A Game of Birds and Wolves: The Ingenious Young Women Whose Secret Board Game Helped Win World War II

by Simon Parkin

SC.112, each headed toward three wolfpacks totalling thirty-eight U-boats. Concurrently, one of Roberts’ colleagues, Captain Neville Lake, added three fictional support groups to the wall, shadowing the real convoys. Lake hoped to estimate what effect such reinforcements might have on the looming battle. He populated his support groups with markers to represent real warships that were currently under construction, or nearing operational capability, and used his ghost escorts to support the real convoys, fending off wolfpacks while the battle played out in almost real time on the map. As well as adhering to the current weather conditions, Lake took into account fuel consumption and the depletion of depth charges to ensure that his exercise, overlaid on the real battle, was as accurate as possible. Although many of the Wrens forced to play out Lake’s game while simultaneously trying to plot the real battle were frustrated (they described it as ‘Lake’s folly’14), the final results were clear and, for Horton, conclusive. At the end of the battle for HX.229 and SC.112, which German radio reported as ‘Die grösste Geleitzugschlacht aller Zeiten’–‘the greatest convoy battle of all time’15–twenty-one Allied ships lay on the ocean floor. Lake estimated that, had his fictional support groups been real, at least eight ships would have been saved.