The Mainland Diesels are a group of diesel shunters who live and work on the Mainland at Bridlington Goods Yard. During the Great Railway Show, these diesels were seen shunting trucks around the yard for the contestants. One of them is named Ulli.
The diesel shunters are all painted in a livery similar to the EWS orange-red and yellow livery. They have black and yellow hazard stripes painted on their fronts, white ladders, yellow counterweights and red buffers.
- The diesel shunters all appear to have faces similar to Paxton, Sidney, and Diesel (with minor modifications). One of the diesels also appears to have a face similar in appearance to Diesel's original face from the Thomas and the Stinky Cheese CGI test episode.