ASME A18.1 pdf download Safety Standard for Platform Lifts and Stairway Chairlifts pit: that portion of a runway extending from the sill level ofthe lowest landing to the floor at the bottom of the runway.platform: the load-carrying unit, including, but not limitedto frame, floor,enclosure, seat, and door or gate. platform frame: a structural frame composed of intercon-necting members that supports...