Flooded 3rd rails and possible earthing issues.

[pethadine82]

I could not find my answer, but perhaps those with an engineering or electrical background may be able to answer this.
Say if flooding immerses all 3 rails underwater, why doesn't the track side equipment short, and how are trains still able to run, as I would have thought the electrons would have taken the path of least resistance. Also is there any electrolysis of the rails, I am not sure if they are made out of the same metal then they would have the same electrochemical properties?

Really would welcome any replies.
Thank you

 

[matchmaker]

I'm no expert, but I understand that fresh water isn't a particularly good conductor of electricity.

 

[Surreytraveller]

Water isn't as good a conductor of electricity as people often believe. I still wouldn't step into flood water that is in contact with electrical equipment though

 

[AM9]

I'm no expert, but I understand that fresh water isn't a particularly good conductor of electricity.

Not only fresh (as in salt free) but clean water. Certain impurities would provide conduction paths, I suspect that brake dust/rust would be the most likely. There is a similar issue with high voltage behaviour in the presence of rain. In high pollution areas, the carbon particilates in the air can collect on insulators and provide paths over which leakage current can track, hence the buzzing of OLE when there is fog/mist or sometimes heavy rain. Clean water on clean insulators is rarely an issue.

 

[dgl]

At work if you go near any of the pylons when it's damp you can clearly hear an electrical "sizzle", let's you know what the weather's going to be like.
A for shorting of 3rd rail during flooding, I would guess the immense amperages involved in the 3rd rail system man that any shorting due to flooding has little effect as the resistance of the water won't create the amperages needed to cause a breaker to blow.

 

[philthetube]

If track circuits the first thin that happens is that you get a signal failure as the running rails are lower than the juice rail, water is a good enough conductor of electricity to cause that.