| Avro Lancaster | |
|---|---|
| Royal Air Force Avro Lancaster B I PA474 of the Battle of Britain Memorial Flight. | |
| Role | Heavy bomber |
| Manufacturer | Avro |
| Designer | Roy Chadwick |
| First flight | 8 January 1941 |
| Introduction | 1942 |
| Retired | 1963 (Canada) |
| Primary users | Royal Air Force Royal Canadian Air Force Royal Australian Air Force Royal New Zealand Air Force |
| Number built | 7,377 |
| Unit cost | £45-50,000 |
| Developed from | Avro Manchester |
| Variants | Avro Lancastrian |
| Developed into | Avro York Avro Lincoln |
The Avro Lancaster is a British four-engined Second World War heavy bomber designed and built by Avro for the Royal Air Force (RAF). It first saw active service with RAF Bomber Command in 1942 and, as the strategic bombing offensive over Europe gathered momentum, it became the main heavy bomber used by the RAF, the RCAF, and squadrons from other Commonwealth and European countries serving within the RAF, overshadowing its close contemporaries the Handley Page Halifax and Short Stirling.[1] The "Lanc", as it was affectionately known,[2] thus became the most famous and most successful of the Second World War night bombers, "delivering 608,612 tons of bombs in 156,000 sorties."[3]
The Lancaster, an evolution of the the troublesome Avro Manchester, was designed by Roy Chadwick and was powered by four Rolls-Royce Merlins, or, in one version, Bristol Hercules engines.
A long, unobstructed bomb-bay meant that the Lancaster could take even the largest bombs used by the RAF, including, the 4,000 lb (1,812 kg) , 8,000 lb (3,629 kg), or 12,000 lb (5,443 kg) Blockbusters, loads often supplemented with smaller bombs or incendiaries. The versatility of the Lancaster was such that it was chosen to equip 617 Squadron, and was modified to carry the Barnes Wallis designed Upkeep "Bouncing bomb" for Operation Chastise, the attack on Germany's Ruhr Valley dams. Although the Lancaster was primarily a night bomber, it excelled in many other roles, including daylight precision bombing: in the latter role some Lancasters were adapted to carry the 12,000 lb (5,443 kg) Tallboy and, ultimately, the 22,000 lb (9,979 kg) Grand Slam "earthquake" bombs (also designed by Wallis).[4]
As early as 1943 a Lancaster was converted to become an engine test bed for the Metropolitan-Vickers F.2 turbojet. Lancasters were later used to test several different engines, including the Armstrong Siddeley Mamba and Rolls-Royce Dart turboprops, and the Avro Canada Orenda turbojet. Post-War 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 a trans-Atlantic passenger and postal delivery airliner.
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The origins of the Lancaster stem from a twin-engined bomber design submitted to meet Specification P.13/36, which was for a new generation of twin-engined medium bombers for "worldwide use", the engine specified as the Rolls-Royce Vulture.[5] The resulting aircraft was the Manchester, which, although a capable aircraft, was underpowered and troubled by the unreliability of the Vulture engine. Only 200 Manchesters were built and they were withdrawn from service in 1942.[6]
Avro's chief designer, Roy Chadwick, was already working on an improved Manchester design using four of the more reliable but less powerful Rolls-Royce Merlin engines on a larger wing. The aircraft was initially designated Avro Type 683 Manchester III, and later re-named the Lancaster. The prototype aircraft BT308 was assembled by Avro's experimental flight department at Manchester's Ringway Airport from where test pilot H.A. "Bill" Thorn took the controls for its first flight on Thursday, 9 January 1941. The aircraft proved to be a great improvement on its predecessor, being "one of the few warplanes in history to be 'right' from the start."[7] Its initial three-finned tail layout, a result of the design being adapted from the Manchester I, was quickly changed on the second prototype DG595 and subsequent production aircraft to the familiar twin-finned specification also used on the later Manchesters (below).
