Modern-Aviation

The origins of the Lancaster are with a twin-engined bomber design submitted to meet Air Ministry Specification P13/36 and the resulting aircraft, the Avro Manchester. Although a capable aircraft, the Manchester proved underpowered by its Rolls-Royce Vulture engines and the type was withdrawn from service in 1942.

Avro's chief designer Roy Chadwick had been already working on an improved Manchester design using four of the more reliable, but less powerful Rolls-Royce Merlin engines fixed on larger wings. The aircraft, initially designated Type 683 Manchester III was later renamed the Avro Lancaster.

The prototype aircraft (BT308) was assembled by Avro's Experimental Flight Department at Manchester's Ringway Airport and made its first flight on 9th January 1941. It proved to be a great improvement on its predecessor, being ‘one of the few warplanes in history to be 'right' from the start’.

Its initial three-finned tail layout was quickly changed on the second prototype (DG595) and subsequent production aircraft, to the familiar twin-finned specification.

The Lancaster is a mid-wing cantilever monoplane with an all-metal fuselage. The wings were constructed in five main sections as was the fuselage. All main sections were built separately and were fitted with all the required equipment before final assembly. Initially, it was powered by four Rolls-Royce Merlin water-cooled piston engines driving de Havilland Hydromatic three-bladed airscrews and had retractable main landing gear with a fixed tail-wheel.

The majority of the aircraft built during the war years were manufactured by Avro at their factory at Chadderton near Oldham, Lancashire. They were then assembled and test flown from Woodford Aerodrome in Cheshire. Others were built by Metropolitan-Vickers and Armstrong Whitworth whilst a number were also produced at the Austin Motor Company works in Longbridge, Birmingham. In later years some were also produced at Chester and Castle Bromwich (both Vickers-Armstrong factories).

Utilising a long, unobstructed bomb bay meant the Lancaster could take even the largest bombs used by the RAF, including, the 4,000, 8,000, or 12,000 lb Blockbusters. The versatility of the aircraft was such that it was chosen to equip 617 Squadron, and modified to carry the Barnes Wallis designed Upkeep "Bouncing bomb" for Operation Chastise, the attack on Germany's dams at the Ruhr Valley.

Although Lancaster was primarily a night bomber, it excelled in many other roles including daylight and precision bombing and in the latter role some were adapted to carry the 12,000 lb Tallboy and ultimately the 22,000 lb Grand Slam Earthquake bombs (also designed by Wallis).

Postwar, the Lancaster was supplanted as the RAF's main strategic bomber by the Avro Lincoln, itself a larger permutation of the Lancaster.

Instead the Lancaster took on the role of long range anti-submarine patrol aircraft (later supplanted by the Avro Shackleton) and air-sea rescue. It was also used in roles as diverse as photo-reconnaissance and aerial mapping, as a flying tanker for aerial refueling and as the Avro Lancastrian, a long-range, high-speed transatlantic passenger and postal delivery airliner.

In March 1946, a Lancastrian of BSAA flew the first scheduled flight from the then new London Heathrow Airport.

Of the 19 Lancasters which took off for the dams raid with their 133 crew, eight planes and 56 men did not return. Five planes crashed or were shot down en route to their targets. Two were destroyed while delivering their attacks and another was shot down on the way home. Two more were so badly damaged that they had to abandon their missions. No.617 Squadron, known from this time onwards as the "Dambusters", had become famous.

The attack had huge propaganda value and made Gibson a national hero. Gibson was awarded the Victoria Cross for bringing round his Lancaster to give covering fire to the Lancasters that were following up his attack on the Mohne Dam. Thirty-one other members of 617 Squadron were also decorated. Severe flooding occurred where the Mohne Dam was breached.

Six small electricity works were damaged and rail lines passing through the Mohne Valley were disrupted. But industrial production was not affected in the long term. When the Eder Dam broke, there were similar results. Kassel, an important arms-producing town, was breached by the flood- water, but little actual damage was done. Had the Sorpe Dam been breached, the damage would have been much greater' The potential for a major disaster was recognized by Albert Speer who commented, "Ruhr production would have suffered the heaviest possible blow."

In the short and long term, the damage done by 617 Squadron was repaired quite quickly. But the most important impact of the raid was that 20,000 men working on the Atlantic Wall had to be moved to the Ruhr to carry out repairs to the damaged and breached dams. This work was completed before the rains of the autumn appeared.