Hi Ian,

The writer was a Huff Duff Operator in the Canadian Navy during WWII. I Cannot tell you of any specific victories or advantages brought about by the use of the Enigma Machine.

What I can tell you, from my observations, having monitored the German U-Boat frequencies, ashore and afloat, from 1943 through May of 1945, is that the Enigma machine appears to have created a false sense of security on the part of the German High Command of their Kreigsmarine.

H.F./D.F. played a significant role in beating Karl Donitz' at his own game, by making it difficult to apply the wolf pack principle to its potential. Some U-boat commanders probably suspected that we were monitoring their boat's transmissions, when an enemy surface escort would suddenly appear on the scene a short time after they had transmitted a coded message on short wave.

Had one of the best kept secrets come to be known by German HQ they could very easily have countered this particular Allied effort by establishing a predetermined changing grid of frequencies upon which to have U-Boats transmit their sighting, shadowing and weather reports, as opposed to using the same high frequencies to transmit, as were being used to transmit by shore stations. It would possibly have meant two as opposed to a single trans-receiver, a small price to pay, even with radio room at a premium.

Cheers,

J.R.C.