Tail track
Work in progress: This section is still a work in progress — content is being added and revised continuously.
What is checked? At switchback spurs (destination reachable only via a reversal): is the run-round segment long enough for a locomotive plus one car?
Why does it matter? To work the spur, the locomotive with at least one car must fit completely onto the intermediate track before pushing back. If it is too short, the spur is effectively unworkable — one of the most common “wish I’d known” mistakes on real layouts.
How to fix it: Lengthen the segment by the shortfall (often just one or two track pieces) — or register a shorter shunting locomotive in the train profile if the spur really is worked only by the small diesel.
Numbers & defaults: longest locomotive + longest car from the train profile (H0 default: 260 + 264 mm).