The S&G was called upon by Shell at this year’s Revival to tell a few stories to support its ongoing partnership with Goodwood. The first of these was a timely and unsung tale of how Shell developed fuels that made their debut in the aircraft of Fighter Command in the summer of 1940.
One might have thought that the arrival of a new fuel grade that boosted the power and endurance that was made available to fighter aircraft defending Britain in the summer of 1940 might have merited the occasional mention before now. Indeed, it did – in a rather colourful tome called Time’s Forelock: a Record of Shell’s Contribution to Aviation in the Second World War, written by Wing Commander George Kerr in 1948.
It’s an astonishing piece of work, and sets the scene that, with a little bit of Transatlantic archive plundering, produced the following story:
National commemorations to mark the 75th anniversary of the Battle of Britain, including those at the Goodwood Revival, are an opportunity to reflect not only upon the heroic efforts of the men and machines of RAF Fighter Command throughout the summer of 1940, but also those who serviced and supported their great endeavours. The pilots who flew into battle were immortalised by Winston Churchill as ‘the Few’, but those who worked tirelessly away from the fighting were the many – and among them was Shell.
Developing innovative products for the aviation industry has been Shell’s mission from the outset of powered flight. In 1919, Shell engaged Harry Ricardo to investigate the fundamental properties needed to make aviation fuels more effective. Improving the fuels became a process that ran parallel to improvements in engine technology, identifying the correct blends to deliver optimum performance that became known, from 1930 onwards, as the fuel’s octane number.
Throughout the 1930s, in laboratories spanning the UK, Netherlands and USA, Shell scientists created blends of various octane levels and with specific lean and rich running properties to suit a variety of roles, with an 87-octane blend becoming the global industry standard through the 1930s. Nevertheless, further increases in the octane rating of aviation fuel were sought, led by the world-famous air racer and manager of the aviation department of Shell in the USA, Jimmy Doolittle.
General Doolittle (in uniform) visiting Shell’s laboratories in 1945
As a direct result of Doolittle’s insistence, Shell constructed a dedicated plant producing 100-octane fuel in the USA by 1934. The 100-octane blend provided high performance aircraft with a 15 to 30 percent increase in power over a compatible engine burning 87-octane fuel, with measurable increases in terms of shorter take off runs and faster rate of climb as well as overall reduced fuel consumption – qualities that would prove invaluable for the fast response of interceptor aircraft like the Spitfire and Hurricane during the Battle of Britain.
The Royal Air Force had agreed to a limited supply of 100-octane fuel in 1938, but the outbreak of war placed supply routes under threat until the USA invoked a revised Neutrality Act in late 1939; allowing large quantities of 100-octane fuel to be shipped from the United States. Those supplies began to reach front-line squadrons in bulk through the first half of 1940 and would see its first use in battle in defending the evacuation of Dunkirk, immediately prior to the Battle of Britain.
Delivering those supplies was a fleet of tankers that was forced to brave not only the rigours of the North Atlantic but also the concentrated attacks of submarine and surface vessels. In total 29 fuel and oil tankers were sunk in the Atlantic during the period of the Battle of Britain, with the loss of 260 merchant sailors. Their sacrifice in attempting to deliver desperately needed fuel to the front line cannot be forgotten.
The Shell tanker Pecten, sunk on 20 August 1940 delivering 100-octane fuel to the RAF
As a result of using 100-octane fuel, the Rolls-Royce Merlin engines fitted to the Hawker Hurricane and Supermarine Spitfire were able to make maximum use of their increased power and range.
With 100-octane fuel, the supercharged Merlins of the RAF fighters could, once adjusted, be “boosted” from +6.25 lbs/sq.in. to +12 lbs/sq.in., increasing peak power from 880 hp (656 kW) to 1,310 hp (977 kW). This increased power substantially improved the rate of climb for Britain’s first line of defence, especially at low to medium altitudes, and increased top speed by up to 45 mph in level flight.
The development of aviation fuels would be accelerated dramatically throughout the next five years at war. Octane levels rose from 100- to 130- and finally 150-octane by the war’s end, by which time the piston-engined aircraft was at the limit of its development. But as early as May 6 1941, Shell scientists had been on hand to witness their kerosene at work in the first flight of an aircraft using an all-new form of aero engine: the jet.
By then the Battle of Britain had been declared a victory by the British Prime Minister and ‘the Few’ had been garlanded. In those 16 weeks, the Royal Air Force had beaten off the threat of surrendering control of the skies over its homeland, and the ‘Few’ of Fighter Command were justifiably the heroes of the hour.