Misplaced Pages

#60939

113-487: The Vickers Wellington is a British twin-engined, long-range medium bomber . It was designed during the mid-1930s at Brooklands in Weybridge, Surrey . Led by Vickers-Armstrongs ' chief designer Rex Pierson , a key feature of the aircraft is its geodetic airframe fuselage structure, which was principally designed by Barnes Wallis . Development had been started in response to Air Ministry Specification B.9/32, issued in

226-695: A de Havilland Mosquito and a Bristol Beaufighter fighter intercepting Heinkel He 111 bombers flying from Dutch airbases and carrying out airborne launches of the V-1 flying bomb . The FIU operators on the Wellington would search for the He 111 aircraft climbing to launch altitude, then direct the Beaufighter to attack the bomber, while the Mosquito would attempt to intercept the V-1 if it

339-477: A "cuff" sleeve in the cylinder head instead of the cylinder proper, providing a more "classic" layout compared with traditional poppet valve engines. This design also had the advantage of not having the piston within the sleeve, although in practice this appears to have had little practical value. On the downside, this arrangement limited the size of the ports to that of the cylinder head, whereas in-cylinder sleeves could have much larger ports. The main advantages of

452-400: A 24-inch search light in the 'dustbin' turret of a DWI Wellington testing it from January 1941. This prototype substituted batteries for the engine and generator setup to reduce weight and this carried forward into production Leigh light-equipped Wellingtons Together with accurate radar altimeters, Wellingtons could fly safely down to 50 ft, illuminating the target submarine at around half

565-414: A 500 cc single-cylinder engine, with a specific fuel consumption of 177–205 g/HP/hr (0.39–0.45 lb/HP/hr), the engine being able to work on creosote , and with no specific lubrication supply for the sleeve; they said having solved the oil consumption issue by adding a Dykes ring on 'Junk Head'. An unusual form of four-stroke model engine that uses what is essentially a sleeve-valve format,

678-439: A German Messerschmitt Bf 110 night-fighter attacked a Wellington returning from an attack on Münster , causing a fire at the rear of the starboard engine. The second pilot, Sergeant James Allen Ward ( RNZAF ) climbed out of the fuselage, kicked holes in the doped fabric of the wing for foot and hand holds to reach the starboard engine and smothered the burning upper wing covering. He and the aircraft returned home safely and Ward

791-542: A Wellington B.X, on 11 May 1944. In March 1948 the front gun turret was removed in its conversion to a T.10 for its role as a postwar aircrew trainer. This aircraft is the Wellington seen taking off in The Dam Busters and was also used for some air-to-air photography on the movie. Medium bomber The term was used prior to and during World War II , based on available parameters of engine and aeronautical technology for bomber aircraft designs at that time. After

904-527: A case against Argyll for infringement of their original 1905 patent. This patent described an engine with a single moving sleeve, whereas the Daimler engines being built at the time were based on the 1908 Knight patent which had engines with two moving sleeves. As part of the litigation an engine was built according to the 1905 specification and developed no more than a fraction of the rated RAC horsepower . This fact coupled with other legal and technical arguments led

1017-428: A corresponding works order was issued for the Wellington. On 15 June 1936, K4049 conducted its maiden flight from Brooklands. Vickers chief test pilot Joseph Summers flew K4049 on its first flight, accompanied by Wallis and Trevor Westbrook. The aircraft soon came to be widely regarded as being an advanced design for its era and proved to have considerable merit during its flight trials. On 19 April 1937, K4049

1130-573: A cruising speed of 125 knots carrying 1,500 lb of bombs or depth charges. It was used for anti-submarine operations; on 6 July 1942, a Wellington sank its first enemy vessel. In 1944, Wellingtons of Coastal Command were sent to Greece and performed various support duties during the British intervention in the Greek Civil War . A few Wellingtons were operated by the Hellenic Air Force . While

1243-515: A directive by the Air Staff to replace them. At the same time a development contract was placed with Nash & Thompson for a turret that could be used for both front and rear positions. The resulting FN.5 was also used on Short Stirling and Avro Manchester Due to the specialised nature of increasingly advanced turrets, these were treated as ancillary equipment, being designed and supplied independently and replacing Vickers' own turrets developed for

SECTION 10

#1732845502061

1356-487: A formation of Wellingtons to penetrate strongly defended hostile airspace was validated. On 14 December 1939, 12 Wellingtons of No. 99 Squadron conducted a low-level raid upon German shipping at the Schillig Roads and Wilhelmshaven . Encountering enemy fire from warships, flak , and Luftwaffe aircraft, the Wellington formation lost five aircraft, along with another that crashed near its base, while only one enemy fighter

1469-628: A greater quantity produced than any other British bomber. On 13 October 1945, the last Wellington to be produced rolled out. The Wellington Mk I was quickly superseded by improved variants. Improvements to the turrets and the strengthening of the undercarriage quickly resulted in the Wellington Mk IA . The Mk IA was specified to be based on the Merlin X engined Wellington Mk II design and was in theory to be able to be fitted with either Merlins or Pegasus but in practice only radials were fitted. The Mark IA

1582-494: A lot of lubricating oil or to seize due to lack of it. The Scottish Argyll company used its own, much simpler and more efficient, single sleeve system (Burt-McCollum) in its cars, a system which, after extensive development, saw substantial use in British aircraft engines of the 1940s, such as the Napier Sabre , Bristol Hercules , Centaurus , and the promising but never mass-produced Rolls-Royce Crecy , only to be supplanted by

