She, herself, described her childhood playing with Meccano, building wireless sets and investing pocket money in penknives and simple hand tools. At this time opposition to women entering engineering was widespread in both its trade unions and professional associations. In 1926 Tilly began a three year apprenticeship as an electrical engineer with a company run by Margaret Partridge, who was also closely involved with the fledgling Women’s Engineering Society. Partridge encouraged her to take a degree in electrical engineering at Manchester University and arranged for an interest free loan from the WES to support her tuition. She enrolled in 1929 as one of only two women students in the first year that women took the course. At Manchester her love of motor cycles continued when she took up racing with the University club. She graduated with honours in 1932 and stayed on for a further year to take an MSc. in mechanical engineering. In 1934 while working as a Research Assistant she began racing her Norton 500cc. motorcycle at Brooklands where she became only the second woman to lap its rough concrete track at over 100 mph, gaining a gold star in the process. She went on to be the first woman entered at scratch in a race open to both men and women.
In 1936 she was accepted as a member of staff at the prestigious Royal Aircraft Establishment, the national centre for aeronautical research. Three years later she had become a specialist in aircraft carburettors and had met her future husband George Naylor, a mathematician who worked in the RAE’s mechanical test department. He was a burley six footer to Tilly’s five feet and a quarter inches and he also raced motor cycles. Tradition has it that Tilly refused to marry him until he got his own Brookland’s Gold Star, following which they married at Aldershot’s Registry Office on July 21st 1938. The start of the war ended motor cycle racing and Tilly’s Norton was detuned to become her normal form of transport.
By 1940 during the Battle of Britain a serious problem arose with the carburettors of Rolls Royce Merlin engines in Hurricanes and Spitfires. When they dived the negative G-force flooded their carburettors thus causing the engines to stall. More important still the problem was not shared by the German Bf 109 and 110 fighters with their fuel injection engines. In consequence Tilly rapidly developed a simple device to solve the problem in the form of a small metal disc with a hole in the middle that restricted and regulated the flow of fuel. By March 1941 she led a small team that toured RAF fighter bases and installed the devices. Arriving on her Norton her brusque manner and bag of tools became something of a legend. Tilly’s modification dubbed by the pilots as ‘Miss Shilling’s orifice’ remained standard until a modified carburettor was ready for service in 1943. In 1949 she was awarded an OBE for her wartime contributions, including her fuel restrictor.
During the war George served as a bomber pilot before rejoining Tilly at Farnborough where they continued motor racing. By 1947 the emphasis at the RAE turned to jet propulsion and Tilly led the Ramjet section of the guided weapons department where she became an expert in the dynamics of heat transfer. However, her further promotion prospects were not helped when she refused to move to nearby Pyestock that took over the RAE’s Ramjet work. In fairness she herself acknowledged that she was not good at being pleasant to superiors, especially if she thought they did not merit their superiority and she was no fan of what she saw as unnecessary bureaucracy. There was also the question of her carelessness with her appearance, she usually dressed in a well-used jacket and corduroy trousers with the jacket’s pockets invariably full of pens, with her hair dragged back in a bun and more than one tooth missing as a result of an earlier racing accident. In fairness for official group photographs Tilly was always smart in a dress and matching jacket.
Transferred to the Mechanical Engineering department she took part in major accident investigations and among other programmes worked on life support for crews at high altitude. Her final task was to help make airfields safer by researching the effects of a wet runway on aircraft braking during take-off and landing. In 1969 she retired as a senior principal scientific officer rather than a departmental head that someone of her ability surely deserved. Her technical achievements for instance, had been recognised during her retirement year by the award of an Honorary Doctorate from the University of Surrey.
Tilly, however, was not only a woman in a predominantly male world but a highly unorthodox one operating in a strictly graduated work environment. She undoubtedly lived and worked to her own standards; while able and highly committed she was a chain smoker who was unconcerned with small talk to put people at their ease and fond of cryptic, humorous one liners that tended to silence normal conversation.
This said her unquestioned engineering ability, distinctiveness and rare courage made her one of the Royal Aircraft Establishment’s most memorable employees during the war and beyond.
At Farnborough her memory lives on to this day in the name of its J D Wetherspoon pub, ‘The Tilly Shilling’.
By Peter Reese