ceesquared

This is for a non dcc layout. I want to have a system for stopping a train/carrages at a buffer. I have tried using a micro switch to cut off power but that can result in a derailment. I have thought of using an IR beam interrupt to cut the power, setting up the tx is not a problem, it is the rx that I begin to run out of ideas on what I need for the circuit board. Has anybody else solved this problem? If so how, what components do you need exactly? Exit from the buffer is not a problem as it can be solved with a diode.