Are we to assume that the loop is not long enough to hold both commuter and liner, and that the molasses must not be touched?
1. Draw commuter train forward towards Dromod, clear of points.
2. Set back train into loop. Uncouple.
3. Run forward towards Dromod, clear of points.
4. Set back into liner road and couple to liner.
5. Draw forward towards Dromod, clear of points.
6. Set liner back into main line. Uncouple.
7. Run forward towards Dromod, clear of points.
8. Set back into loop, couple to commuter.
9. Draw forward towards Dromod, clear of points.
10. Set commuter back into liner road vacated in 4/5 above. Uncouple.
11. Run forward towards Dromod, clear of points.
12. Set back and run through loop towards Edgeworthstown, clear of points.
13. Set back onto main. Couple to liner.
14. Draw liner forward towards Edgeworthstown, clear of points.
15. Set liner back into loop.
End.
I'm sure the whole thing could be done in fewer moves if there were enough space on the cem&fert line.....