The interior dimensions of the clear space provided for single or double track tunnels shall not at any
point be less than those recommended in Chapter 28, Clearances, Part 2, Equipment Diagrams (see
Figure 1-8-1 this Chapter). For tunnels located on curves, additional clearances must be provided for
overhang and tilting from super elevation. Where legal requirements are greater than those listed, the
former shall govern.
b. Where tunnels are to be lined, dimensions must be increased to provide that such lining does not
encroach within the clearances described above