Hoisting Cables

(1) Only iron (low carbon steel) or steel wire cables with fiber cores, having the commercial classification "elevator wire cable," shall be used for the suspension of elevator cars and counterweights. The wire material for cables shall be manufactured by the open-hearth or electric-furnace process or their equivalent. (2) Suspension means shall be not less than 2 iron or steel wire cables having a minimum diameter of ¼ inch. (3) The factor of safety of the suspension means shall be not less than seven. (4) The arc of contact of a wire rope on a traction sheave shall be sufficient to produce adequate traction under all load conditions. (5) All wire ropes anchored to a winding drum shall have not less than one full turn of rope on the drum when the car or counterweight has reached its limit of possible overtravel. (6) No car or counterweight wire rope shall be lengthened or repaired by splicing. (7) The winding-drum ends of car and counterweight wire ropes shall be secured by clamps on the inside of the drum. (8) The car or counterweight ends of wire ropes shall be fastened by return loop, by properly made individual tapered babbitted sockets or by properly attached fittings as recommended by wire rope manufacturers. Clamps of the U-bolt type shall not be used.