Not Much of an Engineer

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Not Much of an Engineer Page 14

by Stanley Hooker


  Dr Smith was a very sound and methodical engineer, but had no experience of aircraft engines. Nonetheless, the F.2, which afterwards was named the Beryl, was a gallant first attempt. Smith followed with an absolutely first-class turbojet, the F.9 Sapphire. When the Ministry decided that in the post-war era there was no place for an additional aircraft engine company, and requested Metrovick to withdraw from that field, details of the Sapphire were handed to Armstrong Siddeley.

  At Armstrong Siddeley, Pat Lindsey, their brilliant young engineer, had graduated like myself from the development of superchargers on piston engines to a consideration of turbine engines. He designed a test axial compressor in which all the blades could be varied in angle individually, and thus rapidly acquired insight into the behaviour of these multi-stage machines. I had many discussions with him, and was convinced that there were many aerodynamic and mechanical problems to be solved before the axial compressor could be regarded as a sound substitute for the well-proven and rugged centrifugal compressor. The problem was compounded by the proponents of the axial compressor claiming not only a higher efficiency, but also a higher pressure ratio. Whittle’s engine had been designed for about 4:1 compression, but for the AJ.65 Griffith was postulating more than 7:1 on paper. The advantages of 7:1 and 85 per cent efficiency over Whittle’s mere 4:1 and 80 per cent made the prize very great. So we leaped off into the deep end and landed in such trouble that it took about seven years before the AJ.65 could get a clean bill of health. Seven years, when we had made the Nene in as many months!

  We started the design at Barnoldswick, and it was not long before Lombard was in my office saying that there was no way we could meet the projected weight of the engine — in fact, we would be 50 per cent heavier than Griffith’s optimistic estimate. At the same time, Harry Pearson was worried about the high pressure ratio, and so I took the decision to drop this to 6.3:1, and told Lom the weight must stay at his design estimate. Morley, who was doing the mechanical design of the compressor, was mindful of the fact that the blades all stuck out like tuning forks, and that resonant vibrations (as had been experienced on Metrovick’s F.2) was a major hazard, causing the blades to break off at the roots. His solution was to fix the blades with a pin root so that they were all loose, and hopefully would not vibrate. In the event, this was an excellent proposal, but at high rpm the centrifugal forces on the blades caused the roots to lock-up and resonant vibrations did cause failures. But at least the problem was limited to the high-speed end of the running range.

  In the aerodynamic design of an axial compressor, the fundamental dimensions are fixed by the design pressure ratio. In the case of the AJ.65, this actually settled at 6.3:1, and each of the 12 stages of blading was designed to do an equal amount of work on the air in compressing it. Thus, as the air passed from one stage to the next, the height of each blade row was made smaller than the preceding one in order that, as the air was gradually compressed from stage to stage, the velocity with which it travelled along the compressor remained constant. This meant that the outlet area was only about one-quarter of the inlet area.

  This arrangement is fine when the compressor is running at full speed at its design pressure ratio. At lower speeds, during starting and acceleration, the pressure ratio is extremely small. In this condition the outlet area and the inlet are completely out of balance. For example, under starting conditions, where the pressure ratio may be about 2:1, the outlet area should only be 20 per cent less than the inlet area. But because the outlet area is, in fact, only one-quarter of the inlet area, the airflow is severely restricted; putting it crudely, the air taken in at the front cannot get out at the back. This causes the blades at the front of the compressor to stall, vibrate, and not infrequently to snap off. The compressor surges and is also very inefficient under these conditions, and this makes the engine extremely difficult to start.

  Looked at another way, compressing air is somewhat analogous to driving water up a slope and over a ramp with a broom. One can take almighty strokes, and over the water goes. This is the method adopted by the centrifugal impeller. Alternatively, hundreds of small brushes can be used in quick small strokes gradually forcing the water up the slope. When arranged correctly, this will be much more efficient than the almighty slosh. This is the method adopted by the axial compressor running at full speed, the small brushes corresponding to the large number of blades in the axial ‘spool’. If, however, as the top of the ramp is approached the rate of sweeping is reducing (as at part-speed), then some of the water will run backwards to the bottom. This is similar to surging, when the direction of the airflow through the compressor reverses itself and flows backwards.