Some of the later orders for Manchesters were changed in favour of Lancasters; the designs were very similar and both featured the same distinctive greenhouse cockpit, turret nose, and twin tail. The Lancaster discarded the stubby central third tail fin of the early Manchesters and used the wider span tailplane and larger elliptical twin fins from the later Manchester IA.
The Lancaster is a mid-wing cantilever monoplane with an oval all-metal fuselage. The wing was constructed in five main sections, the fuselage in five sections. All wing and fuselage sections were built separately and fitted with all the required equipment before final assembly. The tail unit had twin oval fins and rudders. The Lancaster was initially powered by four wing-mounted Rolls-Royce Merlin piston engines with three-bladed airscrews. It had retractable main landing gear and fixed tail-wheel, with the hydraulically operated main landing gear raising rearwards into the inner engine nacelles.[8]
The majority of Lancasters built during the war years were manufactured by Avro at their factory at Chadderton near Oldham, Lancashire, and test flown from Woodford Aerodrome in Cheshire. Other Lancasters were built by Metropolitan-Vickers (1080, also tested at Woodford), and Armstrong Whitworth. The aircraft was also produced at the Austin Motor Company works in Longbridge, Birmingham, later in the Second World War and postwar by Vickers-Armstrongs at Chester as well as at the Vickers Armstrong factory, Castle Bromwich, Birmingham. Only 300 of the Lancaster B II fitted with Bristol Hercules engines were constructed; this was a stopgap modification caused by a shortage of Merlin engines as fighter production was of higher priority. Many BIIs were lost after running out of fuel. The Lancaster B III had Packard Merlin engines but was otherwise identical to contemporary B Is, with 3,030 B IIIs built, almost all at A.V. Roe's Newton Heath factory. The B I and B III were built concurrently, and minor modifications were made to both marks as new batches were ordered. Examples of these modifications were the relocation of the pitot head from the nose to the side of the cockpit, and the change from de Havilland "needle blade" propellers to Hamilton Standard or Nash Kelvinator made "paddle blade" propellers.[9]
Of later variants, only the Canadian-built Lancaster B X, manufactured by Victory Aircraft in Malton, Ontario, was produced in significant numbers. A total of 430 of this type were built, earlier examples differing little from their British-built predecessors, except for using Packard-built Merlin engines and American-style instrumentation and electrics. Late-series models replaced the Frazer Nash mid-upper turret with a differently configured Martin turret, mounted slightly further forward for weight balance. A total of 7,377 Lancasters of all marks were built throughout the duration of the war, each at a 1943 cost of £45-50,000 (approximately £1.5 million-£1.67 million today).
Starting at the nose, the bomb aimer had two positions to man. His primary location was lying prone on the floor of the nose of the aircraft, with access to the controls for the bombsight head in front, with the bombsight computer on his left and bomb release selectors on the right. He would also use his view out of the large transparent perspex nose cupola to assist the navigator with map reading. To man the Frazer Nash FN5 nose turret, he simply had to stand up and he would be in position behind the triggers of his twin .303 in (7.7 mm) guns. The bomb aimer's position contained the nose parachute exit in the floor.
Moving back, on the roof of the bomb bay the pilot and flight engineer sat side-by-side under the expansive canopy, with the pilot sitting on the left on a raised portion of the floor. The flight engineer sat on a collapsible seat (known as a "second dicky seat") to the pilot's right, with the fuel selectors and gauges on a panel behind him and to his right.
Behind these crew members, and behind a curtain fitted to allow him to use light to work, sat the navigator. His position faced to port with a large chart table in front of him. An instrument panel showing the airspeed, altitude, and other details required for navigation was mounted on the side of the fuselage above the chart table.
The radios for the wireless operator were mounted on the left-hand end of the chart table, facing towards the rear of the aircraft. Behind these radios, facing forwards, on a seat at the front of the main spar sat the wireless operator. To his left was a window, and above him was the astrodome, used for visual signalling and also by the navigator for celestial navigation.
