from the early 1860s until the end of World War II in 1945, and in fact saw their final use, in a somewhat strange form, by the US Navy during the Vietnam War.

The first monitor was designed in the USA during 1861 by John Ericsson, who named his ship Monitor. This and subsequent ships of the same basic type were designed for operations in shallow waters, and therefore served as coastal ships. The term ‘monitor’ was also used for the later and more useful breastwork monitor, which had a raised turret or turrets as well as a heavier superstructure on a platform above the hull, for superior capability in the shore bombardment rather than ship versus ship role.

The shore bombardment role appealed strongly to the British, with their considerable heritage of involvement in European wars through the use of landed troops supported by the powerful guns on warships lying close inshore. In this role, the monitor required little in the way of speed, range or manoeuvrability, which were therefore sacrificed to a broader beam (providing a more stable firing platform), shallower draught (allowing the ship to approach the coast more closely) and very heavy armament.  The strongest of the riverine warcraft were known as river monitors. In the early 20th century, the term monitor was revived for shallow-draft armoured shore bombardment vessels, particularly those of the Royal Navy: two of the eight ‘Lord Clive’ class monitors, launched in 1915 with a primary armament of two 12-in (305-mm) guns in a single turret, were later adapted also to carry one 18-in (457-mm) gun firing the heaviest shell ever fired by a warship out to a range of 36,000 yards (32920 m), which was the longest range at which a Royal Navy vessel ever engaged a target using guns; a third conversion had not been completed before the end of World War I in 1918.

The smaller Royal Navy monitors were mostly scrapped following World War I, though Erebus and Terror survived to fight in World War II. When the requirement for shore support returned, two large new Roberts class monitors, Roberts and Abercrombie, were constructed and fitted with 15-inch (380 mm) guns from older battleships. Most of the 40 British monitors built in World War I with 6-, 9.2-, 12-, 15- and 18-in (152-, 234-, 305-, 381- and 457-in) guns, were removed from service after the end of that war, some of them for adaptation to other tasks, but two ‘Erebus’ class ships, each armed with two 15-in (381-mm) guns, were retained and saw service in World War II.

New construction

These two ships were supplemented by the two ships of the ‘Roberts’ class, which were Roberts, built by John Brown on Clydebank and completed in 1941, and Abercrombie, built by Vickers-Armstrongs at Wallsend-on-Tyne and completed in 1943.

The design of the ‘Roberts’ class was a development of that of the ‘Erebus’ class, Roberts being built to utilise the 15-in (381-mm) turret from Marshal Soult, a monitor disarmed in 1940, while Abercrombie had one of the 15-in (381-mm) turrets originally constructed as a standby for the light battle-cruiser Furious if the latter’s 18-in 457-mm) guns were failures. This turret was brought up to date and the mountings in both ships allowed a maximum elevation angle of 30°. The turret, carrying the two 15-in (381-mm) Mk I L/42 guns, was carried above a tall barbette ahead of the superstructure: each gun had a muzzle velocity of 2,458 ft (749 m) per second, and fired its 1,938-lb (879-kg) shell to a maximum range of 33,550 yards (30680 m) at a gun elevation angle of 30°. The secondary armament comprised eight 4-in (102-mm) QF Mk XVI L/45 anti-aircraft guns in four twin turrets installed on the upper deck in Roberts and on the shelter deck in Abercrombie. The secondary anti-aircraft armament was 16 2-pdr ‘pom-pom’ guns in one octuple and two quadruple mountings, and Roberts had eight single 40-mm Bofors light anti-aircraft guns added in July 1945, and the greatest number of 20-mm Oerlikon cannon in either ship seems to have been 20.

Armour protection was provided on only a modest scale. The conning tower has armour between 2 and 3 in (51 and 76 mm) tick. The belt, between 4 and 5 in (102 and 127 mm) thick, sloped outward along the top of the anti-torpedo bulge and extended between the main and lower decks from a point well forward of the barbette to the main mast. The turret had a 13-in (330-mm) face, 11-in (279-mm) sides and rear, and a 5- or 6-in (127- or 152-mm) roof. The armour deck at main deck level was between 2 and 4 in (51 and 102 mm) thick with a greater area of the thicker armour in Abercrombie, and both ships had a glacis between 4 and 6 in (102 and 152 mm) thick, and a raised deck over the 15-in (381-mm) magazine, which also had splinter protection 1.5 in (38 mm) thick. The lower deck was 3 in (76 mm) thick over the steering gear. The anti-torpedo bulge on each side was of the sandwich type with a width of 17 ft (15.54 m) amidships with a 1.5-in (38-mm) protective bulkhead, and the system was designed to withstand the detonation of a 1,000-lb (454-kg) charge.

Good survivability

During World War II, Roberts was hit by two 1,102-lb (500-kg) bombs, which her armour withstood while nonetheless suffering considerable damage, and Abercrombie was twice damaged by moored contact mines, on the second occasion striking two of them. As a result Abercrombie’s wartime career was much less active than that of Roberts.

Other features of the class were shallow draught for operations close inshore, broad beam to give stability and also added resistance to torpedoes and mines, and a tall observation platform to observe the fall of shot.

Roberts was completed on 27 October 1941 and provided bombardment support during the ‘Torch’ landings of November 1942 in French North-West Africa, where she was damaged by two bombs as noted above. She was repaired in time to support the ‘Husky’ invasion of Sicily in July 1943, the ‘Avalanche’ landing near Salerno on the Italian mainland in September 1943, the ‘Overlord’ landing in Normandy in June 1944, and the Walcheren operations of late 1944.

Roberts was sold for scrapping shortly after the end of World War II, but hired back by the Royal Navy as an accommodation ship at Devonport until 1965, when she was broken up for scrap.

Abercrombie was completed on 5 May 1943 and was damaged by contact mines on several occasions while supporting the invasion of Italy, but was repaired. On the completion of her repairs, the monitor was sent for service in the Pacific theatre, but the war ended before her arrival. The monitor was used as a gunnery training and accommodation ship at Chatham after the war, and broken up for scrap in 1954.

Other data for the ships included a displacement of (Roberts) 7,973 tons standard and 9,150 tons full load, and (Abercrombie) 8,536 tons standard and 9,717 tons full load, length of 373 ft 4 in (113.79 m) overall, beam of 89 ft 9 in (27.36 m), draught of (Roberts) 13 ft 6 in (4.11 m) and (Abercrombie) 14 ft 5 in (4.39 m), propulsion by two Admiralty three-drum boilers supplying steam to two sets of Parsons steam turbines delivering 4,800 shp (3579 kW) to two shafts, oil capacity of 491 tons (498.9 tonnes), speed of 12.5 kt, and complement of between 442 and 460.