92 Ill. Adm. Code 1500.150
Ladder Tracks
Section 1500
Section 1500.150 Ladder
Tracks
a) The distance from the center line of any subsidiary track to
the centerline of any adjacent ladder track where the switches are operated
mechanically, shall not be less than 15 feet; where the switches are not
operated mechanically, not less than 17 feet.
b) The distance between the centerlines of two adjacent parallel
ladder tracks where the switches in both are operated mechanically, shall be
not less than 17 feet; where the switches in either or both are not operated
mechanically, not less than 19 feet.