Behind the wireless operator were the two spars for the wing, which created a major obstacle for crew members moving down the fuselage even on the ground. On reaching the end of the bomb bay the floor dropped down to the bottom of the fuselage, and the mid upper gunner's Frazer Nash FN50 or FN150 turret was reached. His position allowed a 360° view over the top of the aircraft, with two .303 in (7.7 mm) M1919 Browning machine guns to protect the aircraft from above and to the side. The mid-upper gunner had perhaps the most uncomfortable ride of all the crew, as he was seated on a rectangle of canvas that was slung beneath the turret once the gunner had occupied his position. He could be required to occupy this seat for up to eight hours at a time.
To the rear of the turret was the side crew door, on the starboard side of the fuselage. This was the main entrance to the aircraft, and also could be used as a parachute exit. Right at the tail-end of the fuselage, over the spars for the tailplane, the rear gunner sat in his exposed position in the FN20, FN120 or Rose Rice turret, which was entered through a small hatch in the rear of the fuselage. Depending on the size of the rear gunner, the area was so cramped that the gunner would often hang his parachute on a hook inside the fuselage, near the turret doors. In the FN20 and FN120 turrets, he had four .303 in (7.7 mm) Brownings, and in the Rose Rice turret he had two .50 in (12.7 mm) Brownings. Neither the mid upper nor the rear gunner's position was heated, and the gunners had to wear electrically heated suits to prevent hypothermia and frostbite. Many rear gunners insisted on having the centre section of perspex removed from the turret to give a completely unobstructed view.
The Avro Lancaster was initially equipped with four Nash & Thomson Frazer Nash hydraulically operated turrets mounted in the nose, tail, mid upper and underside. The original tail turret was equipped with four 0.303 inch (7.7 mm) Browning machine guns and all other turrets with 2 such machine guns.[10][11]
Only the FN-5A[10] nose turret which was similar to the FN-5 used on the preceeding Avro Manchester, the Vickers Wellington and the Short Stirling remained unchanged during the life of the design, excepting instances where it was removed entirely.
The ventral (underside) FN-64 turret quickly proved to be dead weight, being both difficult to sight because it relied on a persiscope which limited the gunners view to a 20 degree arc,[10] and it was too slow to keep a target within its sights. (Similar problems afflicted the ventral turret in the North American B-25 Mitchell and other bombers). Aside from early B Is and the prototype B IIs, the FN-64 was almost never used. When the Luftwaffe began using Schräge Musik to make attacks from below in the winter of 1943/1944, modifications were made, including downward observation blisters mounted behind the bomb aimer's blister[12] and official[13] and unofficial mounts for .50 in (12.7 mm) machine guns or even 20 mm cannon, firing through the ventral holes of the removed FN-64. The fitting of these guns was hampered as the same ventral position was used for mounting the H2S blister, which limited installations to those aircraft fitted with bulged bomb-bays which interfered with the H2S.[10]
The mid-upper (dorsal or top turret) was an FN-50[11][10] on early examples and the very similar FN-150 with improved sights and controls[10] on later examples. On all but the earliest examples this turret was surrounded by a coaming which provided a track for a cam operated interuptor device which prevented the gunner from shooting the tail of his own aircraft.[10] The Mk.VII and late Mk.X Lancasters used the heavier electrically controlled Martin 250 CE 23A turret equipped with two .50 caliber machine guns[10] which was mounted further forward to preserve the aircraft's longitudinal balance, and because it had an internal machanism to prevent own-goals, it did not require a coaming. This was the same turret used on many American bombers including the Consolidated B-24 Liberator.[10] Other experimental turrets were tried out, including the FN-79 and the Boulton-Paul Type H barbette system.[10]
The tail turret was the most important element in the aircrafts defense and carried the heaviest armament. Despite this, the turrets used, starting with the FN-20, were never entirely satisfactory and numerous designs were tried. The FN-20 was replaced by the very similar FN-120 which used an improved gyroscopic gun sight[10]. Gunners using both the FN-20 and 120 removed perspex and armour from the turret to improve visibility, however trials by the RAF showed that a Mosquito night fighter was still able to get within a very short distance of the tail gunner without being spotted, confirming what the Luftwaffe had already figured out. The Rose-Rice Type R turret attempted to improve on the FN turrets by being completely open to the rear (improving visibility and allowing easier emergency egress) and by being fitted with two .50 caliber machine guns and was installed in a small number of Lancasters but never became common.[10] The answer however wasn't better visibility - it was with radar. The FN-121 was the Automatic Gun Laying Turret or AGLT and was an FN-120 fitted with Village Inn gun-laying radar.[10] Aircraft fitted with Village Inn were used as bait, flying behind the main formations to confront the night fighters that followed the formations and took down the stragglers. This significantly reduced operational losses and examples of the final turret used would also use gun laying radar. Prior to the end of the war, Lancasters built in the UK standardized on the FN-82 fitted with two .50 caliber machine guns and fitted with gun-laying radar as production allowed, which would also be used on early models of the Avro Lincoln.