1695-514: A mile away just as the air-to-surface-vessel (ASV) radar lost the target among returns from the water's surface. In late 1944, a radar-equipped Wellington XIV from 407 Sqn. RCAF was modified for use by the RAF's Fighter Interception Unit as what would now be described as an airborne early warning and control aircraft. It operated at an altitude of 4,000 ft (1,200 m) over the North Sea to control

1808-463: A mixture of Wellington Mk I and Mk IA aircraft. On 4 September 1939, less than 24 hours after the commencement of hostilities, a total of 14 Wellingtons of No. 9 and No. 149 Squadrons, alongside a number of Bristol Blenheim aircraft, performed the first RAF bombing raid of the war, against German shipping at Brunsbüttel . The bombing of the harbour had not been permitted by Chamberlain's War Cabinet for fear of injuring civilians. The effectiveness of

1921-540: A new engine which replaced the sleeve valve starting with the Mark V tank . Among the companies using Knight's technology were Avions Voisin , Daimler (1909–1930s) including their V12 Double Six , Panhard (1911–39), Mercedes (1909–24), Willys (as the Willys-Knight , plus the associated Falcon-Knight), Stearns , Mors , Peugeot , and Belgium's Minerva company that was forced to stop their sleeve-valve line of engines as

2034-433: A nominal load of 8,000 pounds (3,600 kg) or more, and light bombers carried up to 2,000 lb (907 kg). These distinctions were beginning to disappear by the middle of World War II, when the average fighter aircraft could now carry a 2,000 lb (907 kg) bombload. Advances in powerplants and designs eventually allowed light bombers , tactical bombers , and later jet fighter-bombers to take over

2147-533: A raised ceiling. The Vickers Wellington was a twin-engined long-range medium bomber , initially powered by a pair of Bristol Pegasus radial engines, which drove a pair of de Havilland two-pitch propellers. Various engines and propeller combinations were used on variants of the aircraft, which included models of the Bristol Hercules and the Rolls-Royce Merlin engines. Recognisable characteristics of

2260-531: A rapidly climbing interceptor powered by the lightweight Crecy engine had become an aircraft without a purpose. Following World War II, the sleeve valve became utilised less, Roy Fedden, very early involved in the S-V research, built some flat-six single sleeve-valve engines intended for general aviation around 1947; after this, just the French SNECMA produced some SSV engines under Bristol license that were installed in

2373-504: A reappraisal of the strength of its armed forces, especially that of the Royal Air Force". By 1936, the need for a high priority to be placed on the creation of a large bomber force, which would form the spearhead of British offensive power, had been recognised; accordingly, a new command organisation within the RAF, Bomber Command , was formed that year to deliver upon this requirement. In early 1936, an initial prototype, K4049 , which

SECTION 20

#1732845502061

2486-640: A reshaped elevator and deepened fuselage which accommodated a larger bombload and the increased crew from four to five members. Other changes made included the adoption of a retractable tailwheel and constant-speed propellers ; the Air Ministry also requested the adoption of a Nash & Thompson -design ventral turret in place of the Vickers design. On 23 December 1937, the first production Wellington Mk I , L4212 , conducted its first flight, followed by an intensive flight programme. Flight trials with L4212 confirmed

2599-439: A result of the limitations imposed on them by the winners of WWII, some thirty companies in all. Itala also experimented with rotary and sleeve valves in their 'Avalve' cars. Upon Knight's return to America he was able to get some firms to use his design; here his brand name was " Silent Knight " (1905–1907)—the selling point was that his engines were quieter than those with standard poppet valves. The best known of these were

2712-420: A second on 13 January. In the latter the aircraft flew below the safe 35 ft altitude and was caught in the explosive blast though remained flyable. The hoop was an aluminium coil in an aerodynamic balsa case; turrets were faired over and unnecessary equipment removed to reduce weight. The first mine detonation unit No. 1 GRU at RAF Manston was joined by a second (No. 2 GRU) at RAF Bircham Newton . To protect

2825-489: A sleeve valve that leaks very little oil. However, most advanced engine research is concentrated on improving other types of internal combustion engine designs, such as the Wankel . Mike Hewland with his assistant John Logan, and also independently Keith Duckworth , experimented with a single-cylinder sleeve-valve test engine when looking at Cosworth DFV replacements. Hewland claimed to have obtained 72 hp (54 kW) from

2938-444: A very high specific output, and surprisingly good specific fuel consumption (SFC). In 1945 the single-cylinder test-engine (Ricardo E65) produced the equivalent of 5,000 HP (192 BHP/Litre) when water injected, although the full V12 would probably have been initially type rated at circa 2,500 hp (1,900 kW). Ricardo, who specified the layout and design goals, felt that a reliable 4,000 HP military rating would be possible. Ricardo

3051-507: Is a type of valve mechanism for piston engines , distinct from the usual poppet valve . Sleeve valve engines saw use in a number of pre– World War II luxury cars and in the United States in the Willys-Knight car and light truck. They subsequently fell from use due to advances in poppet-valve technology, including sodium cooling, and the Knight system double sleeve engine's tendency to burn

3164-485: Is no longer used, development of aircraft that fulfil a 'medium bomber' mission in all but name continued and these have been employed in various post-World War II conflicts; examples include dedicated tactical bombers such as the Su-24 , Su-34 , F-111 , J-16 and F-15E which have greater payload and range capability than fighter-bombers, but less than heavier strategic bombers. Sleeve valve The sleeve valve

