(vacuum break system)

Should have some way of turning it on and off

errr "Vacuum brake?" Converse with me on this, i'll learn ya about train air brake ;)

It'd be interesting if cars where affected by gravity, (and didn't have autobrakes). you could then create a hump yard.

Make a tool that can manually release/engage brakes. (setting would be overruled while in a consist with a locomotive)