(a) Existing hoistways for freight elevators provided with trap doors capable of sustaining a load of not less than 50 pounds per square foot, when closed and so arranged as to open and close with the passage of the car, will be accepted in lieu of the enclosure required in section 8-1.13, provided that in addition to such trap doors the hoistway shall be adequately protected on all sides, all floors, with a standard railing as specified in section 8-1.54, or enclosure at least 42 inches high, placed 12 inches from the hoistway line on all sides. Self-closing gates not less than 42 inches high shall be provided at all landings. Where enclosures are not less than 72 inches high and gates not less than 66 inches high they may be set less than 12 inches from the hoistway line.

(b) Where self-closing gates are provided, the lowest horizontal member shall be 10 inches or less from the floor.

(c) In existing installations a hinged bar 42 inches high will be accepted in lieu of the gates herein required, if upon inspection such bar is found to be self-closing and provides adequate protection.

(d) No car shall be permitted to remain in such position as to keep trap doors open except when at landings. Where height between floor necessitates trap doors being held partially open, the gates shall extend to floor level the full width of the floor opening.

(e) Automatic trap doors shall not be permitted in future installations at more than two landings.