In 1933, a gigantic (for the time) and very powerful ‘flying battleship’ for the RAF named the Blackburn Perth was built and launched. The cost was about £50,000 (equivalent to £4.5 million today). The Perth flying boat was created mainly for over-sea observation, reconnaissance and coastal patrol, but it had a very powerful gun in its bow.
The Perth was designed and built by the Blackburn Aeroplane & Motor Company Limited at Brough, West Yorkshire, (just west of Hull). The Blackburn R.B.3A Perth biplane flying boat undertook its first flight on 10 October 1933. The weather conditions at Brough, fog and rain had caused a launch postponement from the previous day. The weather improved the next day, but there was still a slight fog and a curtain of mist to be seen as the Perth was towed from its hangar to the slipway by a traction engine.
According to newspaper reports of the event, the aircrafts three 825 hp engines started with a mighty roar. The wind generated by the propellers blew away the hats of the spectators. Captain Alfred ‘Dasher’ Montague Blake, the Blackburn chief test pilot then took control, and it glided on its own launching trolley down the slipway and took to the water. The powerful and loud gun in the bow was then tested against a submarine dummy target out in the river.
The Perth taxied out to midstream on the River Humber, and then came the mightiest roar of all as the Perth took off into the wind. At first ploughing through the choppy water at great speed and then rising gracefully without the slightest hesitation into the air. There were cries of “she’s up” from the crowds on the riverbank and for upwards of an hour tests were carried out at various altitudes over land and water. The Perth was accompanied for the greater part of the trials by a nippy Blackburn Bluebird, single-engine biplane light trainer which was seen to be darting over and under the Perth. The Bluebird also affording a striking contrast in the size of the aeroplane.
Rising gracefully without the slightest hesitation, the Perth climbed, making tests at various altitudes. It flew over the Hessle and North Ferriby areas and then came low over the River Humber, where there followed a succession of thrills for the watching crowd. The Perth dropped its bombs into the water sending up showers of spray and smoke.
The landing of the gigantic seaplane was described as so light to make the weight of the aircraft at 15 tons seem incredible. The Perth then took up a position near to a Vickers Supermarine Southampton flying boat which was to accompany it to the Royal Air Force ‘experimental’ station at Felixstowe. After a report was sent ashore that all trials had been successfully carried through, the Perth and the Southampton Supermarine took off. The two aircraft circled over the Blackburn works before heading down the Humber to begin their 180-mile flight to Felixstowe.
The Blackburn Perth joined RAF 209 Squadron on 20 January 1934 to succeed the Blackburn Iris which they received in 1930. The Perth was designed to Air Ministry Specification 20/32,
Four Blackburn Perth’s were built K3580, K3581, K3582 and K4011; it was the largest aircraft of its type. It entered RAF service the following year, 1934. The Blackburn R.B.3A Perth Flying Boat was armed with 3 Lewis Machine Guns and a single Coventry Ordnance Works (COW) 37 mm (1½ lb) canon on a rotary mounting in the bow (WW1 designed gun). It was powered by three 825hp Rolls Royce “Buzzard IIMS” water cooled engines, of much greater power than the Iris’s Condors. The aircraft had a range of 1,500 sea miles and a top speed of 132 mph (115 knots) with a cruising speed of 109mph (95 knots).
The COW gun was capable of firing 100 shells a minute in bursts of six with a range of one mile (1.6Km). The maximum gross weight of the aircraft was 38,000lb (19 tons). The crew compliment was five, two pilots sitting side by side with dual controls, immediately aft the navigator’s compartment, a wardroom with sleeping berths, a canteen, more sleeping berths and living quarters, the wireless cabin, the engineer’s station and in the cockpit in the tail with machine gun mounting, an air gunner. It could carry up to 2,000 pounds of bomb ordnance and the dimensions were: span 97ft, length 70ft, height 25ft 5½ inches. Equipment included a 4 hp auxiliary petrol electrical generator to work the bilge pump, air compressor and wireless apparatus.
The Perth’s of RAF 209 Squadron excersided mainly over the Irish Sea, using an advanced alighting area at Stranraer. The Perth’s were withdrawn from service between October 1934 and July 1935 owing to problems with their tail assembly.
