Yeah nails are a good idea too. I think the all around border is the best idea. The way I see it,you only get one second chance.
One display at a show had a 2" high banister around their layout that they had lined with 1/2" thick soft foam. They lightly spray painted the foam to represent foliage of various colors, so was not that noticeable. Because they allowed kids to operate trains the parent (hopefully) might buy, the banister was saving broken engines when the kid tried to see how fast the train would go! He said the parent always walked away, refusing to pay any damages. So, why not use a block of soft foam glued to a couple of nails to protect the coupler and the car body shell? Or use a Bean Bag paper weight?
Barring any more roll offs I should be ok. My operating speeds are very much in the slow range. Big freights just look cooler creeping around the layout rather than speeding.
