Colossus - the first true electronic computer

Found - in a paperback novel from the 1980s this press cutting. It is from a glossy magazine (possibly Electronics World) and is a letter from one G.O. Hayward. This is the war hero Gil Hayward who had worked at Bletchley Park and was given a medal by the Prime Minister in 2010 and died a year later aged 93. He had worked on the "Tunny" decryption machines at  at the Post Office Research Station at Dollis Hill, North London, and later at Bletchley Park. These were used to break the code of even higher grade secret messages than the Enigma machine. Towards the end of the war, up to 15 of the Tunny machines were in use at Bletchley Park, providing Allied leaders with around 300 messages from the German High Command a week. Among other things, Tunny provided key intelligence for D-Day. The Colossus computer was developed from it...

His Telegraph obituary notes that he was interested in electronics from an early age - "On his own motorcycle.. he built an indicator which integrated a clock with his speedometer and indicated his average speed.

The rebuilt Colossus seen from the rear

He also built a new type of weaving machine and a device for surveyors which instantly measured the distance between walls without a tape measure." In the 1980s Hayward
used his code breaking technology to patent the world’s first electronic security seal. With his son Mark he set up Encrypta Electronics to manufacture the device which was sold all over the world.


In retirement he helped researchers rebuild Colossus and Tunny, which had been broken up after the war, by making 600 pattern plugs and 1,000 valve holders. Luckily he had squirrelled away plans for the machines – against the orders of Churchill, who had feared that the technology might find its way into Russian hands. He writes from his company Encrypta Electronics in 1987:

In "LETTER" (EW Septermber 2, 1987) Cyril Smith refers to the first electronic computer, but much of what he says needs to be corrected.

I was one of the team of Post Office engineers engaged, on the design and construction of Colossus and its associated equipment under the direction of Tommy Flowers at Dollis Hill in early 1944.

Several of these machines were built at DH, but were assembled and commissioned at Bletchley Park. They were not used to break the Enigma cypher, as stated by Mr. Smith, but were engaged by exclusively on breaking the "Geheimschreiber" German naval cypher. This was a real time encyphering of five unit teleprinter code, in which the five mark or space elements were altered in an apparently random manner.

Colossus was able to examine characters on teleprinter message tapes at the very respectable rate of 5000 chapters per second, and to make a number of statistical analyses required by the cryptanalysts. This enabled electromechanical simulations of the German machines to be set correctly to produce deciphered text. 

Although it was not a stored programme device, Colossus was indeed the first true electronic computer counting, storing and comparing a massive amount of data at high-speed.

Britain beat the Americans to this one by some years. G. O. Hayward, Technical Director, Encrypta Electronics.