21. Codebreakers contributed to the Allied effectiveness throughout much of the battle

The story of the Polish and British cracking of the German codes processed through Enigma machines is far too extensive for inclusion here. What is pertinent is the German Navy’s use of an Enigma-based code called TRITON beginning in 1942. USS TRITON used the four-wheel version of the Enigma system. The change to TRITON temporarily left the British codebreakers in the dark. In late October, 1942, a German U-boat was attacked by HMS Petard in the Mediterranean. In company with other British destroyers, Petard forced the U-boat to the surface, and its crew abandoned the ship near Port Said. A team from Petard boarded the sinking submarine.
A complete four-wheel Enigma machine and some TRITON code books and documents were left behind by the Germans. The British were able to capture the code books and return them to Petard. The submarine sank quickly, taking the Enigma and two British seamen who attempted to extract it to the bottom. With the information recovered by Petard, the British were able to crack the remainder of the TRITON code, and were made aware of the operations controlled by Doenitz. It allowed the British and Americans to be ready and waiting when the U-boats made an appearance.



