General Electric T58 / CT58
Bristol Siddeley Gnome
The General Electric T58 is an American turboshaft engine developed for helicopter use. First run in 1955, it remained in production until 1984, by which time some 6,300 units had been built. On July 1, 1959, it became the first turbine engine to gain FAA certification for civil helicopter use.
Development commenced with a 1953 US Navy requirement for a helicopter turboshaft to weigh under 400 lb (180 kg) while delivering 800 hp (600 kW). The engine General Electric eventually built weighed only 250 lb (110 kg) and delivered 1,050 hp (780 kW) and was soon ordered into production. First flight was on a modified Sikorsky HSS-1 in 1957, and civil certification for the CT58-100 variant was obtained two years later.
The main production version of the engine was the T58-GE-10, developing 1,400 hp (1,044 kW). The most powerful version, the T58-GE-16, produces 1,870 hp (1,390 kW).
The Rolls-Royce Gnome is a single spool turboshaft engine originally developed by the de Havilland Engine Company as a licence-built General Electric T58—a mid-1950s design. The Gnome came to Rolls-Royce after their takeover of Bristol Siddeley in 1966, Bristol having absorbed de Havilland Engines Limited in 1961.
A licence to manufacture the T58 was purchased in 1958. The T58 had begun bench testing in 1955 and by 1958 had already been used in helicopters and de Havilland were able to test their first engines in a Westland Whirlwind and Wasp helicopters in August 1959.
A free-turbine turboshaft, it was used in helicopters such as the Westland Sea King and Westland Whirlwind. The design was sub-licensed to Alfa-Romeo and the IHI Corporation.
There were two series produced: the "H" turboshaft for helicopter use, and the "P" turboprop for fixed-wing aircraft.
A single-stage turbine drives the 10 stage all-axial compressor, whilst a two-stage free power turbine drives the load. The combustor is annular. The Gnome differed from the T-58 in having a British developed fuel control system (Lucas).
Because an all-axial design is employed, the final stage compressor rotor blades are amongst the smallest ever manufactured. Normally, a small engine such as this would feature an axial/centrifugal or even a double centrifugal compressor.
The engine was one of the first developed with an analogue computer, de Havilland's own, as part of the fuel control system, specifically to control fuel flow during acceleration to prevent engine surge from occurring.
The General Electric T58 remained in production until 1984, by which time some 6,300 units had been built. On July 1, 1959, it became the first turbine engine to gain FAA certification for civil helicopter use.
T58s, have been converted to turbojet by the removal of the power turbines and were used as jet engines on:
Maverick TwinJet 1200
Gross Panther Replica
T58 converted to turbojet by Les Shockley (2003). Named SHOCKWAVE 800+
The engine weighs just 300 pounds and is capable of producing up to 840 pounds of thrust.
The Carroll Shelby turbine cars entered in the 1968 Indianapolis 500 race were powered by T58s. The cars were found to be using variable inlets to get around the USAC regulations on the maximum allowable inlet size and were disqualified.
Turboshaft engines like the GE T58, Lycoming T53/T55 are also used to power high performance powerboats, such as aport and offshore vee, and catamaran hulls like the Skater "Jet Set" or Mystic Powerboats "My Way", water jet river racers like Unatural Dissaster and hydroplanes. Some of these boats run in excess of 200 mph, despite them being open cockpit pleasure boats.
Gnome Mk 660
Application: General Electric T58
Applications: Rolls Royce Gnome