The Collaborative International Dictionary
Torpedo tube \Torpedo tube\ (Nav.) A tube fixed below or near the water line through which a torpedo is fired, usually by a small charge of gunpowder. On torpedo vessels the tubes are on deck and usually in broadside, on larger vessels usually submerged in broadside and fitted with a movable shield which is pushed out from the vessel's side to protect the torpedo until clear, but formerly sometimes in the bow. In submarine torpedo boats they are in the bow.
Wiktionary
n. (context nautical English) The tube, through the hull of a submarine, though which torpedoes are launched
WordNet
n. a tube near the waterline of a vessel through which a torpedo is fired
Wikipedia
A torpedo tube is a cylinder shaped device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed aboard surface vessels. Deck-mounted torpedo launchers are usually designed for a specific type of torpedo, while submarine torpedo tubes are general-purpose launchers, and are often also capable of deploying mines and cruise missiles. Most modern launchers are standardised on a diameter for light torpedoes (deck mounted aboard ship) or a diameter for heavy torpedoes (underwater tubes), although other sizes of torpedo tube have been used: see Torpedo classes and diameters.
Usage examples of "torpedo tube".
It was Murphy, the man who had accompanied me when we'd closed the torpedo tube door.
The ASROC and torpedo tube directors are to be manned at all times.
Of course, it was generally designed to be removed in some place that was slightly more spacious than the inside of a photon-torpedo tube.
The impact had smashed ten square meters of bow plating, annihilated the sonar dome, knocked a torpedo tube askew, and nearly flooded the torpedo room.
To the side, sailors aboard PT-601 uncovered a torpedo tube and trained it on the ship.
That meant that the gunboat was less than a dozen yards from the sixteen-inch midships torpedo tube, armed and flooded.
He was passing the shattered canteen when he saw a tall, shadowy figure standing in the gap between the snow covered lip of the outer torpedo tube and the end stanchion of the guard rails, trying to open a jammed extinguisher valve by striking it against the stanchion.
If the captain had been in sonar as he raced up the ladder outside the wardroom, he would have heard the telltale sound of the missile leaving its torpedo tube.