(1) You must make sure elevator machines are driven by approved type units.

(a) On direct drive or approved worm gear driven type, a mechanically actuated, electrically released brake must be installed on the driving unit.

(b) On V belt driven types, a minimum of four belts, one-half inch minimum size, must be used to transmit power from the motor to the drive shaft and a mechanically actuated, electrically released brake must be installed on the final drive shaft.

(2) You must install elevator machines on the top side of their supporting structure, wherever practical.

(3) You must make sure all components of the driving mechanism and parts subject to stress involved in suspending the load or related equipment are designed to withstand eight times the total weight to be suspended, including load, counterweight, car and cables.

(4) You must make sure gears are made of steel or equivalent material. Cast iron gears are prohibited.