Bristol Blenheim, part seven. Early Blenheims.

 

In 1933 Frank Barnwell, chief designer of Bristol Aeroplane Company travelled to the United States to gather information about their latest twin-engined, low-wing monoplane airliners. He was particularly interested in the Lockheed Electra Model 12A, and he drawn a design that would match it, employing the Bristol Aquila engine which yielded 500 hp of power, the same amount that the engines of the Electra produced. This design, which was identical to the Electra was named as Type 135 by Bristol. 

One year later, Lord Rothermere, owner of Daily Mail newspaper challenged the British aviation industry to build an airplane capable of carrying six passengers and two crew members at high speeds. This was done to catch the German designs, which at the time, they were breaking many speed records, like the Heinkel He.70. Rothermere wanted not only the prestige of having the fastest passenger airplane in the world, as well as purchase it. 

He became aware of the Type 135 and, on 3rd March 1934 Barnwell issued him with a quote of the specifications and expected performance of the type, with an estimated speed of 240 mph (390 km/h) at 6.500 ft (2.000 m), with the supercharged Bristol Mercury engines instead of the original Aquila ones, as these were shelved, considered outdated. Rothermere considered the design as suitable, however some changes needed to be made to suit it to his requirements and thus, the Type 142 was designed. In late March 1934 Rothermere ordered a single Type 142, for which he payed £18.500.

On 12th April 1935 the Type 142, named as "Britain's First", made its maiden flight at Filton aerodrome, in Gloucestershire. Flight testing showed the type to be faster than the Bristol Bulldog and the Hawker Fury, which were the main fighters of the Royal Air Force (RAF) at the time. The Type 142 achieved a top speed of 307 mph (494 km/h). 

In 1935 British Air Ministry showed interest on the type and on 9th July a conference was held at Bristol's headquarters to deal with the question of converting the Type 142 into a viable medium bomber. 

After that conference, Air Ministry issued Specification B.28/35 which sought for prototypes for a bomber version, with the interim designation of Type 142M (the letter M standing for Military). One important change from the Type 142 and the 142M was the repositioning of the wing, from a low-wing to a mid-wing position, to allow internal space for a bomb load. Other modifications included a bomb-aimer position, a Browning machine-gun at the nose and a semi-retractable turret in the dorsal position.

In September 1935 an initial order for 150 aircraft was placed. The type was ordered directly off the drawing board as the Air Ministry sought a quick expansion and modernization of the RAF. The first aircraft produced, on 25th June 1936 acted as the prototype and the type received the name of Blenheim, after the battle of the War of the Spanish Succession. On 10th March 1937 the first batches were officially delivered to the RAF, being No.114 Squadron the first one to receive the type. Later, on 13th January 1938, the No. 30 Squadron became the first overseas squadron to operate the type and, in early 1939 the Blenheim arrived in India.

Sources:

1. https://en.wikipedia.org/wiki/Bristol_Blenheim

2. Hall Park Books - Warpaint 26 - Bristol Blenheim

3.Osprey Publishing - Combat Aircraft 5 - Blenheim Squadrons of World War 2