Rolls-Royce Olympus

The Rolls-Royce Olympus (originally the Bristol B.E.10 Olympus) was the world's first two-spool axial-flow turbojet aircraft engine design dating from November 1946, although not the first to run or enter service. It was originally developed and produced by Bristol Aero Engines. First running in 1950, its initial use was as the powerplant of the Avro Vulcan V bomber. The design was further developed for supersonic performance as part of the BAC TSR-2 programme. Later it saw production as the Rolls-Royce/Snecma Olympus 593, the powerplant for Concorde SST. Versions of the engine were licensed to Curtiss-Wright in the US as the TJ-32 or J67 (military designation) and the TJ-38 'Zephyr'. The Olympus was also developed with success as marine and industrial gas turbines.

Bristol Aero Engines (formerly Bristol Engine Company) merged with Armstrong Siddeley Motors in 1959 to form Bristol Siddeley Engines Limited (BSEL), which in turn was taken over by Rolls-Royce in 1966.

As of 2012, the Olympus remains in service as both a marine and industrial gas turbine. It also powers the restored Avro Vulcan XH558.

Origins
At the end of World War II, the Bristol Engine Company’s major effort was the development of the Hercules and Centaurus radial piston engines. 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. 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. The Bristol design was the Type 172 and was to be powered by four or six Bristol engines of 9000 lbf thrust to the Ministry engine specification TE.1/46.

The thrust required of the new engine, then designated B.E.10 (later Olympus), would initially be 9000 lbf with growth potential to 12000 lbf. The pressure ratio would be an unheard of 9:1. To achieve this, the initial design used a low-pressure (LP) axial compressor and a high-pressure (HP) centrifugal compressor, each being driven by its own single-stage turbine. 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. Nor could they accelerate to high speeds with fast acceleration times ("spool up") without surge. The design was progressively modified and the centrifugal HP compressor was replaced by an axial HP compressor. This reduced the diameter of the new engine to the design specification of 40 in. The Bristol Type 172 was cancelled though development continued for the Avro Vulcan and other projects.

Initial Development


The first engine, its development designation being BOl.1 (Bristol Olympus 1), had six LP compressor stages and eight HP stages, each driven by a single-stage turbine. The combustion system was novel in that ten connected flame tubes were housed within a cannular system: a hybrid of separate flame cans and a true annular system. Separate combustion cans would have exceeded the diameter beyond the design limit, and a true annular system was considered too advanced.

In 1950, Dr (later Sir) Stanley Hooker was appointed as Chief Engineer of Bristol Aero Engines.

The BOl.1 first ran on 16 May 1950 and was designed to produce 9140 lbf thrust and to be free from destructive rotating stall on start up to idle speed and to be free from surging on fast accelerations to maximum thrust. 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. The thrustmeter showed 10000 lbf. The next development was the BOl.1/2 which produced 9500 lbf thrust in December 1950. 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. The somewhat revised BOl.1/2B, ran in December 1951 producing 9750 lbf thrust. The engine was by now ready for air testing and the first flight engines, designated Olympus Mk 99, were fitted into a Canberra WD952 which first flew with these engines derated to 8000 lbf thrust in August 1952. In May 1953, this aircraft reached a world record altitude of 63668 ft. (Fitted with more powerful Mk 102 engines, the Canberra increased the record to 65876 ft in August 1955. )

