Misplaced Pages

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171-603: Today the term GCI refers to the style of battle direction, but during WWII it also referred to the radars themselves. Specifically, the term was used to describe a new generation of radars that spun on their vertical axis in order to provide a complete 360 degree view of the sky around the station. Previous systems, notably Chain Home (CH), could only be directed along angles in front of the antennas, and were unable to direct traffic once it passed behind their shore-side locations. GCI radars began to replace CH starting in 1941/42, allowing

342-472: A cathode-ray tube (CRT) to a directional Adcock antenna array, originally built by the RRS but now unused. The combined system, later known as huff-duff (from HF/DF, high frequency direction finding), allowed the almost instantaneous determination of the bearing of a signal. The Met Office began using it to produce storm warnings for aviators. During this period, Edward Appleton of King's College, Cambridge

513-592: A 360 degree pattern proved surprisingly easy, and test systems were available by late 1940. Starting in 1941 the RAF began deploying production models of the GCI radar, first with expedient solutions known as the AMES Type 8 , and then permanent stations based on the much larger AMES Type 7 . Unlike the earlier system where radar data was forwarded by telephone and plotted on a map, GCI radars combined all of these functions into

684-603: A Beaufighter conducted a raid which Moyes said was "perhaps the most impudent of the war". T4800 , a Beaufighter Mk.1C of No. 236 Squadron, flew from Thorney Island to occupied Paris at an extremely low altitude in daylight to drop a tricolore on the Arc de Triomphe and strafe the Gestapo headquarters in the Place de la Concorde . The Beaufighter soon commenced service overseas, where its ruggedness and reliability quickly made

855-485: A German newspaper with an image of a large radio antenna that had been installed on Feldberg in the same area. Although highly skeptical about claims of engine-stopping rays and death rays, the Air Ministry could not ignore them as they were theoretically possible. If such systems could be built, it might render bombers useless. If this were to happen, the night bomber deterrent might evaporate overnight, leaving

1026-466: A bombing raid) were delivered. Flight tests found that the Merlins left the aircraft underpowered, with a pronounced tendency to swing to port, making take-offs and landings difficult and resulting in a high accident rate – out of 337 Merlin-powered aircraft, 102 were lost to accidents. On 2 April 1940, R2052 was delivered to the RAF; it was followed by R2053 two weeks later. On 27 July 1940,

1197-675: A breezy interview, Watson-Watt and Jock Herd stated the job was his if he could sing the Welsh national anthem . He agreed, but only if they would sing the Scottish one in return. They declined, and gave him the job. Starting with the BBC transmitter electronics, but using a new transmitter valve from the Navy, Bowen produced a system that transmitted a 25 kW signal at 6 MHz (50 metre wavelength), sending out 25 μs long pulses 25 times

1368-568: A cannon-only armament. The design of the cannons and the armament configuration was revised on most aircraft. The addition of six .303 Browning machine guns made the Beaufighter the most heavily armed fighter aircraft in the world, capable of delivering a theoretical weight of fire of up to 780 lb (350 kg) per minute; the practical rate of fire was much lower due to gun overheating and ammunition capacity. Further armament trials and experimental modifications were performed throughout

1539-497: A complete " power egg "; the design and approach of the Beaufighter's Merlin installation was later incorporated into the design for the much larger Avro Lancaster bomber. Success with the Merlin-equipped aircraft was expected to lead to production aircraft in 1941. In June 1940, the first Merlin-powered aircraft conducted its first flight. In late 1940, the two Merlin-equipped prototypes (the third having been destroyed in

1710-462: A complete radar could be built. While such a system could determine the angle to a target, it could not determine its range and provide a location in space. To do so, two such measurements would have to be made from different locations. Watt's huff-duff technique solved the problem of making rapid measurements, but the issue of coordinating the measurement at two stations remained, as did any inaccuracies in measurement or differences in calibration between

1881-409: A considerable number of mast and aerial systems". Several members of the team went on scouting trips with Watt to the north of Orfordness but found nothing suitable. Then Wilkins recalled having come across an interesting site about 10 mi (16 km) south of Orfordness, some time earlier while on a Sunday drive. He recalled it because it was some 70–80 ft (21–24 m) above sea level, which

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2052-439: A distance of 5 kilometres (3.1 mi) from 98 to 105 °F (37 to 41 °C). To Watt's bemusement, Wilkins immediately surmised this was a question about a death ray. He made a number of back-of-the-envelope calculations demonstrating the amount of energy needed would be impossible given the state of the art in electronics. According to R. V. Jones , when Wilkins reported the negative results, Watt asked, "Well then, if

2223-637: A fashion similar to SAGE, but was years late, significantly underpowered, and never operated properly. There was some thought given to sending directions to the English Electric Lightning interceptors in a fashion similar to SAGE, but this was never implemented. GCI is typically augmented with the presence of extremely large early warning radar arrays, which could alert GCI to inbound hostile aircraft hours before they arrive, giving enough time to prepare and launch aircraft and set them up for an intercept either using their own radars or with

2394-477: A few aircraft are more vulnerable than many ground-based radar stations. If a single AEW&C aircraft is shot down or otherwise taken out of the picture, there will be a serious gap in air defence until another can replace it, where in the case of GCI, many radar stations would have to be taken off the air before it became a serious problem. In both cases a strike on a command center could be very serious. Either GCI or AEW&C can be used to give defending aircraft

2565-517: A few months of his joining the Committee, what had previously been an innovative and forward-looking group became riven with strife. It was strictly Lindemann versus the rest, with his hostility to radar and his insistence on totally impractical ideas about intercepting enemy aircraft by means of wires dangled from balloons, or by infrared, which at that time simply did not have the sensitivity to detect aircraft at long range. Churchill's backing meant

2736-726: A fighter development of the Beaufort to the Air Ministry . The timing of the suggestion happened to coincide with delays in the development and production of the Westland Whirlwind cannon-armed twin-engine fighter. While there was some scepticism that the aircraft was too big for a fighter, the proposal was given a warm reception by the Air Staff . The Air Ministry produced draft Specification F.11/37 in response to Bristol's suggestion for an "interim" aircraft, pending

2907-601: A joint AMES-GPO group. The Treasury gave approval for full-scale deployment in August, and the first production contracts were sent out for 20 sets in November, at a total cost of £380,000. Installation of 15 of these sets was carried out in 1937 and 1938. In June 1938 a London headquarters was established to organize the rapidly growing force. This became the Directorate of Communications Development (DCD), with Watt named as

3078-468: A long-range heavy fighter aircraft such as the Beaufighter and in early 1941, Bristol proceeded with the development of the Beaufighter Mk.IC long-range fighter. Based on the standard Mk.I model, the initial batch of 97 Coastal Command Beaufighters were hastily manufactured, making it impossible to incorporate the intended additional wing fuel tanks on the production line and so 50-gallon tanks from

3249-554: A loss of 120 Beaufighters and 241 aircrew killed or missing. This was half the total tonnage sunk by all strike wings between 1942 and 1945. The Beaufighter arrived at squadrons in Asia and the Pacific in mid-1942. A British journalist said that Japanese soldiers called it the "whispering death" for its quiet engines, although this is not supported by Japanese sources. The Beaufighter's Hercules engines used sleeve valves , which lacked

3420-420: A major advantage during the actual interception by allowing them to sneak up on enemy aircraft without giving themselves away by using their own radar sets. Typically, to perform an interception by themselves beyond visual range, the aircraft would have to search the sky for intruders with their radars, the energy from which might be noticed by the intruder's radar warning receiver (RWR) electronics, thus alerting

3591-460: A prototype pulsed transmitter and by June 1935 it detected an aircraft that happened to be flying past. Basic development was completed by the end of the year, with detection ranges on the order of 100 mi (160 km). In 1936 attention was focused on a production version, and early 1937 saw the addition of height finding. The first five stations, covering the approaches to London, were installed by 1937 and began full-time operation in 1938. Over

