During switching, the crew member watching the point counts down car lengths to the engineer, five cars, three, two, one, and finishes with that'll do when the movement must stop. Engineers stop on that call without question. Every count is also a limit: if no new instruction comes, the move must stop within half the distance last given, so a silent radio means stop too.
Heard on the job
Ten cars to a joint, five, three, two, one, that'll do.
Also heard as
- that'll be good
- that's good
- that'll do it