Bristol Beaufort

The Bristol Beaufort (manufacturer designation Type 152) was a British twin-engined torpedo bomber designed by the Bristol Aeroplane Company, and developed from experience gained designing and building the earlier Blenheim light bomber.

Beauforts first saw service with Royal Air Force Coastal Command and then the Royal Navy Fleet Air Arm from 1940. They were used as torpedo bombers, conventional bombers and mine-layers until 1942, when they were removed from active service and were then used as trainer aircraft until being declared obsolete in 1945. Beauforts also saw considerable action in the Mediterranean; Beaufort squadrons based in Egypt and on Malta helped put an end to Axis shipping supplying Rommel's Deutsches Afrikakorps in North Africa.

Beauforts saw their most extensive use with the Royal Australian Air Force in the Pacific theatre, where they were used until the very end of the war. With the exception of six examples delivered from England, Australian Beauforts were locally produced under license.

Although designed as a torpedo-bomber, the Beaufort more often flew as a level-bomber. The Beaufort also flew more hours in training than on operational missions, and more were lost through accidents and mechanical failures than were lost to enemy fire. However, the Beaufort did spawn a long-range heavy fighter variant called the Beaufighter, which proved to be very successful and many Beaufort units eventually converted to the Beaufighter.


Bristol Beaufort
Class Aircraft
Type Bomber
Manufacturer Bristol Aeroplane Company
Origin United Kingdom - UK (Great Britain)
Country Name Origin Year
United Kingdom - UK (Great Britain) 1938
Country Name Operational Year Retirement Year
Australia 1939 1944 View
Canada View
South Africa View
Turkey (Ottoman Empire) View
United Kingdom - UK (Great Britain) 1939 1944 View
New Zealand View
ManufacturerName Production From Production To Quantity
Bristol Aeroplane Company 1121 View

The Beaufort came from Bristol's submission to meet Air Ministry Specifications M.I5/35 and G.24/35 for respectively a land-based twin-engined torpedo-bomber and a general reconnaissance aircraft. With a production order following under Specification 10/36, the Bristol Type 152 was given the name Beaufort after the Duke of Beaufort, whose ancestral home was nearby in Gloucestershire.

The competing torpedo bomber entry from Blackburn was also ordered as the Blackburn Botha. In an unprecedented step both designs were ordered straight off the drawing board, an indication of how urgently the RAF needed a new torpedo bomber. Three hundred and twenty Beauforts were ordered. Initially, because of their commitment to the Blenheim, Bristol were to build 78 at their Filton factory, with the other 242 being built by Blackburn. These allocations would be changed later.

Although the design looked similar in many ways to the Blenheim, it was somewhat larger, with an 18 in (46 cm) increase in wingspan. With the fuselage being made longer in the nose and taller to accommodate a fourth crew member, it was also considerably heavier. The larger bomb-bay was designed to house a semi-recessed torpedo, or it could carry an increased bomb load. Due to the increased weight the Blenheim's Bristol Mercury engines were to be replaced by the more powerful, sleeve valve, Bristol Perseus. It was soon determined that even with the Perseus, the Beaufort would be slower than the Blenheim and so a switch was made to the larger Bristol Taurus engine, also a sleeve valve design. For these engines, chief designer Roy Fedden developed special low-drag NACA cowlings which exhausted air through vertical slots flanking the nacelles under the wings. Air flow was controlled by adjustable flaps.

The basic structure, although similar to the Blenheim, introduced refinements such as the use of high-strength light alloy forgings and extrusions in place of high-tensile steel plates and angles; as a result the overall structural weight was lighter than that of the Blenheim.In addition, the wing centre section was inserted into the centre fuselage and the nacelle structure was an integral part of the ribs to which the main undercarriage was attached. Transport joints were used on the fuselage and wings: this allowed sub-contractors to manufacture the Beaufort in easily transportable sections, and was to be important when Australian production got underway. The Vickers main undercarriage units were similar to, but larger than those of the Blenheim and used hydraulic retraction with a cartridge operated emergency lowering system.

The first prototype rolled out of Filton in mid-1938. Problems immediately arose with the Taurus engines continually overheating during ground testing. New more conventional engine cowlings with circumferential cooling gills had to be designed and installed, delaying the first flight which took place on 15 October 1938. As flight testing progressed it was found that the large apron-type undercarriage doors, similar to those on the Blenheim, were causing the aircraft to yaw on landing. These doors were taken off for subsequent flights. On the second prototype and all production aircraft more conventional split doors, which left a small part of the tyres exposed when retracted, were used.

The results of high level bombing tests carried out at Boscombe Down at an altitude of 10,000 ft (3,000 m) and an airspeed of 238 mph (383 km/h) showed that the Beaufort was in the words of the test pilot: "An exceptionally poor bombing platform, being subject to an excessive and continuous roll which made determination of drift particularly difficult." After 1941, British Beauforts were fitted with semi-circular plates on the trailing edges of the upper wing behind the engine nacelles to smooth airflow and improve directional stability.

