Abstract: A safety apparatus for use on a hoisting crane used to hoist cargo from cargo transport trucks that detects hoisting such trucks and renders the hoisting mechanism inoperative. The safety apparatus includes sensors responsive to an unsafe condition in such trucks to generate a safety signal. A transmitter responsive to the safety signal transmits an operational signal to the hoisting crane that upon receiving and recognizing the operational signal renders the hoisting mechanism inoperative and alerts the crane operator of the unsafe condition.

Abstract: A transmitter attached to the overhang of a hoisting crane that is movable over rails. The transmitter is operative to transmit signals to receivers also mounted on the hoisting crane. During movement of the crane, the signals may be blocked by objects that may come between the transmitter and receivers indicating a pending collision. The receivers upon detecting a blockage are operative to alert the operator of the unsafe condition and deactivate the gantry motors moving the crane.

Abstract: Sensors mounted on respective cargo transport trucks transferring cargo to a hoisting crane and responsive to an unsafe condition in such trucks to generate an electrical safety signal to be transmitted to such crane for rendering the hoisting mechanism inoperative.