3277-580: Is owned by Brooklands Museum at Brooklands , Surrey. Built at Brooklands and first flown in November 1939, this aircraft took part in the RAF's daylight bombing raids on Germany early in the Second World War but later lost power during a training flight on 31 December 1940 and ditched in Loch Ness . All the occupants survived except the rear gunner, who was killed when his parachute failed to open. The aircraft

3390-491: Is run on model glow engine fuel using castor oil (about 2% to 4% content) of the maximum 15%-content lubricant in the fuel allows the "varnish" created through engine operation to provide a better pneumatic seal between the rotating cylinder valve and the unitized engine cylinder/head castings, initially formed while the engine is being broken in. Another concept, the Rotating Liner Engine, has been developed, where

3503-455: Is the British RCV series of "SP" model engines, which use a rotating cylinder liner driven through a bevel gear at the cylinder liner's "bottom", which is actually at the aft end of the cylinder; and, even more unusually, have the propeller shaft—as an integrally machined part of the rotating cylinder liner—emerging from what would normally be the cylinder head , which in this design is placed at

Vickers Wellington - Misplaced Pages Continue

3616-582: The Bristol Freighter and Superfreighter . The Centaurus was also used in the military Hawker Sea Fury , Blackburn Firebrand , Bristol Brigand , Blackburn Beverly and the Fairey Spearfish . The poppet valve's previous problems with sealing and wear had been remedied by the use of better materials and the inertia problems with the use of large valves were reduced by using several smaller valves instead, giving increased flow area and reduced mass, and

3729-695: The English Electric Canberra (along with its derived U.S. counterpart, the Martin B-57 ) and the Soviet Ilyushin Il-28 "Beagle". Subsequent to World War II, only the U.S. Strategic Air Command ever used the term "medium bomber" in the 1950s to distinguish its Boeing B-47 Stratojets from somewhat larger contemporary Boeing B-52 Stratofortress "heavy bombers" in bombardment wings (older B-29 and B-50 heavy bombers were also redesignated as "medium" during this period). This nomenclature

3842-618: The F.B. Stearns Company of Cleveland, which sold a car named the Stearns-Knight , and the Willys firm which offered a car called the Willys-Knight , which was produced in far greater numbers than any other sleeve-valve car. The Burt-McCollum sleeve valve, having its name from the surnames of the two engineers that patented the same concept with weeks of difference, Peter Burt and James Harry Keighly McCollum, patent applications are of August 6 and June 22, 1909, respectively, both engineers hired by

3955-677: The Leigh light was deployed through the mounting for the absent FN9 ventral turret . The Gloster and AWA contracts were transferred to Shadow factories in the north-west. In the late 1930s, Vickers built Wellingtons at a rate of one per day at Weybridge and 50 a month at Broughton in North Wales . Many of the employees on the production lines were only semi-skilled and new to aircraft construction. Peak wartime production in 1942 saw monthly rates of 70 at Weybridge, 130 at Broughton and 102 at Blackpool . Shadow factories were set up to produce parts for

4068-661: The Noratlas transport airplane, also another transport aircraft, the Azor built by the Spanish CASA installed SSV Bristol engines post-WWII. Bristol sleeve valve engines were used however during the post-war air transport boom, in the Vickers Viking and related military Varsity and Valetta , Airspeed Ambassador , used on BEA 's European routes, and Handley Page Hermes (and related military Hastings ), and Short Solent airliners and

4181-409: The Rolls-Royce Merlin engine. In spite of a traditional preference of the establishment to strictly adhere to the restrictive tare weight for the aircraft established in the tender, both Pierson and Wallis firmly believed that their design should adopt the most powerful engine available. Perhaps in response to pressure from Vickers, the Air Ministry overlooked, if not openly accepted, the removal of

4294-537: The Royal Aircraft Establishment , Farnborough , the proposed structure demonstrated not only the required strength factor of six, but reached 11 without any sign of failure, proving the geodetic airframe to possess a strength far in excess of normal levels. This strength allowed for the structure design to be further developed to reduce the size of individual members and adopt simplified standard sections of lighter construction. Vickers studied and compared

4407-652: The African cost with 26 Squadron SAAF based in Takoradi , Gold Coast (now Ghana ), and the Free French 344 Squadron from Dakar . Specialised "Directional Wireless Installation" (DWI), a cover story for the true purpose of the hoop variants, fitted with a 48 ft (15 m) diameter metal hoop, were used for exploding German magnetic mines by generating a powerful magnetic field as it passed over them. The first successful mine detonation occurred on 8 January 1940 followed by

4520-442: The Air Ministry accepted the proposed changes. Other refinements of the design had also been implemented and approved, such as the adoption of variable-pitch propellers , and the use of Vickers-produced gun turrets in the nose and tail positions. By December 1936, the specification had been revised to include front, rear, and midship wind-protected turret mountings. Other specification changes included modified bomb undershields and

4633-594: The Bellman hangar was relocated and restored until taken off display and moved back into the latter building on 25 July 2017. The aeroplane is the centre-piece of the 'Brooklands Aircraft Factory' exhibition about the aircraft industry at Brooklands, which was formally opened on 13 November 2017. Wellington T.10 serial number MF628 is held by the Royal Air Force Museum . It was delivered to RAF No.18 MU (Maintenance Unit) for storage at RAF Tinwald Downs , Dumfries , as

Vickers Wellington - Misplaced Pages Continue

4746-536: The British Air Ministry invited Vickers to tender for the recently issued Specification B.9/32 , which sought a twin-engine medium daylight bomber. In response, Vickers conducted a design study, led by Chief Designer Rex Pierson . Early on, Vickers' chief structures designer Barnes Wallis proposed the use of a geodetic airframe , inspired by his previous work on airships and the single-engined Wellesley light bomber . During structural testing performed at