Variants

 * BOl.1/2A:
 * BOl.1/2B:
 * BOl.1/2C:
 * BOl.2:
 * BOl.3: Of all the early initial developments, BOl.2 to BOl.5 (the BOl.5 was never built ), perhaps the most significant was the BOl.3. Even before the Vulcan first flew, the Olympus 3 was being suggested as the definitive powerplant for the aircraft. In the event, the 'original' Olympus was continuously developed for the Vulcan B1. The BOl.3 was described in 1957 as "a high-ended product intermediate between the Olympus 100 and 200 series."
 * BOl.4:
 * BOl.5:not built
 * BOl.6:(Mk.200)
 * BOl.7:(Mk.201)
 * BOl.7SR:
 * BOl.11:(Mk.102)
 * BOl.12:(Mk.104)
 * BOl.21:(Mk.301)
 * BOl.21R: not built, proposed for R.A.E. Missile (A) designed to meet O.R. 1149 issued May 1956.
 * BOl.22R:(Mk.320)
 * BOl.23: not built, proposed with a 301 compressor, 22R turbine and reheat to give 25,000 lb at take-off (reheat).
 * Olympus Mk 100: (BOl.1/2B) Similar to Olympus Mk 99 rated at 9250 lbf thrust for second Vulcan prototype VX777. First flew September 1953.
 * Olympus Mk 101: (BOl.1/2C) Larger turbine, 11000 lbf thrust for initial production Vulcan B1 aircraft. First flew (XA889) February 1955.
 * Olympus Mk 102: (BOl.11) Additional zero stage on LP compressor, 12000 lbf thrust for later production Vulcan B1 aircraft.
 * Olympus Mk 104: (BOl.12) Designation for Olympus Mk 102 modified on overhaul with new turbine and burners, 13000 lbf thrust initially, 13500 lbf thrust on uprating, standard on Vulcan B1A.
 * 'Olympus 106': Used to describe the development engine for the Olympus 200 (BOl.6). Possibly a corruption of BOl.6 (Olympus 6).
 * Olympus Mk 97: This early engine tested an early annular combustion chamber. It was test flown on Bristol's Avro Ashton test bed WB493.
 * Olympus Mk 201: (BOl.7) Uprated Olympus Mk 200. 17000 lbf thrust. Initial Vulcan B2 aircraft.
 * Olympus Mk 202: Disputed. Either Olympus Mk 201 modified with rapid air starter, or Olympus Mk 201 with redesigned oil separator breathing system. This was the definitive '200 series' engine fitted to Vulcans not fitted with the Mk 301. The restored Vulcan XH558 is fitted with Olympus Mk 202 engines.
 * 'Olympus Mk 203': Very occasional reference to this elusive mark of engine can be found in some official Air Publications relating to the Vulcan B2. It is also noted in a manufacturer's archived document dated circa 1960.
 * Olympus Mk 301: (BOl.21) Additional zero stage on LP compressor. 20000 lbf thrust. Later Vulcan B2 aircraft plus nine earlier aircraft retrofitted. Later derated to 18000 lbf thrust. Restored to original rating for Operation Black Buck.
 * Olympus 510 series: With a thrust in the region of 15000 lbf to 19000 lbf, the 510 series were civilianised versions of the BOl.6. A team was sent to Boeing at Seattle to promote the engine in 1956 but without success.
 * Olympus 551: The Olympus 551 'Zephyr' was a derated and lightened version of the BOl.6 and rated at 13500 lbf thrust. The engine was the subject of a licence agreement between Bristol Aero Engines and the Curtiss-Wright Corporation - the engine being marketed in the US as the Curtiss-Wright TJ-38 Zephyr. There were hopes to fit the Olympus 551 to the Avro Type 740 and Bristol Type 200 trijet airliners which did not progress beyond the project stage. Curtiss-Wright also failed to market the engine.
 * Mk.320:The performance specification for the BAC TSR-2 was issued in 1962. It was to be powered by two BSEL Olympus Mk 320 (BOl.22R) engines each rated at 19610 lbf dry and 30610 lbf with reheat at take-off. The engine, which was re-stressed for supersonic flight at sea level, and over Mach 2.0 at altitude, and featured much use of high-temperature alloys such as titanium and Nimonic, was a cutting edge derivative of the Olympus Mk 301 with a Solar-type afterburner. The engine first ran in March 1961, soon achieving 33000 lbf, and was test flown in February 1962 in an underslung nacelle in the belly of Vulcan B1 XA894 and was demonstrated at the Farnborough Air Show in September. In December 1962 during a full power ground run at Filton, the LP shaft failed. The liberated turbine disc ruptured fuel tanks and the subsequent fire completely destroyed the Vulcan.
 * On its first flight in September 1964 the engines of the TSR-2 were scarcely flightworthy being derated and cleared for one flight. Nevertheless, the risk was deemed acceptable in the political climate of the time. With new engines, the TSR-2 XR219 flew another 23 times before the project was cancelled in 1965.


