Not Much of an Engineer

by Stanley Hooker

  At Muroc, I had my first flight in a jet. The Bell XP-59, powered by two I-16 engines, was really a single-seater, but they had carved a small open cockpit ahead of the pilot in the nose of one of the aircraft, thus transforming it into a two-seater. We were all offered a ride, but when it came to my turn, I was unable to get into the cockpit with a parachute on. It just was not designed for people my size, so I threw the parachute away and had my first flight without one. I was certainly the first man ever to do that in a jet aircraft!

  Everyone knows how different jet propulsion is from the piston-engine/propeller combination, but in those early days, the smoothness and lack of vibration and noise were a revelation. Flying at 400 mph in an open cockpit with nothing but a small deflector windscreen was also quite exciting, and that thrilling experience has stayed with me always.

  While we were at Muroc, a local rancher invited us to an oxroasting. The party was set for the afternoon, and we travelled across the desert by car for about 20 miles to get there. When we arrived, the party was in full swing, and a good deal of the ox had already been consumed, washed down with Bourbon and wine. However, there was plenty left, and the hospitality shown to us by all was splendid. I wandered around by the cabins and found one with a cowboy stretched out on his bunk.

  ‘Ever seen a rattle-snake?’, he enquired.

  I shook my head, and he reached up to a pillow-case that was hanging on a nail above his bunk. He undid the string that fastened the neck, and dumped the case on the floor, whereupon a very large snake began to hiss around in it with its rattles going full blast.

  I said, ‘Good God, can you rest with that thing hanging over you?’ He replied, ‘Sure, you have to get used to them out here’.

  Later, to entertain us, our hosts got out an old carriage which had crossed the desert in the pioneering days, and harnessed four spirited horses to it. People climbed inside and on the top, and the four horses were released and accelerated away into the desert, followed by loud cries of ‘Whoopee’. Eventually the carriage returned for a refill. On the second trip, I was one of about six who got inside, while a large number climbed on to the roof. By this time the horses were even more on their mettle, and once released they took off at high speed in a large arc into the desert. Sure enough, the outfit was now top-heavy and rolled over to starboard, throwing everybody from the top into the desert sand. Inside, where I was, there was chaos as we were all thrown on top of the unfortunates on the right-hand side. It is not nice to have someone of my bulk fall on top of you, but apart from scratches and bruises no-one was hurt badly inside. It was more tragic for the top passengers. In particular, the wife of the Medical Officer at Muroc, who had her back broken and died shortly afterwards. We returned to camp very sadly, although at the time we did not know the extent of the lady’s injuries.

  The rest of our trip was uneventful and eventually we arrived at Baltimore, en route for home. At that time, British Overseas Airways were operating a trans-Atlantic service with Boeing 314As from Baltimore via Botwood (Newfoundland) to Foynes. These great flying boats could sleep 19 passengers in the bunks in the tail, and had a saloon with a round mahogany dining table, where one spent one’s waking hours. I recall it took almost 18 hours for the 1,800-mile trans-Atlantic trip from Botwood to Foynes, and we flew at an altitude of 2,000 - 3,000 ft above miles and miles of deserted ocean. It was July, and after the sweltering damp atmosphere of Washington and Baltimore, the Emerald Isle seemed all that it is cracked up to be. It had an air-conditioned atmosphere! The final surprise was that from Limerick to London, though we flew in a British aircraft, we had the blinds drawn.

  Once back at Barnoldswick, I resolved to design a Whittle engine of 5,000 lb thrust. Our current engine, the Derwent I, was running at 2,000 lb, so it was a big step-forward to take, particularly as there was no aircraft suitable for such a powerful engine, and none was even being considered.

  In 1940, the development of jet engines was co-ordinated for the Ministry by Dr Harold Roxbee Cox, now Lord Kings Norton, who then held the position of Director of Scientific Research. I knew him well because when I was a student at Imperial College, I had attended his lectures on the design of airships. He it was who formed the Gas Turbine Collaboration Committee, in which all the firms involved in turbine work met at frequent intervals to discuss progress and problems. The first meeting took place in the AID headquarters in Birmingham, and in his opening remarks Roxbee referred to us in prophetic terms as ‘the midwives of a new era’. At the height of the controversy about the Lucas fuel system in early 1943, I met with him in London and helped persuade him to support the Lucas fuel system on the basis that, at that time, we could not rely entirely on a gear fuel pump operating at over 1,000 lb per square inch, because of the lack of operating experience at that pressure with fuel as the lubricant, albeit with a small percentage of oil mixed in.

