225 ILCS 705/19.06

In all coal mines more than 200 feet in depth, and opened on or after July 1, 1919, the escapement shaft shall be equipped with both a cage and stairway. However, if the coal mine is equipped with a stairway in the main shaft, no stairway shall be required in the escapement shaft. Subject to the approval of the Mining Board, if a mine has 3 shafts as described in Section 19.05 of this Act, a ladder system as described in Section 19.05 may be used in place of a substantial stairway.