4859-624: The Halford-designed Napier Sabre. It used a single sleeve driven by an eccentric from a timing axle set at 90 degrees to the cylinder axis. Mechanically simpler and more rugged, the Burt-McCollum valve had the additional advantage of reducing oil consumption (compared with other sleeve valve designs), while retaining the combustion chambers and big, uncluttered, porting area established in the Knight system. A small number of designs used

4972-564: The March edition as the 'Burt' engine. Grindlay-Peerless started producing a SSV Barr & Stroud engined 999cc V-twin in 1923. [1] Archived 2013-05-27 at the Wayback Machine and later added a 499cc single SSV as well as the 350cc. Vard Wallace, known for his aftermarket forks for motorcycles, presented in 1947 drawings of a Single Cylinder, Air-Cooled, 250 cc SSV engine. Some small SSV auxiliary boat engines and electric generators were built in

5085-513: The Mark IA, the Mark IB may not have been built or if built re-designated as Mark IA. Further development of various aspects of the aircraft, using knowledge learned was incorporated into the airframe at Weybridge by executive decision. Redesigned hydraulics and 24 volt electrical systems, along with a replacement of the ventral turret gun with two beam machine guns (either .303 Vickers K , or Browning ),

5198-731: The RAF on the outbreak of war and used by 75 Squadron ). In October 1938, the Mk I entered service with 9 Squadron . The Wellington was initially outnumbered by the Handley Page Hampden (also ordered by the Ministry to B.9/32) and the Armstrong Whitworth Whitley (to B.34/3 for a 'night' bomber) but outlasted both rival aircraft in service. The Wellington went on to be built in 16 variants and two post-war training conversions. The number of Wellingtons built totalled 11,462 of all versions,

5311-520: The RAF's first long-range bombers operating in the Far East with the arrival of 99 and 215 Squadrons RAF, providing much needed bombing support for the next two years before being withdrawn and replaced by Liberators in the summer of 1944. Wellingtons were also used for maritime patrols over the Indian Ocean by 36 , and later, 203 Squadrons RAF. The Wellington also served in anti-submarine duties off

5424-528: The Scottish car maker Argyll, consisted of a single sleeve, which was given a combination of up-and-down and partial rotary motion. It was developed in about 1909 and was first used in the 1911 Argyll car. The initial 1900 investment in Argyll was £15,000 and building the magnificent Scotland plant cost £500,000 in 1920. It is reported that litigation by the owners of the Knight patents cost Argyll £50,000, perhaps one of

5537-526: The UK, prepared for burning 'paraffin' from start, or after a bit of heat-up with more complex fuels. A number of sleeve valve aircraft engines were developed following a seminal 1927 research paper from the RAE by Ricardo. This paper outlined the advantages of the sleeve valve and suggested that poppet valve engines would not be able to offer power outputs much beyond 1500 hp (1,100 kW). Napier and Bristol began

5650-521: The Wellington all over the British Isles. In October 1943, as a propaganda and morale-boosting exercise, workers at Broughton gave up their weekend to build Wellington number LN514 rushed by the clock. The bomber was assembled in 23 hours 50 minutes, and took off after 24 hours 48 minutes, beating the record of 48 hours set by a factory in California. Each Wellington was usually built within 60 hours. It

5763-421: The Wellington include the high aspect ratio of its tapered wing , the depth of its fuselage and the use of a tall single fin on its tail unit, which reportedly aided in recognition of the type. The Wellington typically had a crew of five, the bomb-aimer being located in the aircraft's nose. The Wellington could be fitted with dual flight controls, and specialised dual-control conversion sets were developed for

SECTION 50

#1732845502061

5876-633: The Wellington was its geodetic construction, devised by aircraft designer and inventor Barnes Wallis. The fuselage was built from 1,650 elements, consisting of duralumin W-beams which formed into a metal framework. Wooden battens were screwed to the beams and were covered with Irish linen ; the linen, treated with layers of dope , formed the outer skin of the aircraft. The construction proved to be compatible with significant adaptations and alterations including greater all-up weight, larger bombs, tropicalisation and long-range fuel tanks. The metal lattice gave

5989-605: The Wellington was superseded in the European Theatre as more four engined bombers arrived in service, it remained in operational service for much of the war in the Middle East and still formed a key part of the RAF's Mediterranean forces as the allies moved into Italy , with some still serving in March 1945 carrying out bombing raids and dropping supplies to partisans across Southern Europe. In 1942, Wellingtons based in India became

6102-498: The Wellington's design was influenced by the issuing of Specifications B.3/34 and B.1/35, the latter of which led a larger bomber aircraft, the Vickers Warwick With detail design work on both being done at same time and both aircraft using geodetic-inspired construction there was commonality in components. The production model Wellington was a complete redesign, resulting in a lengthened nose for turret and bomb aimer's position,

6215-455: The aerodynamic stability initially encountered by K4049 , but also revealed the aircraft to be nose-heavy during dives, which was attributed to the redesigned elevator. Modifications, including the linking of the flaps and the elevator trim tabs , were tested on L4212 and resolved the problem. In August 1936, an initial order for 180 Wellington Mk I aircraft, powered by a pair of 1,050 hp (780 kW) Bristol Pegasus radial engines ,

6328-477: The aircraft at an all-up weight of 30,500 lb (13.8 t), which aviation author C.F. Andrews described as "a very high figure for a medium bomber of those days". During the development phase of the aircraft, as C F Andrews puts it "the political and military climate of Europe was changing rapidly. The threats of the dictators of Germany and Italy began to exert pressure on the British Government to make