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3762-400: A receiver to give an early indication of approaching aircraft. Watt wrote back to the committee saying the death ray was extremely unlikely, but added: Attention is being turned to the still difficult, but less unpromising, problem of radio detection and numerical considerations on the method of detection by reflected radio waves will be submitted when required. The letter was discussed at

3933-497: A second. Meanwhile, Wilkins and L.H. Bainbridge-Bell built a receiver based on electronics from Ferranti and one of the RRS CRTs. They decided not to assemble the system at the RRS for secrecy reasons. The team, now consisting of three scientific officers and six assistants, began moving the equipment to Orfordness on 13 May 1935. The receiver and transmitter were set up in old huts left over from World War I artillery experiments,

4104-581: A shortage of Hercules engines being expected, jeopardising the aircraft's manufacturing rate. The next variant, the Beaufighter Mk.II , used the Merlin engine instead. On 22 March 1941, the first production Beaufighter Mk.II, R2270 , conducted its maiden flight; squadron deliveries commenced in late April 1941. By mid-1941, manufacture of the Beaufighter varied to meet the demands of RAF Fighter Command and RAF Coastal Command . Early aircraft were able to be outfitted and perform with either command but later,

4275-447: A signal detectable at about 10 miles (16 km). They went on to suggest that the output power could be increased as much as ten times if the system operated in pulses instead of continuously, and that such a system would have the advantage of allowing range to the targets to be determined by measuring the time delay between transmission and reception on an oscilloscope . The rest of the required performance would be made up by increasing

4446-568: A single station to control the entire battle from early detection to directing the fighters to intercept. GCI systems grew in size and sophistication during the post-war era, in response to the overwhelming threat of nuclear attack. The US' SAGE system was perhaps the most complex attempted, using building-filling computers linked to dozens of radars and other sensors to automate the entire task of identifying an enemy aircraft's track and directing interceptor aircraft or surface-to-air missiles against it. In some cases, SAGE sent commands directly to

4617-420: A single station. The PPI was in the form of a 2D top-down display showing both the targets and the intercepting night fighters . Interceptions could be arranged directly from the display, without any need to forward the information over telephone links or similar. This not only greatly eased the task of arranging the interception, but greatly reduced the required manpower as well. As the system became operational

4788-424: A sort of radio-searchlight, but this proved too difficult to use in practice. Another attempt was made by using a height finding radar turned on its side in order to scan an arc in front of the station. This proved very workable, and was soon extended to covering a full 360 degrees by making minor changes to the support and bearing systems. Making a display system, the " Plan Position Indicator " (PPI), that displayed

4959-595: A speech on "The threat of Nazi Germany" in which he pointed out that the Royal Navy could not protect Britain from an enemy who attacked by air. Through the early 1930s, a debate raged within British military and political circles about strategic airpower. Baldwin's famous speech led many to believe the only way to prevent the bombing of British cities was to make a strategic bomber force so large it could, as Baldwin put it, "kill more women and children more quickly than

5130-412: A suitable pulsed transmitter. An engineer familiar with these concepts was needed. Edward George Bowen joined the team after responding to a newspaper advertisement looking for a radio expert. Bowen had previously worked on ionosphere studies under Appleton, and was well acquainted with the basic concepts. He had also used the RRS' RDF systems at Appleton's request and was known to the RRS staff. After

5301-512: A system was becoming increasingly pressing. In 1932, Winston Churchill and his friend, confidant and scientific advisor Frederick Lindemann travelled by car in Europe, where they saw the rapid rebuilding of the German aircraft industry. It was in November of that year that Stanley Baldwin gave his famous speech, stating that " The bomber will always get through ". In the early summer of 1934,

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5472-420: Is a fighter derivative of the Beaufort torpedo-bomber. It is a twin-engine two-seat long-range day and night fighter. The aircraft employed an all-metal monocoque construction, comprising three sections with extensive use of 'Z-section' frames and 'L-section' longeron . The wing of the Beaufighter used a mid-wing cantilever all-metal monoplane arrangement, also constructed out of three sections. Structurally,

5643-481: The Beaufort concluded that it had great structural strength and stiffness in the wings, nacelles, undercarriage and tail, so that the aircraft could be readily developed further for greater speed and manoeuvrability akin to a fighter-class aircraft. The Bristol design team, led by Leslie Frise , commenced the development of a cannon-armed fighter derivative as a private venture. The prospective aircraft had to share

5814-687: The Bristol Aeroplane Company . It was originally conceived as a heavy fighter variant of the Bristol Beaufort torpedo bomber . The Beaufighter proved to be an effective night fighter , which came into service with the Royal Air Force (RAF) during the Battle of Britain , its large size allowing it to carry heavy armament and early aircraft interception radar without major performance penalties. The Beaufighter

5985-555: The Chain Home coastal radar stations was relayed by phone to a number of operators on the ground floor of the "filter room" at Fighter Command's headquarters at RAF Bentley Priory . Here the information from the radar was combined with reports from the Royal Observer Corps and radio direction finding systems and merged to produce a single set of "tracks", identified by number. These tracks were then telephoned to

6156-614: The Met Office in a lab that was colocated at the National Physical Laboratory 's (NPL) Radio Research Section (RRS) at Ditton Park in Slough . Watt became interested in using the fleeting radio signals given off by lightning as a way to track thunderstorms , but existing RDF techniques were too slow to allow the direction to be determined before the signal disappeared. In 1922, he solved this by connecting

6327-640: The South West Pacific Theatre , the Beaufighter Mk.IC was commonly employed in anti-shipping missions. The most famous of these was the Battle of the Bismarck Sea , during which Beaufighters were used in a fire-suppression role in a mixed force with USAAF Douglas A-20 Boston and North American B-25 Mitchell bombers. Earlier in the battle, eight Beauforts from No. 100 Squadron RAAF at Milne Bay had unsuccessfully attacked

6498-479: The Type 156 was given the name 'Beaufighter'. During early development, Bristol had formalised multiple configurations for the prospective aircraft, including variations such as a proposed three-seat bomber outfitted with a dorsal gun turret with a pair of cannons, the Type 157 and what Bristol referred to as a "sports model", with a thinner fuselage, the Type 158 . Bristol proceeded to suggest their concept for

6669-477: The Vickers Wellington were temporarily installed on the floor between the cannon bays. In April/May 1941, this new variant of the Beaufighter entered squadron service in a detachment from 252 Squadron operating from Malta . This inaugural deployment with the squadron proved to be highly successful, leading to the type being retained in that theatre throughout the remainder of the war. In June 1941,

6840-405: The acoustic mirror systems that had been in development for a decade were still limited to only 5 mi (8.0 km) range under most conditions, and were very difficult to use in practice. Work on mirror systems ended, and on 19 December 1935, a £60,000 contract for five RDF stations along the south-east coast was sent out, to be operational by August 1936. The only person not convinced of

7011-530: The gain of the antennas by making them very tall, focusing the signal vertically. The memo concluded with an outline for a complete station using these techniques. The design was almost identical to the CH stations that went into service. The letter was seized on by the Committee, who immediately released £4,000 to begin development. They petitioned Hugh Dowding , the Air Member for Supply and Research , to ask

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7182-640: The "Mk.21". Design changes included Hercules VII or XVIII engines and some minor changes in armament. By September 1945, when British production ended, 5,564 Beaufighters had been built by Bristol and the Fairey Aviation Company at Stockport and RAF Ringway (498); also by the Ministry of Aircraft Production (3336) and Rootes at Blythe Bridge (260). When Australian production ceased in 1946, 364 Mk.21s had been built. The Bristol Beaufighter

7353-402: The 1,000 hp Bristol Taurus engines on the Beaufort. The Hercules was a considerably larger and more powerful engine which required larger propellers. To obtain adequate ground clearance, the engines were mounted centrally on the wing, as opposed to the underslung position on the Beaufort. In October 1938, the project, which received the internal name Type 156 , was outlined. In March 1939,

