Monday, October 17, 2022

Have you heard of Beatrice Shilling, and how she solved the one problem with the Spitfire that all the engineers, mechanics, and pilots - couldn't? The engine cut out on dives and turbulence


Around 1919, the 10-year-old Beatrice grew tired of being left behind by her sisters on cycling trips and began to save for a motorcycle. Aged 12, she built a working Meccano model spinning wheel and promptly won a national competition set by Meccano Magazine.

By the age of 14, she’d achieved her goal, her chosen bike a two-stroke Royal Enfield. When she wasn’t giving her sister Anne pillion rides, she was taking it to bits and putting it back together again, engine and all.

the Women’s Engineering Society. It was borne, in 1919, out of the need to protect the right to work of women who had been allowed to work in arms manufacture and other engineering trades during World War I.

In May 1926, the Society distributed a letter to girls schools throughout the country. Shilling’s mother convinced her to reply. By age 17, she became an apprentice electrical engineer learning the ropes, or more accurately cables, in the new electrical power plant at Bungay, Suffolk.

With support from the Women’s Engineering Society, Shilling joined the Department of Electrical Engineering at the Victoria University of Manchester in October 1929. She was one of only two women accepted that year; up from the none that had been accepted before.

Shilling received her Master of Science in 1933, and promptly joined a lecturer, Dr G.F. Mucklow, in researching fuel consumption, heat loss, and supercharger performance in Rolls-Royce and Napier single cylinder engines.

Shilling would go on to set the record for the fastest woman to lap the circuit at 106 mph, in 1934. Her record stands today.

Shilling was fast for several reasons. Her size was one advantage. At five feet tall, she was short enough to lie more or less flat, reducing drag. And though history doesn’t record all the specifics of the tweaks and modifications Shilling made to her machine, they were numerous. Freudenberg indicates that, in later letters to friends, she experimented with the length of inlet tract. This is the part of the engine that supplies the potent mixture of air and fuel to the cylinders, its length affecting power, torque, and fuel efficiency.

In 1938 and 1939, the Norton motorbike was rebuilt from scratch with a homemade supercharger, and a new fuel tank where the saddle once was. Unfortunately, Shilling was too short to ride it. By then she was married, and her husband George Naylor, who stood a whole foot taller, took to racing instead. He became an able rider with the help of Shilling’s coaching, which was certainly unique: when they married in 1938, it had been on the condition that Naylor first earn himself a Brooklands Gold Star. It came in the nick of time. Racing at Brooklands ended forever in 1939.

Her husband went on to fly Lancaster bombers during World War II,
 
By November 1939, after a series of promotions, she had reached the position of Technical Officer in charge of carburettor research and development work. In other words, she was perfectly positioned to tackle the skittish Merlin engines of the Hurricane and the Spitfire. In lieu of a fix, pilots had devised their own workarounds: dramatic maneuvers deployed if and when the engine cut out.

Tests ordered and overseen by Shilling identified the true problem: the rich cut that followed the weak cut addressed by Lovesey and Fisher.

Shilling worked out the precise volume and pressure of fuel being pumped into the chamber by the Merlin engine and designed a brass restrictor with a hole precisely the diameter needed to allow maximum flow of fuel, and therefore maximum power, without flooding the engine. Crucially, Shilling’s solution could be fitted without the removal of the carburettor, so the fix could be made in situ at operational airfields.

This left only the logistical problem of how to get the restrictors to Fighter Command airfields in good time. Shilling organized a small band of engineers to assist, though inevitably she travelled up and down the country solo, and by her preferred mode of travel: her trusty Norton motorcycle.

Years later, Keith Maddock, chief engineer at Hangar 42, an RAF base during the war, went so far as to describe the restrictor as a war-winning modification. “Beatrice Shilling helped us to win World War II⁠—of that there is no doubt,” he told the BBC in 2017. Her war efforts weren’t limited to improvements to the Merlin engine. She also contributed to a range of engines to improve starting in freezing conditions, and operation at higher altitudes.

Her technical knowledge was very possibly unsurpassed. If nothing else, she was eventually awarded the Order of the British Empire for her wartime efforts.

In 1955, she was promoted to be the Royal Aircraft Establishment’s Senior Principal Scientific Officer.

https://www.damninteresting.com/how-miss-shillings-orifice-helped-win-the-war/ via a short note about her when extensively describing the Merlin engine in https://www.hagerty.com/media/people/in-the-moment-a-lady-an-engine-and-world-war-ii but not really respecting her accomplished engineering solution

1 comment:

  1. It was know as Miss Shilling's orifice.

    ReplyDelete