Landing Craft Assault

Origins[edit]

For centuries the Royal Navy had been landing soldiers on hostile shores, prominent examples being Quebec 1759, Peking 1900, during the Dardanelles campaign 1915-16 and the Zeebrugge Raid 1918.^[4] During the inter-war period, however, a combination of recent experience and economic stringency contributed to the delay in producing a modern infantry assault landing craft.


The costly failure of the Gallipoli campaign during World War I coupled with the emerging potential of airpower satisfied many in naval and military circles that the age of amphibious operations had come to a close.^[5] Still, throughout the 1920s and 1930s, animated discussion in Staff Colleges in Britain and the Indian Army Staff College, Quetta surrounded the strategic potential of the Dardanelles campaign compared with the strategic stalemate of the Western Front. The economic austerity of the worldwide economic depression and the government's adoption of the Ten Year Rule assured that such theoretical talk would not result in the procurement of any equipment.


The Munich Agreement of 1938 delayed the inevitable war between Britain and Germany. Munich also led to many changes in Imperial General Staff policies, among which was the acceptance of a proposal in November from the Inter-Service Training and Development Centre (ISTDC) at Fort Cumberland for amphibious assault procedures and for a new type of landing craft.^[1][6] Up to this time the Landing Craft Committee had produced some Motor Landing Craft but had not formed procedures for the assault role of these boats. Now there were specifications for what the new boat must be able to do.^[6] It must weigh less than ten long tons, enabling lifting by passenger liner davits. The new craft also had to be built around the load - apart from crew it should carry the thirty-one men of a British Army platoon and five assault engineers or signallers – and be so shallow drafted as to be able to land them, wet only up to their knees, in eighteen inches of water.^[1][7] The troops had to unload quickly.^[7] All of these specifications made the LCA personnel carriers; a separate set of requirements were laid down for a vehicle and supplies carrier, although previously the two roles were combined in the Motor Landing Craft.


When the ISTDC approached the Director of Naval Construction (DNC) at the Admiralty to design a craft to these specifications the DNC staff were urgently engaged in designing new ships to serve more immediate priorities.^[7] Germany's coastline was small and the army would be able to engage the enemy through France. Any urgent need for landing craft was not apparent and ISTDC were told it would take seven months to design what was required.^[7] The Board of Trade was therefore approached and asked to suggest a maritime architect. Mr. Fleming of Liverpool was proposed who soon came down to Fort Cumberland and the design of the first LCA began.


Following many visits with new drawings and proposals, a plan was ready by November 1938.^[5][8] Approval was sought from the DNC to build a prototype Fleming LCA. A wooden mock-up of the craft had been built in the model shed in Portsmouth dockyard. Fully equipped troops had practiced embarking and disembarking from it, and the design was altered to meet the practical difficulties discovered. The craft to be put into service was to be built of Birmabright, an aluminium alloy.


A meeting with the DNC was convened to discuss the results. The Fleming craft had few friends in the DNC, though their criticisms were not specific.^[9] They introduced representatives of three shipbuilding firms. The ISTDC were only interested in the Fleming design submitted already, and in trying the craft at a landing on the east coast of England in a matter of months. The DNC accepted this, but asked ISTDC to give their specifications to the firms present so that they could also submit designs. Two of the firms were unable to tender, the third, Messrs Thornycroft, had a proposal on the drawing board in forty-eight hours and ISTDC and the DNC agreed that construction of a prototype should be paid for.^[10] The craft might be constructed for experimental purposes on the understanding that the DNC held no responsibility.


J. S. White of Cowes built a prototype to the Fleming design.^[1] Eight weeks later the craft was doing trials on the Clyde. The craft behaved admirably, though it tended to bury its nose in the sea at full throttle.^[11] Noise from the two 120 hp Chrysler engines was excessive, being amplified by the metal hull. Also, there remained the difficulty of applying armour plate to the hull. The sides were not flat, but rounded – a complicated shape for which to roll an armoured skin. The Birmabright alloy used also presented chemical and physical obstacles for the application of hardened steel plates.^[8]


The Thornycroft design was being built at the same time with a hull of mahogany, the internal arrangements for the troops and exit being generally similar to the mock-up that had been built in Portsmouth Dockyard. The power plant of two 65 hp Ford V8 engines would be much quieter.


The Fleming won competitive trials at Langstone Harbour. Compared to the Thornycroft, the Fleming was superior in many areas. Troops disembarked in a quarter of the time. The silhouette and bow wave were smaller, qualities typically beneficial for surprise landings. However, the Fleming remained noisy. During trials on a misty morning the noisy approaching craft frightened civilians along the shore; tactical surprise was impossible.^[1]


Afterwards, Thornycroft produced a prototype to a revised design based on a double-diagonal mahogany hull. The silhouette and bow wave were small, and the twin engines could be made silent beyond 25 yards. Armour could replace the outer mahogany planking. Beaching qualities were satisfactory, something retained by the LCA. There was a lowerable ramp, but disembarkation speed remained unsatisfactory due to the narrowness. The revised Thornycroft became the basis for the LCA. DNC and Thornycroft collaborated to develop the design further, leading to a third prototype, ALC No 2.^[1]