7524-856: The Beaufighter but it was soon passed over in favour of the rival Griffon engine, as the Hercules VI required extensive development. Due to production of the Griffon being reserved for the Fairey Firefly , the Air Ministry instead opted for the Rolls-Royce Merlin to power the Beaufighter until the manufacturing rate of the Hercules could be raised by a new shadow factory in Accrington . The standard Merlin XX-powered aircraft

7695-511: The Beaufighter rose rapidly upon the commencement of production. Through 1940–41, the manufacturing rate of the Beaufighter steadily rose. On 7 December 1940, the 100th Filton-built aircraft was dispatched; the 200th Filton-built aircraft followed on 10 May 1941. On 7 March 1941, the first Fairey-built Beaufighter Mk.I performed its first test flight; the first Weston-built aircraft reached the same milestone on 20 February 1941. The volume of production involved, along with other factors, had led to

7866-712: The Beaufighter were manufactured in Australia by the Department of Aircraft Production (DAP); such aircraft are sometimes referred to by the name DAP Beaufighter . The concept of the Beaufighter has its origins in 1938. During the Munich Crisis , the Bristol Aeroplane Company recognised that the Royal Air Force (RAF) had an urgent need for a long-range fighter aircraft capable of carrying heavy payloads for maximum destruction. Evaluation of

8037-408: The Beaufighter's operational life. By mid-1941, 20 Beaufighters were reserved for test purposes, including engine development, stability and manoeuvrability improvements and other purposes. In May 1941, the Beaufighter Mk.IIs R2274 and R2306 , were modified to the Beaufighter Mk.III standard; removing the six wing guns and two inboard cannons to install a Boulton-Paul -built four-gun turret behind

8208-545: The Beaufighter-equipped 272 Squadron based on Malta claimed the destruction of 49 enemy aircraft and the damaging of 42 more. The Beaufighter was reputedly very effective in the Mediterranean against Axis shipping, aircraft and ground targets; Coastal Command was, at one point, the majority user of the Beaufighter, replacing its inventory of obsolete Beaufort and Blenheim aircraft. To meet demand, both

8379-627: The Beaufighters during the Battle of the Bismarck Sea was recorded by war correspondent and film-maker Damien Parer , who had flown during the engagement standing behind the pilot of one of the No. 30 Squadron aircraft; the engagement led to the Beaufighter becoming one of the more well-known aircraft in Australian service during the conflict. On 2 November 1943, another high-profile event involving

8550-462: The Beaufort, having been deemed insufficiently powerful for a fighter, were replaced by more powerful two-speed supercharger-equipped Bristol Hercules radial engines . These powered three-bladed Rotol constant-speed propellers ; both fully feathering metal and wooden blades were used. The extra power had presented vibration issues during development; in the final design, the engines were mounted on longer and more flexible struts, which extended from

8721-409: The Beaufort, while the wing centre section was similar apart from certain fittings. The areas for the rear gunner and bomb-aimer were removed, leaving only the pilot in a fighter-type cockpit. The navigator-radar operator sat to the rear under a small Perspex bubble where the Beaufort's dorsal turret had been. Both crew-members had their own hatch in the floor of the aircraft. The front hatch was behind

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8892-663: The British coast they could no longer be tracked by radar; and accordingly the interception direction centres relied on visual and aural sightings of the Observer Corps for continually updated information on the location and heading of enemy aircraft formations. While this arrangement worked acceptably during the daylight raids of the Battle of Britain , subsequent bombing attacks of The Blitz demonstrated that such techniques were wholly inadequate for identifying and tracking aircraft at night. Experiments in addressing this problem started with manually directed radars being used as

9063-491: The British military with claims of having perfected some form of the fabled electric or radio " death ray ". Some turned out to be frauds and none turned out to be feasible. Around the same time, a series of stories suggested another radio weapon was being developed in Germany. The stories varied, with one common thread being a death ray, and another that used the signals to interfere with an engine's ignition system to cause

9234-575: The CH systems were used to detect V2 missile launches. UK radar systems were wound down after the war but the start of the Cold War led to the Chain Home radars being pressed into service in the new ROTOR system until replaced by newer systems in the 1950s. Only a few of the original sites remain. From the earliest days of radio technology, signals had been used for navigation using the radio direction finding (RDF) technique. RDF can determine

9405-734: The Fairey and Weston production lines were, at times, only producing Coastal Command Beaufighters. In 1941, to intensify offensive air operations against Germany and deter the deployment of Luftwaffe forces onto the Eastern Front , Coastal Command Beaufighters began offensive operations over France and Belgium, attacking enemy shipping in European waters. In December 1941, Beaufighters participated in Operation Archery , providing suppressing fire while British Commandos landed on

9576-552: The GPO testing team's observation that aircraft flying near the receiver caused the signal to change in intensity, an annoying effect known as fading . The stage was now set for the development of radar in the UK. Using Wilkins' knowledge that shortwave signals bounced off aircraft, a BBC transmitter to light up the sky as in Appleton's experiment, and Watt's RDF technique to measure angles,

9747-470: The Greek island of Paros . This is possibly Beaufighter TF.X LX998 of 603 Squadron , which was shot down after destroying a German Arado Ar 196 during an anti-shipping mission in November 1943. The Australian crew survived and were rescued by a British submarine. A Mk.VIC Beaufighter, serial A19-130, lies in 204 feet (62 m) of water, just off the coast of Fergusson Island in the western Pacific. It

9918-451: The Group headquarters that would be responsible for dealing with that target. Group would assign fighter squadrons to the tracks, and phone the information to Section headquarters, who were in direct contact with the fighters. These fighter aircraft could then be " scrambled " to intercept the aircraft. Because the Chain Home radar stations faced out to sea, once airborne intruders had crossed

10089-470: The Japanese troop convoy with torpedoes and scored no hits. 13 Beaufighters of No. 30 Squadron flew in at mast height to provide heavy suppressive fire for the waves of attacking bombers. The Japanese convoy, under the impression that they were under torpedo attack from Beauforts, made the tactical error of turning their ships towards the Beaufighters, which allowed the Beaufighters to inflict severe damage on

10260-737: The Met Office and NPL, were combined to form the Radio Research Station (with the same acronym, RRS), run by the NPL with Watt as the Superintendent. This provided Watt with direct contact to the research community, as well as the chief signals officers of the British Army , Royal Navy and Royal Air Force . Watt became a well-known expert in the field of radio technology. This began a long period where Watt agitated for

10431-612: The Mk.X carried centimetric-wavelength ASV (air-to-surface vessel) radar with "herringbone" antennae on the nose and outer wings, but this was replaced in late 1943 by the centimetric AI Mk.VIII radar housed in a " thimble -nose" radome, enabling all-weather and night attacks. The North Coates Strike Wing of Coastal Command, based at RAF North Coates on the Lincolnshire coast, developed tactics that combined large formations of Beaufighters, using cannons and rockets, to suppress flak, while

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10602-482: The NPL to take a more active role in technology development, as opposed to its pure research role. Watt was particularly interested in the use of radio for long-range aircraft navigation, but the NPL management at Teddington was not receptive and these proposals went nowhere. In 1931, Arnold Frederic Wilkins joined Watt's staff in Slough. As the "new boy", he was given a variety of menial tasks to complete. One of these

10773-475: The RAF carried out large-scale exercises with up to 350 aircraft. The forces were split, with bombers attempting to attack London, while fighters, guided by the Observer Corps , attempted to stop them. The results were dismal. In most cases, the vast majority of the bombers reached their target without ever seeing a fighter. To address the one-sided results, the RAF gave increasingly accurate information to

10944-489: The RRS team, along with Rowe representing the Tizard Committee. Watt was so impressed he later claimed to have exclaimed: "Britain has become an island again!" Rowe and Dowding were equally impressed. It was at this point that Watt's previous agitation over development became important; NPL management remained uninterested in practical development of the concept, and was happy to allow the Air Ministry to take over

