How Thrill-Seeking Gearhead Beatrice Shilling Helped Win World War II

Science history's great pantheon of women is packed to the brim with unapologetic badasses. They helped kick down the intellectual and social barriers encircling male-dominated STEM fields, from English paleontologist Mary Anning, who risked her life scouring for fossils on dangerous Dorset cliffsides, to the African-American "West Area computers" recently spotlighted in the acclaimed film Hidden Figures.

Beatrice "Tilly" Shilling, born on March 8, 1909, was among the ranks of these brilliant iconoclasts. Though she passed away in 1990, her birthday now coincides with International Women's Day (IWD), an annual celebration of women's achievements that has been recognized by the United Nations since 1975.

Given this timing, we are hereby enshrining her as our 2017 patron saint of IWD. If you are interested in learning how this brainy daredevil, described by colleagues as "a flaming pathfinder of women's lib," revolutionized aerial dogfight technology while racking up motorcycle racing titles, read on.

Shilling was raised in a middle-class family in Waterlooville, England, and became fascinated by engineering at a young age. By the time she was in her early teens, she had started to pick apart and improve motorcycles, laying the foundations for a lifelong passion for vehicle design.

During her later teen years, at the tail-end of World War I, Shilling nabbed an apprenticeship with engineer, businesswoman, and women's advocate Margaret Partridge. Partridge owned her own electrical company that catered to rural communities in Devon, and she was passionate about encouraging women to pursue engineering careers. Judging by some of her letters, Partridge had also developed a keen wit about navigating her pioneering role in an industry dominated by men. According to the 2000 book Crossing Boundaries, Building Bridges, she wrote to her friend, the famed electrician and feminist Caroline Haslett, to ask advice on the appropriate dress code and behavior for women at industry conventions with their male peers. "Please tell me—am I a lady or an engineer—what are you?" Partridge asked in the 1925 letter. She then brought up the conundrum of whether to join the male engineers for paper discussions, or partake in the side events organized for engineers' wives. Partridge also joked about how she made a top hat with ladylike flourishes that could function in both settings. Haslett quickly shot down the idea of sitting out on discussions, replying that "[o]ne thing I'm quite clear about is that we are both going as engineers or semi-engineers and not as wives," and that Partridge should bring "the kind of hat that engineers and not wives would wear." Though the exchange is lighthearted, it underlines the novelty of the female experience in engineering, and the prejudices that came with it. Read More: How a Victorian Astronomer Fought the Gender Pay Gap, and Won Considering Partridge was Shilling's first mentor in engineering, it's no wonder the young apprentice set her ambitions high. Shilling matriculated at the University of Manchester when she was 20, and earned her degree in electrical engineering in 1932, one of only two female graduates. She went on to complete a Master's degree in mechanical engineering the following year, followed by a research position at the University of Birmingham. It was also in the mid-1930s that Shilling began to earn her stripes as a fearless motorcycle racer. She delighted in improving on existing vehicle designs, and gave her trademark Norton M30 a cozy little mechanical hack by adding a supercharger to the engine. Happy with this DIY upgrade, Shilling revelled in ripping up the famous Brooklands motor circuit at speeds of 106 miles (171 kilometers) per hour. She quickly earned a name for herself as a skilled competitor who could outperform professionals like Noel Pope, and was awarded the Brooklands Gold Star for being the fastest woman on the track.   She kept up this adrenaline-junkie side gig even as she secured a permanent position as an aircraft engineer for the Royal Aircraft Establishment (RAE), in 1936. It was through the racing circuit and RAE that she met her husband, George Naylor; the couple spent decades tinkering with cars in their shared workshop, then racing tweaked roadsters together. They married just before World War II broke out. Shilling kept her maiden name. The war obviously presented both major challenges and opportunities to the RAE, which supplied the Royal Air Force (RAF) with its military aviation technology. One of the biggest technical problems the RAF encountered in early WWII battles was a defect in the Merlin engines that powered the iconic Spitfire and Hurricane warplanes. During aerial dogfights, negative g-forces generated by nosedives caused fluids in the planes' carburettors to flood the engines, resulting in them cutting out. This video explainer from Real Engineering includes a useful animation visualizing the design flaw.

Animated explainer of design flaw in Merlin engines, and Shilling's RAE restrictor improvement. Video: Real Engineering/YouTube

Fixing this critical problem would prove to be Shilling's greatest claim to fame. In 1940, she innovated a special metal disk, similar to a washer, to regulate the fuel flow and effectively prevent stalling.

Officially, her device was known as the RAE restrictor, but as Shilling began touring RAF bases to distribute her quick-save, she made such an impression on the officers that they began calling it "Miss Shilling's orifice" or "Tilly's orifice," because of the puncture in the center of the disk. The innuendo, I'm sure, does not require elaboration.

The restrictor quickly became an integral feature of RAF aircraft, and Shilling was celebrated as a crucial contributor to the eventual Allied victory, receiving the Order of the British Empire in 1948. She continued to work for RAE until her retirement in 1969, and she remained active in the aerospace engineering and racing communities until her death at 81.

Despite the eventful and consequential life Shilling led, she remains one of the many little-known female figures in science history. Beyond a few engineering history enthusiasts or patrons of Shilling's namesake pub in Farnborough, few people know who she was or what she achieved for the war effort, women's empowerment, and the racing community.

Indeed, the only biography of Shilling, authored by Matthew Freudenberg and entitled Negative Gravity, was published in 2003, and copies are now so rare that they are selling for between $100 and $440 on Amazon. Anyone looking for ripe fodder for their next biopic or miniseries would have a hard time coming up with a better subject than this freewheeling, thrill-seeking, feminist gearhead. Hint hint.

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