The GT-1 (Glide Torpedo 1) was an early form of stand-off weaponry developed by the

United States Army Air Forces The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...

during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. Intended to deliver an

aerial torpedo An aerial torpedo (also known as an airborne torpedo or air-dropped torpedo) is a torpedo launched from a torpedo bomber aircraft into the water, after which the weapon propels itself to the target. First used in World War I, air-dropped torped ...

at a safe range from the launching aircraft, the weapon proved successful enough in testing to be approved for operational use, and the GT-1 saw limited use in the closing stages of the war.

Design and development

The GT-1 was derived from the

GB-1 } The GB-1, also known as the "Grapefruit bomb" and as XM-108,379th 2000 p.39. was a glide bomb produced by Aeronca Aircraft for the United States Army Air Forces during World War II. Intended to allow bombers to release bombs from outside the rang ...

series of

glide bomb A glide bomb or stand-off bomb is a standoff weapon with flight control surfaces to give it a flatter, gliding flight path than that of a conventional bomb without such surfaces. This allows it to be released at a distance from the target rat ...

s, developed by Aeronca for the United States Army Air Forces.Parsch 2003 The weapon's airframe was inexpensive and simply designed, with a basic wing and twin tails attached to a cradle for carrying the payload. The flight path of the GT-1 was determined by a preset autopilot that kept the weapon on a steady course after release. The GT-1 was usually released from its carrier aircraft at an altitude of ; this provided a standoff range of as much as under ideal conditions.''

Esquire Esquire (, ; abbreviated Esq.) is usually a courtesy title. In the United Kingdom, ''esquire'' historically was a title of respect accorded to men of higher social rank, particularly members of the landed gentry above the rank of gentlema ...

'' 1947
Volume 28, p.70
The GT-1's warload consisted of a Mark 13 Mod 2A aerial torpedo. The GT-1 was fitted with a paravane, trailing below the main body of the craft; upon the paravane's striking the surface of the water,

explosive bolt A pyrotechnic fastener (also called an explosive bolt, or pyro, within context) is a fastener, usually a nut or bolt, that incorporates a pyrotechnic charge that can be initiated remotely. One or more explosive charges embedded within the bolt a ...

s would fire to release the torpedo, which would then execute a preset search pattern to locate and destroy its target.

Operational history

Initially tested during 1943, the GT-1 proved to be successful, and was issued to a single operational unit for service.Goebel 2010 Launched from

North American B-25 Mitchell The North American B-25 Mitchell is an American medium bomber that was introduced in 1941 and named in honor of Major General William "Billy" Mitchell, a pioneer of U.S. military aviation. Used by many Allied air forces, the B-25 served in e ...

bombers,Hanle 2011 the GT-1 saw brief operational service late in the war;Cate and Craven 1958, p.259. three missions are known to have been flown using the weapon from

Okinawa is a prefecture of Japan. Okinawa Prefecture is the southernmost and westernmost prefecture of Japan, has a population of 1,457,162 (as of 2 February 2020) and a geographic area of 2,281 km2 (880 sq mi). Naha is the capital and largest city ...

in late 1945. On one mission, against

Kagoshima , abbreviated to , is the capital city of Kagoshima Prefecture, Japan. Located at the southwestern tip of the island of Kyushu, Kagoshima is the largest city in the prefecture by some margin. It has been nicknamed the "Naples of the Eastern wor ...

, eleven of thirteen GT-1s launched successfully entered the water; three hits were recorded, against a

fleet carrier A fleet carrier is an aircraft carrier designed to operate with the main fleet of a nation's navy. The term was developed during World War II, to distinguish it from the escort carrier and other less capable types. In addition to many medium-siz ...

, a

light carrier A light aircraft carrier, or light fleet carrier, is an aircraft carrier that is smaller than the standard carriers of a navy. The precise definition of the type varies by country; light carriers typically have a complement of aircraft only one-h ...

, and a freighter. The

Boeing B-17 Flying Fortress The Boeing B-17 Flying Fortress is a four-engined heavy bomber developed in the 1930s for the United States Army Air Corps (USAAC). Relatively fast and high-flying for a bomber of its era, the B-17 was used primarily in the European Theater ...

was also capable of carrying the GT-1.''Army Ordnance'', Volume 30, 1946. American Defense Preparedness Association
p.384
Following the end of World War II, the aerial torpedo rapidly fell out of favor as a weapon of war against surface ships, and the 'GT' category of weapons was abolished in 1947.Mann 2008, p.256.

References

Notes

Bibliography

* * * * * *

External links