Allison J33

The General Electric/Allison J33 is an American centrifugal-flow jet engine, a development of the General Electric J31, enlarged to produce significantly greater thrust, starting at 4000 lbf and ending at 4600 lbf with an additional low-altitude boost to 5400 lbf with water-alcohol injection.

Development
The J33 was originally developed by General Electric as a follow-on to their work with the designs of Frank Whittle during World War II. Their first engine was known as the General Electric I-A, but after major changes to adapt it to US production and to increase thrust, it started limited production as the I-16 in 1942, the 16 referring to its 1600 lbf thrust. Full production started as the J31 when the United States Army Air Forces introduced common naming for all their engine projects.

Along with the I-16, GE also started work on an enlarged version, known as the I-40. As the name implied, the engine was designed to provide 4000 lbf. Apart from size, the main difference between I-16 and the I-40 was the combustion system: the I-16 had ten reverse-flow cans, whereas the I-40 had 14 straight-through combustors. The development cycle was remarkably rapid. Design work started in mid-1943 and the first prototype underwent static testing on 13 January 1944.

Lockheed was in the midst of the XP-80 project at the time, originally intending to power their design with a US-produced version of the Halford H-1 of about 3000 lbf. Production of the H-1 by Allis-Chalmers ran into delays, and since the I-40 would dramatically improve performance, plans were made to fit the prototypes with the I-40 instead.

The I-40 became important to the USAAF's plans when the I-16 powered P-59 was skipped over in favor of the I-40 powered P-80 as the US's first production jet fighter. In 1945, the license to actually produce the engine was not given to General Electric, but to Allison instead. Allison, working largely from government-owned wartime factories, could produce the engine in quantity more quickly and cheaply.

By the time the production lines were shut down, Allison had built over 6,600 J33's and General Electric another 300 (mostly the early runs).

In 1958, surplus J33s were used in jet donkeys pushing dead loads at 200 knots to test aircraft carrier arresting gear cables and tailhooks at Lakehurst.

A model of the J33 intended for civil use, designated the Allison 400-C4, in 1948 became the first US gas turbine certificated for commercial transport use.

Variants


Data from: Aircraft engines of the World 1953, Aircraft engines of the World 1957, Aircraft engines of the World 1953,
 * J33-A-4: similar to -21 without water injection.
 * J33-A-6: 4600 lbf, United States Navy (USN)
 * J33-A-8: 4600 lbf, (USN)
 * J33-A-10: 4600 lbf, (USN) Used as mixed propulsion engine system with P&W R-4360 on Martin P4M
 * J33-A-14: A short life engine powering the Chance-Vought Regulus, 4600 lbf thrust.
 * J33-A-16: Similar to the -16A, 5850 lbf
 * J33-A-16A: Powering the Grumman F9F-7, 5400 lbf thrust.
 * J33-A-17:similar to -21 without water injection
 * J33-A-17A:
 * J33-A-18A: A short life engine powering the Chance-Vought Regulus.
 * J33-A-20:
 * J33-A-21: 4500 lbf thrust.
 * J33-A-22: Powering the Lockheed T2V-1 with bleed air for boundary-layer control.
 * J33-A-23: similar to -35, 4600 lbf thrust.
 * J33-A-24: 6100 lbf thrust, powers the Lockheed T2V.
 * J33-A-24A: 6100 lbf thrust, powers the Lockheed T2V.
 * J33-A-25: similar to -35
 * J33-A-27: United States Air Force (USAF), similar to the -16A,
 * J33-A-29: 8200 lbf re-heat thrust.
 * J33-A-31: similar to -35
 * J33-A-33: 6000 lbf re-heat thrust.
 * J33-A-35: 4600 lbf thrust / 5400 lbf with water-alcohol injection, powers the Lockheed T2V and Lockheed T-33.
 * J33-A-37: A short life engine powering the Martin Matador, 4600 lbf thrust.
 * Model 400-C4:Company designation, for commercial use, similar to J33-A-21.
 * Model 400-C5:Company designation of J33-A-23.
 * Model 400-C13:Company designation of the -35
 * Model 400-D9:Company designation of the -33

Applications

 * Convair XF-92
 * Lockheed P-80 Shooting Star
 * Lockheed T-33 Shooting Star
 * Lockheed F-94A / F-94B Starfire
 * Lockheed T2V SeaStar
 * North American AJ Savage
 * Martin P4M Mercator
 * Martin MGM-1 Matador
 * Martin MGM-13 Mace
 * Vought SSM-N-8 Regulus

Engines on display

 * A J33 is on public display at the City of Norwich Aviation Museum in Horsham St Faith, Norfolk.