 * Olympus 593: The Rolls-Royce/Snecma Olympus 593 was a reheated version of the Olympus which powered the supersonic airliner Concorde. The Olympus 593 project was started in 1964, using the TSR2's Olympus Mk 320 as a basis for development. BSEL and Snecma Moteurs of France were to share the project. Acquiring BSEL in 1966, Rolls-Royce continued as the British partner.
 * 593D: Formerly Olympus 593. 28100 lbf thrust. (the 'D' in the engine designation equalling 'derivation' - for smaller, short-range version of Concorde that was later cancelled)
 * 593B: Flight test and prototype aircraft. 34370 lbf thrust with reheat. (the 'B' in the engine designation equalling 'big' - for long-range Concorde that subsequently entered service)
 * 593-602:Production. Annular combustion chamber to reduce smoke
 * 593-610:Last production. 38075 lbf thrust with reheat.
 * Curtiss-Wright TJ-32: Examples of the BOl.1/2A were delivered to Curtiss-Wright in 1950. The engine was Americanised during 1951 and flew under a Boeing B-29 testbed as the TJ-32.
 * Curtiss-Wright J67: To meet a USAF demand for an engine in the 15000 lb thrust class, the engine was the subject of a development contract, redesigned and designated J67. Development was protracted and in 1955, the USAF announced that there would be no production contract for the present J67. Several aircraft had been intended to receive the J67 including the Convair F-102 Delta Dagger.
 * Curtiss-Wright T47: The T47 was an attempt to produce a turboprop based upon the J67.
 * TJ-38 Zephyr: See Olympus 551 (above).

Variant notes

 * Second-generation Engines: The initial design of the second-generation 'Olympus 6' began in 1952. This was a major redesign with five LP and seven HP compressor stages and a canullar combustor with eight interconected flame tubes. In spite of a much greater mass flow, the size and weight of the BOl.6 was little different from earlier models.

Rival manufacturers Rolls-Royce lobbied very hard to have its Conway engine installed in the Vulcan B2 to achieve commonality with the Victor B2. As a consequence, Bristols undertook to complete development using company funds and peg the price to that of its fully government-funded rival.
 * Olympus Mk 200: (BOl.6) 16000 lbf thrust. First B2 (XH533) only.


 * Civilianised Olympus:Plans to civilianise the Olympus go back as far as 1953 with the unveiling of the Avro Atlantic airliner based upon the Vulcan. However, most of the civilian derivatives, except for supersonic airliners, were developed from the BOl.6.


 * Thin-wing Javelin:One project that got beyond the drawing board was a supersonic development of the Gloster Javelin, the P370, powered by two BOl.6, 7, or 7SR engines. The design evolved into the P376 with two BOl.21R engines rated at 28500 lbf with reheat. Eighteen aircraft were ordered in 1955. The project was abandoned the following year.


 * Afterburning Olympus: As early as 1952, Bristols had considered the use of reheat, or afterburning, to augment the thrust of the Olympus. Initially, a system called Bristol Simplifed Reheat was devised which was tested on a Rolls-Royce Derwent V mounted in an Avro Lincoln. Later it was tested on an Orenda engine in Canada and on an Olympus Mk 100 in the Avro Ashton test bed. Fully variable reheat became possible after an agreement with the Solar Aircraft Company of San Diego which manufactured bench units for the Olympus Mks 101 and 102. An afterburning Olympus was just one proposal for the Vulcan Phase 6, a 350,000 lb aircraft with a 13/14 hour endurance.


