Abstract: In a cutting machine having a cutter arm which is mounted at one end for universal pivotal movement and which carries at its free end a cutting tool: a walk-on platform covering at least part of the cutter arm, said platform being box-shaped in cross-section and having a width greater than the width of the cutter arm so as to protrude beyond the sides of the cutter arm and said platform having a generally planar top wall and a bottom wall which conforms to and rests on the exterior surface of the cutter arm; and at least one walk-on plate hinged to the platform at a side edge thereof for swinging movement about an axis which is approximately parallel to the axis of the cutter arm, said plate having a width less than the width of the upper wall of the platform movable from a position in which it lies on the top wall of the platform to an extended position in which it is approximately co-planar with the top wall of the platform.