  But by the time the decision to build the 5,000 lb-thrust engine was taken, Roxbee had moved on to higher things, and his place had been taken by Group Captain George Watt of the Royal New Zealand Air Force. George was an expert test pilot, and no mean engineer, and being a big man he always took a big view. I telephoned him from Barnoldswick and said,

  ‘George, I want to build a 5,000 lb engine. We must get cracking or the Americans will beat us to it’.

  His reply was ‘Are you sure the thrust should be as much as 5,000 lb?’

  I said, ‘Of course not, let us say a figure of 4,200 lb, and we will design for 5,000 lb’.

  ‘OK’, he said, ‘I will issue a specification for an engine of 4,200 lb, and you can go ahead now. If you get 5,000 lb so much the better’.

  I do not remember consulting Hs about this, although I suppose we must have kept him informed of our intentions. But the war was on, and the big boys at Derby were busy helping to win it with the Merlin and Griffon, and were content for us to go our own way at Barnoldswick.

  And so Lombard, Pearson, Morley and myself set out to do the project design of the new turbojet, which was later to become the famous Nene. We got down to the task on 1 May 1944, and for the first time were able to start with a real ‘clean sheet of paper’. Moreover, at last we felt we had enough experience to know exactly how to design a better turbojet. We set the airflow at 80 lb/sec and designed the best compressor impeller we could, with a diameter of 28.8 in (732 mm) compared with 20.68 in for the Derwent I. We enclosed the impeller in a casing based on the marvellous new pattern Whittle had created for the W.2/500, which was not only aerodynamically more efficient but eliminated cracking.

  The turbine disc and rear main shaft bearing had never been adequately cooled, so we incorporated a small centrifugal compressor designed solely to cool these two components. We adopted the straight-through combustion system as on the Derwent I, and Stanley Clarke produced a new design of combustion chamber, which had a low pressure-drop and a high efficiency. We did not ask for a larger fuel pump from Lucas, but just fitted two of the existing C-size pumps as used on the Derwent I, and which were beginning to be very reliable.

  Our first study was the B.40, and in the summer of 1944, as the Meteors began shooting down the V.l buzz-bombs, we refined this into the B.41 and began to release drawings to the shops. We were frankly impressed at the result, because, while we had increased the diameter of the impeller by 40 per cent, we had held the increase in overall diameter of the engine to under 20 per cent, from 41.5 in to 49.5 in, 5.5 in within our target. Dry weight of the first engine was a remarkable 1,600 lb, the design target maximum being 2,200 lb!

  At last, on 27 October 1944, the great day arrived when the Nene was ready for test. As usual, the last-minute adjustments to the engine and the test bed had taken all day, and it was approaching 10.00 pm before we were ready to press the starter button. Driven by the big electric starter, the new engine started to rotate and go through the light-up sequence. This consisted of opening the fuel shut-off cock at a predetermined fuel pressure so that a spray of fuel, and not a dribble, went into t
he combustion chambers, and then ignition was to occur from two igniter plugs (like large car sparking plugs) inserted in opposite combustion chambers.

  The positioning of those plugs was always subject to a certain amount of trial and error, and we had got it wrong, because no light-up took place. The whole works had gathered to see the engine run for the first time, and a groan went up when it failed to start. A repeat was tried with the same result.

  Dizzy Drew and Ballantyne, our ignition experts, were equal to the problem. Out came one of the igniter plugs, and an oxyacetylene torch was unceremoniously plunged into the hole! The engine lit with a bang, and some nice flames came from the jet pipe from internal pools of fuel. But in a few seconds it was running beautifully, and all instruments were reading correctly. (Thus, incidentally, was born the almost universally used torch igniter).

