Avro Manchester
from Below
|
|
The Avro Manchester was one of the least successful British aircraft of the Second World War. However, it was also the parent of probably the best British bomber of the war, the Avro Lancaster.
The Manchester was developed in response to Air Ministry Specification P.13/36 of May 1936. This called for a twin engined heavy bomber powered by the new Rolls Royce Vulture engine. The Vulture was still under development in 1936, and consisted of two twelve cylinder Rolls Royce Kestrel engines (another design to be developed from the Kestrel was the Peregrine, also not a great success). Specification P.13/36 also produced the Boulton Paul P.91 and the early version of the Handley Page Halifax.
The specification also made a series of other demands which were later abandoned, including the ability to act as a dive bomber, drop torpedoes and the capacity for catapult assisted take-off. As a result of these demands, the Manchester was a very strong aircraft, with a very large single celled bomb bay that took up some two thirds of the length of the fuselage.
Avro received an order for 200 Manchesters on 1 July 1937, purely on the strength of the design. The first prototype would not fly until 25 July 1939. By the time the prototype took to the air, the Vulture project was running into problems. By 1938 it had become clear that the new engine was not as powerful as had been expected, nor was it proving to be very reliable.
The first prototype was very clearly the ancestor of the Lancaster. It used a similar twin finned tail plane to the later aircraft. The design called for nose and tail turrets, not installed in the first prototype, and Avro had begun to make provision for a dorsal turret. Tests on the new aircraft revealed some minor problems – the wings had to be extended by ten feet, from a span of 80ft 2ins to one of 90ft, and the aircraft suffered from directional instability. This was reduced by added a third tail-fin on the rear fuselage. This third fin would be the most obvious visual difference between the Manchester Mk I and the Lancaster (other than the number of engines of course!).
A bigger problem was that the Vulture engines were not producing enough power to give the Manchester its expected performance. This problem would never be solved – Rolls Royce had more urgent jobs in 1939-40 than fixing the Vulture, and the entire project would soon be dropped.
Work now began on modifying the Manchester to use different engines. Two main approaches were taken – to either use two radial engines (Napier Sabre or Bristol Centaurus engines were suggested), under the name Manchester Mk II, or use four of the less powerful but much more reliable Rolls Royce Merlin engines, under the name Manchester Mk III. The prototype Manchester Mk III flew on 9 January 1941, and was a clear success. It was this aircraft, soon renamed the Avro Lancaster, that would eventually become the mainstay of Bomber Command.
In the meantime the Avro Manchester Mk I began to enter service. The Mk I carried sight .303in machine guns in three turrets in the nose (2 guns), dorsal (2 guns) and rear (4 guns) positions. A proposed ventral turret as not installed. The first squadron to receive the Manchester was No. 207 Squadron, which was reformed at Waddington on 1 November 1940. Their first raid came on 24 February 1941, against a German cruiser in Brest harbour, and for the Manchester was a relative success – none were shot down, and only one crashed on its return to base. However, this first raid came six weeks after the first flight of the Lancaster. The Manchester’s days were numbered, and only the desperate need for new aircraft kept it in front line service.
The Manchester’s performance statistics are somewhat misleading. Although the type had a service ceiling of 19,200 feet, with a full load it was forced to operate at nearer to 10,000 feet. In theory it could fly on one engine, and the unreliable Vulture forced it to do this far too often. In reality it was rare for a Manchester to cover any distance on one engine.
The Manchester remained in squadron service from November 1940 until the end of June 1942. In all 202 Manchesters were built before production switched to the Lancaster. Of those aircraft, around 80 were lost in action, and another 50 to general unreliability. Early problems with the tail were solved by used the twin finned design being developed for the Lancaster, under the designation Manchester Mk IA. This version truly resembles the later aircraft.
The Manchester did have some good features. The bomb bay was the biggest of any Bomber Command aircraft, and this would allow the Lancaster to carry increasingly large bomb loads to Germany later in the war. Even the Manchester could manage the 4,000lb “cookie”. The bomb aimer had a well designed position with a good view, again a feature that was carried over to the Lancaster. Avro’s design was sound, but the Vulture was not. It was only the urgent requirement for new aircraft in the face of the looming threat of war with Germany that forced the Manchester into service.
Performance Statistics
Engines: Two Rolls Royce Vultures
Horsepower: Theoretically 1,760hp, in practise 1,500hp
Max Speed: 265mph at 17,000 ft
Cruising Speed: 185 mph at 15,000 ft
Ceiling: 19,200 ft
Range: 1630 miles with 8,100lb of bombs, 1200 miles with 10,350lb of bombs
Span: 90 feet 1 inch
Length: 69 ft 4 inches
Bomb load: 10,350lb
Front turret: FN5
Rear turret: FN20
Dorsal turret: FN7/ FN21A