Unlike today’s vacuum flushed train toilets, which lead to air-sealed storage containers for holding waste, toilets used to flush directly out of a hole in the bottom of the train car.
These toilets were known as Hopper toilets.
While moving along in open country, flushing onto the track seemed a common sense way of disposing of waste.
However, it also made sense not to do this while the train was parked in a bustling station.
In Asia, travelers were often surprised to find that “toilets” in trains were just holes in the floor, so they could watch the tracks and ground below whiz by as they prepared to relieve themselves.
A little risky and definitely drafty.