Bletchley Park’s Secret Source – Churchill’s Wrens and the Y Service in World War II. By Peter Hore. Greenhill Books, Barnsley, UK. ISBN 978-1-78438-581-1.
Reviewed by David Hobbs
BUY NOW FROM BOOKTOPIA
The work of the British Government’s Code and Cypher School at Bletchley Park has been widely described but the source of the enemy signals which provided the raw material for its decryption work has received much less attention. From the perspective of the war at sea, the Royal Navy’s ‘Y’ Service was that source but today its work is largely unknown.
The term ‘Y’ was derived from wireless intercept and its coastal listening stations were operated to a large extent by women of the newly-formed Special Duties Branch of the WRNS, most of them in their late teens or early twenties. Many responded to advertisements placed by the Admiralty and were recruited direct from civilian life because of their ability to speak German.
As the war went on Italian and Japanese linguists were also recruited. They were taught to search wireless frequency bands for enemy transmissions in both plain language and morse code and, as their skills developed, they were able to ‘fingerprint’ individual enemy operators from their ‘fist’, the individual style with which they keyed their morse transmitions. Their training also had to give them the ability to understand German naval terms and techniques in order to translate what they heard; the ability to speak colloquial German was just a starting point.
Voice intercepts with their greater immediacy tended to be used at a tactical level while encoded morse interceptions were sent to Bletchley Park for decryption and analysis. Most special duties women were rated as Petty Officer or Chief Petty Officer Wrens on completion of their training to give them status when they worked alongside the Admiralty’s civilian shore wireless service. A few were granted commissions to take charge of small groups stationed at isolated wireless intercept stations. Whatever their skills searching the radio waves for enemy transmissions, one of the first things these young women had to grasp was the need to persuade senior officers up to and including Commanders-in-Chief that their input had value.
Prejudice that a woman, especially a young one, could not comprehend naval operations was widespread at the time and it required some tact and skill to get across the fact that they had acquired a sound working knowledge of enemy intentions and tactics. Among many examples quoted, one was the ability to give early warning that specific German coastal forces were at sea to attack UK east coast convoys in the North Sea.
Royal Navy motor gunboats came to rely on the tactical picture the women passed to their operations room after listening to enemy sailors transmitting in plain language as they set out. They even came to know enemy personalities and, to an extent, what could be expected from them.
Peter Hore is to be congratulated on producing a delightful book that illustrates a number of factors that broaden readers’ understanding of how the war at sea was directed. In addition to describing the evolution of wireless interception as an intelligence tool he describes how women came to be accepted as part of the naval service after overcoming the early prejudice they encountered. He met a number of ladies who had served in the ‘Y’ Service and was able to describe their achievements for the first time.
Most had not spoken about their wartime service until they met Peter and were delighted, at last, to be able to tell their fascinating story to someone who clearly valued and understood what they had achieved.
A number of individual stories add human interest to the text, among them the Third Officer who had to cycle several miles to a bank to collect pay for the Wrens who worked under her command at a remote coastal wireless intercept station. Because their work was secret the Admiralty put about the story that the women in such locations were factory girls on holiday and to maintain this fiction the Third Officer had to stop in a field before reaching the town where the bank was situated and change from uniform into plan clothes behind a hedge. She then had to reverse the process on the return bicycle ride whilst keeping the pay safe and giving the requisite pass words to sentries guarding pathways through restricted coastal areas when they challenged her.
The book describes how ‘Y’ Service WRNS personnel expanded from the small intercept stations established on the outbreak of war with their makeshift accommodation arrangements, through gradual expansion in the UK and the Mediterranean to the Far East Combined Bureau based at the RN Wireless Station at Kranji in Singapore where their work was linked to other Commonwealth and Allied intelligence agencies. It is well illustrated with carefully selected photographs and maps, many of which have never been published before.
ANI members who have read Andrew Boyd’s outstanding book British Naval Intelligence in the Twentieth Century will find this book to be an interesting companion volume that will broaden understanding of signals intelligence, how it was gathered and how it was used. It is an informative and most enjoyable read and I thoroughly recommend it.
