Bristol Phoebus

The Bristol Phoebus was an early turbojet engine developed by Bristol Engines. It was based on the gas generator core of the Bristol Proteus. The Phoebus was used for development but only a handful were made. As with other Bristol engines, it took its name from classical mythology.

Bristol avoided gas turbine development work at first, as Roy Fedden considered that Bristol's limited wartime resources were already occupied with the enlarged generation of sleeve valve radial engines such as the Hercules and Centaurus then under development and that a useful turbojet engine was at least ten years away. This policy changed under Frank Owner and this became one of the reasons behind Fedden's falling out with Bristol and his departure from them in 1942.

Bristol began gas turbine design work with Owner's 1943 proposal for a 4,000 hp turboprop, which entered service as the more modest 2,000 hp Theseus. Given Bristol's experience with large radials for heavy transport aircraft, they chose to address the same applications for their first turbine engines, thus chose tubroprops rather than the turbojets for fast fighters which all the other manufacturers were developing. In late 1944 work began on another tuboprop, the Proteus.

For the Bristol Type 172 fast jet bomber and also with an eye to post-war developments and the likelihood of jet travel in fast airliners, Bristol had considered the need for a suitable pure turbojet engine. This B.E.10 engine, which would eventually become the Olympus, began as initial concepts in 1946. Bristol recognised that their lack so far of experience with pure-jet engines could be overcome by developing the core of the Proteus, the compressor, combustion chambers and first turbine, as a stand-alone jet engine. In hindsight, the Phoebus compressor also gave valuable lessons for the design of the Proteus.

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