The Avro Lancaster was designed by Avro's Chief designer Roy Chadwick around the 'failings' of the Avro Manchester which only had two 'Vulture' engines which were unreliable especially for the task of heavy bombing operations.
The Avro Lancaster, initially designated Avro 683 Manchester III, was designed with a larger wing to house four Rolls Royce Merlin engines giving the aircraft a top speed of 286mph. The first prototype Lancaster was flown by H.A Thorn on 9th January 1941 and was a success although the three tail fins were changed to the familiar two on the second prototype.
The Lancaster was a 'modular' design with the wings and fuselage each being manufactured in five complete sub assemblies. The main undercarriage was hydraulically retracted rearwards into the inboard engine nacelles with the rear tail wheel being fixed.
The majority of Lancasters were manufactured by Avro at Chadderton, others were built at Metropolitan-Vickers and Austin Motor Company Longbridge. Due to a shortage of Rolls Royce Merlin engines some 300 Lancaster BII's were fitted with Bristol Hercules engines and many were lost after running out of fuel.
The Lancaster entered service with the RAF in early 1942 with 44 squadron the first to recieve them. 7,366 were built during the war, more than any other British bomber. The seven man crew of the Lancaster were able to deliver around 14,000lbs of high explosive over the designated target at a range of around 1,660 miles.
For Air defence, the Lancaster had eight 0.303" Browning machine guns mounted in the nose, mid turret and tail, with latter versions having two 0.50" machine guns in the mid turret and the tail, refer variants.
The Lancasters original bomb bay was 33ft long and capable of carrying 4,000lb bombs. Modified doors were added to the Mk.Ib bomb bay which were 'bulged' allowing larger bombs to be carried, initially 8,000lb and then 12,000lb.
As the end of the war neared modified Mk.BI's could carry 21ft long 12,000lb bombs (Tallboy) and 25.5ft long 22,000lb 'earthquake' bombs (Grand Slam).
To enable the Lancaster to carry the 'Grand Slam' earthquake bomb there had to be extensive modifications and weight reduction which was achieved by removing the mid turret, machine guns from the rear turret, armour plating from the cockpit and the bomb bay doors. The rear of the bomb bay was relieved to clear the tail of the bomb and also to give additional power, especially during take off, four Rolls Royce Merlin 24 engines were fitted to the aircraft.
156,000 sorties were flown by Lancasters and 608,600 tons of bombs were dropped between 1942 and 1945 with 3,249 Lancasters being lost in action with just 35 aircraft completing more than 100 sorties.
Lancasters were used during the raids on Hamburg, named operation "Gomorrah", which were carried out both by day and night during 1943. The most famous raid to be undertaken by Lancasters was operation "Chastise" to destroy the dams of the Rhur valley. Mk III Lancasters of 617 squadron were fitted with special 'Bouncing bombs' which were designed by Barnes Wallace, to bounce over floating boons, settle against the dam wall and explode as they sank to a set depth. This raid was known as 'The Dam Busters' and later made into a film of that name.
Lancasters were also used to attack the German Battleship "Tirpitz" using the Tallboy 12,000lb bombs which were initially sucessful in disabling the ship and then later sinking her.
|Engine:||4 x Rolls Royce Merlin XX|
|Power:||4 x 1,460hp|
|Armament: - (Refer to Variants for fitment)|
|Machine Guns:||Browning 0.303"|
|Bomb Load:||14,000lb (Normal)|
|Tallboy:||12,000lb (BI Special)|
|Grand Slam:||22,000lb (BI Special)|
Lancaster Variants: -Lancaster BI
Originally the Lancaster was fitted with Rolls Royce Merlin XX V12 engines and SU caburettors, later modifications to the BI saw the use of Rolls Royce Merlin 22 & 24 engines and the air speed indicator (Pitot) mounted on the side of the fuselage under the cockpit rather than on a long mast at the front of the nose.
Lancaster BI Special
To enable the Lancaster to carry the 'Tallboy' and 'Grand Slam' bomb it was fitted with Merlin 24 engines and paddle-bladed propellers and had the mid turret removed to reduce weight and reduce air resistance. To house the 'Tallboy' the bombay doors were bulged and for the 'Grand Slam' they were removed and replaced with fairings.
Lancaster BI (FE)
A variant for the Far East, it had modified radio, it was equipped with radar, navigation aids and had the mid upper turret removed. It was also fitted with a 400 gallon fuel tank in the bomb bay.
Fitted with Bristol Hercules VI (manual mixture control) or XVI engines.
Fitted with Packard Merlin engines with Bendix Stromberg carburretors.
Lancaster BIII (Special)
23 aircraft were modifed to accept the 'Bouncing Bomb' used for the Dam Busters Raid. The bomb bay doors were removed, a hydraulic motor was fitted to rotate the bomb and spot lights were fitted to the nose and tail to accurately control low altitude over water at night. The mid-upper turret was removed and the gunner moved to the front turret.
A prototype re-design of the Lancaster with increased wingspan and a longer fuselage fitted with a new type turret housing two 0.50" machine guns and modification to the nose glazing. The inboard engines were Roll Royce Merlin 85's and later Merlin 68's were fitted to the outboard mounts.
This aircraft became the Lincon B1.
A further prototype with increased wingspan and fuselage and fitted with
two-stage Merlin 85's.
This aircraft became the Lincoln B2.
9 BIII's were fitted with Merlin 85/87 two-staged supercharged engines and four bladed paddle type propellers, which gave improved high altitude performance. These aircraft were used as 'Pathfinders' for No. 7, 83, 405, and 635 squadrons.
The mid-upper turret was moved slightly forward and the tail turret was fitted with four 0.303" Browning machine guns.
Canadian Marks have not been included
Avro Lancaster BI 'PA474' photographed at the 'Royal International Air Tatoo' in 2007 bearing the colour scheme of the 'Phantom of the Rhur', which has the marking of two squadrons. The Port side bears letters 'HW-R' of 100 squadron and her Starboard side bears 'BQ-B' of 550 squadron.
'PA474' is the only airworthy Lancaster in the United Kingdom and is part of the Battle of Britain Memorial Flight, based at RAF Coningsby, and is regularly seen at major airshows.