Hurley came back to sign on the very day the Olympus was to run for the first time. Here was the world’s most advanced and most powerful engine about to be started by testers who had no experience of any jet engine. I knew they would spend days cautiously running the engine in, treating it with the greatest respect. I decided to visit the new Olympus testbed and take the throttle myself, thus protecting the testers by accepting full responsibility. They stood around me while the starter button was pressed. The first Olympus ran up to speed, lit and started perfectly. I waited only a few more seconds and then banged the throttle open, an action which will cause any jet engine to stall unless it is in tip-top aerodynamic shape. The testers stood aghast, horror on their faces, but the Olympus slammed up to full power without the slightest hiccough or hesitation, and there for all to see was 10,000 lb thrust. I closed the throttle, bringing the engine back to idling, and then repeated the slam acceleration to full power, and again the engine responded perfectly.
I can vividly remember the tremendous feeling of exhilaration this gave me. What I did not know was that Rowbotham and Hurley had come onto the bed and were standing just behind me. It certainly was a dramatic moment for everyone, and it clinched the deal with Hurley on the spot.
He returned to Wood-Ridge, New Jersey, and planned his company’s conversion to turbines in two stages. First he would mass-produce the Sapphire as the J65, at 7,000 to 8,000 lb thrust — and, after a thousand times the expected trouble in Americanizing the engine, he did just this. Next, he intended to build the J67, an American version of the Olympus. I told him he must quadruple the size of the Wright experimental shops, but he was up against the reactionary disinterest of Chief Engineer Bill Lundqvist, who was convinced the Turbo-Compound would go on for ever. He was also up against the US Air Force, which stipulated its next turbojet must have a thrust of 13,500 lb. We at Bristol considered this fractionally more than the original Olympus 100-series could be developed to give (in fact, it wasn’t) and Wright thereupon decided to embark on a bold redesign of the J67 to give more thrust, and this was the final nail in their coffin.
First, they made the mistake of exactly following the USAF Specification. Sir Sydney Camm used to say ‘Follow the spec. and you are dead!’ For one thing, in those days engines had a habit of coming out overweight and deficient in power, and it was sound practice to aim at a power appreciably above that demanded. At Bristol I did just this, and succeeded in getting Ministry support for the Olympus 6, later produced as the 200-series, with a design thrust of 16,000 lb. We kept the external size and shape about the same, and even slightly reduced the peak diameter, but cut away the inside to increase the cross-sectional area of the airflow path, so that we could greatly increase the mass flow. At the same time we managed to get so much work out of each stage of compression that we cut back the LP spool from 6 stages to 5, and the HP spool from 8 to 7, without lowering the pressure-ratio.
We kept in close touch with Wright, and each week the J67 would get bigger and heavier, though it was still aimed at only 13,500 lb. I did not have the courage to take the bull by the horns and tell Hurley and Lundqvist to drop it and take our Olympus 6, because after all we were to some extent beginners too. When the J67 at last got on the bench it was entirely uncompetitive with Pratt & Whitney’s J75 — and from that moment on Curtiss-Wright ceased to offer any competition in jet engines. Personally I believe we could have got them to have based the J67 on the Olympus 6. Had we done so we would have given Pratt & Whitney the sharpest possible competition, which the USAF likes, but, as it was, both British penetration of the US market and the great Curtiss-Wright company slowly faded away.
Although we did not recognise it at the time, this was a major turning-point in world aviation. Had the engineering capability of Bristol been allied to the vast manufacturing capability of Wright, the future would not have been left to Pratt & Whitney and GE, and Britain would have retained an enormous part of the world gas turbine market quite apart from anything carved out by Rolls-Royce. But, not only do I doubt that this could have been done, for emotional and political reasons, we were also desperately handicapped by the failure of the Bristol manufacturing team. Early in the J67 licence deal Hurley had 19 Olympus engines on order, so that he could get a real development programme going at Wood-Ridge. After a few dozen broken promises it got so that nobody believed the promises of delivery any more. Curtiss-Wright never received a single one of those engines. Even the supply of engines for our own purposes at Bristol was pathetic and always late by anything over a year. It drove me mad with exasperation to see the lead we had gained over Rolls-Royce turned back into a lag.
