There were, however, some very large and elaborately fitted "Q" boats. These had specially constructed torpedo tubes low down in the hull, masked 4.7-inch guns in more than one position, special chutes for depth charges, coal bunkers arranged round the vital machinery to protect it from shell-fire, and, moreover, were filled with wood to make them almost unsinkable even if torpedoed.
Each such vessel was provided with a "panic party," whose duty was to rush to the life-boats when the ship was attacked by a submarine. This gave the final touch to the disguise, and often induced the submarine to save further torpedoes by coming to the surface and continuing the assault with gun-fire.
Fig. 16.—Method of masking a 3, 6, 12 or 13 pounder gun. A. Stern of ship. B. Shield constructed to resemble a life-boat which can be raised or lowered over gun C.
The story of the sinking of the last German submarine in the war by the "Q 19" will give some idea of how these vessels worked. It occurred in the Straits of Gibraltar, about twenty-four hours before the signing of the Armistice. The Q 19 was waiting in the Straits expecting to intercept three big U-boats on their way back to Heligoland. About midnight the first of these craft came along, and sighting the innocent-looking "Q" boat prepared to attack her with gun-fire. For nearly an hour the mystery ship "played" the submarine by pretending to make frantic efforts to escape, but all the time allowing the under-water craft to draw closer and closer.
The "Q" boat was under a heavy fire from the submarine, one shell wounding eleven out of the crew of sixty, another carrying away the mast and a portion of the funnel, but no sign of a gun was yet displayed on board the surface ship. This withholding of fire until the last moment, when the range has become short and the effect certain, is one of the great nerve tests imposed on the crews of all mystery ships. It is an essential of success, for a few wild shots at long range would disclose the fact that the vessel was heavily armed, and the attacking submarine would either sheer off or else submerge and use her torpedoes.
When the chase had been on for about fifty minutes, and the submarine was only 200 yards astern, the "panic party" in the "Q" boat rushed for the life-boats. The shells were now doing serious damage to both hull and upper works, and the submarine was creeping close to give the coup de grâce.
At this, the psychological moment, the order to open fire was given. The collapsible deck-house, shielding the 4.7 gun, fell away on its hinges. Eleven shots were fired in quick succession, all of which struck the submarine. One blew the commander off the conning-tower and another rent a gaping hole in the vessel's hull. In less than fifteen minutes the fight was over and the last U-boat to be sunk in the Great War of civilisation had disappeared beneath the waters of the Straits of Gibraltar.[4]