Abstract: The APS hydraulic clamping arm on CDQ is an important equipment to connect the coke bucket and crane，mainly to force the quenching car into position after the initial alignment. During operation，damage often occurs when the APS hydraulic clamping arm suddenly lifts and collides with the coke bucket. Adding an audible and visual alarm to the front of the quenching car provides obvious and clear feedback to the operator’s operation so as to avoid collisions.

Key words:  , Coke bucket, Crane, APS hydraulic clamp arm, Audible and visual alarm