# Derailing a train

## Main Question or Discussion Point

I need some physics experts to help settle a debate between me and a coworker. Would it be possible for a large enough puddle to derail a passenger train? Obviously if you tried to drive a train through a lake it would derail, but could there ever be enough water from heavy rainfall to do the trick? Reasonable assumptions regarding speed (50mph) and train size (10-15 cars).

Last edited by a moderator:

Related Other Physics Topics News on Phys.org
rcgldr
Homework Helper
How would the puddle form? In the USA, the rails are set on an small elevated bed of rocks, and there's a drainage setup on both sides of the tracks.

Assuming there is some drainage issue, either blocking, or a less than ideal setup. Basically the debate hinges on whether water could derail a train, let's say 3 feet of standing water. Hope this helps, thx.

rcgldr
Homework Helper
If there was sufficient water to decelerate the train fast enough, the compression force on the leading passenger cars could be enough to lift them up (accordion) and derail them. Once one of them goes, the couplings can pull the other cars along, or the rails of the tracks can get ripped up from the side loads. Note that virtually nothing short of the rails themselves being displaced is going to derail the locomotive car if it's in front.