An important feature of the Lancaster was its large 33 ft (10.05 m) long bomb bay. Initially, the heaviest bomb carried was 4,000 lb (1,820 kg) high capacity HC "Cookie". Bulged doors were added to 30% of B Is to allow the aircraft to carry 8,000 lb (3,600 kg) and later 12,000 lb (5,450 kg) "Cookies". Towards the end of the war, attacking special and hardened targets, the B I Specials could carry the 21 ft (6.4 m) long 12,000 lb (5,450 kg) Tallboy or 25.5 ft (7.77 m) long 22,000 lb (9,980 kg) Grand Slam "earthquake" bombs: the Lancaster was able to deliver the heaviest bombs made. To carry the "Grand Slam" extensive modifications to the aircraft were required which led to them being named B I (Specials). The modifications included removal of the mid-upper turret, two guns from the rear turret, removal of the cockpit armour plating (the pilot's seatback) and installation of Rolls-Royce Merlin Mk 24 Engines which had better take-off performance. The bomb-bay doors were removed and the rear end of the bomb bay cut away to clear the tail of the bomb. Later the nose turret was also removed to further improve performance.[14][4] Aside from these outsized bombs, the Lancaster carried a variety of more mundane weapons, including the Small Bomb Container (SBC) which held 236 4 lb or 24 30 lb incendiary and explosive incendiary bomblets, 250 lb or 500 lb anti-submarine depth charges, 250 lb Semi-Armour-Piercing (SAP) bombs (for use against submarines before 1942), 500 lb and 1,000 lb General Purpose High Explosive (GP/HE) bombs (which came in a variety of designs), 1,850 lb parachute deployed magnetic or acoustic mines, 2,000 lb armour piecing (AP) bombs. Specific bomb loads were standardized and given code names by Bomber Command:[15] .
| Codename | Type of raid or target | Bomb load |
|---|---|---|
| ARSON | incendiary area bombing | 14 SBC, each with 236 x 4 lb Incendiary and Explosive Incendiary bomblets. |
| ABNORMAL | factories, railway yards, dockyards | 14 x 1,000 lb GP/HE bombs using both impact and long delay (up to 144 hours) fuses. |
| COOKIE or PLUMDUFF | Blast, demolition and fire | 1 x 4,000 lb impact-fused HC bomb. 3 x 1,000 lb GP/HE bombs, and up to 6 SBCs with incendiary bomblets. |
| USUAL | Blast and incendiary area bombing | 1 x 4,000 lb impact-fused HC bomb, and 12 SBCs with incendiary bomblets. |
| No-BALL | V-1 flying bomb launch sites | 1 x 4,000 lb impact fused HC and up to 18 x 500 lb GP bombs, with both impact and delay fusing. |
| PIECE | Docks, fortifications and ships | 6 x 2,000 lb short-delay fused AP bombs, plus other GP/HE bombs based on local needs or availability. |
| GARDENING | Ports, canals, rivers and seaways | 6 x 1,850 lb parachute mines. |
| PLUMDUFF-PLUS | Heavy industry | 1 x 8,000 lb impact or barometric fused HC and up to 6 x 500 lbs impact or delay fused GP/HE bombs. |
| TALLBOY | Very strong or durable structures | 1 x 12,000 lb short-delay fused Tallboy bomb |
| GRAND SLAM | Underground or armoured facilities | 1 x 22,000 lb short-delay fused Grand Slam bomb |
| n/a | Medium-range low altitude tactical raids | 6 x 1,000 lb short and long delay fused GP/HE bombs, additional 250 lb GP/HE bombs sometimes added. |
| n/a | Submarines | 6 x 500 lb and 3 x 250 lb anti-submarine depth charge bombs and until 1942 5 x 250 lb short delay fuse SAP bombs for surfaced U-boats. |
Bombsights used on Lancasters included:[16]
The Lancaster had a very advanced communications system for its time. Most British-built Lancasters were fitted with the R1155 receiver and T1154 transmitter, whereas the Canadian built aircraft and those built for service in the Far East had American radios. These provided radio direction-finding, as well as voice and Morse capabilities.
