The goods engine is a tank engine who makes several cameo appearances throughout the series. Its most notable appearance is in the episode High Tide, where the bridge crossing the canal collapses and the tank engine lands in Lord Stinker's hull.
It also sports the words Dock Railway on its sides.
Behind the Scenes
The goods engine superficially resembles a US Army 0-6-0T tank engine and EJ Lavino and Company 34, which is also an 0-6-0T. However, its model is made from "splicing" together various parts from other locomotives (such as the cab, and the front, which, upon close inspection, is a German design in origin) and scratch-building a few parts (most notably, the side tanks). Jeremy King said that the model was disliked by David Mitton, likely because of its low realism.
Scrap pieces of the goods engine appeared in the Thomas and Friends episodes Rusty to the Rescue, Toad Stands By, Stepney Gets Lost.