I'm looking for an answer to this and found only questions - what's the trick? In TS2010 I set the Clean Up Derailed Trains to 5 minutes, or leave it at the default 1 minute, doesn't matter. Whatever I do if there's a derailment SOME cars or engines are removed, others stay there forever. When I have a collision with an AI train the engines and some of the cars derail, other cars are still okay - but if I grab another engine and couple onto the good cars to tow them away I get another derailment. Is there some button you need to push or some key command to activate the cleanup?