There are a great many books on the work of the Allied code breakers in the Second World War, so a new book really needs to stand out in some way to be worthwhile. In this case that has been achieved by focusing on one particular code - the German Navy’s version of the Enigma code, while proved to be rather harder to crack than the Army or Luftwaffe versions, partly because the Navy made fewer mistakes that allowed the code breakers in and partly for technical reasons.
Having a single clear focus allows the author to give more space to topics that often get passed over fairly quickly, in particular the various naval efforts to seize key parts of the Enigma system - the machine itself, the rotors that made it work or the paperwork associated with it (including the very important keys that controlled how it was set up for each message). Each of the major naval seizures gets a chapter of its own, making it clear just how much effort and planning went into apparently simple operations such as the seizure of a weather reporting boat. There is also more space dedicated to explaining how the Enigma was broken (although I must admit I didn’t quite grasp all of it on the first read, that’s really because the topic is intrinsically complex). This section also explains why the Navy enigma was harder to break.
There is also an examination of the various German enquires into the security of the Enigma and why they continued to believe that it was secure. There is also an interesting appendix on how an Enigma message was encoded by the German operators, which turns out to be a rather complex process.
The author doesn’t overplay the importance of the code breaking efforts, and portrays it as one aspect of the intelligence war and one aspect of the overall battle of the Atlantic, with other elements such as improved weapons, more ships, more aircraft and escort carriers also playing a role.
This book makes you realise how many people were involved in breaking the Enigma - some are familiar, but plenty of fairly unknown people made major contributions. It also makes it clear how code breaking changed during the Second World War, from something that required linguists making individual breakthroughs into something that required mathematicians, engineers and brute force mechanical repetition to get into the Enigma code.
1 - A Staff School Memory
2 - The Wreck of the Magdeburg
3 - The Man, the Machine, the Choice
4 - The Codebreaker and the Spy
5 - Racing German Changes
6 - Failure at Broadway Buildings
8 - Phantoms
9 - The Rotors
10 - Royal Flags Wave Kings Above
11 - Kisses
12 - A Trawler Surprised
13 - The Staff School Memory
14 - 'All This Rubbish?'
15 - The Great Man Himself
16 - When Sailors Look for Leaks
17 - Blackout '42
18 - The George Cross
19 - Enter the Americans
20 - SC 127
21 - The Cavity Magnetron Clue
22 - The U-Tankers
23 - The Reckoning
Author: David Kahn
Year: 2017 edition of 2012 third edition