6441-597: The aircraft, one with each of the selected powerplants, were submitted to the tender. In September 1933, the Air Ministry issued a pilot contract for the Goshawk-powered version. In August 1934, Vickers proposed to use either the Pegasus or the sleeve-valve 9-cylinder radial Bristol Perseus engines instead of the evaporative-cooled Goshawk, which promised improvements in speed, climb rate, ceiling, and single-engine flight capabilities without any major increase in all-up weight;

6554-434: The aircraft. The Vickers-built ventral turret of the Mk I was replaced by a Nash & Thompson-built FN.25 counterpart as standard. The squadrons were critical of the ventral turrets; when extended they slowed the aircraft by 10 mph, the single narrow window pane limited visibility and sometimes froze in place and had to be jettisoned. The ventral turrets were not fitted after the first batch of Wellington IA A novelty of

6667-607: The design in England in 1908. The patent for the US was granted in 1910. As part of the licensing agreement, "Knight" was to be included in the car's name. Six-cylinder Daimler sleeve valve engines were used in the first British tanks in WW1, up to and including the Mark IV . As a result of the tendency of the engines to smoke and hence give away the tank positions, Harry Ricardo was brought in, and devised

6780-562: The development of sleeve-valve engines that would eventually result in limited production of two of the most powerful piston engines in the world: the Napier Sabre and Bristol Centaurus . The Continental Motors Company , around the years of the Great Depression, developed prototypes of single sleeve-valve engines for a range of applications, from cars to trains to airplanes, and thought that production would be easier, and costs would be lower, than its counterpart poppet valve engines. Due to

6893-424: The end of 1937, Vickers set about simplifying the manufacturing process of the aircraft and announced a target of building one Wellington per day. The geodetic design took longer to build than comparable aircraft using the more conventional monocoque approach, leading to some criticism of the Wellington. In addition it was difficult to cut holes in the fuselage for access or equipment fixtures; to aid manufacturing,

SECTION 60

#1732845502061

7006-531: The engine used was not the one originally intended. Despite the original specification, the Wellington was used as a night bomber in the early years of the Second World War , performing as one of the principal bombers used by Bomber Command . During 1943, it started to be superseded as a bomber by the larger four-engined " heavies " such as the Avro Lancaster . The Wellington continued to serve throughout

7119-448: The exhaust valve hot spot by Sodium-cooled valves. Up to that point, the single sleeve valve had won every contest against the poppet valve in comparison of power to displacement. The difficulty of Nitride hardening, then finish-grinding the sleeve valve for truing the circularity, may have been a factor in its lack of more commercial applications. When the Argyll car was launched in 1911, the Knight and Kilbourne Company immediately brought

7232-456: The extreme front of the engine, achieving a 2:1 gear reduction ratio compared to the vertically oriented crankshaft's rotational speed. The same firm's "CD" series of model engines use a conventional upright single cylinder with the crankshaft used to spin the propeller directly and also use the rotating cylinder valve. As a parallel with the earlier Charles Knight-designed sleeve-valved automotive powerplants, any RCV sleeve-valved model engine that

7345-575: The financial problems of Continental, this line of engines never entered production. ('Continental! Its motors and its people', William Wagner, Armed Forces Journal International and Aero Publishers, 1983, ISBN   0-8168-4506-9 ) Potentially the most powerful of all sleeve-valve engines (though it never reached production) was the Rolls-Royce Crecy V-12 (oddly, using a 90-degree V-angle), two-stroke, direct-injected, turbocharged (force-scavenged) aero-engine of 26.1 litres capacity. It achieved

7458-424: The first flight of the type's effective prototype in 1936. On 15 September 2016, after having its outer wings removed the day before, N2980 was towed from the Bellman hangar in which it was restored and where it had been displayed for nearly 30 years. This move was the first time that 'R' for 'Robert' had moved on its undercarriage since its last flight in 1940. The aircraft was exhibited in a temporary building while

7571-407: The front and rear, the Wellington had no defences against attacks from the beam and above, as it had not been believed that such attacks were possible owing to the high speed of aircraft involved and the deflection shooting required. Unescorted day bombing was abandoned and Bomber Command decided to use the Wellington force to attack German communications and industrial targets instead. The Wellington

7684-410: The inclusion of spring-loaded bomb bay doors. The proposal had also been developed further, a mid-wing arrangement was adopted instead of a shoulder-mounted wing for greater pilot visibility during formation flight and improved aerodynamic performance, as well as a substantially increased overall weight of the aircraft. Design studies were also conducted on behalf of the Air Ministry into the adoption of

7797-438: The incoming bombers near to Heligoland and attacked the formation for much of the way home. Twelve of the bombers were destroyed and a further three were badly damaged. The Wellingtons shot down four aircraft. The action at Heligoland highlighted the Wellington's vulnerability to attacking fighters, possessing neither self-sealing fuel tanks nor sufficient defensive armament. The nose and tail turrets protected against attacks from

7910-405: The jet engines. A sleeve valve takes the form of one (or in the case of double sleeve valves, two) machined cylinders which fit concentrically between the piston and the cylinder block bore of an internal combustion engine having cross-flow induction/exhaust. These sleeves have inlet and exhaust ports machined in the periphery, analogous to a two-stroke motor. Ports (apertures) in the periphery of

