USS ''LSM-60'' was a

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

era landing ship, medium (LSM)

amphibious assault ship An amphibious assault ship is a type of warship employed to land and support ground forces on enemy territory during an armed conflict. The design evolved from aircraft carriers converted for use as helicopter carriers (which, as a result, ar ...

of the

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

. It was notable for being used as the float to suspend a

fission bomb A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear expl ...

underwater during the

Operation Crossroads Operation Crossroads was a pair of nuclear weapon tests conducted by the United States at Bikini Atoll in mid-1946. They were the first nuclear weapon tests since Trinity on July 16, 1945, and the first detonations of nuclear devices sinc ...

BAKER test, becoming the first naval vessel to deploy a nuclear weapon.

World War II Service

''LSM-60s keel was laid on 7 July 1944 and she was launched on 29 July. She was commissioned on 25 August. ''LSM-60'' participated in the assault landings at Iwo Jima, where she earned one

battle star A service star is a miniature bronze or silver five-pointed star in diameter that is authorized to be worn by members of the eight uniformed services of the United States on medals and ribbons to denote an additional award or service period. T ...

Operation Crossroads "ground" zero

In 1946, the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

conducted the first

nuclear weapon test Nuclear weapons tests are experiments carried out to determine the performance of nuclear weapons and the effects of their explosion. Nuclear testing is a sensitive political issue. Governments have often performed tests to signal strength. Bec ...

s designed to measure nuclear explosion effects on ships,

. The second shot of this test, BAKER, was designed to test the effects of an underwater nuclear blast on surface ships and submarines. ''LSM-60'' was 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 "Fat Man" (also known as Mark III) was the design of the nuclear weapon the United States used for seven of the first eight nuclear weapons ever detonated in history. It is also the most powerful design to ever be used in warfare. A Fat Man ...

" type atomic bomb, nicknamed ''Helen of Bikini'', placed in a watertight casing, was suspended 90 feet below ''LSM-60'' in the lagoon of

Bikini Atoll Bikini Atoll ( or ; Marshallese language, Marshallese: , , ), known as Eschscholtz Atoll between the 19th century and 1946, is a coral reef in the Marshall Islands consisting of 23 islands surrounding a central lagoon. The atoll is at the no ...

in the

Marshall Islands The Marshall Islands, officially the Republic of the Marshall Islands, is an island country west of the International Date Line and north of the equator in the Micronesia region of the Northwestern Pacific Ocean. The territory consists of 29 c ...

. At 0835 local time the bomb was detonated, destroying ''LSM-60'' and eight target ships, including . A seaman present claimed that "there was not one identifiable piece of the ''LSM-60'' ever located", however a British naval constructor present reports he saw a square piece of ''LSM-60'' on the deck of a target ship afterward.

External links

References

{{DEFAULTSORT:Lsm-060 World War II amphibious warfare vessels of the United States Ships built in Houston LSM-1-class landing ships medium 1944 ships Ships sunk as targets Ships involved in Operation Crossroads Maritime incidents in 1946