Timothy "Big Tim" Timken is a diesel engine who lives at Kahlville Junction.
Big Tim first appeared breaking down at Great Wolf Forest leading Montana to break. The next episode, he arrived at Kahlville Sheds to tell Casey Jr that Sir Allen Featherington rewarded Casey with a trip to Boston for delivering all the mail the night before.
Timothy "Big Tim" Timken is one of the longer (but short hieghted) diesels on the Crotoonian Railways, and one of the few fitted with a big booster unit! Back in the 50's, Big Tim was the talk of the railyards and workshops in America! His revolutionary roller bearings, that prevented "Kid Friction" from creating a hot box, were a big help to mending problems with the rail cars and engines! Nowadays, they don't seem as special, but Big Tim doesn't mind nor seem too conceited about it. He's just happy to roll along his fine little rails, hauling loads of freight up and down the line. He's still got hints of the over-excitement and jovial attitude from his young days, but he's still a hard worker, and will be on hand the keep the freight of Crotoonia running on time no matter what.
Big Tim is an EMD F-Unit. Wilson is another member of this class.
Big Tim is painted cool yellow with red lining. He carries the number 22 and his name "Timothy Timken" on his sides.
- He originates from a UPA-produced short film entitled "Big Tim", produced to sell Timken Roller Bearings to railroad companies.