11115-457: The RRS. The system consisted of several parallel dipoles separated vertically on the receiver masts. Normally the RDF goniometer was connected to two crossed dipoles at the same height and used to determine the bearing to a target return. For height finding, the operator instead connected two antennas at different heights and carried out the same basic operation to determine the vertical angle. Because

11286-612: The Torbeaus attacked at low level with torpedoes. These tactics were put into practice in mid-1943 and in ten months, 29,762 tons (84,226 m ) of shipping were sunk. Tactics were further refined when shipping was moved from port during the night. The North Coates Strike Wing operated as the largest anti-shipping force of the Second World War and accounted for over 150,000 tons (424,500 m ) of shipping and 117 vessels, most of which were small fishing and coastal vessels, for

11457-550: The Treasury for another £10,000. Dowding was extremely impressed with the concept, but demanded a practical demonstration before further funding was released. Wilkins suggested using the new 10 kW, 49.8 m BBC Borough Hill shortwave station in Daventry , Northamptonshire as a suitable ad hoc transmitter. The receiver and an oscilloscope were placed in a delivery van the RRS used for measuring radio reception around

11628-487: The UK open to attack by Germany's ever-growing air fleet. Conversely, if the UK had such a device, the population could be protected. In 1934, along with a movement to establish a scientific committee to examine these new types of weapons, the RAF offered a £1,000 prize to anyone who could demonstrate a working model of a death ray that could kill a sheep at 100 yards; it went unclaimed. The need to research better forms of air defense prompted Harry Wimperis to press for

11799-468: The UK, US, Japan, Germany and others had all considered this concept and put at least some amount of effort into developing it. Lacking ranging information, such systems remained of limited use in practical terms; two angle measurements could be used, but these took time to complete using existing RDF equipment and the rapid movement of the aircraft during the measurement would make coordination difficult. Since 1915, Robert Watson-Watt had been working for

11970-407: The Vickers gun being installed on an anti-tank Hawker Hurricane IID. Large orders for the Beaufighter were placed around the outbreak of the Second World War, including one for 918 aircraft shortly after the arrival of the initial production examples. In mid-1940, during an official visit to Bristol's Filton facility by the Minister of Aircraft Production, Lord Beaverbrook , the minister spoke of

12141-591: The Westland Whirlwind had been cancelled due to production problems with its Rolls-Royce Peregrine engines. On 12 August 1940, the first production Beaufighter was delivered to RAF Tangmere for trials with the Fighter Interception Unit . On 2 September 1940, 25 Squadron , 29 Squadron , 219 Squadron , and 604 Squadron became the first operational squadrons to receive production aircraft, each squadron received one Beaufighter that day to begin converting from their Blenheim IF aircraft. The re-equipping and conversion training process took several months to complete; on

12312-495: The air (and back), and then flying in a parking orbit until called for. When an interception mission started, the SAGE computers automatically flew the plane into range of the target, allowing the pilot to concentrate solely on operating the complex onboard radar. The RAF's post-war system was originally ROTOR , which was largely an expanded and rationalized version of their wartime system and remained entirely manual in operation. This

12483-468: The aircraft popular with crews. However, it was heavy on the controls and not easy to fly, with landing being a particular challenge for inexperienced pilots. Due to wartime shortages, some Beaufighters entered operational service without feathering equipment for their propellers. As some models of the twin-engined Beaufighter could not stay aloft on one engine unless the dead propeller was feathered, this deficiency contributed to several operational losses and

12654-449: The aircraft's autopilot , bringing the aircraft within attack range entirely under computer control. The RAF counterpart, ROTOR remained a mostly manual system. Today, GCI is still important for most nations, although Airborne Early Warning and Control , with or without support from GCI, generally offers much greater range due to the much more distant radar horizon . In the original Dowding system of fighter control, information from

12825-497: The aircraft's usefulness, improved radars became available in January 1941, promptly making the Beaufighter one of the more effective night fighters of the era. By fighter standards, the Beaufighter Mk.I was rather heavy and slow, with an all-up weight of 16,000 lb (7,000 kg) and a maximum speed of 335 mph (540 km/h) at 16,800 ft (5,000 m). The Beaufighter was the only heavy fighter aircraft available, as

12996-599: The assistance of regular radar stations once the bogeys approach their coverage. An example of this type of system is Australia 's Jindalee over-the-horizon radar . Such radars typically operate by bouncing their signal off layers in the atmosphere. In more recent years, GCI has been supplanted, or replaced outright, with the introduction of Airborne Early Warning and Control (AEW&C, often called AWACS) aircraft. AEW&C tends to be superior in that, being airborne and being able to look down, it can see targets fairly far away at low level, as long as it can pick them out from

13167-485: The bearing to a radio transmitter, and several such measurements can be combined to produce a radio fix , allowing the receiver's position to be calculated. Given some basic changes to the broadcast signal, it was possible for the receiver to determine its location using a single station. The UK pioneered one such service in the form of the Orfordness Beacon . Through the early period of radio development it

13338-405: The bearing to the target, not the range, and due to the low power of radio equipment of that era, they were useful only for short-range detection. This led to their use for iceberg and collision warning in fog or bad weather, where all that was required was the rough bearing of nearby objects. The use of radio detection specifically against aircraft was first considered in the early 1930s. Teams in

13509-516: The changing wavelengths. The application of this technique to a detection system was not lost on those working in the field, and such a system was prototyped by W. A. S. Butement and P. E. Pollard of the British Signals Experimental Establishment (SEE) in 1931. The War Office proved uninterested in the concept and the development remained little known outside SEE. At the same time, the need for such

13680-481: The countryside. On 26 February 1935, they parked the van in a field near Upper Stowe and connected it to wire antennas stretched across the field on top of wooden poles. A Handley Page Heyford made four passes over the area, producing clearly notable effects on the CRT display on three of the passes. A memorial stone was placed at the site of the test. Observing the test were Watt, Wilkins, and several other members of

13851-414: The death ray is not possible, how can we help them?" Wilkins recalled the earlier report from the GPO, and noted that the wingspan of a contemporary bomber aircraft , about 25 m (82 ft), would be just right to form a half-wavelength dipole antenna for signals in the range of 50 m wavelength, or about 6 MHz. In theory, this would efficiently reflect the signal and could be picked up by

14022-936: The deaths of aircrew. In the Mediterranean, the United States Army Air Forces (USAAF) 414th , 415th , 416th and 417th night fighter squadrons received a hundred Beaufighters in the summer of 1943, achieving their first victory in July 1943. Through the summer, the squadrons conducted daytime convoy escort and ground-attack operations but primarily flew as night fighters. Although the Northrop P-61 Black Widow fighter began to arrive in December 1944, USAAF Beaufighters continued to fly night operations in Italy and France until late in

14193-431: The defenders, eventually telling the observers where and when the attacks would be taking place. Even then, 70 per cent of the bombers reached their targets unhindered. The numbers suggested any targets in the city would be destroyed. Squadron Leader P. R. Burchall summed up the results by noting that "a feeling of defencelessness and dismay, or at all events of uneasiness, has seized the public." In November, Churchill gave

14364-694: The director. Wilkins followed him to the DCD, and A. P. Rowe took over AMES at Bawdsey. In August 1938, the first five stations were declared operational and entered service during the Munich crisis , starting full-time operation in September. Bristol Beaufighter The Bristol Type 156 Beaufighter (often called the Beau) is a British multi-role aircraft developed during the Second World War by

14535-548: The earlier Beaufort in Australia and the great success of British-made Beaufighters used by the Royal Australian Air Force (RAAF), contributed to the Australian government deciding in January 1943 to manufacture Beaufighters under the Department of Aircraft Production (DAP) organisation at Fishermans Bend , Melbourne , Victoria from 1944. The DAP Beaufighter was an attack and torpedo bomber known as