 * Olympus driving aft fan: BS.81 rated at 28,000lb. As an alternative to afterburning a fan mounted at the trailing edge of the wing was proposed for the Vulcan Phase 6. The fan was driven by a turbine in the engine exhaust at the end of the jetpipe.


 * Vectored thrust Olympus: A vertical take-off Vulcan was proposed in 1960. It used 4 vectored-thrust Olympus as well as 10 lift engines.

Derivitives

 * Rolls-Royce Marine Olympus

Industrial power generation
The Olympus entered service as a peak demand industrial power generator in 1962 when the Central Electricity Generating Board (CEGB) commissioned a single prototype installation at its Hams Hall power station. Power was provided by an Olympus 201 exhausting through a two-stage turbine powering a Brush synchronous alternator providing 20 MW at 3000 rpm. By 1972, the CEGB had installed 42 Olympus generating sets. Olympus engines are also used to provide back up power in case of a loss of grid electrical power at some of Britain's nuclear power stations.

Many sets were exported and many found use on offshore platforms. By 1990, over 320 sets had been sold to 21 countries, many of which remain in service.

Applications

 * Avro Vulcan
 * BAC TSR-2

Proposed aircraft applications
Over the years, the Olympus was proposed for numerous other applications including:
 * C104 which led to the C105 Avro Arrow: BOl.3
 * Avro 718: BOl.3 The Type 718 was a military transport aircraft with up to 110 seats.
 * Avro 739 to OR339 (the requirement that culminated in TSR2): BOl.21R
 * Avro 740: 3 x Mk 551
 * Avro 750: 2 x Mk 551
 * Avro Vulcan Phase 6 (B3): BOl.23, a development of the Mk 301. Different engine configurations, BOl.21, BOl.21/2 and BOl.23, with either reheat or an aft fan, were proposed for this aircraft to provide the required increase in take-off thrust.
 * Bristol T172: B.E.10
 * Bristol T177
 * Bristol T180
 * Bristol T198: Mk 591. Early supersonic airliner design (132 seats). The engine was a civilianised BOl.22R.
 * Bristol T201: Mk 551
 * Bristol T202
 * Bristol T204 to OR339: BOl.22SR (simplified reheat)
 * Bristol T205: Mark 551
 * Bristol T213
 * Bristol T223: Mk 593. Later supersonic airliner design (100 seats). Engine as Mk 591 with zero stage LP compressor and cooled HP turbine.
 * de Havilland design to OR339: BOl.14R, BOl.15R. Developed from BOl.6R.
 * Handley Page HP98: Pathfinder variant of Victor.
 * Handley Page Victor B1: Mk 104
 * Handley Page Victor Phase 3
 * Handley Page HP107
 * Handley Page Pacific
 * Hawker P.1121: BOl.21R
 * Hawker P.1129 to OR339: BOl.15R
 * Martin/General Dynamics RB-57F Canberra: Mk 701 developed from Mk 301.
 * Gloster P492/3: Mk 591
 * Republic F-105 Thunderchief: BOl.21 for possible sale to RAF.
 * Saab 36
 * Saab 37 Viggen
 * Vickers VC10: Development of Mk 555 with aft fan.

Engines on display

 * Bristol Aero Collection Kemble Airfield - Mk 104, 593B
 * Imperial War Museum North, Manchester - Mk 101
 * RAF Museum Cosford - Mk 320
 * Gatwick Aviation Museum Charlwood Surrey - Two Mk 320
 * Yorkshire Air Museum Elvington, North Yorkshire - Mk 593
 * Brooklands Museum Weybridge, Surrey - Mk 593B
 * Montrose Air Station Heritage Centre - Bristol B.E.10
 * Museum of Science and Industry (Manchester) - Mk 202 (Engine is displayed as a Mk 201 but its ECU plate reveals it as a Mk 202)