Donald and Douglas

Donald and Douglas were designed by John F. McIntosh and built by the St. Rollox Works for the Caledonian Railway in 1909. Upon nationalisation, they became part of the Scottish Region of British Railways, where they were renumbered 57646 and 57647. In 1959, Sir Topham Hatt needed a goods engine and by his request, BR decided to transfer 57646 (Donald) to Sodor.

To Sir Topham Hatt's surprise though, two engines arrived. Donald's twin Douglas (57647) could not stand to be separated from his brother and was smart enough to realise he would eventually be scrapped if he stayed in Scotland. Unfortunately for Sir Topham Hatt and any other worker, neither engine could be told apart: both claimed to have forgotten their numbers and indeed their number plates had "slyly slipped off" during the journey from Scotland. This caused the Fat Controller to keep both until he could determine which engine was freeloading on his hospitality. It was later revealed that this piece of skullduggery had been planned not only by the two engines but also by their drivers and firemen, who were related as well.

The Fat Controller was unaware of Douglas' motive and threatened the two that whichever engine he found out to be the truant would be sent home. Both engines resolved to give outstanding service so that Sir Topham Hatt would want to keep both of them. This plan quickly went to pieces, however, after Douglas accidentally shunted Thomas' special coach, full of passengers, into a siding at Tidmouth, causing a great deal of fury for the passengers. Things went from bad to worse when Donald crashed into a signal box at Knapford and Douglas accidentally destroyed a Spiteful Brake Van, who had caused trouble for him earlier.

Despite all this grief, the twins' professionalism, competency, strong work ethic and personable natures had begun to win them support, particularly when they demonstrated an aptitude for snowplough work that they had learned in Scotland. After rescuing Henry from just such a snowy ordeal, the other engines came over to Donald and Douglas' side which ultimately led to the engines of Sodor taking industrial action. After a suggestion by Edward and being pushed into it by Gordon, Percy was presented to the Fat Controller as a deputation to argue the twins' case on their behalf and pleading that if they were sent away, they would be scrapped. Although Sir Topham Hatt did not approve or appreciate them trying to interfere with his decision-making, he understood the engines' feelings upon the matters of saving steam engines and scrapping in general. In the end, Percy's statement and the twins' excellent performance was enough for The Fat Controller to take pity on the twins and keep both. He demonstrated this intent with an offer of a fresh coat of paint for both engines, as well as giving them both nameplates to avoid any more confusion. By their request, they were painted NWR blue, in honour of their Caledonian heritage.

In 1967, Douglas helped save Oliver, Isabel and Toad from the prospect of scrap. The Fat Controller soon found out and arranged for the three to be repaired and painted in Great Western colours. Toad asked to be Douglas' brake van as a show of gratitude.

Since then, the twins have, by all accounts, "transformed" goods traffic on the mainline. Such is their versatility that they regularly see service on the Little Western and Edward's Branch Line, as well as duties as station-pilots at Tidmouth. A turntable has been provided for them at Arlesburgh, although briefly decommissioned after Oliver was pushed into it by some trucks. They expressed their disgruntlement to him in the Scots.

After Donald teased Duck about his "quacking", Duck's crew got a humorous payback by slipping a small duckling into Donald's tender. When discovered, the duckling became friends with Donald and his crew and eventually settled down at Haultraugh, where a small pond was nearby. She was named Dilly by the stationmaster, but she is known to everyone else as Donald's duck.

Such a demanding work-load has begun to tax them however and in 1993 the Fat Controller borrowed a navy saddle tank engine named Wilbert from the Dean Forest Railway to deputise for them on the Arlesburgh branch, with the intention of obtaining another engine of Wilbert's class to permanently fill that role.

In 2011, after bringing ballast from the Arlesdale Railway, they each slipped into a set of buffers which were nearly finished.