The birth of the turboprop engine
As demand for air travel expanded in the late 1940s, the challenge was to produce more effective engines that could carry passengers and goods further and faster.
While work continued apace to develop the jet engine, there was also increasing interest in the idea of the turboprop, which combined a turbine engine with a propeller. Rolls-Royce, a pioneer of engine technology since the early days of flight, led the way in the development of the turboprop, which delivered higher performance compared to traditional piston engines in use at the time. Among the first engines it developed was the RB53 Dart, the first of a turboprop engine family that remained in service for decades.
However, bringing this advanced turboprop into service required a test regime that would put the engine, and its lubricating oils, through their paces at extremely low operating temperatures. Rolls-Royce turned to Shell Aviation to develop this testing programme. A major challenge faced was the need to understand the behaviour of oil and flow rates at very low temperatures, something that was impossible to achieve with the standard laboratory equipment of the day. To solve this issue Shell installed a Dart engine in the “Cold Chamber” at its Aero-Engine Laboratory at Thornton in the north of England. This facility was the only one capable of simulating the all-important oil flow characteristics at low temperatures.
The tests were successful and the Dart made its first ground run in 1946 and powered the four-engined, 75-seat, Vickers Viscount airliner on its maiden flight in July 1948. The first scheduled service, carrying 14 paying passengers between Northolt in London and Paris–Le Bourget Airport, took place in 1950 and the Viscount became the first turboprop-powered aircraft to enter airline service with British European Airways (BEA) in 1953.
Shell’s support in the successful development of the Dart enabled Rolls-Royce to create a family of engines that remained in service well into the 1980s, powering aircraft such as the popular Avro 748 and Fairchild F-27.
Despite the development of the jet engine, turboprop powered aircraft continue to be reliable options to this day, essentially filling the gap between high speed, high altitude jets and low flying light aircraft.
Rolls-Royce and Shell’s collaboration in supporting the aviation industry has continued in the years since testing of the RB53 Dart. Notably, Shell developed an advanced synthetic oil, Aeroshell 555, for Concorde’s Rolls-Royce/Snecma Olympus 593 Mk610 engines. This high performance lubricant was capable of dealing with the greater combustion temperatures and load-carrying requirements of supersonic aircraft. Shell also worked extensively to help define the fuel requirements for Concorde’s engines.
Today, Rolls-Royce and Shell continue to work together closely, supporting the aviation industry in the development of sustainable aviation fuel, which has the potential to help significantly reduce emissions, helping the sector on its challenging journey to net zero.
Shell Aviation News, 1949, p. 274.
R. van Egmond and A. Westra, Shell and aviation. The story of more than a century of collaboration. Shell International B.V., 2019, p. 80-81
Shell Aviation News, 1975 and 1976.
Shell historical archives.