Tunnelling
The military, Royal Canadian Mounted Police and camp guards monitored the German prisoners as they began to secretly dig several tunnels, at least one of which would eventually lead outside the camp boundaries. The tunnellers also created a crude railway that could haul the soil out of the tunnel, allowing the work to proceed more quickly and efficiently. At one point the excavated dirt from one of the tunnels collapsed part of the ceiling in a camp building where it was being hidden, however the camp guards, aware of the ruse, did not stop the project.
As the date of the escape attempt drew closer, the Royal Canadian Mounted Police and military guards moved in and seized the prisoners as they sought to implement their plan and collapsed the tunnel. In desperation, one of the Kriegsmarine officers, Wolfgang Heyda, managed to escape over the camp walls using a crude zip-wire on electrical cables. Heyda eluded search parties and the massive police response and somehow made his way on Canadian National Railways passenger trains from southern Ontario to Pointe de Maisonnette. Heyda arrived at the location at the appointed time only to be arrested by mounted police and naval personnel, who were waiting to co-ordinate a surface task force that would attempt to attack and or seize the U-boat.
Read more about this topic: Operation Kiebitz