The total failure of manufacturing forced Verdon into the unpleasant task of retiring Rowbotham and Attwood in 1951. He appointed as managing director Air Chief Marshal Sir Alec Coryton, who had had a distinguished career in the RAF and Ministry of Supply. He had great powers of leadership, and would listen and consider all viewpoints before reaching a decision. His athletic figure and bristling moustache were often seen in the works, and he was fond of barking at a machine operator ‘Show me how you do that!’ The man would oblige, whereupon the boss would take off his jacket and say ‘I’m going to try to do that’. Turners and fitters would crowd around, eagerly waiting to see the boss scrap the piece. It delighted the work-force and Coryton was popular with everyone.
He had the stature to stamp on the internecine warfare. When he arrived, Production ruled the roost, but there was constant friction between them and Engineering. This was constantly fuelled, on the one hand, by the total failure of Production to keep any of their delivery promises, and on the other by criticism of the engineering design caused by continual failure of the early Proteus engines. Coryton simply welded us into a single team, which got stronger and stronger as mutual trust and respect grew.
While the battle of the Proteus raged, the Olympus simply soared ahead. After running at the 9,750 lb level, it had reached 11,000 lb by the time it flew in a prototype Vulcan in September 1953. The Mk 101 production engine began to come off a revitalized manufacturing line in 1955 at this rating, and while the production Vulcan B.1 and B.1A bombers were being delivered we succeeded in improving the Olympus not only to be tougher and even more reliable (from the start it was the most reliable engine in the RAF) but also to give more power. We produced the Mks 102 and 103 and ended this generation of Olympus with the 104, which gave the 13,500 lb the USAF had wanted and which we had not dared to predict!
Early in the flight development of the Series 100 Olympus our Divisional Chief Test Pilot, Walter Gibb, easily took the world altitude record at 63,668 ft with a Canberra fitted with two prototype engines, and later the same aircraft exceeded 66,000 ft. It always seemed a pity that the Olympus-Canberra was never bought for the RAF, because that would have given us the world’s best high-altitude bomber and reconnaissance aircraft. Meanwhile, we romped ahead with the Olympus 6 and cleared the Mk 201 version for production to power the Vulcan B.2 at a rating of 17,000 lb. Just as this was happening, in 1957, the Ministry decided in its wisdom that Britain only needed one big jet engine and it picked the Rolls-Royce Conway. Accordingly they withheld all support from the Olympus, and moreover instructed Avro to redesign the Vulcan to take the Conway. To give them credit, Avro were very reluctant to do this. The whole thing was said to have been done on financial grounds, and we knew of no attempt to assess the technical merits of the two engines.
At this point Verdon showed immense initiative and courage. He went to the Ministry and said that Bristol would develop the Olympus 200-series at its own expense. Ah, said the officials, we know what that means; we shall have to pay for the development in the production price. Verdon explained that we were prepared to sell the Olympus 200 for the same price as a Conway. This was no small gamble. In those days the development bill for such an engine was in the order of £5 million a year, and the production cost some £50,000 a copy (today it would be more than ten times greater). Thus, assuming a thre
e-year development programme, we should normally have had to add £20,000-odd to the price of each engine on a run of 500 engines. One major hiccough in either development or production costs and Bristol would be bankrupt.
In the event the Olympus 200 went like clockwork, and we far exceeded our design figures without spending anything like £10 million. Likewise Production rose to the occasion and churned them out at a keen price. The Conway, on the other hand, became more and more expensive, partly to pay for changes to suit the civil DC-8 and 707-420, of which a handful had been sold, and partly because the production price was much higher than expectation. We were thus not only able to keep Verdon’s bargain, and keep this splendid engine in the Vulcan, but we made a healthy profit. Even more, we went on to produce the 300-series engine rated at 20,000 lb, more than double the original design figure, by adding a zero-stage to increase the mass flow. These became the standard engines of the RAF’s Vulcan B.2 force, which stayed in use 25 years to 1983. These were the trusty machines which bombed the runway at Port Stanley in what were by far the longest bombing missions in the history of air warfare.