14706-435: The elevator control circuit, increased fin area and lengthening of the main oleo strut of the undercarriage to better accommodate weight increases and hard landings. During the pre-delivery trials, the first prototype R2052 , powered by a pair of two-speed supercharged Hercules I-IS engines, had achieved 335 mph (539 km/h) at 16,800 ft (5,120 m) in a clean configuration. The second prototype, R2053 , which

14877-531: The enemy." Even the highest levels of the RAF came to agree with this policy, publicly stating that their tests suggested that "'The best form of defence is attack' may be all-too-familiar platitudes, but they illustrate the only sound method of defending this country from air invasion. It is attack that counts." As it became clear the Germans were rapidly rearming the Luftwaffe , the fear grew RAF could not meet

15048-461: The engine to stall. One commonly repeated story involved an English couple who were driving in the Black Forest on holiday and had their car fail in the countryside. They claimed they were approached by soldiers who told them to wait while they conducted a test, and were then able to start their engine without trouble when the test was complete. This was followed shortly thereafter by a story in

15219-469: The expected reflectivity of an aircraft. The received signal would be only 10 times as strong as the transmitted one, but such sensitivity was considered to be within the state of the art. To reach this goal, a further improvement in receiver sensitivity of two times was assumed. Their ionospheric systems broadcast only about 1 kW, but commercial shortwave systems were available with 15 amp transmitters (about 10 kW) that they calculated would produce

15390-471: The face of such a threat is inexcusable until it has definitely been shown that all the resources of science and invention have been exhausted." In 1923–24 inventor Harry Grindell Matthews repeatedly claimed to have built a device that projected energy over long ranges and attempted to sell it to the War Office, but it was deemed to be fraudulent. His attempts spurred on many other inventors to contact

15561-599: The first five production Beaufighters were delivered to the RAF along with another five on 3 August 1940. These production aircraft incorporated aerodynamic improvements, reducing aerodynamic drag from the engine nacelles and tail wheel, the oil coolers were also relocated on the leading edge of the wing. The armament of the Beaufighter had also undergone substantial changes, the initial 60-round capacity spring-loaded drum magazine arrangement being awkward and inconvenient; alternative systems were investigated by Bristol. Bristol's proposed recoil -operated ammunition feed system

15732-464: The first official meeting of the Tizard Committee on 28 January 1935. The utility of the concept was evident to all attending, but the question remained whether it was actually possible. Albert Rowe and Wimperis both checked the maths and it appeared to be correct. They immediately wrote back asking for a more detailed consideration. Watt and Wilkins followed up with a 14 February secret memo entitled Detection and Location of Aircraft by Radio Means . In

15903-436: The first, unarmed, prototype, conducted its maiden flight , a little more than eight months after development had formally started. The rapid pace of development is partly due to the re-use of many elements of the Beaufort design along with frequently identical components. R2052 was initially operated by Bristol for testing purposes while it was based at Filton Aerodrome . Early modifications to R2052 included stiffening of

16074-596: The formation of a study group to consider new concepts. Lord Londonderry , then Secretary of State for Air , approved the formation of the Committee for the Scientific Survey of Air Defence in November 1934, asking Henry Tizard to chair the group, which thus became better known to history as the Tizard Committee . When Wimperis sought an expert in radio to help judge the death-ray concept, he

16245-461: The front of the wings. This change moved the centre of gravity (CoG) forward, a typically undesirable feature for an aircraft, thus the CoG was moved back to its proper desirable location by shortening the nose, which was possible as the space within the nose had been previously occupied by a bomb aimer , a role that was unnecessary in a fighter aircraft. The majority of the fuselage was positioned aft of

16416-497: The fuselage required more work than expected and had to be redesigned. Perhaps in anticipation of this, the Air Ministry had requested that Bristol investigate the prospects of a "slim fuselage" configuration. Since the "Beaufort cannon fighter" was a conversion of an existing design, development and production was expected to proceed more quickly than with a new one. Within six months the first F.11/37 prototype, R2052 , had been completed. A total of 2,100 drawings were produced during

16587-582: The ground clutter. AEW&C aircraft are extremely expensive, however, and generally require aircraft to be dedicated to protecting them. A combination of both techniques is really ideal, but GCI is typically only available in the defence of one's homeland, rather than in expeditionary types of battles. The strengths of GCI are that it can cover far more airspace than AEW&C without costing as much and areas that otherwise would be blind-spots for AEW&C can be covered by cleverly placed radar stations. AEW&C also relies on aircraft which may require defence and

16758-406: The importance of the Beaufighter to the war effort and urged its rapid service entry. While the aircraft's size had once caused scepticism, the Beaufighter became the highest performance aircraft capable of carrying the bulky early aircraft interception radars used for night fighter operations, without incurring substantial endurance or armament penalties, and was invaluable as a night fighter. For

16929-518: The improved Beaufighter Mk.VIC . By the end of 1942, Mk.VICs were being equipped with torpedo-carrying gear for the British 18 in (450 mm) or the US 22.5 in (572 mm) torpedo externally; observers were not happy about carrying the torpedo, as they were unable to use the escape hatch until after the torpedo had been dropped. In April 1943, the first successful torpedo attacks by Beaufighters

17100-476: The interceptor's chance of success and survival. Chain Home Chain Home , or CH for short, was the codename for the ring of coastal early warning radar stations built by the Royal Air Force (RAF) before and during the Second World War to detect and track aircraft. Initially known as RDF , and given the official name Air Ministry Experimental Station Type 1 ( AMES Type 1) in 1940,

17271-419: The intruders that they may be coming under attack. With GCI or AEW&C, the defending aircraft can be vectored to an interception course, perhaps sliding in on the intruder's tail position without being noticed, firing passive homing missiles and then turning away. Alternatively, they could turn their radars on at the final moment, so that they can get a radar lock and guide their missiles. This greatly increases

17442-543: The lower fuselage, the vacant nose could accommodate the radar antennas needed, and while early aircraft interception equipment was too bulky to fit in single-engine fighters of the day, it could be accommodated in the Beaufighter's spacious fuselage. At night the onboard radar let the aircraft detect enemy aircraft. The heavy fighter remained fast enough to catch up to German bombers and, with its heavy armament, deal out considerable damage to them. While early radar sets suffered from restrictions in range and thus initially limited

17613-554: The maximum rate of production, sub-contracting of the major components was used wherever possible and two large shadow factories to perform final assembly work on the Beaufighter were established via the Ministry of Aircraft Production ; the first, operated by the Fairey Aviation Company , was at Stockport , Greater Manchester and the second shadow, run by Bristol, was at Weston-super-Mare , Somerset . Output of

17784-405: The new memo, Watson-Watt and Wilkins first considered various natural emanations from the aircraft – light, heat and radio waves from the engine ignition system – and demonstrated that these were too easy for the enemy to mask to a level that would be undetectable at reasonable ranges. They concluded that radio waves from their own transmitter would be needed. Wilkins gave specific calculations for

17955-463: The new system recently completed at Bawdsey failed. The next day, Robert Hanbury-Brown and the new recruit Gerald Touch started up the Orfordness system and were able to run the demonstrations from there. The Orfordness site was not closed until 1937. The system was deliberately developed using existing commercially available technology to speed introduction. The development team could not afford

18126-565: The next two years, additional stations were built while the problem of disseminating the information to the fighter aircraft led to the first integrated ground-controlled interception network, the Dowding system . By the time the war started, most of the east and south coasts had radar coverage. Chain Home proved important during the Battle of Britain in 1940. CH systems could detect enemy aircraft while they were forming over France, giving RAF commanders ample time to marshal their aircraft in

18297-494: The night of 17/18 September 1940, Beaufighters of 29 Squadron conducted their first operational night patrol, conducting an uneventful sortie, the first operational daylight sortie was performed on the following day. On 25 October 1940, the first confirmed Beaufighter kill, a Dornier Do 17 , occurred. Initial production deliveries of the Beaufighter lacked the radar for night fighter operations; these were installed by No. 32 Maintenance Unit at RAF St Athan during late 1940. On