  Slowly, the throttle was opened, and the thrust crept up to 1,000 lb, 2,000 lb and 3,000 lb, and a cheer went up as we passed the design thrust of the de Havilland Goblin. The throttle was opened wider and when the engine passed the 4,000 lb mark, the cheer must have been heard all over Barnoldswick. It had been a thrilling night and was now approaching midnight, so I called a halt so that we could continue next day. We all repaired to the canteen where the chefs and waitresses prepared a real sausage-and-mash spread. Few people in the factory had much sleep that night.

  Next day I telephoned Hs and told him the good news. He replied in what was for him a very unusual way by sending us a telegram. I read ‘Congratulations to all. Well done, you have put Barnoldswick on the map’.

  When it came to the design of the Nene, Pearson made a last desperate effort to persuade me of the advantages of Whittle’s cascade of intake swirl vanes, and so a compromise was made. The engine design had to be such that we could either have them or not, and Lombard was required to satisfy me that a design of vanes could be made which would not fail. The first Nene was completed without the vanes, and the impressive thrust of 4,000 lb was reached on the initial run. But later that night, looking at the instrument readings, it was apparent that the combustion temperature was higher than expected. This was bad news. We would have a struggle to reach the design thrust of 5,000 lb.

  Pearson insisted that the engine tests be stopped, and the intake swirl vanes fitted. Reluctantly I agreed, and then went home.

  The change was made in the small hours, and next day when I arrived in the factory I could hear the engine running and so wandered over to the test bed. To my amazement and joy, 5,000 lb of thrust was being registered at the same temperature as the 4,000 lb on the first test! The simple little static vanes, which Frank Whittle had computed would be so beneficial, had added 1,000 lb to the thrust of the engine, and improved the fuel consumption by 5-10 per cent. As is usual with the way of the world, I got a ‘medal’ for leaving the vanes out in the first place, and another ‘medal’ for putting them back in the Nene. The credit was totally Frank’s.

  I do not think any of us expected that, from scratch, we could create the most powerful aircraft engine in the world in just five months. But at the political level things were moving somewhat slower. It may be that the ‘Dunkirk spirit’ still existed in a few places, but the fact remains that not only was there no aircraft in which to fly the Nene but there was nothing even being planned for it! It would have seemed reasonable to instruct several companies to design high-speed fighters and bombers to make full use of this powerful engine, but at Derby we almost began to wonder why we were bothering. Then, suddenly, we were told a new American jet fighter was being made available to us. It was USAAF No 44-83027, the fifth pre-production Lockheed YP80A Shooting Star, one of four sent to Europe to gain experience under front-line conditions. We very quickly replaced its GE J33 engine by our first flight-cleared Nene and got it flying at Hucknall on 21 July 1945. It was a beautiful machine to fly, but where did we go from there? The answer was nowhere much, though the Nene passed its Type Test in November 1945. On 14 August 1946, more than a year after the Nene’s first flight, we got a couple of Nenes flying in the outboard engine positions of a Lancastrian, VH742, in the hands of company Chief Test Pilot Capt R. T. Shepherd.

  Although we were now far outstripping him, Frank was delighted with the success of the Nene, and came to Barnoldswick to see it run. We had a celebration dinner at the Swan and Royal at Clitheroe. Everyone bewailed the lack of an aircraft for the Nene, and the suggestion was made that we should scale the Nene down to fit the Meteor nacelle and determine what thrust we could get. Lombard did the design exercise on the tablecloth, and the answer came out at an amazing 3,650 lb. The current production engine was the Derwent I at 2,000 lb, and we were all excited at the prospect of over 3,500 lb from a same size engine, and the great increase in performance that this would give to the Meteor. Currently, it had a maximum speed of about 450 mph; with 75 per cent more thrust, we could predict about 30 per cent more speed, and the goal of 600 mph seemed suddenly within our grasp. Moreover, the RAE had just modified the engine nacelle shape in order to reduce its drag at speeds at which air compressibility effects, or Mach number drag-rise, became significant.

