The Rolls-Royce Derwent is an early centrifugal-flow turbojet associated principally with the Gloster Meteor. Its first prototype ran in 1943, continuing the development of British jet propulsion from Frank Whittle's earlier work. Later Derwent versions changed considerably, with the Derwent V effectively representing a new engine within the established name.[1][2]
The original Meteor installation
The Derwent I had to fit the same Meteor nacelle as the Welland and was therefore designed to the same diameter. It introduced straight-through gas flow and targeted 2,000 lbf thrust. Drawings began in April 1943, and the engine completed a 100-hour test at that rating in November. Meteor flight tests followed in April 1944 at an 1,800 lbf rating, with the engine weighing 920 lb.[2]
Centrifugal layout
The engine's central centrifugal compressor supplied a ring of individual combustion chambers around its exterior. The Science Museum contrasts this arrangement with later engines using a single annular combustion chamber. The early layout produced a relatively wide and short engine, a characteristic visible in preserved Derwents and important to understanding the nacelle constraints of the first Meteor installations.[1]
A substantially revised successor
Derwent II, III and IV models followed the initial engine. The larger Nene was developed from the underlying design approach, and a scaled-down version of the Nene became the Derwent V. This was consequently much more than a small rating change. The RAF Museum notes that the additional power was useful for larger and heavier Meteor night fighters.[1][2]
Surviving machinery
The Science Museum Group preserves a Derwent V made around 1946, believed to be an early example from Barnoldswick rather than the main Derby production location. The RAF Museum also holds a Derwent at its Midlands site. These surviving engines document the rapid evolution of British turbojets from wartime prototypes into more powerful postwar aircraft installations.[1][2]