Mark 50 torpedo

Mark 50 Advanced Lightweight Torpedo
Mark 50 torpedo being fired
Type	Torpedo
Place of origin	United States
Service history
Used by	United States Navy
Production history
Designer	Honeywell
Designed	1974
Manufacturer	Alliant Techsystems
Produced	1991-
Number built	1000
Specifications
Weight	approx. 800 lb (360 kg)
Length	9.5 ft (2.9 m)
Width	12.75 in (0.324 m)
Warhead	HE shaped charge
Warhead weight	100 lb (45 kg)
Engine	Stored chemical energy propulsion system pump-jet
Operational range	15 km (9.3 mi)
Maximum depth	> 1,900 ft (580 m)
Speed	> 40 kn (46 mph)
Guidance system	Active or passive/active Acoustic homing
Launch platform	Mark 32 surface vessel torpedo tubes, ASW aircraft (P-3 Orion), RUM-139 VL-ASROC

The Mark 50 torpedo is a U.S. Navy advanced lightweight torpedo for use against fast, deep-diving submarines. The Mk 50 can be launched from all anti-submarine aircraft and from torpedo tubes aboard surface combatant ships. The Mk 50 was intended to replace the Mk 46 as the fleet's lightweight torpedo. Instead the Mark 46 will be replaced with the Mark 54 LHT.

The torpedo's stored chemical energy propulsion system uses a small tank of sulfur hexafluoride gas, which is sprayed over a block of solid lithium, which generates enormous quantities of heat, which generates steam. The steam propels the torpedo in a closed Rankine cycle, supplying power to a pump-jet. This propulsion system offers the very important deep-water performance advantage in that the combustion products—sulfur and lithium fluoride—occupy less volume than the reactants, so the torpedo does not have to force these out against increasing water pressure as it approaches a deep-diving submarine.