was developed for use on messages from those networks that disallowed the plugboard (Stecker) connection of adjacent letters, was the Consecutive Stecker Knock Out. This was fitted to 40 bombes and produced a useful reduction in false stops. Initially the bombes were operated by ex-BTM servicemen, but in March 1941 the first detachment of members of the Women's Royal Naval Service (known as Wrens) arrived at Bletchley Park to become bombe operators. By 1945 there were some 2,000 Wrens operating the bombes. Because of the risk of bombing, relatively few of the bombes were located at Bletchley Park. The largest two outstations were at Eastcote (some 110 bombes and 800 Wrens) and Stanmore (some 50 bombes and 500 Wrens). There were also bombe outstations at Wavendon, Adstock and Gayhurst. Communication with Bletchley Park was by teleprinter links. When the German Navy started using 4-rotor Enigmas, about sixty 4-rotor bombes were produced at Letchworth, some with the assistance of the General Post Office. The NCR-manufactured US Navy 4-rotor bombes were, however, very fast and the most successful. They were extensively used by Bletchley Park over teleprinter links (using the Combined Cipher Machine) to OP-20-G for both 3-rotor and 4-rotor jobs. Luftwaffe Enigma Although the German army, SS, police, and railway all used Enigma with similar procedures, it was the Luftwaffe (Air Force) that was the first and most fruitful source of Ultra intelligence during the war. The messages were decrypted in Hut 6 at Bletchley Park and turned into intelligence reports in Hut 3. The network code-named 'Red' at Bletchley Park was broken regularly and quickly from 22 May 1940 until the end of hostilities. Indeed, the Air Force section of Hut 3 expected the new day's Enigma settings to have been established in Hut 6 by breakfast time. The relative ease of solving this network's settings was a product of plentiful cribs and frequent German operating mistakes. Luftwaffe chief Hermann Göring was known to use it for trivial communications, including informing squadron commanders to make sure the pilots he was going to decorate had been properly deloused. Such messages became known as "Göring funnies" to the staff at Bletchley Park. Abwehr Enigma Dilly Knox's last great cryptanalytical success, before his untimely death in February 1943, was the solving of the Abwehr Enigma in 1941. Intercepts of traffic which had an 8-letter indicator sequence before the usual 5-letter groups led to