in trains, when they have different carriages that you can walk into, why do they have doors on them? Why not just have an open train?

Question

This is for trains in the UK that are near London, I don’t know if it’s the same in other places.

In: 0

Answer 1

There are several reasons. Train cars are often disconnected and reconnected to each other. So you need a door where there is no connection or it is connected to a non-passenger car. The ability to disconnect also makes it very hard to seal the cars to each other. So the space between the doors, between the cars, tends to be partially open to the elements through gaps in the seal. Without the doors the inside of the car would get quite hot/cold, dusty and noisy. But even within a car there might be doors. These are primarily to make sure that noise from the passengers do not spread to the entire car or even neighboring cars. Just imagine having to listen to a crying baby from the neighboring car or juveniles taking the train to a party.