How are trains run when tracks are flooded?
Flooding is very dangerous to the permanent way. The earthworks become unstable, ballast can be washed away, and the forces of the water by its movement, buoyancy, and scouring action can seriously weaken and move the track so that it is no longer stable and secure enough to support the weight of a train reliably. Hence, great care is taken when flood waters rise and affect a railway track. If the trackbed is known to have been laid in a stable manner (or specially built to withstand floods in a flood-prone area), certain rules of thumb are adopted. If the water level does not cover the ballast and the track can be seen to be undamaged, trains may in general move (with caution) over the affected sections. When the water level rises to cover part or all of the ballast, special operating rules go into effect, which differ based on local conditions. In some divisions, the rules are that if the water does not cover the rails, it may be piloted across with gangmen walking ahead of it and ob
