(225 ILCS 710/45.37)
(from Ch. 96 1/2, par. 4290)
In vertical workings not exceeding 100 feet in depth or height, ladders may be fixed vertically; no vertical ladders shall be used with a
greater height or depth than 100 feet. Provided, however, that around every
such vertical ladder, collars or platform shall be built which shall be not
more than 20 feet apart and shall be constructed as provided by section
45.35 of this Act.
(Source: Laws 1945, p. 1035.)