18468-564: The night of 19/20 May 1941, 24 aircraft were shot down by fighters against two by anti-aircraft ground fire . In late April 1941, the first two Beaufighter Mk.II aircraft, R2277 and R2278 , were delivered to 600 and 604 Squadrons; the former squadron being the first to receive the type in quantity in the following month. The Mk.II was also supplied to the Fleet Air Arm of the Royal Navy . A night-fighter Beaufighter Mk.VIF

18639-454: The night of 19/20 November 1940, the first kill by a radar-equipped Beaufighter occurred, of a Junkers Ju 88 . More advanced radar units were installed in early 1941, which soon allowed the Beaufighter to become an effective counter to the night raids of the Luftwaffe . By March 1941, half of the 22 German aircraft claimed by British fighters were by Beaufighters. During a raid on London on

18810-713: The noisy valve gear common to poppet valve engines. This was most apparent in a reduced noise level at the front of the engine. In the South-East Asian Theatre , the Beaufighter Mk.VIF operated from India as a night fighter and on operations against Japanese lines of communication in Burma and Thailand. Mk.X Beaufighters were also flown on long range daylight intruder missions over Burma. The high-speed, low-level attacks were very effective, despite often atrocious weather conditions and makeshift repair and maintenance facilities. The Royal Australian Air Force (RAAF)

18981-460: The objective of winning such a tit-for-tat exchange and many suggested they invest in a massive bomber building exercise. Others felt advances in fighters meant the bomber was increasingly vulnerable and suggested at least exploring a defensive approach. Among the latter group was Lindemann, test pilot and scientist, who noted in The Times in August 1934 that "To adopt a defeatist attitude in

19152-706: The occupied Norwegian island of Vågsøy . In 1942, long range patrols of the Bay of Biscay were routinely conducted by Beaufighters, intercepting aircraft such as the Ju-88 and Focke-Wulf Fw 200 Condor operating against Allied anti-submarine patrols. Beaufighters also cooperated with the British Eighth Army during action in the Western Desert Campaign , often in the form of ground strafing. In mid-1942, Coastal Command began to take delivery of

19323-418: The other experiments at the RRS at Slough, and expressing their gratitude that the Air Ministry had granted them access to unused land at Orfordness to continue their efforts. Bowen continued increasing the voltage in the transmitter, starting with the 5000  volt maximum suggested by the Navy, but increasing in steps over several months to 12,000 V, which produced pulses of 200 kW. Arcing between

19494-466: The other members' complaints about his behaviour were ignored. The matter was eventually referred back to Lord Swinton , the new Secretary of State for Air. Swinton solved the problem by dissolving the original Committee and reforming it with Appleton in Lindemann's place. As the development effort grew, Watt requested a central research station be established "of large size and with ground space for

19665-428: The path of the raid. This had the effect of multiplying the effectiveness of the RAF to the point that it was as if they had three times as many fighters, allowing them to defeat frequently larger German forces. The Chain Home network was continually expanded, with over 40 stations operational by the war's end, including mobile versions for use overseas. Late in the war, when the threat of Luftwaffe bombing had ended,

19836-413: The pilot's seat. As there was no room to climb around the seat-back, the back collapsed to allow the pilot to climb over and into the seat. In an emergency, the pilot could operate a lever that remotely released the hatch, grasp two steel overhead tubes and lift himself out of his seat, swing his legs over the open hatchway, then let go to drop through. Evacuating the aircraft was easier for the navigator, as

20007-428: The pilot, to overcome the effect of recoil and nose-down tendency when firing the usual armament but was found to obstruct the emergency egress of the pilot. The fourth prototype, R2055 , had its regular armament replaced by a pair of 40 mm guns for attacking ground targets, the two guns being a Vickers S gun mounted on the starboard fuselage and a Rolls-Royce BH gun mounted on the port fuselage; these trials led to

20178-533: The proper introduction of the Whirlwind. On 16 November 1938, Bristol received formal authorisation to commence the detailed design phase of the project and to proceed with the construction of four prototypes. Amongst the design requirements, the aircraft had to be able to accommodate the Rolls-Royce Griffon engine as an alternative to the Hercules and that it have maximum interchangeability between

20349-415: The radar operator to change the ammunition drums manually—an arduous and unpopular task, especially at night and while chasing a bomber. They were soon replaced by Hispano Mk. II cannon featuring a belt-feed system. The cannons were supplemented by six .303 in (7.7 mm) Browning machine guns in the wings (four starboard, two port, the asymmetry caused by the port mounting of the landing light). This

20520-401: The radar units were also known as Chain Home for most of their life. Chain Home was the first early warning radar network in the world and the first military radar system to reach operational status. Its effect on the war made it one of the most powerful systems of what became known as the "Wizard War". In late 1934, the Tizard Committee asked radio expert Robert Watson-Watt to comment on

20691-402: The range was continually pushed out. During a 24 July test, the receiver detected a target at 40 mi (64 km) and the signal was strong enough that they could determine the target was actually three aircraft in close formation. By September the range was consistently 40 miles, increasing to 80 miles (130 km) by the end of the year, and with the power improvements Bowen worked into

20862-414: The rear hatch was in front of him and without obstruction. The Beaufighter's armament was located in various positions on the lower fuselage and wings. The bomb bay of the Beaufort had been entirely omitted, but a small bomb load could be carried externally. A total of four forward-firing 20 mm Hispano Mk.I cannon were mounted in the lower fuselage area. These were fed from 60-round drums, requiring

21033-467: The repeated claims of radio death rays and reports suggesting Germany had built some sort of radio weapon. His assistant, Arnold Wilkins , demonstrated that a death ray was impossible but suggested radio could be used for long-range detection. In February 1935, a successful demonstration was arranged by placing a receiver near a BBC short wave transmitter and flying an aircraft around the area. Using commercial short wave radio hardware, Watt's team built

21204-416: The roles and equipment diverged, leading to the production of distinct models, distinguished by the suffixes F for Fighter Command and C for Coastal Command were used. Often, one command opted for modifications and features that the other did not. This occurred with the bellows -type dive brake that became standard for Coastal Command Beaufighters for its usefulness in torpedo-bombing. Production of

21375-409: The same jigs as the Beaufort so that production could easily be switched from one aircraft to the other. As a torpedo bomber and aerial reconnaissance aircraft, the Beaufort had a modest performance. To achieve the fighter-like performance desired for the Beaufighter, Bristol suggested that they equip the aircraft with a pair of its new Hercules engines, capable of around 1,500 hp, in place of

21546-408: The ships' anti-aircraft guns, bridges and crews during strafing runs with their four 20 mm nose cannons and six wing-mounted .303 in (7.7 mm) machine guns. The Japanese ships were left exposed to mast-height bombing and skip bombing attacks by the US medium bombers . Eight transports and four destroyers were sunk for the loss of five aircraft, including one Beaufighter. The role of

21717-424: The shorter wavelength produced no loss of performance. This led to a further reduction to 13 m, and finally the ability to tune between 10 and 13 m, (roughly 30-20 MHz) to provide some frequency agility to help avoid jamming. Wilkins' method of height-finding was added in 1937. He had originally developed this system as a way to measure the vertical angle of transatlantic broadcasts while working at

21888-598: The site on 15 June to examine the team's progress. Watt secretly arranged for a Vickers Valentia to fly nearby, and years later insisted that he saw the echoes on the display, but no one else recalls seeing these. Watt decided not to return to the RRS with the rest of the Tizard group and stayed with the team for another day. With no changes made to the equipment, on 17 June the system was turned on and immediately provided returns from an object at 17 mi (27 km). After tracking it for some time, they watched it fly off to