One of the four Perth aircraft, K3851 took part in a formation fly-past of flying boats at the Hendon RAF Display in 1934. The other flying boats at Hendon that day were a Supermarine Scapa, Short Singapore, Short Sarafand, Short S18 (Knuckleduster) and a Saunders-Roe Saro Cloud.
On 5 January 1934 a Blackburn Perth from the Blackburn works at Brough flew via Great Yarmouth, Felixstowe and North Foreland (Broadstairs) to join RAF 209 Squadron at RAF Mount Batten, Plymouth, arriving at 3.30pm. The Perth’s remained in service until 1937; one aircraft was retained by the Marine Experimental Establishment at Felixstowe until 1938. The Perth’s were operated by RAF 204 and 209 Squadrons.
British Pathé link: Nice shots of a British flying boat taking off (the Perth).
British Pathé link: “Brough. New ‘Battleship of the Air’! Shots of the Perth, the RAF’s new huge flying boat – with its impressive big gun.
A short video of the Perth’s launch can also be seen on YouTube:
https://youtu.be/Rz1MSHglGP4?si=_lLuUu_Foeso46Fu
Notes:
The recall from firing the Cow gun temporarily caused a slight reduction in the aircrafts speed. It was not expected to cause any damage to the aircraft as it was reported as being well adapted for receiving the shocks of the cannon firing. The problem of adequate aircraft armament had troubled aircraft designers for many years, and it was hoped that this type of armament would be the forerunner of even larger and more elaborate types.
The Blackburn Perth’s COW gun was seen as being effective against small vessels and submarines. The COW 37 mm was later used for the development of the 40 mm Vickers S gun which was used by Hawker Hurricanes as an anti-tank weapon. COW guns were also used as the armament for fifty-five WW2 Mk III version of the Armadillo armoured fighting vehicle. ( an improvised vehicle, a lorry with the canon gun mounted on the flat bed)
The Blackburn Perth was described in Janes All the World’s Aircraft publication as an equal wing unstaggered biplane.
Amongst the Blackburn machines which had their initial tests with Captain Blake as Chief Test Pilot, were the single seater fighter Lincock, a carrier-borne torpedo bomber, the Shark and the flying boats Iris, Perth and Sydney.
Present at the Blackburn Perth launch was Air Marshall Sir Hugh C. T. Dowding, who was born in Moffat, Scotland. Dowding went on to be Air Officer Commanding RAF Fighter Command during the Battle of Britain. Other dignitaries at the launch included representatives from Estonia, Japan, Spain, Sweden and the USA.
Blackburn Perth K3580 had a float torn away by heavy seas on 14 September 1935 whilst attempting to take off from Stornoway. It was driven towards shore where there was danger of it breaking up. Rocket signals were answered by a drifter fishing boat and a lifeboat which took off the crew. The aircraft was taken in tow and safely beached. The Blackburn Perth was on its way to Oban having just been refuelled.
The Marine Aircraft Experimental Establishment at Felixstowe operated from 1 April 1924 until the end of the Second World War. It was also used as a base by the Schneider Trophy team, (the High-Speed Flight). RAF Felixstowe closed 21 June 1962.
Notable members of the RAF were based at Felixstowe, included, among others, Frank Whittle, who is credited with the invention of the turbojet engine, and T. E. Lawrence, commonly known as Lawrence of Arabia.
The chief designer of the Supermarine Southampton was R. J. Mitchell who two years later at a test flight on 5 March 1936 presented to the world his genius in the form of what was to become the legendary single engine fighter aircraft of World War Two, the Supermarine Spitfire.
John Douglas Rennie the chief designer at the Blackburn Aeroplane and Motor Company Limited was educated at Glasgow Academy. Rennie’s most unique design, covered by patent 433925, was the experimental Blackburn B-20 flying boat with a retractable pontoon float that retracted upwards towards the fuselage. The prototype was built at Blackburn’s factory at Barge Park, Dumbarton (beside Dumbarton Rock) on the River Clyde, and flew for the first time on 26 March 1940.
Research by Ken Bruce
11 October 1933
