Abstract: To prevent the accumulation of a gas bubble at the inner end portion of a torpedo tube, exhaust gases are not discharged from an improved torpedo until after the torpedo has moved out of the torpedo tube. The improved torpedo includes a gas powered engine which rotates a hollow drive shaft to effect rotation of torpedo drive propellers in a known manner. During operation of the engine, there is a continuous flow of gas through the engine into the hollow drive shaft. When the torpedo is in the torpedo tube, gas is conducted from the hollow drive shaft through a manifold to a storage tank. Water which may accumulate in the hollow drive shaft is centrifugally slung outwardly against the side wall of the rotating drive shaft. Tubes extend through the water to a central portion of the drive shaft so that the gas can be conducted through the water in the shaft to the manifold and storage tank.