The clearance between the car and the counterweight shall be not less than 1 inch. The clearance between counterweight and the counterweight screen and between counterweight and the hoistway enclosure shall be not less than 3/4 inch.
The weight of the counterweight shall be not more than the total weight of the car plus 50% of the rated load.
A hoist car shall not be used to counterbalance another hoist car.
Compensating chains or ropes, when used, shall be fastened to the counterweight or to the counterweight frame and shall not be fastened to tie rods.
Cal. Code Regs. Tit. 8, § 1604.15