Ernst Wiesner, who was a circuit overseer in Germany at that time, described some of the security measures: “Two brothers went ahead and whenever they met anyone, they at once signaled with their flashlights.
برادران حامل بار که حدود ۱۰۰ متر [۳۲۸ فوت] پشت سر آن‌ها بودند با دیدن آن علامت در پشت بوته‌ها مخفی می‌شدند .‏