The Landing Craft, Support (Large) were two distinct classes of amphibious warfare vesselss were used by the United States Navy in Pacific and the Royal Navy in World War II. The USN versions which were later reclassified Landing Ship Support, Large also performed radar picket duty and fire fighting.
The original designation for the ships was LCS(L)(3), which stood for "Landing Craft Support (Large) Mark 3". In 1949 the class was reclassified to "Landing Ship Support, Large" (LSSL). The United States Navy had to have the designation LCS(L) because there was also a smaller class named LCL, that were built mainly for rescue and smoke laying during amphibious operation.
A total of 130 were made. Three different ship building yards did the construction: George Lawley & Son (Neponset, Massachusetts); Commercial Iron Works (Portland, Oregon); and Albina Engine Works (Portland, Oregon).
The hull was the same as the Landing Craft Infantry ships. They were 158 ft 6 in (48.31 m) long, displaced 250 long tons (250 t), 23 ft 3 in (7.09 m) wide and drew 5 ft 10 in (1.78 m) when fully loaded. The flat bottom and skegs between and on either side of the twin screws allowed the ships to safely beach. The anchor is at the stern of the ship so it can be used to help pull the ship off the beach if necessary.
The twin variable pitch screws were each driven by a bank of four Grey Marine (later General Motors) diesel engines, with a total power for all eight engines of 1,600 horsepower (1,200 kW). These engines gave a maximum speed of 16.5 knots (30.6 km/h), but normally the ships sailed at 12 knots (22 km/h). The ships had a range of 5,500 nautical miles (10,200 km).
Armour for the gun mounts, pilot house and conning tower was provided by 10-lb. STS splinter shields.
LCS(L) vessels could be produced in as little as 10 days, and final fitting out would take a further few weeks.
The ships had a smoke generator which was used to obscure landing craft approaching the beach.
The ships also made very good fire fighting ships. A fire fighting manifold was fitted in front of the bow gun and two monitors with pumps fitted just forward of the aft gun.
The LCS(L)(3) ships provided more firepower per ton than any ship ever built for the U.S. Navy. Three guns and 10 rocket launchers were the main armaments. The bow gun was a 3"/50 caliber gun, a single 40 mm gun or a twin 40 mm gun. The forward and aft deck guns were twin 40 mm gun. The 10 mark 7 rocket launchers were situated behind the bow gun and forward deck house. Four 20 mm cannons were also mounted and other arms stowed inside. The rifle locker held 4 M1 carbines, 4 Thompson sub machine guns, and 1911A1 45cal semi auto pistols.
The Battle of Tarawa showed a gap in Navy resources for close in support of landing troops. The time interval between the end of shelling from the large ships and the arrival of the landing craft on the beach allowed the defenders to regroup. The Landing Craft Support was designed to fill this void.
After providing close in support during the landings at Okinawa, many Landing Craft Support ships were placed on the radar picket stations as anti-aircraft platforms. When not on a picket stations, the ship would create smoke to hide the fleet at anchor and perform "skunk patrol" screening for suicide boats.
During World War II, five LCS(L)(3)s were sunk in combat (see below) and 21 were damaged. Three of these small warships received Presidential Unit Citations, while six were awarded Navy Unit citations. Importantly, LT Richard M. McCool, skipper of the USS LCS(L)(3) 122, was awarded the Congressional Medal of Honor.
USS LCS(L)(3)-7 sunk by Suicide boat off Mariveles, Corregidor Channel, Luzon, Philippine Islands, 16 February 1945.
USS LCS(L)(3)-15 sunk by kamikaze aircraft off Okinawa, Ryukyu Islands, 22 April 1945.
USS LCS(L)(3)-26 sunk by Suicide boat off Mariveles, Corregidor Channel, Luzon, Philippine Islands, 16 February 1945.
USS LCS(L)(3)-33 sunk by shore batteries off Iwo Jima, Volcano Islands, 19 February 1945.
USS LCS(L)(3)-49 sunk by suicide boat off Mariveles, Corregidor Channel, Luzon, Philippine Islands, 16 February 1945.
At the end of the war, surviving ships returned to the United States. Some were restored to action for the Korean War. Many were transferred to Japan, France (and on to South Vietnam), Cambodia, Thailand, Greece, and other nations.
Only two ships are known to still exist. One has been highly modified as a fishing boat. The second was in Thailand and was kept in very similar configuration to its original (HTMS Nakha, formerly USS LCS(L)-102). The National Association of USS LCS(L) 1–130 was successful in having the HTMS Nakha transferred to the association for public display in the United States. She was officially released from the Royal Thai Navy on November 10, 2007 after being returned to the USA in September of that year. As of May 2017 the USS LCS(L)-102 is under restoration and upkeep. It is open to the public on Tuesdays, Thursdays and Saturdays or by special arrangements, and tours at the former Naval Ship yard, Mare Island, in Vallejo, California.