Some weeks ago there was a discussion on 1000Steine.de how to dump LEGO train cars. One of the posts had a link to a private site showing a solution for H0 trains.
Now I built this in LEGO with focus on simplicity so my kids can handle this on their own:
The stop at te end is strong enough to stop the train if it's not too fast.
More pictures on brickshelf - once it's moderated.
This is not yet finished: It needs some modifications to look more like a real train facility and it's rather annoying to get the technic-pins back into the cars manually. But I did not think about this much and I'm open to suggestions (conveyor, excavator, ...)
Steffen