  Clearly, if the big slosh of the centrifugal is not hard enough, or the slope too steep, the water will never reach the top of the ramp and even the centrifugal compressor will surge; but this is much less likely to occur than in the case of the small continuous sweeping action of the axial compressor. The slope, of course, corresponds to the pressure ratio — the steeper, the higher the compression.

  Thus, a little thought showed that the axial compressor bristled with mechanical and aerodynamic problems, and so it proved to be. Even GE in America, who had started on the TG-180 axial engine in 1941, took almost six years before it reached fruition. Thus, unknowingly, Hs had been truly prophetic when he told Frank Whittle, ‘Just leave it to us, we will soon design the simplicity out of it’.

  But we soldiered on as best we could, and in 1946 we had the first AJ.65 engine on test at Barnoldswick. Sure enough, it was difficult to start, would not accelerate, broke its first-stage blades and could only be coaxed reluctantly to 5,000 lb thrust. It was, comparatively speaking, a hell of a mess. In his heart, Hs blamed me personally. Up to that time, everything I had touched had turned to gold, and Hs had come to regard the turbine engine as a piece of cake. Suddenly my life was full of big problems; in contrast, the war had merely been hard work.

  Hs knew that my marriage had broken up, and that I was staying in odd pubs, and even sleeping from time to time in my office — a complete wandering Jew. He recognised immediately that the axial engine presented an almighty challenge, and decided to move the whole of the turbine design and development from Barnoldswick to Derby so that the big battalions could take over.

  The move was precipitated when Marshal of the Royal Air Force Sir Charles Portal and his entourage visited Barnoldswick and, en route, passed through Derby without stopping! Hs’ immediate reaction was,

  ‘We can’t have that. Derby is the centre of Rolls-Royce, not Hooker’s bloody garage at Barnoldswick’.

  Lombard, Herriot and myself viewed the inevitable move with nervousness. How would we be fitted into the ranks at Derby? We were the acknowledged world leaders of the jet age, and the prospect was not particularly pleasing after the independence that we had enjoyed at Barnoldswick. Though we had no reason to doubt the friendliness of our welcome, there were obviously going to be problems of position and status. I adopted a ‘couldn’t care less’ attitude — ‘Tell me what to do and I will do it’ — which surprised Hs, and rightly made him suspicious.

  I felt fairly secure, because at the height of the success of the Nene and Derwent V, he had invited me, Cyril Lovesey and Ray Dorey to a private dinner at the company guest house at Duffield Bank. He told us that the future of Rolls-Royce would lie in our hands — Dorey as his successor as General Manager, Lovesey as Chief Development Engineer — a position he had occupied for some years already — and me as Chief Engineer. (In the event, only Lovesey survived. Dorey was shunted off as General Manager of the Motor Car Division at Crewe under Llewellyn Smith, and I left the Company).

  Why Hs got us together to tell us this I shall never know. It was quite unlike him to commit himself ahead of time, and he had years to go himself, so there was no need to nominate the heir apparent. For myself, I can honestly say that I was struck dumb by the promise that I would be the Chief Engineer of Rolls-Royce. I was already very high in the hierarchy, and the
great rapport between Hs and myself seemed to grow stronger every day. I held him in the greatest possible respect and affection, for he had given me great power. For his part, he said later that he regarded me as his son; but when he dangled the plum job before me, things were never the same again. I was intoxicated by the thought, and since I was under 40, the great question that filled my mind was when, when, when? I felt ready for the job and responsibility, and I also felt that I would have the backing of all the engineers in the company. Of course, things are different today. I know many a promising young engineer who will never see 50 again!

