Two of her four funnels were removed, and the forward two were cut at an angle to resemble those of a German destroyer. The bow was packed with 4.5 tons of high explosives, which were set in concrete. It was decided that the explosive charge would be timed to detonate after the raiders had left the harbour. To prevent the Germans towing her away, the crew would open the ship's seacocks before abandoning the ship. Should she become disabled or sunk before getting to the dock, four motor launches had been detailed to take off the crew and put the commandos ashore. The charge would be reset to explode after the last boat had left.