By the end of 1946, the company had only 10 hours of turbojet experience with a small experimental engine called the Phoebus which was the gas generator or core of the Proteus turboprop then in development.

[6] In early 1947, the parent Bristol Aeroplane Company submitted a proposal for a medium-range bomber to the same specification B.35/46 which led to the Avro Vulcan and Handley Page Victor.

This two-spool design eliminated the need for features such as variable inlet guide vanes (Avon, J79), inlet ramps (J65), variable stators (J79) or compressor bleed (Avon) which were required on single spool compressors with pressure ratios above about 6:1.

Without these features an engine could not be started nor run at low speeds without destructive blade vibrations.

Separate combustion cans would have exceeded the diameter beyond the design limit, and a true annular system was considered too advanced.

The engine started without a problem and Hooker, supervising the first test run and displaying the confidence he had in the design, slammed the throttle to give a surge-free acceleration to maximum power.

Examples of the similar BOl.1/2A were constructed for US manufacturer Curtiss-Wright which had bought a licence for developing the engine as the TJ-32 or J67 for the projected F-102.

[17] The Olympus was developed extensively throughout its production run, and the many variants can be described as belonging to four main groups.

The first reheat variant, the Bristol Siddeley Olympus Mk 320, powered the cancelled BAC TSR-2 supersonic strike aircraft.

Archived from the original on 29 July 2013. and Lecture Notes, Vulcan Bristol Aero Engine School Related development