  We tried the proposal on Hs at one of his Monday afternoon meetings. He was not amused; after all, Rolls-Royce had just completed the new turbojet production factory at Newcastle-under-Lyme, and it was tooled-up to make the Derwent I, which was then just going into service with the RAF. Hs did not say yes but he did not say no, so that, on a dark winter’s night motoring back from Derby to Barnoldswick, Lombard and I decided to go ahead anyway. To celebrate this, we called in at the Station Hotel in Manchester to have dinner, and after a few drinks we had the best the hotel could provide, including a bottle of wine, a rare thing in Britain in 1944. When the bill arrived, I tossed it to Lombard and said:

  ‘You pay this, I haven’t got any money’.

  He replied, ‘I haven’t got any either’.

  Our hearts sank, and the waiter hovering nearby came over and asked if anything was wrong. We told him of our predicament, and he said ‘Haven’t you got any money at all?’ We searched our pockets and our combined wealth came to just over ten shillings, which he said would have to do. I replied, ‘Just a moment, our coats are out there, and we shall have to give the attendant a tip’. So I took a couple of shillings back, and the waiter went off without any fuss at all. I had pictured having to leave my wrist-watch on account, but not a bit of it. Of course, he was only legally entitled to charge us five shillings (25p), the limit for a wartime meal, but we had all forgotten that. Needless to say, on the next occasion we dropped in and settled the matter.

  We started the design of the Derwent V, as it was called, on 1 January 1945, and I laid down the rule that it was to be a photographic copy of the Nene, scaled down by a factor of 0.855. Thus no design calculations were necessary, and by 7 June we had the first engine on the test-bed ready to run. On its first test it ran 100 hours non-stop at a rating of 2,600 lb, and later we gradually increased the thrust to 3,500 lb.

  By 15 August 1945, two Derwent V engines were installed in a Meteor, and the first flight took place at Moreton Valence in Gloucestershire, which was the home of the Meteor. Eric Greenwood was the Gloster Chief Test Pilot, and I motored down from Barnoldswick. The aircraft took off like a rocket, and disappeared in a clap of thunder. When Greenwood returned he just said ‘At last we have a real aeroplane’. He was full of enthusiasm and praise for the new engine. Within weeks he was clocking 570 mph at 10,000 ft, and calculations showed that if we could give him 4,000 lb thrust for a short period, then 600 mph at sea level could be exceeded, and the Meteor would be the first aeroplane in the world to be officially timed at that coveted figure.

  The official World Speed Record, which then had to be made at sea level, stood at 469 mph, made by a Messerschmitt with a Daimler-Benz piston engine just before the war. I always doubted the authenticity of that record, because I calculated that it must have required at least 4,000 hp, but after the war we discovered that the aircraft was
not a Bf 109 fighter at all but a small racer given the same number. It was a great propaganda effort by the Germans just prior to the war, and designed to intimidate all.

  The next milestone was, of course, 500 mph, and I believed this to have been reached by the Lockheed XP-80A Shooting Star in the USA using an I-40, the 4,000 lb-thrust engine which I saw running at GE in 1943.

  And so, by a special test of 1 hour duration, we cleared the Derwent V at 4,000 lb for the speed-record attempt. Two strengthened aircraft were selected to make the attempt at Herne Bay, one to be piloted by Eric Greenwood and the other by an RAF officer, Group Captain H. J. ‘Willie’ Wilson, whom I did not know. All engines vary a little in performance, so I gave instructions at Barnoldswick that the best two were to be installed in Eric’s Meteor, and the inferior ones in Wilson’s.

  All went well in the trials from Manston over the course at Herne Bay, and when the record attempts were made by the two pilots, sure enough the first news came through that Eric had broken the record at 603 mph, and Wilson had been slightly slower. Science triumphs again, I thought, but it was too soon. A correction came through saying that Wilson had the record after all. It speaks volumes for the consistency of aircraft drag and turbojet performance that both aircraft were within 2 mph of each other. Such consistency was never achieved with pistonengine/propeller combinations.

  During these speed records Frank Whittle was at last able to fly a jet. In early October he flew a Meteor I, powered by W.2B/700 engines, at Bruntingthorpe. A few days later he visited the trials at Manston and, at the request of a Ministry of Supply official and while suffering from the effects of a Rolls-Royce party, he flew a Meteor III with Derwent Is.