More than this, the Olympus went on, as I shall relate, to power the TSR.2 and Concorde. Other versions are the standard engines of the Royal Navy’s warships, including such giants as HMS Invincible, while hundreds of others generate electricity all over the world. Had it not been for the exceptional nerve of Sir Reginald Verdon Smith the pundits in the Ministry would have scrapped the whole programme back in 1957. As for the Conway, the last few engines in Victor tankers are now being retired, and the engine gained no further applications.
The Minister at the time was Reginald Maudling, and I remember a very painful and acrimonious meeting in Coryton’s office as we fought to explain why we felt the Olympus should not be killed off. Eventually Coryton said it was lunchtime, and stamped angrily out, leaving me alone with the Minister. I asked him ‘I suppose you wonder how we got into this mess?’ He replied ‘No, but I wonder how I got into it.’
In general an engine’s power is related to the mass flow through its HP spool and combustion system. Though the Conway looked larger than the Olympus, because of its bypass duct, its HP spool was smaller, so it had less potential for further development. In 1960 two extremely large and important new aircraft were being planned in Britain, both to achieve Mach 2.2, the limit for aluminium airframes without compromising structural life. One was the RAF’s new strike and reconnaissance aircraft, TSR.2, and the other was the SST that matured as the Concorde. These projects were regarded as inter-related, the TSR.2 being earlier in timing. This enabled the RAF programme to underpin and read across to the later civil SST. It was eventually decided that both would be powered by versions of the most powerful Olympus.
Back in 1952 English Electric’s designer, Freddie Page — later Sir Frederick Page, chairman of the British Aerospace Aircraft Group — came to ask me about prospects for replacing the Avon with the Olympus in advanced versions of Canberra and Lightning. The Avon used in these aircraft was clearly going to run out of steam long before the bigger Olympus, and moreover the latter’s higher pressure-ratio, for remarkably low weight, gave a much better specific fuel consumption. I told Page that the Olympus was good for Mach 1.8, but that above that Mach number the aluminium compressor would have to be redesigned in titanium because of the very high temperature.
Thus in 1958 the embryonic form of TSR.2 was born. This was the start of a so-called ‘weapon system concept’ which, in my view, has cost the RAF and this country dearly because of resulting delays and escalating costs, resulting in fewer aircraft for vastly greater prices. One of the demands made for TSR.2 was that the aircraft should be able to fly at its maximum Mach number of 2.2 for a full 45 minutes. This meant a total redesign of the Olympus in high-temperature materials able to soak at the Mach 2.2 ambient conditions (which had previously been met only for about a minute at a time, outside the USA). It was also evident that the engine would need a lot more thrust, as well as a reheat system (afterburner) capable of being fully modulated over the entire range of augmentation, instead of being a mere on/off device as had previous British afterburners. This in turn led to the demand for a complicated system to control the nozzle as it varied in area over a range of 50%, with variable profile leading, in the Mach 2.2 regime, to a large expanding final section to accelerate the supersonic jet.
Also demanded was an operational radius of 1,000 nautical miles. I met the Vice-Chief of Air Staff, Sir Geoffrey Tuttle, on the Folland airfield at Hamble. I asked him ‘Geoffrey, why do you insist on a 1,000-mile range? It is clearly a number carved out of the sky. Do you realize that the final 100 miles will cost you something like a million pounds a mile for engineering development?’ (That was certainly an underestimate.) He waved his arms in a gesture of despair, and we just went on with what proved to be pouring effort and money down the drain. I had already formed the view that the fresh arrivals of brilliant and dedicated young RAF officers in the Operational Requirements branch tended to justify their existence by changing, usually upwards, the numbers cranked into official specifications. As they stay for five years, while each major programme today takes 10, continuity is lost. Though it is nothing like as ludicrous as the life of governments — to say nothing of ministers — this short timescale makes it impossible to collaborate with the same experienced team throughout a major project.
