Mark 8 Landing Craft Tank

Design

In October 1943, the Director of Naval Construction was instructed to prepare plans for a class of Landing Craft Tank vessels suitable for travelling to and operating in the Far East. They had to be capable of ocean operations and able to keep up with Landing Ship, Infantry convoys. Greater ranges and more lengthy periods of sustained operation than in the European or Mediterranean theatres would require a larger vessel with better seakeeping ability. Design and capabilities were heavily influenced by the United States' Mark 7 LCT (which was later re-categorised as Landing Ship Medium), which was capable of transporting multiple tanks over large distances. The Mark 8 was a synthesis of the best qualities of previous amphibious warfare vessels: the design was based on an enlarged version of the Mark 4 LCT, incorporating its light construction and suitability for mass-production, while including the robustness of the Mark 3 design, and adopting the bow layout and other elements from the Mark 2 Landing Ship Tank.

The vessels were 225 feet (69 m) long between perpendiculars and 231.2 feet (70.5 m) long overall, with a beam of 38 feet (12 m). Although retaining the open tank deck of previous LCT designs, the Mark 8 was protected by a taller bow section, which was fitted with powered doors and ramp. The capacity was eight 30-ton tanks, up to 13 fully loaded 3-ton trucks, or 350 tons of cargo. Maximum displacement and draught varied depending on the loadout: trucks would result in a 650-ton displacement, 3-foot (0.91 m) draught at the bow, and 4-foot-8-inch (1.42 m) draught at the stern; for tanks, it was 780 tons, 3 feet 9 inches (1.14 m) forward, and 5 feet (1.5 m) aft; while a full load of cargo resulted in a displacement of 880 tons, and draughts of 4 feet 8 inches (1.42 m) and 5 feet 2 inches (1.57 m). Maximum displacement was 1,017 tons. The deeper draughts compared to previous vessels helped improve seakeeping.

An enlarged engine room compared to previous designs allowed the installation of four 460 shaft horsepower (340 kW), 12-cylinder Davey Paxman 12TPM diesel engines, coupled in two tandem sets to drive the two propeller shafts. These had a maximum combined output of 1,840 brake horsepower (1,370 kW) (roughly doubling that of previous LCTs), although output was capped at 1,600 brake horsepower (1,200 kW). Cruising speed was 8 knots (15 km/h; 9.2 mph), with a maximum speed of 12.5 knots (23.2 km/h; 14.4 mph). The landing craft could travel 4,000 nautical miles (7,400 km; 4,600 mi) at cruising speed, or 2,500 nautical miles (4,600 km; 2,900 mi) at 10 knots (19 km/h; 12 mph).

The expanded engine room required a lengthening of the poop deck, which allowed for improved accommodation spaces and an enlarged superstructure. During design, the vessel's complement was pegged at 25 (including three officers), but by the late 1960s, this had expanded to between 33 and 37. Additional accommodation was provided for up to 42 personnel (including six officers): typically the crews of any vehicles being transported. For defence, the vessels were fitted with four single 20 mm Oerlikon guns. There were also plans to fit some of the vessels with a Hedgerow: a modified Hedgehog anti-submarine mortar which would be fired to clear mines and obstructions from beaches prior to the landing of troops. The bridge, wireless telegraphy office, and gun platforms were armoured with 0.25-inch (6.4 mm), 15-pound (6.8 kg) D1 HT plating.

Construction

187 vessels were ordered. They were identified with the pennant numbers L4001 through to L4187. 96 were ordered in the initial batch on 7 April 1944. This was followed by orders of 9 at an unknown date, 22 on 9 October 1944, batches of 20, 16, and 12 at unknown dates during late 1944, then the final 12 on 6 January 1945.

Shipyards and companies involved in the vessels' construction included Stockton Construction at Thornaby (46), A. Findlay at Old Kilpatrick (27), Arrol at Alloa (25), Tees-Side Bridge at Middlesbrough (17), MacLellan at Bo'ness (12), Motherwell Bridge at Meadowside (12), Fairfield at Chepstow (12), Redpath Brown at Meadowside (11), Cleveland Dockyard at Middlesbrough (7), Warren Point Shipyard (8), Lagan at Belfast (8), and White at Cowes (2). In addition, individual hull sections were fabricated by Cargo Fleet of Stockton, Cleveland Bridge of Darlington, Whessoe Foundry of Darlington, Head Wrightson of Thornaby, and Appleby-Frodingham. Building designs were provided for both riveted and welded versions.

The first vessel was completed in June 1945. 30 were completed for the Royal Navy before the end of World War II meant that the vessels were no longer required; none of those completed saw wartime service. Of the remaining 157, 6 were sold into civilian service (4 directly, 2 to intermediate parties for conversion), while the rest were cancelled, scrapped in their incomplete state, or otherwise disposed of.

Royal Navy

Nine ships in the class (HM Ships Redoubt, Rampart, Citadel, Parapet, Bastion, Counterguard, Portcullis, Sallyport, and Buttress) served during the 1956 Suez Crisis under Royal Navy control, while a tenth (L4086, later named HMAV Arromanches) operated with a civilian crew.

In 1961, Bastion, Redoubt, and the landing ship tank HMS Striker transported heavy stores and vehicles from Bahrain to Kuwait in support of Operation Vantage.

Army

The Suez Crisis highlighted the Army's need to train landing craft crews to respond to similar emergencies. Beginning in 1957, twelve LCT (8)s were transferred to the Army and stationed at Portsmouth: seven entered Army service between January and March of that year, while the other five followed later. The vessels were given names of Second World War battles, and were crewed by men of 76 Company, Royal Army Service Corps (RASC). The RASC Water Transport Training Unit, based at Fort Victoria on the Isle of Wight began running LCT training courses and supplied the vessels with crews (men on their National Service) until the unit closed in 1962.

In 1957–58, several of the LCTs took part in Operation Hardrock, a joint Army/RAF operation to create a guided weapons tracking station in the Hebrides. The vessels made exploratory voyages and subsequently delivered men and equipment to islands like St Kilda, South Ford, and Lochboisdale. In the following years, they made supply runs from their base at Cairnryan to the islands. Landings were dangerous, due to weather and beach conditions, and on one occasion, Abbeville became grounded at Village Bay in St Kilda for three days.

In 1960, three of the LCTs (Ardennes, Agedabia and Arromanches) were transferred to Singapore. Whilst in service there, they carried out routine transport and ammunition-dumping activities, and were deployed in the Indonesian Confrontation in 1962. Two more LCTs (Antwerp and Arakan) were despatched to the region the following year.

When the LCTs first entered service with the British Army, they were designated as Royal Army Service Corps Vessels (RASCV). In 1965, the RASC was amalgamated with the transportation arm of the Corps of Royal Engineers to form the Royal Corps of Transport. The following year, a Royal Warrant dictated that all RCT vessels would have their prefix changed to Her Majesty's Army Vessel (HMAV).

Other forces and civilian service

During the late 1950s, Jawada was loaned to the Qatar Petroleum Company. The landing craft was briefly recommissioned during late 1956 and early 1957 to serve as a tender to the cruiser HMS Superb, which was visiting Bahrain for amphibious warfare exercises.

Buttress was sold to the French Navy in July 1965; she was redesignated L 9061, then later Issole. She was then resold to the Military of Comoros in 1976, and operated as the naval vessel Ville de Nimachova. Counterguard was sold to the Royal Malaysian Navy in 1965 and renamed Sri Langkawi. The vessel operated under this name until February 1968, when she was disposed of. Ardennes and Arromanches were sold to the Singaporean Navy in 1970, operating as Cairn Hill and Tanglin.