Boulton & Paul Ltd, was a Norwich based manufacturing company that started life as an ironmonger's shop. It was situated in Cockey Lane, Norwich, and opened by William Moore in 1797. Over the next century it changed its name several times, becoming an ironfounders, a wire netting manufacturer, and became famous for the construction of prefabricated wooden buildings. The company produced the huts for Scott's Antarctic expedition, and also made motor boat engines and structural steelwork.

In 1914 Boulton & Paul Ltd began to manufacture items for the war effort. As part of this the company was asked to produce aircraft, and in 1915 began building RAF factory designed FE.2B's. The company built a total of 550, and then received an order for Sopwith Camels, producing  an average of 28 a week.

 It was decided that aircraft production would continue after the war, and so the company opened a design department with John North as chief engineer. He had been Chief Engineer at Grahame White Aviation, in charge of a workforce of 70 at the age of only 21. He then became superintendent of aircraft production at Austin Motors before moving to Norwich.


A 1917 P.6 biplane.

The first aircraft to be designed in the new department was the P.3 Bobolink fighter, which didn't sell well due to competition from the Sopwith Snipe. Boulton Paul's P.6, one of the first aircraft to be designed for aerodynamic research, was a handy two seater biplane. After the war it became the company's own transport. The next design, the P.7 Bourges, the first effective twin-engined fighter bomber, came too late, because the war soon ended and no major orders followed.

The Blackburn Roc.

 

photograph courtesy of Eardley Lewis.

After the war the P.6 became the P.9 which was developed as a private light aircraft. The P.7 Bourges became the P.8 Atlantic, an 8 seater airliner constructed in metal. Only a few orders were received because of the large number of cheap war surplus aircraft that were on the market at the time.

The next model, the all-steel P.10 biplane became the sensation of the 1919 Paris Air Show. This led to a number of orders including one for the design and construction of the R.101 airship. In 1925 Malcolm Campbell pushed the land speed record to 150.87m.p.h. in a Sunbeam car. Prior to the record attempt, Sunbeam sent a model of the car to Boulton Paul for tests in their wind tunnel. After a series of tests Boulton Paul redesigned the car to improve its aerodynamic performance. 

The company's first significant aircraft to go into production was the Sidestrand bomber. 18 were ordered to equip no.101 squadron. The twin engined aircraft first flew in 1926 and could loop, spin and roll. It had a top speed of 140mph. The aircraft entered service in 1929. The high speed Sidestrand made John North realise that the nose gunner needed some protection. As a result he designed a fully enclosed, power operated gun turret containing a single Lewis gun, powered by compressed air bottles, and a compressor driven from one of the engines. This was fitted to the Overstrand which became the last of the company's designs to be built at Norwich and the first aircraft in the world to have such a turret. French engineer De Boysson developed a 4 gun electro-hydraulic turret. John North saw its potential and the company brought the manufacturing rights. This formed the basis for much of the company's future. The turret fitted to the Overstrand was an immediate success and led to a large number of orders. Over the years a whole range of gun turrets were designed and fitted to many of the most successful aircraft of the day.

During the 1920's and 30's orders were few and far between, and so the company decided to sell its aircraft department. This became Boulton Paul Aircraft Ltd, and moved to a new factory at Pendeford, Wolverhampton, in 1934. Most of the 800 strong workforce moved to Wolverhampton but further skilled labour was required. A number of people were recruited from Ulster and Scotland, and a training school was set up at Cannock. 

Blackburn Roc production at Wolverhampton.

 

photograph courtesy of Eardley Lewis.

The first aircraft built at Pendeford was the Hawker 'Demon' two seater fighter. A total of 106 were produced; the first one flew on 21st August 1926. The aircraft, fitted with a 584hp. Mark V Kestrel engine had a top speed of 182m.p.h. at 16,400ft. From October all the Demons were fitted with a Frazer-Nash hydraulic turret with folding shield.  The factory was extended in 1937, eventually covering three times the area of the original Pendeford works. The number of employees also increased, reaching a wartime peak of 4,800.

In March of the same year the company received an order for 87 Defiants. The Defiant fighter was Boulton Paul's first aircraft incorporating an all metal stressed skin. A very smooth surface was achieved by using counter sunk holes and riveting the skin while still flat. The aircraft, powered by a Rolls Royce Merlin 1 engine developed 1030hp. The first flight took place on 11th August 1937 and flight trials continued during the following year. A second prototype was flown on 18th May 1939, powered by a Merlin 2 engine and achieved a top speed of 303m.p.h. at 16,500 ft. It was fitted with a Boulton Paul type 'A' Mk.IID turret with 4 Browning .303 machine guns. The first production aircraft flew on 30th July 1939. Initially 363 Defiants were built, followed by orders for another 113. A mark 2 version, powered by a Rolls Royce Merlin XX engine was developed, which produced 1260hp. and had a top speed of 313m.p.h. at 19,000ft.

The Royal Navy put out tenders for a turret equipped fighter. The contract went to Blackburn for its Roc aircraft. Blackburn had a lot of orders at the time for other aircraft, and so Boulton Paul was subcontracted to manufacture the aircraft, which were basically Blackburn Skua dive-bombers fitted with Boulton Paul type 'A' turrets. Bouton Paul did all of the redesign work, and the first aircraft flew on 23rd December 1938.

The Blackburn Roc.
A total of 136 were built.

 

photograph courtesy of Eardley Lewis.

Blackburn Roc production at the works.

 

photograph courtesy of Eardley Lewis.

