The Mark 65 one thousand-pound (450 kg)

general-purpose bomb A general-purpose bomb is an air-dropped bomb intended as a compromise between blast damage, penetration, and fragmentation in explosive effect. They are designed to be effective against enemy troops, vehicles, and buildings. Characteristics ...

was developed for the U.S. military in 1939. The designation was AN-M65.

Design

The M65 design was specialized to contain a higher portion of explosive weight in a lighter casing. Up until this period a typical general-purpose bomb was 50% casing weight and 50% explosive material. The AN series of designs used a lighter-weight higher-strength steel casing with the goal of having up to 65% of the finished bomb weight be explosive material. {{cite book, title=OP 1280 Aircraft Bombs, publisher=

Bureau of Ordnance The Bureau of Ordnance (BuOrd) was a United States Navy organization, which was responsible for the procurement, storage, and deployment of all naval weapons, between the years 1862 and 1959. History The Bureau of Ordnance was established as part ...

, url=https://archive.org/details/bombs-navord-op-1280-1955, year=1955

Operational history

The Mark 65 entered production in 1939 and was used extensively in

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 ...

and the

Korean War The Korean War (25 June 1950 – 27 July 1953) was an armed conflict on the Korean Peninsula fought between North Korea (Democratic People's Republic of Korea; DPRK) and South Korea (Republic of Korea; ROK) and their allies. North Korea was s ...

. As more bombing roles were shifted to light

jet aircraft A jet aircraft (or simply jet) is an aircraft (nearly always a fixed-wing aircraft) propelled by one or more jet engines. Whereas the engines in Propeller (aircraft), propeller-powered aircraft generally achieve their maximum efficiency at much ...

that carried bombs externally rather than inside an internal bomb bay, the shape of bomb casings was studied. In the early 1950s this research caused production to shift from the AN series bombs to the Mark 80 series streamlined designs still in use today. During the height of the American bombing campaign in Vietnam during 1967, the Mark 80 series bombs were being used faster than they were being manufactured, leading to a shortage in the Mark 83 one thousand-pound bomb that had replaced the Mark 65 in naval service. To fill the shortage until new Mark 83 bombs could be delivered, the

U.S. Navy The United States Navy (USN) is the maritime service branch of the United States Department of Defense. It is the world's most powerful navy with the largest displacement, at 4.5 million tons in 2021. It has the world's largest aircraft ...

used the remaining Mark 65 bombs it had left over from the Korean War. An indeterminate number of these stored Mark 65 weapons were used until the supply was exhausted. This weapon was involved in the 1967 USS ''Forrestal'' fire, which killed 134 sailors and injured 161.

References

Cold War aerial bombs of the United States World War II aerial bombs of the United States