Can Puddle Derail a Train? Physics Experts Needed

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  • Thread starter Thread starter Donald Josephso
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Discussion Overview

The discussion centers around the hypothetical scenario of whether a large enough puddle could derail a passenger train, particularly under conditions of heavy rainfall. Participants explore the physics involved, including the effects of water on train dynamics and the infrastructure of railway systems.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant questions the feasibility of a puddle forming large enough to derail a train, considering the typical drainage systems in place along railway tracks.
  • Another participant suggests that if there were a drainage issue, such as blockage, it might allow for standing water to accumulate, potentially reaching depths of 3 feet.
  • A further contribution posits that if sufficient water were present to decelerate the train rapidly, the resulting compression forces could lift the leading passenger cars, leading to a derailment scenario.
  • This participant also notes that once one car derails, it could cause a chain reaction affecting the other cars and possibly damaging the track itself, while emphasizing that derailing the locomotive would be more challenging.

Areas of Agreement / Disagreement

Participants express differing views on the likelihood and mechanics of a puddle causing a derailment, with no consensus reached on the feasibility of such an event.

Contextual Notes

The discussion relies on assumptions regarding drainage effectiveness and the specific conditions under which water could accumulate on the tracks. The potential impact of water depth and train speed is also considered but remains unresolved.

Donald Josephso
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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).
Thanks for your help.
 
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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.
 
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.
 

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