Really Useful Coaches is a magazine story.
Annie and Clarabel are cross when they overhear the Fat Controller praising Thomas; after all, they do as much work as he does and they seldom get praised. Later, Thomas was given the special job of taking some soldiers to the countryside for a training exercise. He took the soldiers to Gordon's Hill where they embark on their training. Thomas then chuffs up the hill to return to the station. As he does, snow begins to fall and the coupling between Annie and Thomas snaps. Thomas is too busy worrying about the weather to notice until he's almost at the top of the hill. He reverses to get his coaches but a snowdrift had blocked his line, so he has no choice but to return to the station without them. Thomas is upset, but the Fat Controller assures him that they will find Annie and Clarabel the next day, but the Fat Controller is more worried about the soldiers being outside in a blizzard.
Next day, Thomas and the Fat Controller find Annie and Clarabel at the bottom of Gordon's Hill. They had some special passengers - the soldiers! They had taken shelter in the coaches overnight. The Fat Controller tells the coaches that they are "really useful", much to the coaches' delight.