Heather Kay
Western Thunderer
Ahem, stop blocks?
My first thought, too.
Having had the misfortune of a loco high diving from an exhibition layout while we tested it at home without the ends fitted, it's always the first thing I think of.
The loco survived. It hadn't been painted, and bounced off a chair on its way down. The chimney was knocked off, and the cab roof slightly dented. We still have it now, and it runs just as sweetly as the day it took to flying.