- "'Tis a bairn's play compared wi' some o' the gaeings-on on oor auld line, eh Donald?"
- ―Douglas on the twins' plan
The Twins' Passing Problem is a 1985 annual story.
Donald and Douglas are helping on Edward's Branch Line. One day, Donald and Douglas both have long trains. When they reach the loop, the two drivers, the two firemen, the signalman, and the engines discuss how to get past. Then, the twins have an ingenious idea: Donald goes back and leaves half of his train well clear of the points, then comes back into the loop and stops. Douglas runs right through on the other line and Donald goes forward with the trucks he has. Then Douglas comes back, pushing his own trucks and pulling Donald's. Douglas leaves Donald's trucks in the loop and carries on until he is clear of the points. Douglas can then get clear away and all Donald has to do is back onto the other half of his train.
- The trucks have neither buffers nor couplings.
- The loop is far too sharp to accommodate Donald or Douglas' wheelbase.
- The twins' tenders are too short in length.
- Donald and Douglas are missing their nameplates.