Changes

The use of thermionic valves was felt by many of those concerned to be a weak point in the design of this kind of machine. Flowers made the revolutionary claim that a valve left on all the time, and not switched on and off as required, would have a very long life. The Staff Engineer in charge at DH had faith in Flowers, and backed him. A small design team was formed in great secrecy to work on the first and subsequent machines, the last of which were the 10 Colossus machines, having 2,500 valves apiece, which were so successfully employed at Bletchley Park.

The use of thermionic valves was felt by many of those concerned to be a weak point in the design of this kind of machine. Flowers made the revolutionary claim that a valve left on all the time, and not switched on and off as required, would have a very long life. The Staff Engineer in charge at DH had faith in Flowers, and backed him. A small design team was formed in great secrecy to work on the first and subsequent machines, the last of which were the 10 Colossus machines, having 2,500 valves apiece, which were so successfully employed at Bletchley Park.

Colossus was designed to deal with the complex intelligence known as Fish, with messages sometimes 10,000 characters in length sent between Hitler's High Command and commanders in the field, and containing vital information on troop dispositions, ration strengths, and even details of leave arrangements for generals. The Morse-transmitted Enigma code, on the other hand, although very complex, used messages of a purely tactical nature, which were never more than 250 characters long. This work had no association with Colossus.

Colossus was designed to deal with the complex intelligence known as Fish, with messages sometimes 10,000 characters in length sent between Hitler's High Command and commanders in the field, and containing vital information on troop dispositions, ration strengths, and even details of leave arrangements for generals. The Morse-transmitted '''Enigma''' code, on the other hand, although very complex, was used for messages of a purely tactical nature, which were never more than 250 characters long. This work had no association with Colossus.

Colossus was engaged on the statistical analysis of the enemy teleprinter intercepts. A separate machine to use this data to decipher each message was needed, and Flowers arranged for a former member of the DH staff, then in the Army in North Africa engaged on another DH-backed project, to be posted home to join his team. Busy though he was, Flowers made a daily visit to his small band working in a small laboratory to observe progress.

Colossus was engaged on the statistical analysis of the enemy teleprinter intercepts. A separate machine to use this data to decipher each message was needed, and Flowers arranged for a former member of the DH staff, then in the Army in North Africa engaged on another DH-backed project, to be posted home to join his team. Busy though he was, Flowers made a daily visit to his small band working in a small laboratory to observe progress.