The General Electric J87 was a

nuclear-powered Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced b ...

turbojet The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, and ...

engine designed to power the proposed

WS-125 The WS-125 was an American super long-range strategic bomber project during the Cold War to develop a nuclear-powered aircraft. Development In 1954, the United States Air Force (USAF) issued a weapons system requirement for a nuclear-powered b ...

long-range bomber. The program was started in 1955 in conjunction with

Convair Convair, previously Consolidated Vultee, was an American aircraft manufacturing company that later expanded into rockets and spacecraft. The company was formed in 1943 by the merger of Consolidated Aircraft and Vultee Aircraft. In 1953, i ...

for a joint engine/airframe proposal for the WS-125. It was one of two nuclear-powered gas turbine projects undertaken by GE, the other one being the X39 project.

Design and development

The J87 was a large turbojet, designed to operate as a paired unit, with a nuclear reactor power section. The complete power-plant was given the project designation X211. The X211 was a relatively large multiple turbojet engine of conventional layout, save for the combustion chambers being replaced by a nuclear reactor where half of the total air-flow through the turbojet sections was used for direct-cycle cooling of the reactor. The J87 components featured variable-stator compressors and chemically-fuelled afterburners and a single nuclear reactor to supply heat to both J87 engines. Several arrangements for the X211 were studied but eventually the paired J87 was chosen and development was started at General Electrics Evandale factory. The air by-passed around the XMA-1A nuclear reactor passed through can style combustion chambers arranged around the core, used for starting, burning normal jet fuel to ensure cooling air flow for the reactor as soon as it was started-up. The reactor core sat in the middle of the combustion section, fed with cooling air from a large

plenum chamber A plenum chamber is a pressurised housing containing a fluid (typically air) at positive pressure. One of its functions is to equalise pressure for more even distribution, compensating for irregular supply or demand. It is typically relatively la ...

. Heated exhaust air was collected by another plenum chamber to be fed to the turbine sections. Testing of the X211 was confined to the XJ87 turbojet sections. In 1956, the

United States Air Force The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal ...

(USAF) decided that the proposed WS-125 bomber was unfeasible as an operational strategic aircraft. In spite of this, the X211 program was continued for another 3 years, albeit with no target application. It was finally terminated in mid-1959 and by 1961 all funding for nuclear propulsion was removed. The competing

Pratt & Whitney Pratt & Whitney is an American aerospace manufacturer with global service operations. It is a subsidiary of Raytheon Technologies. Pratt & Whitney's aircraft engines are widely used in both civil aviation (especially airlines) and military aviat ...

indirect-cycle engines used J91 turbojet sections in the

X287 X, or x, is the twenty-fourth and third-to-last letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''"ex"'' (pronounced ), ...

and

X291 X, or x, is the twenty-fourth and third-to-last letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''"ex"'' (pronounced ), ...

projects, which were also cancelled with the demise of the nuclear-powered bomber program.

Specifications (single J87)

References

{{USAF gas turbine engines 1950s turbojet engines Abandoned military aircraft engine projects of the United States