The first RAF squadron to convert to the Lancaster was No. 44 Squadron RAF in early 1942.
Lancasters flew 156,000 sorties and dropped 608,612 long tons (618,378 tonnes) of bombs between 1942 and 1945. Just 35 Lancasters completed more than 100 successful operations each, and 3,249 were lost in action. The most successful survivor completed 139 operations, and was scrapped in 1947.
Lancs took part in the devastating round-the-clock raids on Hamburg during Air Chief Marshal Harris' "Operation Gomorrah" in July 1943. A famous Lancaster bombing raid was the 1943 mission, codenamed Operation Chastise, to destroy the dams of the Ruhr Valley. The operation was carried out by 617 Squadron in modified Mk IIIs carrying special drum shaped bouncing bombs designed by Barnes Wallis. The story of the operation was later made into a film, The Dam Busters. Also famous was a series of Lancaster attacks using Tallboy bombs against the German battleship Tirpitz, which first disabled and later sank the ship.
Lancasters from Bomber Command were to have formed the main strength of Tiger Force, the Commonwealth bomber contingent scheduled to take part in Operation Downfall, the codename for the planned invasion of Japan in late 1945. Together with the new Avro Lincoln and Liberators they would have operated from bases on Okinawa; the invasion was made unnecessary by the Japanese surrender.
RAF Lancasters dropped food into the Holland region of the occupied Netherlands, with the acquiescence of the occupying German forces, to feed people who were in danger of starvation. The mission was named 'Operation Manna' after the food Manna which is said to have miraculously appeared for the Israelites in the Book of Exodus. The aircraft involved were from 1, 3, and 8 Groups, and consisted of 145 Mosquitoes and 3,156 Lancasters, flying between them a total of 3,298 sorties. The first of the two RAF Lancasters chosen for the test flight was nicknamed "Bad Penny" from the old expression: "a bad penny always turns up." This bomber, with a crew of seven men (five Canadians including pilot Robert Upcott of Windsor, Ontario), took off in bad weather on the morning of 29 April 1945 without a ceasefire agreement from the German forces, and successfully dropped her cargo.
A development of the Lancaster was the Avro Lincoln bomber, initially known as the Lancaster IV and Lancaster V. These two marks became the Lincoln B1 and B2 respectively. A civilian airliner was based on the Lancaster, the Lancastrian. Other developments were the York, a square-bodied transport and, via the Lincoln, the Shackleton which continued in airborne early warning service up to 1992.
In June 1947, the Argentinian Air Force received 15 Lancasters. During its Argentinian service, Lancasters saw limited use in military coups, owing to the small number there.
