Donald and Douglas (originally known by their old numbers, 57646 and 57647, respectively) are a pair of Caledonian Railway mixed-traffic tender engines from Scotland. Douglas tagged along with Donald to Sodor in order to escape from scrap, despite Donald being the only engine expected. After proving themselves to be really useful, they were both allowed to stay. They now work as utility engines on the North Western Railway; working wherever they are needed. They work primarily on the Little Western, but sometimes on Edward's Branch Line and the Main Line.