"The Small Controller"
Mr. Fergus Duncan, nicknamed the Small Controller is the General Manager of the Arlesdale Railway. He is actually taller than the Fat Controller and the Thin Controller (Mr. Percival in the television series); his nickname refers to the fact that his railway is often called the "Small Railway".
He was appointed by the Fat Controller, the Thin Controller, and the Owner to run the line in 1967 so they could get the supplies of ballast that reside in the hills on the line. He lives in a house at Arlesdale Green, which he built himself.
In 2005, he was approaching a remarkable 40 years of service to the line. Despite nearing 70, he was still hale and hearty, but he had let it be known he intended to retire on achieving that landmark in 2007. It is felt in many quarters that the example set in his service to the line will be a difficult one to follow.
The Small Controller is very passionate about his work, and never married. He preferred instead to devote his life entirely to work on his railway.
Fergus Duncan's attire consists of a yellow waistcoat over a white shirt with a red tie and a brown jacket over it, with mustard windowpane chequered trousers. He wears a yellow flower on his jacket.
- In Sodor: Reading Between the Lines, he is referred to as Francis Duncan.
- Unlike Sir Topham Hatt and Mr. Percival, he is referred to by his nickname in the US version of the television series.