I am totally unconvinced of the merits of multirole all-can-do aircraft, and even less convinced of the need for everything to do Mach 2. The Harrier has proved so useful because it escaped the British-style weapon system concept. The engine came first, and there was no question of Mach 2. Thus there was always a body of opinion in the RAF that this is a very pedestrian and not very useful aircraft. This opinion ceased to be fashionable after the Falklands campaign.
Do not think that I, or anyone at Bristol, did not do our best to produce good engines for TSR.2. In this programme even the Olympus did its best to bite us, when one blew up during ground running under the Vulcan flying test-bed. After much effort we identified a bell-like ‘ringing’ vibration of the large-diameter HP shaft, energised by the high-frequency pulsations of jets of cooling air. This was fully cured soon after the first flight on 27 September 1964, but though the TSR.2 and its engines matured swiftly, and gave every promise of being a world-beating all-British aircraft, the whole programme was cancelled in April 1965 along with all the other new British aircraft for the RAF, as the Labour government’s answer to the problem of the RAF being — in their own words — ‘dangerously overstretched and seriously under-equipped’. Fortunately this wholesale bout of cancellations brought to an end ten years of the worst mismanagement of the RAF’s equipment and of the British aircraft industry that could possibly have been arranged.
The one lasting effect of the TSR.2 programme on the British aerospace industry, was that it was used by the government of the day to enforce mergers between what had been rival companies. This is discussed in a later chapter.
The last and most challenging application of the Olympus is the Concorde SST (supersonic transport). This mighty programme, which like so many non-American endeavours failed to reap commercial rewards, was begun in November 1956. By then it was obvious that BOAC’s refusal to show interest in the all-British Vickers VC7 — commercial version of the V. 1000 transport for the RAF — was bound to hand an entire generation of subsonic jetliners to the Americans on a plate. This situation was accelerated by BOAC’s decision, soon after disclaiming any interest in jets in this class, to buy a fleet of Boeing 707s! The only possible thing for Britain to do seemed to be to leapfrog ahead with the world’s first SST. The Royal Aircraft Establishment at Farnborough was charged with organizing a programme, and under its Deputy Director, M. B. (later Sir Morien) Morgan, it formed the STAC (Supersonic Transport Aircraft Committee). All the chief airframe companies attended at Chief Designer level, as did Rolls-Royce and Bristol Aero-Engines, the company formed in that year from the Bristol Aer
oplane Company’s Engine Division.
After prolonged study of several alternatives the STAC Final Report of March 1959 recommended an SST to cruise at Mach 2.2, or 1,450 mph, with transatlantic range. Any speed higher than this would result in structural temperatures too high for long airframe life in the well-tried aluminium alloys, the alternatives of steel and titanium posing great problems in inexperience, cost, weight and, in all probability, a long and troublesome programme. To a rough approximation the rise in skin temperature at cruising speed in °C is equal to the square of the speed measured in hundreds of mph. Thus 100 mph gives a rise of I°C, 500 mph results in 25°C, 1,000 mph causes a rise of 100°C and Concorde speed of 1,450 mph some 210°C. But at very high altitudes the air is initially at some -50°C, and subtracting this gives an actual metal temperature of only 160°C. We felt we would be able to build an SST, complete with rubber tyres, plastic parts and other components, which could soak at this temperature and still satisfy the civil airworthiness authorities.
We looked carefully at a steel/titanium SST cruising at Mach 3, or 2,000 mph, but after analysing the times needed for take-off, climb, subsonic cruise over land, acceleration to cruising speed, deceleration at the destination and the final slow letdown to the terminal airport, the actual saving in journey time on London to New York did not exceed 15 to 20 min — say, 3 hours 15 min instead of 3 hours 30 min. The latter time, for Mach 2.2, was half the best possible with a subsonic airliner, and beyond this speed the law of diminishing returns set in with a vengeance. The one real advantage of Mach 3 was that, while wing lift/drag ratio hardly altered from 7.5 (roughly half as good as a subsonic aircraft), the greater ram compression increases the engine efficiency, which in turn could mean greater range or more payload.
Not Much of an Engineer Page 19
