long curves. Bridges must be strong enough to hold up under the
heavy weight of locomotives; tunnels must be high and wide enough to
allow the passage of military equipment.
As a theater of operations expands, captured rail lines and
their facilities are rehabilitated if needed and if possible. Only
when they are not adequate for military needs are new ones
theater, three phases of operation are used. Phase I, employing only
the military, is used in combat areas or immediately after gaining a
lodgment, such as a beachhead. Phase II, using civilians and
military with the latter in supervisory positions, is normally
civilians under military supervision, thereby releasing military
railroaders for duties in forward areas. In both phases II and III,
the local economy is helped because some civilians are restored to
their jobs and some civilian trains may be operated.