Rolls-Royce SST Engine Designs

[JFC Fuller]

Tartle,


Thank you so much for your input, please keep it coming. May I ask whether you know anything of the engines studied by RR for the SST (Concorde) prior to the formal selection of Concorde? I believe they were Medway derivatives and went under the RB.179 designation?

 

[tartle]

Sealordlawrence,
Thanks for the positive feedback... as to Concorde propulsion... back to the teachests!
AeroFranz... glad you liked the Medway stuff... When we had our first daughter, I put my photo collection in a tea chest and didn't get them out again until 30 years later.... so its great to share!

 

[tartle]

As far as I can make out....
The first design study for an SST was the RB.151 - a 30,000 lb thrust engine in Sept 1958; followed by RB. 158 - a 34,000 lbt one for a M2.0 transport and RB.159 - 16,000 lbt based on Avon RA29-5 ; both allocated in May 1959. A month later came the RB. 160 at 34,000 lbt. The variation in thrust may reflect BAC or Sud design studies and 4 or 6 engines but that is idle speculation; RB.167 was 20,000lbt for M2.2 in Jan 1960. A2-shaft 20,000 lbt engine for SST - Mar 1960; RB.170 a bypass 24,000lbt for M2.7 in Mar 1960 and RB.171 at 20,000lbt bypass for M2.2 also in March. I would guess this must have been the time that Bristol 'got the job' as a supersonic transport disappears from the activity. The RB.179 was a small (6,000lbt) turbofan for a Fokker project - May1961.

In 1977 the Atlantic Monthly published a two-part article on Concorde which included this:

" BRITISH manufacturers, meanwhile, had been continuing technical discussions with British government officials, and with manufacturers in France. These discussions were marked with confusions whose resolution was to prove most costly. First there was the airframe. In 1960 the British government had given the new British Aircraft Corporation a $1 million contract for a feasibility study. BAC was also asked to have informal talks with the Toulouse firm Sud-Aviation, which was drawing up its own preliminary plans. Sir Archibald Russell, BAC's chief supersonic designer, visited his old friend Pierre Satre, Sud's technical director. Russell's first approach was cautious. Considerable savings could be achieved, he argued if each company built separate aircraft but shared the components, such as the engine, and the hydraulic and electrical systems. But this was not enough for the politicians: the Ministry of Aviation told the companies to amalgamate their work completely. The problem was that the two companies favored entirely different versions. BAC was pursuing the Mach 2 transatlantic plane that had been the rationale behind STAC; Sud preferred a medium-range plane (which STAC had also considered). No politician at that time was ready to make a decision.
A bitter commercial battle was also being fought over the choice of engine. The contenders were the two new British engine firms, Bristol-Siddeley and Rolls-Royce. Rolls-Royce showed considerable realism toward the problem of noise. In a two-and-a-half-inch-thick report on the engine requirements, Rolls pointed out that the New York Port Authority had already introduced a takeoff level of 112 Perceived Noise Decibels (PNdB) today's limit at Kennedy, and that Heathrow was considering stricter limits. Rolls concluded: "The next generation of subsonics is being designed to be appreciably quieter -- of the order of 100 PNdB -- and this is the order to which the supersonic should be designed throughout." Rolls's honesty did not win them the contract, and they were politically outflanked by Bristol-Siddeley. whose managing director, Sir Arnold Hall, had realized at an early stage that the only way the project would go ahead was as a joint production. He paid a discreet visit to the French aero-engine company SNECMA and suggested a deal; when the governments came to consider who should build the engine, Bristol Lind SNECMA were able to point to the progress toward collaboration they had already made. The engine chosen was a "civillanized" version of the Olympus which Bristol had been developing for the multirole combat plane the TSR-2 (eventually cancelled by the Labour government in 1965, after $532 had been spent)."

You can see the discussion developing as it is reflected in the RB numbers as they were issued to the drawing office over the early design period when there were two aircraft and then the poltical and technical merging of the concepts into what became the Concord(e).

 

[alertken]

(because the Concorde diversion is stimulating: should we retitle this thread: ferreting in tartle's teachests?)

Atlantic Monthly might have confused its knights. Sir Arnold Hall left RAE to be Technical Director of HSAL in 1955, where he had no involvement in Armstrong Siddeley Motors. Bristol Aero-Engines was so spun off 1/1/56, its incomer MD, AVM Sir Alec Coryton, under the very direct control of Bristol Aeroplane Chairman/part-owner Sir Reginald Verdon Smith. VS sold Bristol Aero-Engines as 50% of Bristol Siddeley Engines, 1/4/59, a merger with ASM. Its sole purpose was to create Olympus 22R for TSR.2, funded 15/12/58 subject to a similar merger of V-A+EE (as BAC, 1/3/60).

After 9/3/59 Report of RAE's Supersonic Transport Aircraft Committee, Minister of Supply Aubrey Jones funded thick wing study at HSAL, thin wing at Bristol Aircraft. He did not fund corresponding study/rig work on their powerplants; he visited France to initiate collaboration, 6/59. Thin wing/BAC was nominated 3/60 as UK SST airframer. There was only one, Nationalised French candidate.

VS had been satisfied with financial performance on a 1948 licence for SNECMA to build Hercules, so would be comfortable with a second date. Difficulties, RR:SNECMA, were perceived in MoS after 1956 (not sure why, but have a niggle around ATAR v.Avon, Super Mystere B-2). As 1958 unfolded, airframers formed team bids for (to be TSR.2), engine firms danced around MoS' policy that its engine, too, was to be a team effort.

Today, beguiled by the Magic of a Name, we forget the nature of UK aero-engine industry in 1958. DH had the big one, Gyron; ASM had the only hot one that worked - Sapphire; Bristol had the only mid-size one that worked - Olympus 101; Napier had the only funded shaft turbine - Gazelle. RR was building Dart (Griffon impellor), dry Avons (Sapphire compressor data), Conway (origins, Power Jets and Napier), and was having great difficulty running a wet, big Avon, vital for rump Fighter Command. All the while pitching to US civil airframers paper turbofan schemes generically Medway (Allison AR963G). When Pratt/JT8D lifted 727 in 1960, RR's finances were less robust than those of ASM (HS Group), Napier (English Electric), the De Havilland Enterprise, or the Bristol industrial conglomerate. RR ignored their Paymaster and, solo, pitched a reheated Medway to TSR.2; solid Bristol cold end was pitched with proven ASM hot end. What would you expect MoS to do?

Politically the proven designer of Caravelle must lead the SST airframe. The only credible case for UK design leadership on its powerplant was a modest variation of B.Ol.22R. Irrespective of the paper merits of supersonic RBs, RR had dished any prospect of business by firstly spurning MoS on teaming for TSR.2, then omitting to cosy up to France's only credible powerhouse.

 

[tartle]

Alertkin,
I agree with the thrust of your narrative... it is easy to believe the mythmaking and not look at the facts when they emerge... the culture of keeping certain firms in the forefront started in 1919 and only died when costs escalated to very high levels that meant the Ministry/government had to make choices... a bit like now in fact. Faced with the political situation of the early sixties I guess I would be looking for a point of difference to keep me in the discussion... hence noise which RR were taking more seriously as they moved more seriously into the international civil market, i.e. the USA.... but that is another story.