  I never knew why Ray Dorey fell from grace, but I can say now that it was one of the greatest disasters that ever befell Rolls-Royce. Dorey was cast in the same mould as Hs. A great inspiring leader with tremendous energy and drive, but, perhaps, not quite the same sense of humour as Hs. He was the Manager of our Flight Centre at Hucknall, and built it up from a few wooden sheds to a large and powerful establishment of vast capability.

  The original idea of Hucknall was that aircraft fitted with Rolls-Royce engines would be tested there in order to ensure that the total engine installation worked properly, and this included the radiators for cooling the water and oil, the air intakes and the exhaust system, which could be made to act like a small jet propulsion unit. We had found that we could not rely on the aircraft manufacturers to do this work, because they were too busy sorting out their own problems.

  In 1939 Hucknall consisted of an aerodrome, a few technical assistants and test pilots, and not much else. During the Battle of Britain, Dorey did a most courageous thing. He rang the Air Ministry and said, ‘Send me the crashed Hurricanes and I will repair them’. Considering that he had no workforce to do it, and no experience, it was remarkable that in a matter of weeks he was receiving crashed Hurricane I aircraft with the Merlin III, repairing them, and installing the more powerful Merlin XX, to send them back to the RAF as Hurricane IIs.

  He followed this remarkable contribution to the Battle of Britain by installing the first two-stage Merlin in a Spitfire, and thus created the Spitfire IX, which was the most famous of them all. Then he undertook to produce the powerplants for the Lancaster bomber programme, and set up a factory at Ilkeston for this purpose. When we took over Whittle’s jet engine, he installed one in the tail of a Wellington bomber, so that we were able to test it under flight conditions without the safety of the aircraft being dependent upon it. In fact, this was the first flying jet test bed.

  When the Nene appeared on the scene, Dorey set forth to put four of them into a Lancaster in place of the Merlins. We had calculated that the four-Nene Lancaster would exceed 400 mph and fly well above 30,000 ft. It would thus be immune to enemy action, either from fighters or AA fire. This project was never completed, because the war ended, but he did instal two Nenes in a Lancastrian, leaving the inboard Merlins unaltered. This aircraft would take off with all four engines working; once in the air, the propellers could be feathered, so that the Lancastrian then flew as a pure jet. This Lancastrian was tremendously valuable, because it could take several passengers. Many important people from all over the world were able to get their first experience of jet propulsion — so smooth, quiet and vibration-free, compared to the racketing Merlins.

  That Dorey’s colossal contribution to the war effort never received any official recognition, will always remain a disgrace to those who serve out such baubles. He was a great man, and when Hs nominated him as his successor, I was not in the least surprised. But it never happened, and Dorey retired to Crewe making the motor cars, and took up farming as a hobby. And so, Hs made his big mistake and sowed the seeds of the creeping disaster that was to overtake Rolls-Royce in 1971.

  In the immediate post-war years, when the production of Merlin and Griffon piston engines fell by about 98 per cent almost overnight, the first move was to transfer the production of the Nene and Derwent V to Derby. It was natural that the design and development of these engines should also be centred at Derby, and this transition was made painlessly enough, so that the engineers at Derby could cut their teeth on turbine engines.

  At this time, the security cloak on gas-turbine engines had been lifted, and I was asked to lecture at the Derby Branch of the Royal Aeronautical Society. With malice aforethought, I entitled the lecture Turbine Engines for Beginners. Hs was not amused at the title, but an enormous audience turned up to hear it, and I had many requests for copies, particularly from the RAF where it was known as ‘Squirts for Twerps’. It was not as elementary as the title implied, and all aviation circles were fascinated by the new method of jet propulsion.

  The year was 1946, and the strains of the work I had put in for the past eight years, and the emotional crisis of my failed marriage, were beginning to tell on me. One day Hs called me to his office and said,

  ‘I have been watching you lately. You don’t look at all well, and I think that you need a holiday. Where would you like to go — anywhere in the world?’

  I protested that I was alright, but he insisted; so, of the top off my head, I said,

  ‘I would like to go to South America’.

