Why Don’t Electric Trains Short Circuit in Rain?

It is snowing here but the NJ Transit train service is running fine. Electric trains don’t seem to care about rain or snow. It is counter intuitive that electric trains run on electricity supplied from overhead power lines but they don’t get short circuited even when there is water all over.

Electric circuits have at least two poles:  positive (+) and negative (-).  In a normal closed circuit, the two poles are kept at different voltages and electricity flows from the higher voltage pole to the lower.  A short circuit occurs when, due to some fault, the voltage at both the poles become equal.

Electric trains cleverly avoid short circuit possibilities. It uses the high voltage overhead power line as the positive pole and the train track connected to the ground as the negative pole.  The two are far apart that it is virtually impossible that the two come in direct contact.

The train makes contact with the high voltage overhead wire using a well-insulated device called the pantograph which creates a metal-on-metal contact. Metals are a better conductor of electricity than water and therefore, electricity flows along the metal (intended path) ignoring the water (the unintended path)

Engineers have indeed tamed electricity. Now if only they could find a way for trains to arrive on time.

References:

https://www.quora.com/How-much-electricity-is-consumed-by-an-electric-train

https://www.quora.com/Can-a-pantograph-send-electricity-from-overhead-wires-to-the-body-of-a-train-engine-during-heavy-rain-as-the-roof-of-the-engine-is-completely-wet

https://www.njtransit.com/pdf/FactsAtaGlance.pdf

https://tonystrains.com/dccprimer-track-protecting-against-short-circuits/

https://www.quora.com/How-does-the-earthing-work-in-an-electric-train

https://www.reddit.com/r/explainlikeimfive/comments/2nhbx6/eli5_why_are_electric_train_tracks_not_effected/