(1) Car enclosures are not required; however, if provided, the car enclosure shall be:

(a) Securely fastened to the car platform so that it cannot become loose or displaced due to ordinary service, application of the conveyance safety, or from the conveyance coming into contact with the buffer.

(b) Built to withstand a 75 lb. pressure, horizontally applied to any point on the wall, without causing deflection to the wall that reduces running clearance below 3/4 in. or above 1 in.

(2) If glass or plastic is used in the car enclosure, it shall be weather resistant plastic or tempered safety glass.

(3) Where there is no car enclosure, a means shall be provided to secure all materials to the platform.