A total of 59 Lancaster B.Is and B.VIIs were overhauled by Avro at Woodford and Langar and delivered to the Aeronavale (France) during 1952/53. These were flown until the mid-1960s by four squadrons in France and New Caledonia in the maritime reconnaissance and search-and-rescue roles. [17]
Beginning in 1946, Lancaster Mk Xs were modified for service with the Royal Canadian Air Force. Fourteen were modified for aerial and photo reconnaissance work and performed much of the mapping of northern Canada until as late as 1962. Throughout the 1950s the RCAF operated seventy modified Lancasters, designated Lancaster 10MR/MPs, as Maritime Reconnaissance and Patrol aircraft in an anti-submarine role. Modifications involved the installation of radar and sonobuoy operators' positions, removal of the rear and mid-upper gun turrets, installation of a 400 gallon fuel tank in the bomb-bay to increase the patrol range, upgraded electronics, radar, and instrumentation, and a cooking stove in the centre section.[18] They served throughout the 1950s until they were replaced by the Lockheed Neptune and Canadair Argus.[19]
Civil conversions continued postwar. In 1946, four Lancasters were converted by Avro at Bracebridge Heath, Lincolnshire as freighters for use by British South American Airways, but proved to be uneconomical, and were withdrawn after a year in service. In addition, four Lancaster IIIs were converted by Flight Refuelling Limited as two pairs of tanker and receiver aircraft for development of in-flight refuelling. In 1947, one aircraft was flown non-stop 3,459 mi (5,567 km) from London to Bermuda. Later the two tanker aircraft were joined by another converted Lancaster and were used in the Berlin Airlift, achieving 757 tanker sorties.
During 1943-1947 the Canadian Government Trans-Atlantic Air Service (CGTAS) provided trans-Atlantic military passenger and postal delivery service using a modified long-distance transport version of Lancaster Mark Xs. Nine of these aircraft were produced, referred to as Lancaster XPPs (for Lancaster Mk.X Passenger Planes), and each was equipped with rudimentary passenger facilities. The inaugural flight from Dorval (Montreal) to Prestwick, Scotland on July 22, 1943, was completed non-stop in a record 12:26 hours; the average crossing time was about 13:25 hours. By the end of the war, these aircraft had completed hundreds of trips across the Atlantic. CGTAS ushered in the era of commercial air travel across the North Atlantic and in 1947 the service became part of Trans-Canada Air Lines, which carried paying civilian passengers in the Lancaster XPPs until they were replaced by Douglas DC-4s in 1947.[19][20][21]
There are 17 known largely complete Avro Lancasters remaining in the world with two airworthy. One of them is based in the UK, operated by The Battle of Britain Memorial Flight and the other is in Canada, operated by the Canadian Warplane Heritage Museum. Lancaster FM-136 was purchased by Lynn Garrison, in 1961, and displayed in Calgary, Alberta as a memorial to those who trained under the British Commonwealth Air Training Plan. It is now being returned to flying condition.
Data from Avro Aircraft since 1908[31]
General characteristics
Performance
Armament
Many Lancaster crew members were highly decorated for actions while flying the aircraft. Amongst those who received the Victoria Cross were:
The Avro Lancaster featured prominently in the 1955 film The Dam Busters, and a number of B VII Lancasters in storage were modified to the original configuration of the B III (Special) for use on screen. The Lancaster also plays a central role in Bomber, the 1970 novel by Len Deighton about a night raid on a fictional German town by a formation of RAF bombers. It also featured in a 1989 British commercial for Carling Black Label lager which reused footage in a Dam Busters parody sequence in which a German soldier on top of a dam was catching the bombs in the manner of a football goalkeeper. The pilot of the attacking Lancaster then delivers the brand slogan: "I bet he drinks Carling Black Label!" The commercial ran for many years, frequently appearing in commercial breaks in both the 1955 film and documentaries about Operation Chastise.[38] The Avro Lancaster was also featured in the UK TV series Pathfinders, airing in 1972 and released on DVD in 2006, concentrating on the lives of the aircrew of a fictional Pathfinder squadron during the Second World War. [39] Other films in which the Lancaster appeared include Appointment in London (1952) and The Guns of Navarone (1961).
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