After a period of indifference, in June 1939 a demonstration of the Power Jets WU was made before a delegation of the Air Ministry, notably Dr Pye, Director of Scientific Research. The demonstration was so successful that the Ministry quickly arranged to buy the engine to give Power Jets working capital, lending it back to them for testing.

Power Jets W.1 Article

At the same time, a contract was placed for a “flight engine”, the W.1 (sometimes called the Whittle W.1). Designed by Frank Whittle and Power Jets, the W.1 was built under contract by British Thomson-Houston (BTH). Unlike the Whittle WU, that began bench testing in 1937, the W.1 was a symmetrical engine designed to facilitate, after development, installation in an aircraft. The W.1 used a double-sided centrifugal compressor of Hiduminium RR.59 alloy, reverse-flow combustion chambers and a water-cooled axial-flow turbine section; this was later modified to use air-cooling. The turbine blades were of Firth-Vickers Rex 78, a stainless steel developed under Dr. W. H Hatfield.

As development of the new design dragged on, it was decided to build a test unit “early engine” using any components that were deemed unairworthy along with test items. This was assembled to become the one-off W.1X.This officially unairworthy unit powered the Gloster E.28/39 on a short ‘hop’ during taxiing trials in April 1941, with flight trials taking place on 15 May 1941 at RAF Cranwell with a definitive W.1 engine.

After a visit to England in 1941, General Henry H. Arnold arranged for the W.1X to be shipped to the U.S, along with drawings for the more powerful W.2B engine. The former became the prototype of the General Electric I-16 and by April 1943 had been developed to produce 1,650 pounds force (750 kgf).

The Gloster E.28/39 and the Power Jets W.1 engine that powered it are both on public display at the Science Museum (London).

The W.1A is preserved at the RAF College Cranwell, and the W.1X is at the Smithsonian Institution, Washington DC.

Variants:
W.1(T)
Bench-testing only.

W.1(3)

W.1X
Intended for ground use only (aircraft taxi tests).

W.1A
1,450 lbf (6.45KN) air-cooled turbine disc

Variation:
General Electric I-16
American-built version of W.1A. This is the only version of the W.1 to go into mass production.

Specifications:
W.1 early development engine
Type: Centrifugal flow turbojet
Dry weight: 700 lb (320 kg)
Compressor: Single-stage double-sided centrifugal flow
Combustors: 10 reverse-flow can
Turbine: Single stage axial flow
Fuel type: Kerosene
Maximum thrust: 850 lbf (3.8 kN) at 16,500 rpm
Fuel consumption: 1,170 lb/hr (531 kg/h)
Specific fuel consumption: 1.376 lb/hr/lb (38.98 g/s·kN)
Thrust-to-weight ratio: 1.214:1

W.1 later development engine
Type: Centrifugal flow turbojet
Dry weight: 700 lb (320 kg)
Compressor: Single-stage double-sided centrifugal flow
Combustors: 10 reverse-flow can
Turbine: Single stage axial flow
Fuel type: Kerosene
Maximum thrust: ~1,032 lbf (4.59 kN)
Overall pressure ratio: ~3.8:1
Turbine inlet temperature: ~1,430 °C (2,610 °F)
Fuel consumption: ~1401 lb/hr (~636 kg/h)
Specific fuel consumption: ~1.358 lb/hr/lb (~38.47 g/s·kN)
Thrust-to-weight ratio: ~1.474:1