Infantry landing ship

LCAs leave HMS Rocksand, a landing ship, infantry, for the island of Nancowry in the British occupation of the Nicobar Islands, October 1945
Class overview
Name:	Landing ship, infantry
Operators:	Royal Navy Ministry of War Transport Royal Canadian Navy Royal Indian Navy Royal Australian Navy
Succeeded by:	Landing ship logistics
Built:	1938–1945
Completed:	~40
Active:	0
General characteristics
Troops:	150 to 1,500,
Crew:	120 to 300 officers and ratings
Armament:	Typically a range of anti-aircraft guns
Armour:	Typically anti-splinter mattresses and gun shields

A Landing ship, infantry (LSI) or infantry landing ship was one of a number of types of British Commonwealth vessels used to transport landing craft and troops engaged in amphibious warfare during the Second World War. LSIs were operated by the Royal Navy, British Merchant Navy, Royal Canadian Navy, Royal Indian Navy, and Royal Australian Navy. They transported British Commonwealth and other Allied troops in sea assaults and invasions throughout the war.

Typically, a landing ship, infantry would transport its cargo of infantry from its embarkation port to close to the coast to be invaded. This location (known as a "transport area" in a US Navy task force, or "lowering position" in a Royal Navy task force) was approximately 6–11 miles off shore (11 miles was amphibious doctrine for the USN by mid-war, while the RN tended to accept the risks associated with drawing nearer the shore). The troops would then transfer to landing craft, most commonly LCAs, for the journey to the beach. The landing craft would return to the LSI after disembarking their cargo and be hoisted up to embark additional troops.

In the years immediately before war was declared the Inter-Service Training and Development Centre sought to identify ships suitable to carry Army and Royal Marine formations being employed in amphibious operations. Such ships would not be purpose-built, but would be found within the lists of merchant marine vessels. These ships needed to be fast and have davits capable of lowering the new landing craft assault fully loaded with troops.Glengyle and her sisters, Glenearn, Glenroy, and Breconshire, then abuilding, were determined to be ideal for infantry landing ships. This class of four fast passenger and cargo liners were intended for the Far East trade route. The Admiralty acquired the four Glens shortly after their launchings, and converted them into fast supply ships. By June 1940, Glengyle, Glenearn, and Glenroy were under conversion to LSI(L)s. The Admiralty insisted on keeping Breconshire in a fast cargo configuration, so the ISTDC consulted the Director of Naval Construction about suitable requisitioned ships. The Dutch Continental passenger steamers Queen Emma and Princess Beatrix were converted to LSIs. Displacing approximately 3,000 gross registered tons and able to make 22 knots, these vessels could carry as many as 800 troops apiece. These were the original 5 LSIs. More LSIs would be found in the years to come from requisitioning or new construction provided by the United States under Lend-Lease.