with two or three of these mounts with between five and twelve tubes in total. The Japanese went one better, covering their tube mounts with splinter protection and adding reloading gear (both unlike any other navy in the world), making them true turrets and increasing the broadside without adding tubes and top hamper (as the quadruple and quintuple mounts did). Considering that their Type 93s were very effective weapons, the IJN equipped their cruisers with torpedoes. The Germans also equipped their capital ships with torpedoes. Smaller vessels such as PT boats carried their torpedoes in fixed deck-mounted tubes using compressed air. These were either aligned to fire forward or at an offset angle from the centerline. Later, lightweight mounts for homing torpedoes were developed for anti-submarine use consisting of triple launch tubes used on the decks of ships. These were the 1960 Mk 32 torpedo launcher in the US and part of STWS (Shipborne Torpedo Weapon System) in the UK. Later a below-decks launcher was used by the RN. This basic launch system continues to be used today with improved torpedoes and fire control systems. Submarines Modern submarines use either swim-out systems or a pulse of water to discharge the torpedo from the tube, both of which have the advantage of being significantly quieter than previous systems, helping avoid detection of the firing from passive sonar. Earlier designs used a pulse of compressed air or a hydraulic ram. Early submarines, when they carried torpedoes, were fitted with a variety of torpedo launching mechanisms in a range of locations; on the deck, in the bow or stern, amidships, with some launch mechanisms permitting the torpedo to be aimed over a wide arc. By World War II, designs favored multiple bow tubes and fewer or no stern tubes. Modern submarine bows are usually occupied by a large sonar array, necessitating midships tubes angled outward, while stern tubes have largely disappeared. The first French and Russian submarines carried their torpedoes externally in Drzewiecki drop collars. These were cheaper than tubes but less reliable. Both the United Kingdom and the United States experimented with external tubes in World War II. External tubes offered a cheap and easy way of increasing torpedo capacity without radical redesign, something neither had time or resources to do before nor early in, the war. British T-class submarines carried up to 13 torpedo tubes, up to 5 of them external.