Also want to highlight this for another reason. At slow speeds rail and boats suffer from far less “moving” friction than road vehicles. So once off there is very little slowing them down vs cars and trucks that suffer from high rolling friction.
Grady Hillhouse of Practical Engineering recently did a great demo of this. He was able to pull his car in neutral and an empty train car on rails with roughly the same force.
I think it's actually in an earlier video, and he wasn't able to actually pull the train car due to track irregularity -- but according to calculations he should have been able to if there was a safe way to give it a bit of a nudge.
Mostly the same as it would work on a car with a brake shoe applied to the steel wheel.
The only major difference is that they often use a safety air brake system shared across an entire consist (train) that requires “charged” pressure (above atmosphere) to disengage the brake (although I think they have moved to an electronic system that now monitors air pressure in each car individually).
