Abstract: A fault-location operating system for use with transmission networks using repeaters with loopback capabilities. A plurality of bidirectional transmission links L.sub.i, for i=1 through N, are used for transmission of data between the terminals. A test control unit is connected at the first terminal to the first end of the first transmission link L.sub.1, and controls transmission of control signals across the first transmission link L.sub.1. A plurality of repeaters R.sub.i, for i=1 through N-1, are used for interconnecting the plurality of bidirectional links. Each repeater R.sub.i is connected to the first end of one transmission link L.sub.i and to the second end of another transmission link L.sub.i+1. Each repeater includes a first circuit for repeating data transmitted from the one transmission link L.sub.i for transmission on the other transmission link L.sub.i+1, and a second circuit for repeating data transmitted from the other transmission link L.sub.

Abstract: An undersea weapon comprising a warhead, a rocket motor, detection, homing and control systems and a hydropulse underwater propulsion system in an integral unit. The weapon is launched at a previously detected target, such as a submarine, on a ballistic trajectory through the air by means of the rocket motor. The weapon enters the water near the submarine, which is thereafter detected by an on-board system incorporating active and/or passive detection. The thus-determined submarine direction is utilized by the control system to guide the weapon toward the submarine under water. A hydropulse motor utilizes the empty rocket motor as the propulsion chamber and provides the underwater propulsion to propel the weapon through the water toward the submarine, where the warhead then detonates on contact with the submarine. Alternatively, the weapon may be air dropped near a previously detected target, in which case there need be no propellant in the rocket motor.

Abstract: A ship anti-torpedo defense system includes a detecting device for detecting and locating an incoming threat, such as a torpedo, and an interrelated missile launching and control system for firing at least one warhead carrying missile into the path of the oncoming threat, the missile having an active acoustic fuze system including a highly directional sensing system for continuously monitoring the position and proximity of the incoming threat and for detonating the warhead at the optimum proximity of the incoming threat with the missile. The missile floats at a predetermined depth determined by the predetermined depth of the torpedo to be intercepted.