188.8.131.52 Car Top Access Panel
(b) The car top access panel shall have an area not less than 0.58 m2 (900 in.2) and shall measure not less than 635 mm (25 in.) on any side. The panel shall open outward or slide over the car top. It shall be hinged, or be retained in a track. The movable portion of the access panel, if hinged, shall be provided with means to counterbalance the panel and restrain it from closing when in the open position. The force required to open the access panel or prevent it from closing shall not exceed 45 N (10 lbf). When in the fully opened position, the access panel shall resist accidental closing. The movable portion of the access panel shall not reduce the running clearance. The access panel shall be openable without the use of tools or keys.
(c) The car top access panel shall be provided with a switch whose contacts are positively opened mechanically, and their opening shall not be dependent on springs that will initiate a controlled slowdown and stop when the access panel is opened. A permanently mounted emergency stop switch shall be located on top of the car, adjacent to the access panel, to secure the car prior to transferring to inspection operation.