Bristol Siddeley Orpheus

The Bristol-Siddeley Orpheus was a single spool turbojet developed by Bristol Aero Engines for various light fighter/trainer applications such as the Folland Gnat and the Fiat G91. Later, the Orpheus formed the core of the first Bristol Pegasus vectored thrust turbofan as used for the Hawker Siddeley Harrier "jump jet".

Design and development

The engine had its genesis in a 1952 request by Folland for an engine in the 5,000 lbf class to power a new trainer and lightweight fighter-bomber they were developing. Stanley Hooker, relatively new to the company after an earlier career at Rolls-Royce, took the project under his wing. He delivered a relatively simple and easy to maintain engine, which was put into use in the Folland Gnat, flying in 1955. Developing a Sea Level Static thrust of 4,520 lbf (6,128 Nm), the Orpheus 701 had a 7 stage axial compressor driven by a single stage turbine.

Other users, mostly trainers, soon followed, including the Fuji T-1, Hindustan Marut, and the experimental Hunting H.126 and Short SB5. In 1957 NATO ran a competition for a light fighter design, asking for entries in both engine and airframe categories. The Orpheus was the unanimous winner of the engine contest, and was thus selected to power the Fiat G.91R and G.91T using Fiat-built versions of the engine.

Many companies in the 1950's were looking at ways of producing a vertical take off and landing aircraft. Michel Wibault had the idea of using a turboshaft engine to drive four large centrifugal blowers which could be swivelled to vector the thrust. Hooker's engineers decided on using the Orpheus to drive a single large fan that would supply air to a pair of rotating nozzles, while the exhaust flow from the Orpheus was split into two and would supply another pair of nozzles at the rear of the engine. This experimental system developed into the Pegasus.

An Orpheus powered the Bluebird K7 hydroplane in which Donald Campbell was killed whilst attempting the water speed record on Lake Coniston in 1967.

A dragster powered by an Orpheus, the "Vampire", is the current holder of the British land speed record.

pecifications (Orpheus 801)

"Data from:" [FAA TDC] jetspecs

type=Turbojet
length=93.47 in (2.374 m)
diameter=32.4 in (823 mm)
weight=975 lb (442 kg)
compressor=7 stage axial compressor
combustion=Can-annular with 7 flame tubes
turbine=Single stage turbine
fueltype=Kerosene
oilsystem=
power=
thrust=4,850 lb (21.99 kN)
compression=
aircon=
turbinetemp=1,184 degrees Fahrenheit (640 degrees Celsius, maximum continuous)
fuelcon=
specfuelcon=
power/weight=
thrust/weight=4.97

See also

Aeroenginecontent

related=
* Rolls-Royce Pegasus

similar aircraft=
* Armstrong Siddeley Sapphire
* Rolls-Royce Avon
lists=
* List of aircraft engines

References

* [http://rgl.faa.gov/Regulatory_and_Guidance_Library%5CrgMakeModel.nsf/0/92F9B402DF47365B862572AC00476572/$FILE/E9eu.pdf FAA Type Data Certificate] Retrieved: 29 September 2008

External Links

* [http://www.flightglobal.com/pdfarchive/view/1957/1957%20-%201719.html?search=Bristol%20Orpheus Flight Global online archive - Detailed description of the Orpheus, November 1957.]