- "You may be a little diesel, but you're as strong as a big steamie."
"I only look like a diesel, Gordon. I'm a steamie, a shunter..."
"...and a Really Useful Engine!"
- ―Logan and Gordon, Logan and the Big Blue Engines
Logan is a steam shunter who looks like a diesel. He briefly worked at the Crosby Coal Company before returning to the Mainland.
Logan arrived on Sodor on the day of the Sodor Talent Show. He was responsible for arranging trains for Edward and Gordon in preparation for the show. When Edward and Gordon arrived at the coaling plant to pick fill up on coal and collect their trains, Logan could not tell them apart because they were facing him tender-first. As a result, he gave Gordon a train of Bubblesome Trucks filled with bubble liquid for Mr. Bubbles, believing Gordon to be Edward. When Logan gave Gordon's coaches to Edward, he realized his mistake and set off to catch up with Gordon.
Gordon at first mistook Logan for a diesel. However, after a friendly chat, Gordon learned that Logan was a steam shunter and praised him for his work ethic. Later that day, Logan returned to his work at the coal mine.
Logan is a rough and tumble, strong little shunter. He is very friendly and hardworking. When he had a mishap with Edward and Gordon, he quickly discovered how it is indeed possible to correct a mistake.
Logan is based on a Radstock Sentinel Shunter. These were two small vertical-boilered, chain-driven steam locomotives used for shunting coal wagons on the colliery branchlines around Radstock. They were scrapped in 1959 and 1961 respectively. He carries the number of the larger Two-Engined Sentinel No. 7109 "Joyce", which is preserved. Unlike either of his bases, however, Logan has a funnel in his illustrations and on his CGI model.
Logan is painted deep blue and yellow with black hazard stripes on his bufferbeam. The number "7109" is painted on the blue half of his cab in yellow and, in his book and merchandise, his name is painted on the yellow half of his boiler in blue. However, his Wooden Railway model is painted navy blue.
- Logan is the first character created exclusively for merchandise, with a book tie-in for Wooden Railway's "Sodor Story Collection" series.
- Logan is not illustrated with any couplings, but did receive them on his CGI model.
- Logan's whistle sound is the same as Percy's from the third season/Toby's from the fourth season.
- Wooden Railway (normal and dirty; limited release)