Highlights from Not Much of an Engineer (Sir Stanley Hooker)

On the English boarding school system (which are known as public schools)

I must confess that I had always been jealous and envious of public school boys. Coming from my humble origins, I expected to get the cold shoulder, and was prepared to be cold and distant myself. After all, was I not already 24 years old with a Bachelor’s Degree in mathematics, so why should I bother about these snobbish young puppies, who had been born with a silver spoon in their mouths? But I had got it all wrong; and they soon showed me what a fool I had been. I was immediately accepted by all, and spent four of the happiest years of my life enjoying the great camaraderie that existed in BNC. There is no doubt that the public schools give to their product an indefinable something which is of inestimable value to Britain. Those jealous and bigoted people who seek to destroy them — in the name of anti-class privilege or for votecatching — are misguided, small-minded fools. We should have more public schools, and not fewer; thus could we increase the output of leaders for all walks of life, with their unparalleled record of excellence.

Alas, the young men I lived with in BNC for those unforgettable four years were ripe for slaughter in World War II. It is so terribly sad to read their many names on the Roll of Honour at the entrance to the College Chapel. Yet I always remember them as generous, happy, high-spirited young men, who promised to have the world at their feet.

Regretting the relaxation of the previously strict rules concerning dress and behavior at Oxford

Today, all is changed, and it is sad for me to go back and see men dressed in any old clothes, lounging around in mixed company at all hours. This so-called freedom is at the expense of that happy though mildly disciplined life which had been going on for centuries, and was, to me, a part of Oxford’s great contribution to the moulding of character.

There were certain subjects that were taboo at table. If anyone transgressed, an application could be made to the High Table, at which the Dons dined in style, always in black ties, for permission to “sconce” the offender. If granted, a magnificent two-handled, heavily embossed silver mug would be brought in by the scouts, and filled with at least two pints of Audit Ale. The accused then had to rise and empty the mug in one drink. If he failed he had to buy ale for all, but I never saw anyone fail; struggle hard perhaps, but fail — never.

On insight

I used to work in my office at the Lab on most mornings and afternoons. I have always been disposed to work in fits and starts, and I suppose this is only natural when one is doing theoretical work, because one can only move forward when the inspiration comes along. One cannot solve a mathematical problem by just sheer hard application. There has to be a spark of insight, which can, however, be cultivated by simply mulling continuously over the problem. On most occasions the means of moving forward comes almost unconsciously, like a flash of light as one’s brain continuously sifts the facts that have been fed into it. Once the light has dawned, a quite valuable paper can be written in a week; that is, one worthy of publication in the Proceedings of the Royal Society, the Philosophical Magazine or the Reports & Memoranda of the Aeronautical Research Committee. It was upon one’s output to these journals that one was judged.

On design engineers

The word ‘engineer’ covers a variety of expertises and people of very varying backgrounds. In my experience, the crème de la crème of these are the designers and, if it be true that the status of engineers is too low in Britain, then the charge applies first and foremost to designers. They are enthusiasts who seek after something more than wealth and power. They lead a tiring and exacting life, standing long hours at their boards drawing in two dimensions engine parts that they visualise in their minds in three dimensions. Not only must they create the drawings which can be explicitly interpreted into instructions, which can be made by the many manufacturing processes available in the shops, but they must liaise with the designers on each side to ensure that their parts will match exactly with those of their colleagues, and that the whole can be manufactured and assembled as an engine with convenient access for inspection of the vulnerable parts. They are fed (often to the teeth) with information and advice from experts in specialized fields such as performance and gas dynamics, mechanical integrity and material properties, and they must work within the limits of stress imposed by the experts. They are the ‘keepers of the Trade’, which embodies all the details of past experience so hardly learned. They are indeed an elite body, yet they are almost always quiet and modest, capable of defending their creation with lucid arguments. At the end of the day, they have the most satisfying and rewarding job of all. They can look at an engine and say, ‘I created those parts, and they are exactly as I saw them in my mind when I took my pencil and began to draw on a blank sheet of paper, and they work!’

The balloon demonstration

On 15 May 1941 Whittle’s W.1 engine flew in the Gloster E.28 aircraft, and the flight trials were a roaring success, as well as a source of amazement to those privileged to see them. The strange whistling roar of the engine, and the absence of the propeller or any other obvious means of propulsion, caused a great deal of speculation amongst the uninitiated onlookers. Was the aircraft pushed by the jet or sucked along by the intake? was the question on the lips of the uninitiated. Many thought it was was sucked along ‘like a bloody great vacuum cleaner’ as one RAF man was heard to say. When I began to lecture on the new jet engines after the war, this question continually arose. To demonstrate, I used to take with me a blown up balloon, and, at the appropriate time, used to release it when it would be blown into the audience by the escaping air jet. On one occasion I forgot to blow it up, and at the last moment nipped down to the men’s room to do so. I went into one of the cubicles, and was blowing it up when it burst with a loud bang. An amazed voice from a nearby cubicle called out ‘Are you all right in there?’ The mind boggled.

Helping the Chinese engine program

[The Chinese] still had no background of design and development experience on which to draw, nor any designers or experienced engineers. As a result, though they strove to produce perfect engines, they were helpless in the face of in-service failures. They, therefore, had to limit the life of each engine to 100 to 200 hours, and a large part of their output was devoted to making replacement engines for ones that had failed. They showed me two persistent failures they had suffered for years. One was at a particular location on the fir-tree root of the WP-7 turbine blade, which was prone to experience first a small crack and then total failure, letting the blade fly through the engine casing — no joke in a single-engine supersonic fighter. The second was the cracks which appeared in the sheet-metal combustion chambers, spreading rapidly until a large chunk would break off and smash into the turbine nozzle vanes, often passing right through the turbine and causing severe damage. There is an immense amount of finesse in the design of a fir-tree root, and its manufacture is far from simple. I knew therefore, that we could not deal with that problem on the spot, so I took my courage in both hands and offered to send them a detailed drawing of the root of a Spey turbine blade. After all, they had plenty of Speys in commercial service in Tridents, and could have studied the root for themselves. In fact, Chinese civil and military aviation seemed to be two distinct watertight compartments, and there was no way that a solution to a military problem could have been found in a civil engine. Their eyes shone with gratitude at this offer, and a year later they showed me their new Spey-type blade root which, they said, worked much better. The cracking of the combustion chambers was a problem I felt we could deal with there and then. Back on Frank Whittle’s engine I had run into the same problem caused by the use of thick and thin sheets welded together. As the temperature varies, according to throttle position, the thin sheet heats and cools quicker than the one to which it is attached, and the unequal expansion and contraction between the two causes severe cyclic stress which soon gives rise to a crack. The solution is to make the thin sheet thicker, and to cut in it what we used to call ‘keyhole slots’ to allow for any slight dimensional changes. In fact the Russian chamber was a singularly bad design. The hemispherical head was a heavy casting, which actually had fins machined in it for extra cooling, though it was obvious from its colour that it was running very hot. Downstream was a thin sheet flame-tube, and the cracking naturally began at the junction between the two, which was a seam weld. I explained all this to them, and they followed my reasoning completely. I suggested that they try making the hemispherical head from sheet of about the same gauge as the cylindrical portion, and provide it with expansion slots. Again they could have seen all this on the Nene in the Institute. A year later they had done it all. From our brief discussion and a quick pencil sketch they had redesigned the chamber and completely solved the problem, and my reputation was sky-high. I took the opportunity of pointing out that there were many, many such practical tips we could give them if a basis of co-operation could be found.