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".

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.

The flat bottom and skegs between and on either side of the twin screws allowed the ships to safely beach.

Armour for the gun mounts, pilot house and conning tower was provided by 10 lb (4.5 kg) STS splinter shields.

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.

When not on a picket station, the ship would create smoke to hide the fleet at anchor and perform "skunk patrol" screening for suicide boats.

Importantly, Lieutenant Richard M. McCool, skipper of USS LCS(L)(3) 122, was awarded the Medal of Honor.

It is open to the public on Tuesdays, Thursdays and Saturdays or by special arrangements, and tours at the former Mare Island Naval Shipyard, in Vallejo, California.