8023-561: The judge to rule, at the end of July 1912, that the holders of the original Knight patent could not be supported in their claim that it gave them master rights encompassing the Argyll design. Costs of litigation against claims by Knight patent holders seem having substantially contributed to bankrupt of Argyll in Scotland. The sleeve valve has begun to make something of a comeback, thanks to modern materials, dramatically better engineering tolerances and modern construction techniques, which produce

8136-423: The middle of 1932, for a bomber for the Royal Air Force. This specification called for a twin-engined day bomber capable of delivering higher performance than any previous design. Other aircraft developed to the same specification include the Armstrong Whitworth Whitley and the Handley Page Hampden . During the development process, performance requirements such as for the tare weight changed substantially, and

8249-597: The name "Crecy" was chosen for the type, and it was publicly displayed as such. On 15 August 1936, the aircraft was accepted for production. On 8 September 1936, the service name Wellington was adopted for the type; it fitted with Air Ministry nomenclature of naming bombers after towns and followed the Vickers Wellesley in referring to the Napoleonic War general Arthur Wellesley, the Duke of Wellington . On 12 December 1936,

8362-409: The other with the piston inside the inner sleeve. The sleeves were operated by small connected rods actuated by an eccentric shaft. They had ports cut out at their upper ends. The design was remarkably quiet, and the sleeve valves needed little attention. It was, however, more expensive to manufacture due to the precision grinding required on the sleeves' surfaces. It also used more oil at high speeds and

8475-574: The performance of various air- and liquid-cooled engines to power the bomber, including the Bristol Pegasus IS2 , Pegasus IIS2, and Armstrong Siddeley Tiger radials, and the Rolls-Royce Goshawk I inline. The Pegasus was selected as the engine for air-cooled versions of the bomber, while the Goshawk engine was chosen for the liquid-cooled engine variant. On 28 February 1933, two versions of

8588-558: The prototype Mk II, performed its maiden flight; this had been delayed due to production delays of its Merlin X engines. Stability and balance problems were encountered during flight tests of the prototype, resulting in further changes such as the enlargement of the tailplane. By late 1939, the Mk II was capable of delivering superior performance to the Mk IC, such as higher cruising and top speeds, increased all-up weight or alternatively greater range and

8701-433: The purpose of performing training upon the type. The cockpit also contained provisions for heating and de-icing equipment, which was introduced on later models of the Wellington. The Wellington Mk I had a maximum offensive bomb load of 4,500 lb (2,000 kg), more than one-fifth of the aircraft's 21,000 lb (9,500 kg) all-up weight. Additional munitions and an expanded bombing capacity were changes in many of

8814-510: The raid was diminished by poor weather and high amounts of anti-aircraft fire. A pair of Wellingtons became the first aircraft to be lost on the Western Front . On 3 December 1939, 24 Wellingtons of No. 38, No. 115 and No. 147 Squadrons attacked the German fleet moored at Heligoland . The bombing commenced from high altitude and, while results of the bombing itself proved negligible, the ability of

8927-558: The reasons for the temporary shutdown of their plant. Another car maker that used the Argyll SSV patents, and others of their own (patent GB118407), was Piccard-Pictet (Pic-Pic); Louis Chevrolet and others founded Frontenac Motors in 1923 with the aim of producing an 8-L SSV engined luxury car, but this never reached production for reasons connected to the time limits to the Argyll patents in the USA. The greatest success for single sleeve valves (SSV)

9040-501: The roles performed by mediums. After the war, use of the term generally vanished; some of this was due to mass demobilization of the participant air forces' existing equipment, and the fact that several of the most-produced medium bomber types were now technologically obsolescent. Although a number of later aircraft were designed in this performance and load-carrying range, they were henceforth referred to as tactical bombers or strike aircraft instead. Examples of post-war mediums include

9153-487: The single sleeve valve: In 1901 Knight bought an air-cooled, single-cylinder three-wheeler whose noisy valves annoyed him. He believed that he could design a better engine and did so, inventing his double sleeve principle in 1904. Backed by Chicago entrepreneur L.B. Kilbourne, a number of engines were constructed, followed by the "Silent Knight" touring car, which was shown at the 1906 Chicago Auto Show. Knight's design had two cast-iron sleeves per cylinder, one sliding inside

9266-431: The sleeve-valve engine are: Most of these advantages were evaluated and established during the 1920s by Roy Fedden , Niven, and Ricardo, possibly the sleeve valve engine's greatest advocate. He conceded that some of these advantages were significantly eroded as fuels improved up to and during World War II and as sodium-cooled exhaust valves were introduced in high-output aircraft engines. A number of disadvantages plagued

9379-484: The sleeves come into alignment with the cylinder's inlet and exhaust ports at the appropriate stages in the engine's cycle. The first successful sleeve valve was patented by Charles Yale Knight , and used twin reciprocating sleeves per cylinder. It was used in some luxury automobiles, notably Willys , Stearns, Daimler , Mercedes-Benz , Minerva , Panhard , Peugeot and Avions Voisin . Mors adopted double sleeve-valve engines made by Minerva. The higher oil consumption

9492-458: The speed and manoeuvrability necessary to keep up with the new generations of opposing fighter aircraft. The Vickers design put the gunner in a fixed seat behind the guns (a pair of .303 in (7.7 mm) Browning machine guns. ) which were mounted on a pillar with a Nash & Thompson control unit, and fired through a moving slot in the framed canopy. Although roomy, there were problems with malfunctions and poor gunnery and Vickers were given

9605-415: The structure considerable strength, with any stringer able to support a portion of load from the opposite side of the aircraft. Damaged or destroyed beams on one side could still leave the aircraft structure viable; as a result, Wellingtons with huge areas of framework missing were often able to return when other types would not have survived, leading to stories of the aircraft's "invulnerability". The effect

