Abstract: An indoor fire hydrant apparatus includes a fire hose having electrical conductors extending along its length and connected to a switch mounted near the nozzle end of the hose. Closure of the switch causes energization of a solenoid-actuated valve which is connected between a source of water under pressure and the hose. Closure of the switch also causes energization of a pump to build up the water pressure. A single person may pull the hose from a rack, extend it toward a fire, and actuate the switch thereby causing water under pressure to be dispersed through the nozzle. The electrical conductors may be embedded in a wall of the fire hose or mounted on an exterior surface of the hose. The hose may be of the folding type or the type which maintains its generally circular shape.

Abstract: Apparatus for locating buried objects such as underground pipes, cables or the like where a transmitter (1) generates an alternating current signal which is fed into the object to produce an alternating field emanating from the object, and a receiver (2) locates this radiation to identify the position of the object. A secondary transmitter (T) transmits a reference signal of the same frequency and phase as the original signal, and a signal processor in a receiver (2a) combines the two signals to eliminate the effects of noise.