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Aviation History
1959
1959 - 2122.PDF
4 September 1959 141 Bristol Siddelay Vipar 11 Military »ingl«-shaft turbojet. Seven-stage compressor, annular combus- tion chamber with 24 vaporizing burners and single- stage turbine. Overall diameter, 24.55in; intake external diameter, 1B.5in; length, exclusive of nose bullet, 63.7in; dry weight, 500 Ib: max rating, 2,460 Ib dry at 13,400 r.p.m. with mas* flow and pressure ratio of 42 Ib/sec and 3.85:1 and s.f.c. of 1.115. deliveries of the Olympus Mk 104 were rated at 13,000 lb. As the powerplant of the Vulcan B.I, a large number of 100-series Olympus are in R.A.F. service; they are at once the R.A.F.'s most powerful, most efficient and most reliable combat engines, with the highest overhaul life and lowest premature-removal rate. It has also been officially acknowledged that the handling characteristics of these powerplants are superior to those of any other engine in the world, particularly at altitudes above 50,000ft. Production is now being concentrated upon the largely redesigned 200-series engine. While retaining a carcase similar in size to that of the earlier units, these new engines are designed to take advantage of recent improvements in aerodynamics and thermo- dynamics; the number of stages on both compressor spools has been reduced, thus effecting a substantial reduction in engine weight, while retaining an approximately similar pressure ratio. At the same time the mass flow has been very greatly increased so that the dry thrust of the current Mk 201 version is no less than 17,000 Ib. Engines of this general family are fitted to the yulcan B.2, and portions of these units have doubtless been incorporated into the new Bristol Siddeley ducted-fan family. Development has also been proceeding upon a special range of Olympus fined with an afterburner for supersonic propulsion. It is known that the powerplant of the forth- coming TSR.2 aircraft will be an advanced Bristol Siddeley turbojet. It seems fair to assume that this engine will in fact be the ultimate version of the supersonic reheat Olympus family. One of these has been fined with Bristol-Solar fully variable reheat, giving a maximum static thrust of no less than 33,000 lb. Orpheus Originally planned as a medium-thrust turbojet to replace such centri- fugal engines as the Nene, the Orpheus has achieved success in such diverse types of aircraft as trainers, transports, transonic fighters and ground-attack machines. From the outset the engineering design has been weighted heavily in favour of simplicity, low cost and easy maintenance; and the rapid development of the Orpheus, and its outstanding performance in arduous service, underlines the lightness of the concept. At present the most numerous Orpheus are 5,000 lb thrust engines of the Mk 803 variety, which are fitted to the Fiat G.91s used by several NATO Air Forces (the out- standing serviceability of which aircraft is fast becoming a byword). A related engine is the 4,700 Ib thrust Mk 701, fitted to the Folland Gnat lightweight intercepter; and a special version for training purposes, characterized by increased robustness and a rating reduced to 4,230 Ib, is the Mk 100 fitted to the Gnat Trainer. Development is proceeding upon slightly enlarged engines, of which the first example is the BOr.12. The basic BOr.12 is rated at 6,810 lb dry, and with "simplified reheat" has a maximum raring of 8,170 lb. First run on the bench late last year, it achieved its full reheat rating 12 weeks later and is shortly to take the air as the powerplant of a Sabre. Production BOr.l2s will be available next year for such aircraft as the Breguet Taon and for certain supersonic intercepters. Special transport Orpheus have also been projected, incorporating such refinements as thrust reyersers and two-position nozzles to match the engines to take-off or cruising flight regimes. Doubtless the Orpheus also forms the basis of some of the company's new family of fan engines. PR.23 Developed at Ansty by the company's rocket division, the PR.23 is an exceptionally small and compact liquid-propellant rocket package intended for a variety of applications—the most important of which is presumably the vernier propulsion of large ballistic vehicles. The unit comprises a rigid frame—which can be mounted on gimbals if necessary—housing a single chamber fed with H.T.P. and kerosine. The complete package weighs 32 lb; maximum sea-level rating is 500 lb, and the unit can be throttled to around 150 lb thrust with only a slight reduction in specific impulse. Proteus Since its introduction to passenger-carrying service in February 1957, the original Proteus 705 has logged almost half a million hours and currently has an overhaul life of 2,000 hr. The more powerful Proteus 765, fined to current Britannias, is entering service with an initial life of 850 hr and a maximum rating of 4,400 e.h.p. Shortly to be available is the Proteus 770, in which maximum power has been raised to 4,615 e.h.p. Sapphire The latest and most powerful version of this excellent single-shaft turbojet is the ASSa.7R, which, with simple reheat, has a rating of 12,230 lb. It is fair to assume that engines of this type are fined to the latest marks of Javelin all-weather fighter. Thor Permission has now been granted for Bristol Siddeley to display a sectioned ramjet, and an early Thor BT-1 will be so exhibited at Farnborough. This engine was fitted to the initial production Bloodhounds used during R.A.F. service acceptance trials at Woomera. A more powerful version of Thor is now in production for the Bloodhound missile, and larger engines—doubtless designed for still higher supersonic Mach numbers —are at present in various stages of development. Viper Originally a short-life engine of 1,640 Ib thrust for the early Jindivik targets, the Viper has been progressively increased in mass flow and top temperature until the ASV.ll long-life engine is now in production at 2,500 Ib. The ASV.ll has been ordered in quantity for the Italian Macchi MB.326 Trainer and for the Jindivik Mk 3 supersonic drone. The bulk of Vipers currently in service are of the ASV.8 type, rated at 1.750 lb thrust and fined to the Hunting Jet Provost and Jindivik Mk 2B. At present the ultimate development of the Viper is the ASV.12, in which minor improvements have permitted the maximum rating to be established at 2,700 lb. Bristol Siddalay PR.23 Liquid-propellant rocket motor. Single, fixed, regeneratively cooled chamber fed by turbopumps with H.T.P. and kerosine from remote tankage, mounted in one package complete with control system. Overall enclosing diameter, 8.25in; nozzle external diameter, 4.25in: overall length, 39in; dry weight, 30 to 32 Ib; thrust, variable from 500 to 800 Ib at sea level; specific impulse. 207 at sea level. 250 at 30,000ft and 264 at 60,000ft. Bristol Siddeley BEJS Turbofan engine with multi-stage low-pressure fan compressor, multi-stage high-pressure compressor, can-annular combustion chamber and independent high- and low-pressure turbines. No quantitative information may be quoted for this engine, but inspection shows that the intake diameter is some 48in, the overall height (including alternator) about 69in and the length, as depicted, about 126in; maximum rating is likely to be about 15,000 Ib, for a specific consumption of around 0.6 and a dry weight of well under 3,000 Ib.
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