22059-408: The south and disappear. Watt phoned the nearby Seaplane Experimental Station at Felixstowe and the superintendent stated that a Supermarine Scapa flying boat had just landed. Watt requested the aircraft return to make more passes. This event is considered the official birth date of radar in the UK. Aircraft from RAF Martlesham Heath took over the job of providing targets for the system, and

22230-723: The success of the RAF night fighter force began to shoot up. This was further aided by the introduction of the Bristol Beaufighter and its AI Mk. IV radar which became available in numbers at the same time. These two systems proved to be a potent combination, and interception rates doubled every month from January 1941 until the Luftwaffe campaign ended in May. The Germans were quite slow to follow in terms of PPI and did not order operational versions of their Jagdschloss radar until late in 1943, with deliveries being relatively slow after that. Many were still under construction when

22401-466: The target simply by selecting them on the terminal. Messages would then automatically be routed back out via teleprinter to the fighter airbases with interception instructions on them. The system was later upgraded to relay directional information directly to the autopilots of the interceptor aircraft like the F-106 Delta Dart . The pilot was tasked primarily with getting the aircraft into

22572-407: The team. Days later, the Treasury released £12,300 for further development, and a small team of the RRS researchers were sworn to secrecy and began developing the concept. A system was to be built at the RRS station, and then moved to Orfordness for over-water testing. Wilkins would develop the receiver based on the GPO units, along with suitable antenna systems. This left the problem of developing

22743-685: The time to develop and debug new technology. Watt, a pragmatic engineer, believed "third-best" would do if "second-best" would not be available in time and "best" never available at all. This led to the use of the 50 m wavelength (around 6 MHz), which Wilkins suggested would resonate in a bomber's wings and improve the signal. Unfortunately, this also meant that the system was increasingly blanketed by noise as new commercial broadcasts began taking up this formerly high-frequency spectrum . The team responded by reducing their own wavelength to 26 m (around 11 MHz) to get clear spectrum. To everyone's delight, and contrary to Wilkins' 1935 calculations,

22914-429: The transition from Beaufort to the prototype Beaufighter, more than twice as many were created during later development, between the prototype Beaufighter and the fully operational production models. Two weeks prior to the prototype's first flight, an initial production contract for 300 aircraft under Specification F.11/37 was issued by the Air Ministry, ordering the type "off the drawing board". On 17 July 1939, R2052 ,

23085-437: The transmitter antenna was a single dipole strung horizontally between two 75 foot (23 m) poles, and the receiver a similar arrangement of two crossed wires. The system showed little success against aircraft, although echoes from the ionosphere as far as 1,000 miles away were noted. The group released several reports on these effects as a cover story , claiming that their ionospheric studies had been interfering with

23256-399: The transmitter antenna was deliberately focused vertically to improve gain, a single pair of such antennas would only cover a thin vertical angle. A series of such antennas was used, each pair with a different center angle, providing continuous coverage from about 2.5 degrees over the horizon to as much as 40 degrees above it. With this addition, the final remaining piece of Watt's original memo

23427-403: The transmitter, was over 100 mi (160 km) by early 1936. In August 1935, Albert Rowe , secretary of the Tizard Committee, coined the term "Radio Direction and Finding" (RDF), deliberately choosing a name that could be confused with "Radio Direction Finding", a term already in widespread use. In a 9 September 1935 memo, Watson-Watt outlined the progress to date. At that time the range

23598-469: The two engines, which would feature removable installations . Bristol began building an initial prototype by taking a partly-built Beaufort out of the production line. This conversion served to speed progress; Bristol had promised series production in early 1940 on the basis of an order being placed in February 1939. Designers expected that maximum re-use of Beaufort components would speed the process but

23769-621: The two stations. The missing technique that made radar practical was the use of pulses to determine range by measuring the time between the transmission of the signal and reception of the reflected signal. This would allow a single station to measure angle and range simultaneously. In 1924, two researchers at the Naval Research Laboratory in the United States, Merle Tuve and Gregory Briet, decided to recreate Appleton's experiment using timed pulsed signals instead of

23940-494: The type as an anti-shipping aircraft, such as during the Battle of the Bismarck Sea . The Beaufighter saw extensive service during the war with the RAF (59 squadrons), Fleet Air Arm (15 squadrons), RAAF (seven squadrons), Royal Canadian Air Force (four squadrons), United States Army Air Forces (four squadrons), Royal New Zealand Air Force (two squadrons), South African Air Force (two squadrons) and Polskie Siły Powietrzne (Free Polish Air Force; one squadron). Variants of

24111-621: The type occurred when a Beaufighter, A19-54 , won the second of two unofficial races against an A-20 Boston bomber. From late 1944, RAF Beaufighter units were engaged in the Greek Civil War , finally withdrawing in 1946. Beaufighters were replaced in some roles by the Bristol Type 164 Brigand , which had been designed using components of the Beaufighter's failed stablemate, the Bristol Buckingham . The Beaufighter

24282-464: The utility of RDF was Lindemann. He had been placed on the Committee at the insistence of his friend, Churchill, and proved unimpressed with the team's work. When he visited the site, he was upset by the crude conditions, and apparently, by the box lunch he had to eat. Lindemann strongly advocated the use of infrared systems for detection and tracking and numerous observers have noted Lindemann's continual interference with radar. As Bowen put it, Within

24453-400: The valves required the transmitter to be rebuilt with more room between them, while arcing on the antenna was solved by hanging copper balls from the dipole to reduce corona discharge . By June the system was working well, although Bainbridge-Bell proved to be so skeptical of success that Watt eventually returned him to the RRS and replaced him with Nick Carter. The Tizard Committee visited

24624-588: The war ended in 1945. More recently, in both the Korean and Vietnam wars, the North Koreans and North Vietnamese had important GCI systems which helped them harass the opposing forces (although in both cases due to the superiority in the number of US planes the effect was eventually minimised). GCI was important to the US and allied forces during these conflicts also, although not so much as for their opponents. The most advanced GCI system deployed to date

24795-503: The war. By the autumn of 1943, the Mosquito was available in enough numbers to replace the Beaufighter as the primary night fighter of the RAF. By the end of the war, some 70 pilots serving with RAF units had become aces while flying Beaufighters. At least one captured Beaufighter was operated by the Luftwaffe  – a photograph exists of the aircraft in flight, with German markings. It was recognised that RAF Coastal Command required

24966-409: The wing and, with the engine cowlings and propellers now further forward than the tip of the nose, gave the Beaufighter a characteristically stubby appearance. In general, with the exception of the powerplants used, the differences between the preceding Beaufort and Beaufighter were minor. The wings, control surfaces, retractable landing gear and aft section of the fuselage were identical to those of

25137-498: The wing consisted of two spars with single-sheet webs and extruding flanges, completed with a stressed-skin covering, and featured metal-framed ailerons with fabric coverings along with hydraulically -actuated flaps located between the fuselage and the ailerons. Hydraulics were also used to retract the independent units of undercarriage, while the brakes were pneumatically -actuated. The twin Bristol Taurus engines of

25308-486: The wreck of a Beaufighter (probably a Mk.IC flown by Sgt Donald Frazie and navigator Sgt Sandery of No. 272 Squadron RAF) was identified about 0.5-mile (0.80 km) off the north coast of Malta. The aircraft ditched in March 1943, after an engine failure occurred soon after take-off and lies inverted on the sea bed, in 38 metres (125 ft) of water. Another Mediterranean wreck lies in 34 metres (112 ft) of water near

25479-717: Was a keen operator of the Beaufighter during the Second World War. On 20 April 1942, the RAAF's first Beaufighter IC (an Australian designation given to various models of the aircraft, including Beaufighter VIC , Beaufighter X , and Beaufighter XIC ), which had been imported from Britain, was delivered; the last aircraft was delivered on 20 August 1945. Initial RAAF deliveries were directed to No. 30 Squadron in New Guinea and No. 31 Squadron in North-West Australia. Before DAP Beaufighters arrived at RAAF units in