With Blenheim production taking priority and continued overheating of the Taurus engines there were delays in production, so while the bomber had first flown in October 1938 and should have been available almost immediately, it was not until November 1939 that production started in earnest. Several of the first production Beauforts were engaged in working-up trials and final service entry began in January 1940 with 22 Squadron of RAF Coastal Command.

Although it did see some use in the torpedo bomber role, notably in attacks on the battleships Scharnhorst and Gneisenau while in port in Brest, the Beaufort more often used bombs while in European service.

In early 1940, 22 Squadron equipped with Vildebeests, began to receive Beauforts. The Beaufort was a much faster, heavier aircraft than the biplane and the crews needed a great deal of training in torpedo-dropping using new techniques required by the Beaufort. The lighter, slower Vildebeest was able to dive then flatten out before launching the torpedo; Beauforts carried too much speed after diving so it needed a longer, level approach to the torpedo drop. Because of this, and because of a shortage of torpedoes the squadron's first operations consisted of laying magnetic mines ("Gardening" in RAF parlance) and dropping conventional bombs. As an alternative to the torpedo the Beaufort could carry a 2,000 lb (910 kg) bomb using a purpose built carrier. On one of its first bombing operations, on 7 May 1940, a Beaufort dropped the first British 2,000 lb (910 kg) bomb, aiming at a German cruiser anchored off Norderney.

The first Beaufort operation took place on the night of 15/16 April, when nine Beauforts successfully laid mines in the Schillig Roads (north of Wilhelmshaven). One Beaufort failed to return. A second unit, 42 Squadron began to re-equip with Beauforts, starting in April. The Beaufort, however still had teething problems and, after some Beauforts were lost in mysterious circumstances, a Court of Enquiry in June 1940 concluded that the Taurus engines were still unreliable and both operational squadrons were grounded until the engines could be modified.

The first RAF torpedo attack of the war came on 11 September 1940, when five aircraft of 22 Squadron attacked a convoy of three merchant ships off Ostend (Oostende in Belgium). One torpedo hit a 6,000 ton (5,440 tonne) ship. Four days later, the first "Rover" was mounted; a Rover was an armed reconnaissance mission carried out against enemy shipping by a small number of aircraft operating independently. "Rovers" became a major part of Beaufort operations over the next 18 months. Other more hazardous operations were to follow, with one Beaufort pilot being awarded a posthumous VC.

The only other UK based units to be equipped and fly operationally with the Beaufort, 86 Squadron and 217 Squadron, were operational by the middle of 1941. Beauforts also equipped some Commonwealth Article XV squadrons serving within the RAF, but, because of supply shortages, were replaced by other aircraft types before the units flew operationally.

Role Torpedo bomber
Manufacturer Bristol Aeroplane Company
First flight 15 October 1938
Introduction 1939
Retired 1944
Primary users Royal Australian Air Force
RAF Coastal Command
Fleet Air Arm
Number built 1,121 (+700 in Australia)
Developed from Bristol Blenheim
Variants Bristol Beaufighter


General characteristics

  • Crew: 4
  • Length: 44 ft 2 in (13.46 m)
  • Wingspan: 57 ft 10 in (17.63 m)
  • Height: 14 ft 3 in (4.34 m)
  • Wing area: 503 ft² (46.73 m²)
  • Empty weight: 13,107 lb (5,945 kg)
  • Loaded weight: 21,230 lb (9,629 kg)
  • Powerplant: 2 × Bristol Taurus II, III, VI, XII or XVI 14-Cylinder sleeve valve radial engine, 1,130 hp (843 kW) each

Performance

  • Maximum speed: 271.5 mph (236 kn, 420 km/h) at 6,500 ft (1,981 m).
  • Cruise speed: 255 mph at 6,500 ft (221 kn, 410 km/h) at 6,500 ft (1,981 m)
  • Range: 1,600 mi (1,400 nmi, 2,600 km)
  • Service ceiling: 16,500 ft (5,030 m)
  • Rate of climb: 1,200 ft/min (6.096 m/s)
  • Wing loading: 42.2 lb/ft² (206 kg/m²)
  • Power/mass: 0.106 hp/lb (0.175 kW/kg)

Armament

  • Guns:
    3 .303 in (7.7 mm) Vickers GO machine guns (two in Bristol Mk IV dorsal turret, one in port wing).
    6 .303 in (7.7 mm) Vickers GO machine guns (Two fixed in nose, two in turret, one in port wing and one firing laterally from entry hatch.) Late production.
    1 .303 in (7.7 mm) Browning machine gun in rear-firing chin blister
  • Bombs:
    1 1,605 lb (728 kg) 18 in Mk XII torpedo or.
    2,000 lb (907 kg) of bombs or mines.

End notes