A wood chipper includes a frame, an infeed system, a rotatable cutting system, and at least one feed wheel disposed between the infeed system and the cutting system to feed wood material to the cutting system. The wood chipper also includes a winch which includes a winch line having a first end, and a collar disposed adjacent the first end of the winch line. The wood chipper further includes a detector adapted to detect a first and a second position of the winch line, wherein the detector is adapted to allow operation of the at least one feed wheel and prohibit operation of the winch when the first position of the winch line is detected, and to allow operation of the winch and allow operation of the at least one feed wheel in a predefined manner when the second position is detected.