25650-405: Was about 40 mi (64 km), so Watson-Watt suggested building a complete network of stations 20 mi (32 km) apart along the entire east coast. Since the transmitters and receivers were separate, to save development costs he suggested placing a transmitter at every other station. The transmitter signal could be used by a receiver at that site as well as the ones on each side of it. This

25821-495: Was accomplished and the system was ready to go into production. Industry partners were canvassed in early 1937, and a production network was organized covering many companies. Metropolitan-Vickers took over design and production of the transmitters, AC Cossor did the same for the receivers, the Radio Transmission Equipment Company worked on the goniometers, and the antennas were designed by

25992-667: Was also used by the air forces of Portugal , Turkey and the Dominican Republic. It was used briefly by the Israeli Air Force after some ex-RAF examples were clandestinely purchased in 1948. Many Mk.10 aircraft were converted to the target tug role postwar as the TT.10 and served with several RAF support units until 1960. The last flight of a Beaufighter in RAF service was by TT.10 RD761 from RAF Seletar on 12 May 1960. A number of sunken aircraft are known; in 2005,

26163-660: Was carrying out experiments that would lead to him winning the Nobel Prize in Physics . Using a BBC transmitter set up in 1923 in Bournemouth and listening for its signal with a receiver at Oxford University , he was able to use changes in wavelength to measure the distance to a reflective layer in the atmosphere then known as the Heaviside layer . After the initial experiments at Oxford, an NPL transmitter at Teddington

26334-406: Was commonly operated as a night fighter , such as during the Battle of Britain . Mass production of the type had coincidentally occurred at almost exactly the same time as the first British aircraft interception radar sets were becoming available; the two technologies quickly became a natural match in the night fighter role. As the aircraft's accompaniment of four 20 mm cannons were mounted in

26505-535: Was furnished with Hercules I-M engines (similar to Hercules II) and was laden with operational equipment, had attained a lower speed of 309 mph at 15,000 ft. According to aviation author Philip Moyes, the performance of the second prototype was considered disappointing, particularly as the Hercules III engines of the initial production aircraft would likely provide little improvement, especially in light of additional operational equipment being installed; it

26676-412: Was later called the Beaufighter Mk.IIF ; the planned slim-fuselage aircraft, alternatively equipped with Hercules IV and Griffon engines, the Beaufighter Mk.III and Beaufighter Mk.IV respectively, were not built. In February 1940, an order was placed for three Beaufighters, converted to use the alternative Merlin engine. The Merlin engine installations and nacelles were designed by Rolls-Royce as

26847-581: Was lost in almost identical circumstances to the Malta aircraft – it ditched in August 1943 after an engine failure soon after takeoff. The aircraft sank within seconds, but both crew and their passenger escaped and swam to shore. The wreck was located in 2000. A Beaufighter lies at a depth of around 30 metres in the Høydalsfjorden in Norway. This aircraft was shot-down on the 7 February 1945, during

27018-434: Was naturally directed to Watt. He wrote to Watt "on the practicability of proposals of the type colloquially called 'death ray'". The two met on 18 January 1935, and Watt promised to look into the matter. Watt turned to Wilkins for help but wanted to keep the underlying question a secret. He asked Wilkins to calculate what sort of radio energy would be needed to raise the temperature of 8 imperial pints (4.5 L) of water at

27189-403: Was one of the heavier, if not the heaviest, fighter armament of its time. When Beaufighters were developed as fighter-torpedo bombers, they used their firepower (often the machine guns were removed) to suppress flak fire and hit enemy ships, especially escorts and small vessels. The recoil of the cannons and machine guns could reduce the speed of the aircraft by around 25 knots. The Beaufighter

27360-645: Was performed by 254 Squadron , sinking two merchant ships off Norway . The Hercules Mk.XVII, developing 1,735 hp (1,294 kW) at 500 ft (150 m), was installed in the Mk.VIC airframe to produce the TF Mk.X (torpedo fighter), commonly known as the "Torbeau". The Mk.X became the main production mark of the Beaufighter. The strike variant of the Torbeau was called the Mk.XIC. Beaufighter TF Xs could make precision attacks on shipping at wave-top height with torpedoes or RP-3 (60 lb) rockets. Early models of

27531-466: Was quickly rendered moot by the rapid increases in range. When the Committee next visited the site in October, the range was up to 80 mi (130 km), and Wilkins was working on a method for height finding using multiple antennas. In spite of its ad hoc nature and short development time of less than six months, the Orfordness system had already become a useful and practical system. In comparison,

27702-517: Was recognised that demand for the Hercules engine to power other aircraft such as the Short Stirling bomber posed a potential risk to the production rate of the Beaufighter. These factors had thus sparked considerable interest in the adoption of alternative engines for the type. Roy Fedden , chief designer of the Bristol engine division, was a keen advocate for the improved Hercules VI for

27873-418: Was rejected by officials, which led to a new system being devised and tested on the fourth prototype, R2055 . The initial rejection was later reversed, upon the introduction of a new electrically driven feed derived from Châtellerault designs brought to Britain by Free French officers, which was quite similar to Bristol's original proposal. The initial 50 production aircraft were approved for completion with

28044-459: Was supplied to squadrons in March 1942, equipped with AI Mark VIII radar . The Beaufighter showed its merits as a night fighter but went on to perform in other capacities. As the faster de Havilland Mosquito took over as the main night fighter in mid-to-late 1942, the heavier Beaufighter made valuable contributions in other areas such as anti-shipping, ground attack and long-range interdiction, in every major theatre of operations. On 12 June 1942,

28215-479: Was the US's Semi Automatic Ground Environment (SAGE) system. SAGE used massive computers to combine reports sent in via teleprinter from the Pinetree Line and other radar networks to produce a picture of all of the air traffic in a particular sector's area. The information was then displayed on terminals in the building, allowing operators to pick defensive assets (fighters and missiles) to be directed onto

28386-533: Was to select a new shortwave receiver for ionospheric studies, a task he undertook with great seriousness. After reading everything available on several units, he selected a model from the General Post Office (GPO) that worked at (for that time) very high frequencies. As part of their tests of this system, in June 1932 the GPO published a report, No. 232 Interference by Aeroplanes . The report recounted

28557-566: Was unusual in that area. The large manor house on the property would have ample room for experimental labs and offices. In February and March 1936, the team moved to Bawdsey Manor and established the Air Ministry Experimental Station (AMES). When the scientific team left in 1939, the site became the operational CH site RAF Bawdsey . While the "ness team" began moving to Bawdsey, the Orfordness site remained in use. This proved useful during one demonstration when

28728-575: Was upset by the introduction of the AMES Type 80 radar, which was originally intended as a very long-range early warning system for ROTOR but demonstrated its ability to control interceptions as well. This led to the abandonment of the ROTOR network and its operation being handled at the Type 80 "Master Radar Stations". In the 1960s the Linesman/Mediator project looked to computerize the system in

28899-458: Was used as a source, received by Appleton in an out-station of King's College in the East End of London. Watt learned of these experiments and began conducting the same measurements using his team's receivers in Slough. From then on, the two teams interacted regularly and Watt coined the term ionosphere to describe the multiple atmospheric layers they discovered. In 1927 the two radio labs, at

29070-477: Was used in many roles; receiving the nicknames Rockbeau for its use as a rocket -armed ground attack aircraft and Torbeau as a torpedo bomber against Axis shipping, in which it replaced the Beaufort . In later operations, it served mainly as a maritime strike/ground attack aircraft, RAF Coastal Command having operated the largest number of Beaufighters amongst all other commands at one point. The Royal Australian Air Force (RAAF) also made extensive use of

29241-429: Was widely known that certain materials, especially metal, reflected radio signals. This led to the possibility of determining the location of objects by broadcasting a signal and then using RDF to measure the bearing of any reflections. Such a system saw patents issued to Germany's Christian Hülsmeyer in 1904, and widespread experimentation with the basic concept was carried out from then on. These systems revealed only

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