Manchester was a twin-engined bomber developed during World War II by the Avro for RAF. The Manchester was a failure, being severely under-powered, but it was the forerunner to the famous Avro Lancaster bomber, one of the most successful bombers of the war.
The Manchester was originally designed to the Air Ministry Specification P.13/36 which was the same specification that Handley Page followed in their design of the Halifax bomber. The specification called for a twin-engined heavy bomber using the powerful Rolls-Royce Vulture 24-cylinder X-type engine which was essentially two Rolls-Royce Peregrine Vee-type cylinder blocks on top of each other, the bottom one inverted to give the “X” shape. When developed in 1935, the engine had promise—it was rated at 1,760 hp—but it proved woefully unreliable and had to be derated to between 1,480 and 1,500 hp. Avro’s prototype Manchester first flew on July 25, 1939.
Handley Page’s response to the engine’s faults was to switch the Halifax to four of the less powerful but more reliable Rolls-Royce Merlin X engines however Avro persisted with the Vulture and the Manchester went into production, entering service with RAF Bomber Command in November 1940. Eventually 209 Manchesters entered service, equipping eight bomber squadrons, serving with two others and also being used by Coastal Command.
While the Manchester was designed with twin tail fins, the first production aircraft, designated the Mk I, had a central fin added. However, this was quickly replaced in the Mk IA which reverted to the twin-fin system and this configuration carried over to the Lancaster.
The Mk III Manchester, which first flew on January 9, 1941, was essentially the first Lancaster, being powered by four Merlin engines and with increased wingspan. Manchester production continued until November of that year but some aircraft still in production were completed as Lancasters.
Serials
Prototypes: L7246 and L7247
Production: L7276-L7325, L7373-L7402, L7415-L7434, L7453-L7497, L7515-L7526, (L7517 destroyed at factory 19.11.41), R5768-R5797, R5829-R5841
Source
Chaz Bowyer: Avro Manchester – Aircraft Profile 260
Tony Buttler: Avro Manchester – Warpaint 103
Paul Eden: Encyclopedia of Aircraft of World War II