TECHNICAL

TECHNICAL progress in the Company's normal range of products was resumed soon after the end of the war, accelerated and broadened by wartime activities and their subsequent development.

JET ENGINES AND GAS TURBINES
With the possibilities of gas turbines in mind some years before war broke out, R. W. Bailey's research work on creep phenomena was extended to temperatures well beyond the range of steam plant. Though higher temperatures meant a shorter working life, this was no disadvantage in engines for military aircraft, and in 1937 discussions were started with the Royal Aircraft Establishment, Farnborough. In the following year the Company received a contract from the Government for the development of gas turbines. This work under K. Baumann and D. M. Smith, who later became chief engineer of the new gas turbine department, had far-reaching results, which since the war have led to gas turbines being designed as prime movers, both for ship propulsion and for electricity generation in land power stations and in locomotives.

The original aircraft turbines were of the compound crossover type and were intended to drive propellers and also to give some thrust from an exhaust jet. Tests in 1940 on a simple arrangement of typical components provided experience of great value. However it had already been decided to adopt an in-line design giving a straight through flow, and a machine having a new type of combustion chamber was built in 1941.

Meanwhile the feasibility of jet propulsion alone had been accepted by the Ministry of Aircraft Production, and in July 1940 the Company was requested to undertake the development of an axial-flow jet engine. The outcome was the now famous F2 type in which the gases flowed straight through an axial flow compressor, an annular combustion chamber, a turbine and an exhaust cone. Bench tests began in December 1941, and a year later a modified engine had been passed for experimental flights, which were followed by trials in a Lancaster flying test bed. On November 13,1943, a prototype Gloster Meteor fighter equipped with F2 engines made a flight from Farnborough. This was the first time that a jet propelled aircraft with axial-flow engines had been flown in this country.

Later developments included the 'ducted-fan thrust augmented, a compromise between simple jet propulsion and airscrew propulsion; this device, known as the F3, gave greater thrust for the same fuel consumption at take-off and up to flight speeds of about 400 m.p.h. Other changes were made—always retaining the straight-through design with its small frontal area, a valuable feature on aircraft engines—and these culminated in the F2/4, the prototype of the present Beryl engine.