Work Begins

take on roles as welders, carpenters, torpedo loaders, and even plotted the progress of sea battles on maps in operations rooms. Working with the Wrens also provided these women the freedom they never had due to societal expectations. They no longer had a curfew, could run errands and work without a male escorting them, and were no longer being forced to stay at home to settle down and marry. This freedom turned into enthusiasm for their work, so when VLM was asked to send a group of wrens to the Derby House there were many volunteers eager to do their part. Ten women were selected to report to Roberts: Jean Laidlaw, for her skill with numbers and recordkeeping; Laura Janet Howes, for her skill with math; Elizabeth Drake, for her work at Derby House as an expert plotter; Nancy Wales, for her experience as a sportswoman in tennis, badminton, and hockey, who would know team tactics better than anyone else; and six ratings (junior wrens) who would handle the administrative side of the games as secretaries, coders, and messengers.

Under Gilbert Roberts, the Western Approaches Tactical Unit (WATU) was created with the goals of understanding why the German U-boats had been so successful, facilitating the development of countertactics, and creating the basis for a school where these tactics could be taught to those who would fight at sea. Janet Okell, a rating who along with four others had been assigned to help Roberts set up his tactical school, was welcomed along with the wrens sent by VLM to the Derby House. They got to work immediately by helping Roberts set up games that mimicked previous battles and trying to understand why certain decisions were made by commanders of both sides.

The wargame that Roberts created in the main room of the top floor mimicked the actual visibility at sea. On the floor of brown linoleum were white chalk lines spaced 10 inches apart to represent one nautical mile each, as well as see-through counter markers to represent U-boats, and wooden models of Allied convoy ships and their escorts. While the Allied team’s movements were plainly visible in white chalk, U-boat movements were made undetectable with the use of green chalk. Around the edges of the room were large, white canvas sheets with small peepholes cut into them at eye level. The peepholes were angled in such a way that when you peeked through you would only be able to see up to the equivalent of five miles, just like you would inside an actual warship. Along with Okell, Roberts would stage both recent sea battles as well as imaginary, yet realistic, scenarios while some few wrens would kneel on the playing field and carefully and accurately move pieces based on the players’ decisions. One team would represent the escort ships, while the other—usually commanded by Roberts or his now right-hand woman, Jean Laidlaw—would represent the U-boats. The convoy ships would move automatically to their destination as the escorts fought to protect them from the German force, and both sides would have to take turns making decisions within two-minute time limits to mimic the urgency of battle. Once the game finished, the players

All Wrens went through a 10-day training course where they were taught to decipher naval signals, memorizing ciphers that would detail the location of naval ships and any spotted U-boats. If the German wolfpack force at sea had only one weakness, it would be that they commanders needed to communicate regularly to coordinate their attacks. These signals would be picked up and give the Allies an idea of where the U-boats were located.