The Sound of the Bombe

Thanks to the truly magnificent efforts of John Harper and the Bombe Rebuild Project team, 60 years after the British bombes were broken up, the sound of the Turing bombe can once again be heard at Bletchley Park.

Below, you will find a link to an audio recording of the rebuilt bombe. The recording was made at Bletchley Park in September 2006 and is placed here with the kind permission of John and the rebuild team.

The recording was originally made in high quality 16 bit 44.1 kHz .wav format but this resulted in a file of almost 33 MB. The recording presented here was derived from the original recording and is a 128 kbps .mp3 file of almost 3 MB. Although the size of the file has thus been greatly reduced there is no appreciable reduction in the quality of the recording.

The recording, which starts when the bombe is already running, runs for 3 minutes and 15 seconds. The mechanism which turns over the middle rows of drums and which sounds rather like a shuttle in a mechanical loom, can be heard over the background hum of the fast drums. 2 minutes and 25 seconds into the recording the bombe senses a stop and halts. The operator cuts the power about three quarters of a minute later.

Audrey Wind, a former WREN, who operated a bombe named Split in the Yugoslavia bay at Eastcote, tells me that the Bombe Rebuild at Bletchley Park produces less noise than the bombes at Eastcote, partly, of course, due to the larger number of machines running simultaneously in wartime conditions and partly due to the concrete floor at Eastcote which acted as an acoustic reflector.

The sound of the first Turing bombe, named Victory, was first heard operationally on the 14th March 1940 in Hut 1 at Bletchley Park. To listen to the sound of the Turing Bombe Rebuild, click on the link below: