Mathematician Loves Engines

Not Much of an Engineer”, by Sir Stanley Hooker (1984), ISBN 978-1-85310-285-1, 255 pages.

Stanley Hooker (1907 - 1984) was an English mathematics student who drifted into aerodynamics, and thence into the challenging topic of air flow within engines. His career spanned the rapid improvements in piston engines during World War II and then the subsequent development of jet engines. His autobiography focuses on his technical & managerial career – along with a lot about engines!

In 1926 as a 19 year-old student with a talent for math, he won a scholarship to Imperial College, London. In 1932 at the age of 25 he won an even bigger scholarship to Oxford Uni (very fortunately, since jobs were hard to find during the Depression). In 1935, realizing that the world was sliding towards war, he joined the Royal Navy where he was diverted into the Admiralty’s Scientific & Research Department. This led to his joining Rolls-Royce in 1938 to work on superchargers for piston aero-engines. Hooker took the title of his autobiography from a comment the Works Manager at Rolls-Royce made about Hooker’s stumbling explanation of a Karman Vortex Street. Through World War II, he was involved in the development & upgrading of Rolls-Royce’s Merlin engines which powered the famous Spitfires & Hurricanes, and in the early development of Frank Whittle’s centrifugal-compressor jet engine and later more technically-challenging axial-compressor jet engines.

The period after WWII was difficult due to the contraction in military aviation. In 1948, Hooker left Rolls-Royce, and went to work with the Bristol Aircraft Company on the Olympus engine which powered the Concorde, and later on the Pegasus engine which powered the Vertical Take Off & Landing Harrier jump jet. When Rolls-Royce was driven into bankruptcy in 1970 due to development problems with its RB211 high bypass jet engine, Hooker was brought back as Technical Director. With the aid of a very fine engineering crew, he was able to get the RB211 to deliver its specified performance, thereby helping to revive the company.

His later career included interesting sales-type assignments in Argentina, Romania, and China – where Rolls-Royce provided military engine technology to Mao-era Communists. Capitalists will indeed sell communists the rope they will use to hang them.

Hooker describes many fascinating incidents during his long career, especially for anyone with an interest in engines – along with some old-fashioned English triumphalism, tinged with his more modern regret that the England of the early 1980s (when he was writing this book) had fallen so far from the embattled but hard-working England of the 1940s.

One of those incidents relates to Rolls-Royce during WWII providing the designs of the Merlin engine to a Ford factory in England to enable additional production. Ford found that Rolls-Royce’s manufacturing tolerances were too coarse compared to Ford automobile standards, and had to upgrade the designs.

Another of those incidents related to initial skepticism in Rolls-Royce (and elsewhere) about the utility of jet engines. After all, by 1940 the Merlin engine could produce 1,000 horsepower (steadily increasing), whereas Frank Whittle’s early jet engine could produce only 800 pounds of thrust. Hooker went to work and demonstrated that the two measures were approximately equal.

Yet another incident was Rolls-Royce’s effort to replace metal blades in the giant front fan of the RB211 with strong lightweight carbon fiber blades. All was going well until the standard test of firing a 4-pound supermarket chicken into the running engine.

For any reader who did not learn enough about engines from his autobiography, Hooker ends his text with a series of appendices laying out approximate calculations for supercharging and jet engine efficiency.