  Hs leaned back in his chair and pressed the button behind him. His secretary came in and he said,

  ‘Book him on the slowest boat you can find to South America’. And then he turned to me and said,

  ‘The Argentine are going to buy some Merlins from us, and we need that order badly as we have Merlins running out of our ears. So if you do anything to upset the order, I will break your neck’.

  I protested, why should I want to do that, and he replied,

  ‘I know you won’t be able to stop boasting about those jet engines, and the World’s Speed Record, and they are not ready for jets yet. Besides, we need the order badly’.

  I promised that I would do all that I could to further the sale of Merlins, but resolved also to take with me slides and material so that I could lecture on jet engines. Meanwhile, his secretary had booked my passage on one of the Holder Lines’ meat boats that went from Liverpool to Buenos Aires. This ship had accommodation for about 12 passengers and took 23 days to make the voyage. She sure had found a slow ship, but one that I was to enjoy thoroughly.

  There were currency restrictions at the time, so I was given a letter of credit to spend in Argentina, and Hs’ secretary thoughtfully provided me with £50 of the Holder Lines’ equivalent of money, which could be spent in the ship. I was the only passenger thus endowed, and hence was very popular as the dispenser of booze and tobacco, which were the only things one could spend money on anyway. Gin and whisky were 10s (50p) a bottle.

  The other passengers were a mixed bag. There were two young married couples returning to a bank in Buenos Aires, two Argentinians, one of whom had just finished his apprenticeship at Metrovick, and two British Latin-American Volunteer girls who had been in the WAAF during the War, and were being repatriated home. Both had been radar operators.

  We had to make our own amusement, and the first thing we did was, with the help of the ship’s carpenter, to make a swimming pool on the upper deck. It consisted of a wooden frame with a tarpaulin inside, and water was pumped continuously in from the sea and spilled over the sides. It was a great joy and boon to us all. In the evenings we played cards or danced and sang to the piano music of the Argentinian boy, who was a brilliant player.

  The accommodation was a bit scruffy but, being a meat boat, the food was good and plentiful — at least it seemed so after the rigours of wartime rationing. And so we ambled at about 8 knots southwards across the Bay — which was so rough that only two of us survived seasickness — through calm seas to the Cape Verde Islands, which was the only land we saw on the trip. Then or, through shoals of flying fish, and the magical dawns at the Equator, to the River Plate.

  When we docked at the Embarquero in Buenos Aires I was met by the Rolls-Royce agent, Angeloglou Levante. He was a quiet, thick-set man in his early 50s, and a very shrewd businessman who had made a considerable fortune as an ag
ent for Reynolds chains, Ferodo brake linings and many other British engineering products. He was newly appointed as an agent for Rolls-Royce, and was rightly looking forward to big business in the aeroengine field, with the projected sale of Merlins in the immediate offing.

  At this time, Argentina was very rich, although it consisted of a two-class society — very wealthy and very poor. Peron and Evita were in full control, and had made lots of hay out of the war. The country was by and large very pro-European, being mainly a mixture of Spanish, Italian, German, French and British. Being very polite people, they did not like the brash manners of the Americans, nor were they pleased at the US support for Brazil, who challenged Argentina for the dominating position in the South American continent.

  I was taken off by Levante, and installed in the Palace Hotel, which was the most luxurious in Buenos Aires and, certainly, the best I had ever stayed in. Quiet, dignified and superbly appointed, it was another world after the gloom and rationing of post-war England.

  I was fascinated by the foyer, which was run with superb military precision by the Head Porter. He stood like a ramrod in immaculate uniform at his desk, and ruled with a rod of iron the many bell-boys who stood unobtrusively around, equally immaculate and at attention at strategic vantage points in the huge foyer. It seemed to me that he spoke all the world’s languages with equal fluency. People would go to him and he would converse with them in their native tongue; then he would bark out orders in Spanish, at which one of the bell-boys would spring into action. I had never seen the like before, or since.

 

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