Rolls-Royce/Snecma Olympus 593 - Development

Development

The Olympus 593 project was started in 1964, using the BAC TSR-2's Olympus 320 as a basis for development. Bristol Siddeley of the UK and Snecma Moteurs of France were to share the project. SNECMA and Bristol were also involved in an unrelated joint project, the M45H turbofan.

Acquiring Bristol Siddeley in 1966, Rolls-Royce continued as the British partner. The early stages validated the basic design concept, but many studies were required to achieve desired specifications, e.g.

• The critical factor – fuel consumption
• Pressure Ratio
• Weight/Size
• Turbine entry temperature

Initially, engineers studied using turbojets or turbofans, but the lower frontal cross-sectional area of turbojets in the end was shown to be a critical factor in achieving superior performance. The competing Russian Tu-144 initially used a turbofan, but quickly changed to a turbojet with considerable improvement in performance.

Development of the original Olympus and engine accessories was under Bristol Siddeley, while Snecma was responsible for the variable engine inlet system, the exhaust nozzle/thrust reverser, the afterburner and the noise attenuation system. Britain was to have a larger share in production of the Olympus 593 as France had a larger share in fuselage production.

The Olympus 593B was run in November 1965. The B was a redesign of the 593D which was planned for an earlier smaller Concorde design. Tests of 593D gave further information for the design of the B. The B was dropped later from the designation. SNECMA used an Olympus 301 in testing scaled models of the nozzle system.

In June 1966, a complete Olympus 593 engine and variable geometry exhaust assembly was first run at Melun-Villaroche, Île-de-France, France. At Bristol, flight tests began using a RAF Vulcan bomber with the engine attached to its underside. Due to the Vulcan's aerodynamic limitations, the tests were limited to a speed of Mach 0.98 (1,200 km/h). During these tests, the 593 achieved 35,190 lbf (157 kN) thrust, which exceeded the requirements of the engine.

In early 1966, the Olympus 593 delivered 37,000 lb of thrust with the use of reheat.

In April 1967, the Olympus 593 ran for the first time in a high altitude chamber, at Saclay Île-de-France, France. In January 1968, the Vulcan flying test bed logged 100 flight hours, and the variable geometry exhaust assembly for the Olympus 593 engine was cleared at Melun-Villaroche for flight in the Concorde prototypes.

At 15:40, on March 2, 1969, Concorde prototype 001, captained by chief test pilot André Turcat, started its first take-off run, with afterburners lit. The four Olympus 593 engines accelerated the aircraft, and after 4,700 feet (1.4 km) of runway and at a speed of 205 knots (380 km/h), captain Turcat lifted the aircraft off for the first time.

In the end, 67 of these engines were manufactured.

Plans were drawn up for a quieter and more powerful version of the engine, with an extra turbine section and a larger-diameter air compressor that would have eschewed the reheat and added sound-deadening; this would have improved efficiency across the board and permitted a rather greater range and opened up new routes, particularly across the Pacific as well as transcontinental routes across America. However, the poor sales of Concorde meant that this plan for a Concorde 'B' was never put into practice.