After the outbreak of the second world war the factory was camouflaged, and in 1940 a dummy factory, complete with dummy aircraft, was built a mile along the canal. In April, 1940 two important visitors were received at the factory, King George VI and Queen Elizabeth. They saw an aerobatic display and toured the works. The factory however, never became a target during the many German bombing raids.

The successful Defiant fighter which played an important part in the battle of Britain.

The Defiant found  new roles, important in flying history. 

Paul Barnard writes:

"The Defiant, because it had a rear turret position, was used by Martin Baker for the first successful tests of their prototype ejector seat in an aircraft (albeit with dummies). 

The turret was a French design used by B&P under licence.  I believe the Defiant was selected because its design meant that, by removing the turret assembly, a relatively large space was freed up for test purposes without any impact on the structural integrity of the fuselage.  It also meant that the

pilot's seat was still free for a "volunteer" to taxi the plane along the runway!
 
Martin-Baker moved on to the much faster Gloster Meteor (2 seater version) for testing with humans and, amazingly, are still flying two Meteors to this day and their seats have saved over 7000 lives."
 
An advertisement for the Defiant.

The mark 2 Defiant also found a new role as a target tug. The turret was removed and replaced by a winch and drogue box, mounted beneath the fuselage. 140 were ordered in July 1941, and further orders came from South Africa, Cyprus and many from the UK. In 1943, sixty were sent to the Royal Navy and ended up in locations all over the world, including North Africa, the Gold Coast, Trinidad, and Ceylon. Some tugs even ended up in the American Air Force.

The Defiant was followed by the Fairey Barracuda. Fairey won an order for a naval dive bomber / torpedo / reconnaissance aircraft in January 1940. Orders for 1688 were received in 1941 and so Fairey subcontracted Boulton Paul to produce 300 of the aircraft. It was powered by a Rolls Royce Merlin 3 engine which produced 1640hp. Boulton Paul modified the aircraft to produce the mark 3 Barracuda, an anti-submarine reconnaissance aircraft. An order for 600 was received but only 392 were built because the others were cancelled at the end of the war. 

Part of the Balliol wing production area.

 

From a Boulton Paul advert of 1955.

After the war 270 Wellington bombers were converted to T10 navigation trainers and the Balliol T1 and T2 advanced trainers were built for the RAF. Large numbers were made, and there were many overseas orders including one from the Royal Ceylon Air Force. 


A Balliol in flight.

The prototype Balliol, fitted with a Mercury 35 engine took to the air for the first time on 7th May, 1947 under the control of Boulton Paul's chief test pilot Mr. Lindsay Neale. Right from the word go it was a great success. Initial flying trials were quickly completed at Wolverhampton, Boscombe and Farnborough, well before the second prototype had been completed. The aircraft went into production as the Mk.1 Balliol, powered by an Armstrong Siddeley Mamba gas turbine engine. The aircraft was designed for shore-based or ship-based naval operations. The wings could be folded manually to allow the Balliol to be accommodated in nearly all British fleet and light fleet carriers.


A Balliol Mamba.

The fuselage was built using a light-alloy stressed skin construction, apart from the nose which had a framework of Accles and Pollock and Reynolds light alloy and steel tubes. The aircraft could be broken down into a number of easily transportable units, and some of the main components such as the tailplane units, elevators, ailerons, undercarriage, and wing tanks were interchangeable, to reduce stocks of replacement components.


The speed / altitude curve of a Mamba Balliol.

The spars were made of light-alloy 'T' section extrusions and the wing covering consisted of a light alloy sheet, reinforced by pressed ribs and light stringers. The main undercarriage had two pneumatically operated, interchangeable single-cantilever legs, and the tail wheel was steered from the rudder via a clutch. The aircraft had thee Marston crashproof fuel tanks with Simmonds Pacitor gauges and S.U. float gear. One tank was in the fuselage, and the other two were in the inner wings, with a total capacity of 169 gallons.

Either wing tank could be easily removed from the folded wing by detaching the rib diaphragm and disconnecting the piplines.
All the engine cowling panels had quick release fasteners, and some were hinged to facilitate maintenance.
The Marston covered tank could easily be removed from the top of the fuselage.

The Balliol (Merlin) first flew on 10th July 1948 and in the same year was displayed at the Farnborough show, powered by a Merlin 35 engine with a top speed of 288m.p.h. at 9,000ft. It had a ceiling of 32,500ft, was armed with a single .303 Browning machine gun, and had provision for two 60lb rockets under the wings. Boulton Paul built a 130 of them and Blackburn was subcontracted to built another 30. The aircraft was also redesigned as the Sea Balliol for use as a Royal Navy deck landing trainer with a  strengthened undercarriage, folding wings and an arrester hook. A total of 30 were ordered, the first ones were delivered on 7th December 1954.

Part of the Balliol assembly line.

From a Boulton Paul advert of 1955.

The company carried out a lot of modification work on the English Electric Canberra's. They were the main Canberra contractor and continued this work for 14 years. The company became a world leader in the production of aircraft power control units and fly by wire systems. The electronics department designed and built a computer called 'The Brain' in the early 1950's.  A lot of work was carried out on Vampires for de Havilland, and Boulton Paul became a subcontractor for Beagle Aircraft. The company built the wings and undertook structural testing of the fuselage.

The last two Boulton Paul aircraft to fly were the P.111 and P.120 delta wing jets. The P.111 used a Rolls Royce Nene jet engine, and had a top speed of 650m.p.h. at 35,000ft. It first flew on 6th October 1950 and was developed into the P.120. 

In 1961 Boulton Paul joined the Dowty Group to become solely an aircraft component manufacturer. Today it is a part of the even larger TI group.


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