9718-415: The tare weight restriction, as between the submission of the tender in 1933 and the flight of the first prototype in 1936, the tare weight eventually rose from 6,300 lb (2.9 t) to 11,508 lb (5.220 t). The prescribed bomb load and range requirements were routinely revised upwards by the Air Ministry; by November 1935, figures within the Ministry were interested in the possibility of operating

9831-562: The time. Some of these bombers, such as the Heinkel He 111 , Junkers Ju 86 , Savoia-Marchetti SM.79 , Douglas B-18 , and Armstrong Whitworth Whitley were developed from or in conjunction with existing airliners or transport aircraft. The World War II-era medium bomber was generally considered to be any level bomber design that delivered about 4,000 pounds (1,800 kg) of ordnance over ranges of about 1,500 to 2,000 mi (2,400 to 3,200 km). Typical heavy bombers were those with

9944-677: The torpedo carrying aircraft onto their target were dubbed the "Snoopington". 38 Squadron, based in Shallufah, Egypt had a detachment of Wellingtons operating from RAF Luqa in Malta conducting anti-shipping operations with torpedoes during 1942. The Wellington was also adopted by RAF Coastal Command , in which it contributed to the Battle of the Atlantic . The Mark IC in Coastal had a endurance of over ten hours at

10057-625: The unarmed Wellingtons, Bristol Blenheims of No. 600 Squadron RAF flew escort during the Battle of France . One DWI was detached to the Middle East to act as the pattern for conversion of Wellingtons there. They were used for clearing the Suez Canal Zone and, later during the North Africa campaign , ports along the coast. For the development of what became the Leigh light, squadron leader Leigh fitted

10170-414: The war in other duties, particularly as an anti-submarine aircraft with RAF Coastal Command . The Wellington was the only British bomber that was produced for the duration of the war, and was produced in a greater quantity than any other British-built bomber. The Wellington remained as first-line equipment when the war ended, although it had been increasingly relegated to secondary roles. The Wellington

10283-452: The war, medium bombers were replaced in world air forces by more advanced and capable aircraft. In the early 1930s many air forces were looking to modernize their existing bomber aircraft fleets, which frequently consisted of older biplanes . The new designs were typically twin-engined monoplanes , often of all-metal construction, and optimized for high enough performance and speed to help evade rapidly evolving fighter aircraft designs of

10396-427: The wartime variants of the Wellington, including the carrying of larger bombs. Defensive armament comprised the forward and tail turret gun positions, along with a retractable revolving ventral turret. Due to the high cruising speeds of the Wellington, it had been realised that fully enclosed turrets, as opposed to semi-enclosed or exposed turrets, would be necessary; the turrets were also power-operated to traverse with

10509-419: The wear and friction benefit of the sleeve valve is exploited in a conventional engine layout. A friction reduction of the order of 40% has been reported for a heavy duty diesel. The same company can also supply somewhat larger engines for use in military drones, portable generators and equipment such as lawn mowers. Sleeve valves have occasionally, but unsuccessfully, been used on steam engines, for example

10622-467: Was an open sleeve type, driven from the crankshaft side, while the McCollum design had a sleeve in the head and upper part of the cylinder, and a more complex port arrangement (Source: 'Torque Meter' Magazine, AEHS). The design that entered production was more 'Burt' than 'McCollum.' It was used by the Scottish company Argyll for its cars, and was later adopted by Bristol for its radial aircraft engines and

10735-590: Was awarded the Victoria Cross . A unique feat for the type occurred on 23 December 1944 when a Me 163 Komet was shot down by rear gunner Gerry Elsyon, who was awarded the DFM. In 1942 the Wellington was adapted to conduct night anti-shipping torpedo attacks against German and Italian shipping in the Mediterranean. The torpedo-carrying Wellington was nicknamed the "Fishington", and the radar equipped Wellingtons that guided

10848-516: Was constantly frustrated during the war with Rolls-Royce 's (RR) efforts. Hives & RR were very much focused on their Merlin , Griffon then Eagle and finally Whittle 's jets, which all had a clearly defined production purpose. Ricardo and Tizard eventually realized that the Crecy would never get the development attention it deserved unless it was specified for installation in a particular aircraft but by 1945, their " Spitfire on steroids" concept of

10961-517: Was converted for night operations; on 25 August 1940, the type participated in the first night raid on Berlin . During the First 1,000 bomber raid , on Cologne on 30 May 1942, 599 out of 1,046 RAF aircraft dispatched were Wellingtons; of these, 101 were flown by Polish aircrew. During operations under Bomber Command, Wellingtons flew 47,409 operations, dropped 41,823 tons (37,941 tonnes) of bombs and lost 1,332 aircraft in action. In one incident,

11074-546: Was designated Wellington Mk IC and a Type number generated after the fact. In January 1938, design work on what would become the Wellington Mk II formally commenced. The principal change on this model was the adoption of the Merlin engine in place of the Pegasus XVIII; other modifications included hydraulic and oxygen system revisions along with the installation of cabin heating and an astrodome . On 3 March 1939, L4250 ,

11187-447: Was destroyed by an accident during a service test flight by Maurice Hare. The cause was the failure of the elevator 's horn balance due to excessive slipstream exposure, leading to the aircraft inverting and rapidly descending into terrain. It was destroyed in the crash, which also resulted in the death of the navigator, Smurthwaite. The horn balances were later deleted from the design and were not on production aircraft. Refinement of

