USSLSM-60

LSM-60with modifications for the Baker Test, Bikini Atoll
History
United States
Name	USSLSM-60
Builder	Brown Shipbuilding,Houston, Texas
Laid down	7 July 1944
Launched	29 July 1944
Commissioned	25 August 1944
Honors and awards	1battle star(World War II)
Fate	Destroyed during "Operation Crossroads"Test Baker, 25 July 1946
General characteristics
Class and type	LSM-1 class Landing Ship Medium
Displacement	520 long tons (528 t) light 743 long tons (755 t) landing 1,095 long tons (1,113 t) full load
Length	203 ft 6 in (62.03 m)o/a
Beam	34 ft 6 in (10.52 m)
Draft	3 ft 6 in (1.07 m) forward 7 ft 8 in (2.34 m) aft Fully loaded: 6 ft 4 in (1.93 m) forward 8 ft 3 in (2.51 m) aft
Propulsion	2 ×Fairbanks-Morse(model 38D81/8X10, reversible with hydraulic clutch)diesels.Direct drive with 1,440 bhp (1,074 kW) each @ 720 rpm, twinscrews
Speed	13.2knots(15.2 mph; 24.4 km/h)
Range	4,900nmi(9,100 km) at 12 kn (22 km/h)
Capacity	5 medium or 3 heavytanks,or6LVT's,or9DUKW's
Troops	2 officers, 46 enlisted
Complement	5 officers, 54 enlisted
Armament	6 ×20 mmAAgun mounts
Armour	10-lb. STS splinter shield to gun mounts, pilot house and conning station

USSLSM-60was aWorld War IIeralanding ship, medium(LSM)amphibious assault shipof theUnited States Navy.It was notable for being used as the float to suspend afission bombunderwater during theOperation CrossroadsBAKER test, becoming the first naval vessel to deploy a nuclear weapon.

World War II Service

LSM-60's keel was laid on 7 July 1944 and she was launched on 29 July.She was commissioned on 25 August.

LSM-60participated in theassault landings at Iwo Jima,where she earned onebattle star.

Operation Crossroads "ground" zero

LSM-60is destroyed as part of theOperation CrossroadsBAKER test

See also:Operation Crossroads

In 1946, theUnited Statesconducted the firstnuclear weapon testsdesigned to measure nuclear explosion effects on ships,Operation Crossroads.The second shot of this test, BAKER, was designed to test the effects of an underwater nuclear blast on surface ships and submarines.

LSM-60was modified with a well through the cargo deck and hull, a derrick to lower the bomb through the well, and a large antenna to receive the detonation signal. On 25 July, a standard Mk. 3A "Fat Man"type atomic bomb, nicknamedHelen of Bikini,placed in a watertight casing, was suspended 90 feet belowLSM-60in the lagoon ofBikini Atollin theMarshall Islands.At 0835 local time the bomb was detonated, destroyingLSM-60and eight target ships, includingUSSSaratoga(CV-3).A seaman present claimed that "there was not one identifiable piece of theLSM-60ever located ",however a British naval constructor present reports he saw a 3-inch (7.6 cm) square piece ofLSM-60on the deck of a target ship afterward.

External links

• Photo galleryof USSLSM-60at NavSource Naval History