Section 43.18. Stairways and ladders

(a) In each shaft, except during the period of sinking, there shall be a covered stairway at least 2 1/2 feet wide leading from the bottom of the shaft to the surface. However, in case it is not practicable to construct a stairway, a ladder shall be installed with landings at every 20 feet of sufficient width to permit men to pass. Stairways and ladders shall be kept clear and in good condition at all times. The distance between the centers of the rungs of a ladder shall be 12 inches. Any ladder having a variation in its step or rung spacing of 1/2 inch or more shall be rebuilt to meet the requirements of this chapter. The length of the ladder rungs, that is, the width of the ladder on the inside of the stringers, shall be at least 12 inches. The rungs of a ladder shall be at least 6 1/2 inches from the wall or other obstruction in the shaft or opening in which the ladder shall be used. Under no circumstances shall any ladder inclining backward from the vertical be installed.

(b) At all landings where it is necessary to cross from one side of the shaft to the other, passageways shall be provided and shall be kept free from all obstructions and properly lighted.

(c) Ladderways and stairways in daily use shall be kept clean.