11300-402: Was enhanced by the fabric skin occasionally burning off leaving the naked frames exposed. A further advantage of the geodetic construction of the wings was its enabling of a unique method for housing the fuel, with each wing containing three fuel tanks within the unobstructed space provided between the front and rear spars outboard of the engines. A disadvantage of the geodetic fuselage structure

11413-555: Was filmed for the Ministry of Information for a newsreel Worker's Week-End , and was broadcast in both Britain and America. It was the first time in aviation history that an aircraft manufacturer anywhere in the world had attempted such a feat with a metal aircraft of this scale. A total of 180 Wellington Mk I aircraft were built; 150 for the RAF and 30 for the Royal New Zealand Air Force (RNZAF) (which were transferred to

11526-402: Was harder to start in cold weather. Although he was initially unable to sell his Knight Engine in the United States, a long sojourn in England, involving extensive further development and refinement by Daimler supervised by their consultant Dr Frederick Lanchester , eventually secured Daimler and several luxury car firms as customers willing to pay his expensive premiums. He first patented

11639-405: Was heavily outweighed by the quietness of running and the very high mileages without servicing. Early poppet-valve systems required decarbonization at very low mileages and were prone to valve spring failure before the later advances in spring technology. The Burt-McCollum sleeve valve was named for the two inventors who applied for similar patents within a few weeks of each other. The Burt system

11752-778: Was in Bristol's large aircraft engines, it was also used in the Napier Sabre and Rolls-Royce Eagle engines. The SSV system also reduced the high oil consumption associated with the Knight double sleeve valve. Barr and Stroud Ltd of Anniesland, Glasgow, also licensed the SSV design, and made small versions of the engines that they marketed to motorcycle companies. In an advertisement in Motor Cycle magazine in 1922 Barr & Stroud promoted their 350cc sleeve valve engine and listed Beardmore-Precision , Diamond, Edmund, and Royal Scot as motorcycle manufacturers offering it. This engine had been described in

11865-613: Was its insufficient lengthwise stiffness: when fitted with attachment for towing cargo gliders, its structure "gave" and stretched slightly. On 3 September 1939, the same day the United Kingdom declared war on Germany in response to the invasion of Poland, No. 3 Group Bomber Command based in East Anglia comprised six front line squadrons ( No. 9 , No. 37 , No. 38 , No. 99 , No. 115 and No. 149 Squadrons ) and two reserve squadrons ( No. 214 and No. 215 squadrons ), all equipped with

11978-652: Was launched. A total number of 11,461 aircraft is most often quoted. There is some question over several aircraft, the total may be a few either side of this figure. In combination, the Wellingtons and 846 Warwicks represent over 75 per cent of the total number of aircraft built by the Vickers-Armstrong company. There are two complete surviving Vickers Wellingtons preserved in the United Kingdom. Some other substantial parts also survive. Wellington IA serial number N2980

12091-553: Was one of two bombers named after Arthur Wellesley, 1st Duke of Wellington , the other being the Vickers Wellesley . A larger heavy bomber aircraft designed to Specification B.1/35 , the Vickers Warwick , was developed in parallel with the Wellington; the two aircraft shared around 85% of their structural components. Many elements of the Wellington were also re-used in a civil derivative, the Vickers VC.1 Viking . In October 1932,

12204-411: Was originally designated as a Type 271 , was assembled. The prototype could accommodate a payload of nine 250 lb or 500 lb bombs, and both nose and tail gun positions were fitted with hand-operated turrets with a gun in each; provision for a third retractable gun in a dorsal position was made. It had provision for a crew of four, along with a fifth position for special duties. On 5 June 1936,

12317-569: Was purely semantic and bureaucratic, however as both the B-47 and B-52 strategic bombers were much larger and had far greater performance and load-carrying ability than any of the World War II-era heavy or medium bombers. Similarly, the Royal Air Force referred at times to its V bomber force as medium bombers, but this was in terms of range rather than load-carrying capacity. Although the term

12430-522: Was received by Vickers; it had been placed so rapidly that the order occurred prior to the first meeting intended to decide the details of the production aircraft. In October 1937, an order was placed with Gloster Aircraft Company for production of 100 Wellington Mk Is to be followed by 100 Wellington Mk II aircraft with Rolls-Royce Merlin X . Another order was placed for 64 Wellingtons to be produced by Armstrong Whitworth Aircraft at Coventry With this flurry of order and production having been assured by

12543-500: Was recovered from the bottom of Loch Ness in September 1985 and restored in the late 1980s and 1990s. A new Wellington exhibition featuring N2980 was officially opened by Robin Holmes (who led the recovery team), Penelope Keith (as trustee of Brooklands Museum), Norman Parker (who worked for Vickers) and Ken Wallis (who flew Wellingtons operationally) on 15 June 2011, the 75th anniversary of

12656-573: Was shot down. On 18 December 1939, 24 Wellingtons of No. 9, No. 37 and No. 149 Squadrons participated in the Battle of the Heligoland Bight against the German fleet and naval bases in both the Schillig Roads and Wilhelmshaven. The Wellingtons were unable to drop their bombs as all vessels were in harbour, thus restrictions on endangering civilians prevented their engagement. Having been alerted by radar , Luftwaffe fighter aircraft intercepted

12769-552: Was stressed to the Mark II 28,000 lb and had stronger undercarriage with larger wheels and Frazer-Nash turrets. Due to difficulties with performance of the Vickers turrets on the Mark I that left the Wellington with weaker than intended defences, production of Wellington Mk IB with Frazer Nash armament was proposed for trials but since the Frazer-Nash turrets were already being accepted for

#60939