Lawson, D.I., 1958. THE SAFETY OF FIREMEN WEARING BREATHING APPARATUS. Fire Research Notes 347
This note examines the problem of locating firemen in smokelogged buildings, and describes a communication system whereby the fireman is connected to the control point by cable. A source of sound on the fireman is operated from batteries at the control point, either manually or automatically should the fireman become unconscious. The control point is made aware by a local indicator if a state of alarm arises. The line is continuously monitored and both the control point and the fireman are alerted if the line should break. Telephonic facilities are also provided.