Elevator cars shall be fully enclosed to the car height or to a height of at least 78 in., whichever is greater.

(1) If constructed of solid materials, cars shall be capable of withstanding a horizontal thrust of 75 lbs. while deflecting no more than 1/4 in.

(2) If constructed of perforated materials, all openings shall be capable of rejecting at least a 1 in. diameter ball.

(3) Car frames shall be of substantial metal or wood construction.

(a) Metal frames shall have a safety factor of 4.

(b) Wood frames shall have a safety factor of 6.

(c) Wood frames shall be constructed with gussets and bolts secured with large washers, lock washers and nuts.

(4) Cars shall have platforms whose inside dimensions do not exceed 30 in. on each side (6.25 ft2).

(5) Cars shall have substantial protective tops. These tops:

(a) May have hinged front halves.

(b) Shall be made of No. 9 U.S. wire-gauge screen, No. 11 gauge expanded metal, No. 14 gauge sheet steel, or 1/4 in. or heavier plywood.

(c) If made of wire screen or metal with openings shall reject a 1/2 in. diameter ball.

(6) A properly working fire extinguisher shall be present in each car.

(7) A sign bearing the following information shall be posted in a conspicuous place within the car:

(a) Total load limit in pounds;

(b) Maximum capacity one or two persons where applicable;

(c) "For authorized personnel use only."