(225 ILCS 710/45.34)
(from Ch. 96 1/2, par. 4287)
Every ladderway with an inclination of more than 45 degrees from the horizontal, the vertical distance between the top and the ascent and
descent of persons working in the mines, shall have substantial platforms
at intervals of not more than 20 feet measured vertically and the
inclination of any ladder or section of a ladder shall not exceed 80
degrees from the horizontal.
(Source: Laws 1945, p. 1035.)