A Caterpillar Crane is a mobile crane that runs on caterpillar treads, several
different Caterpillar Cranes can be seen all around Sodor and they are mainly used in quarries and other work sites. A few of these cranes had been seen
several times as scrap decoration.
The ERTL models for the caterpillar cranes incorrectly refers to them as a "he" as if there is only one of them and as if they're sentient.
It's likely that the Caterpillar Cranes may have been intended for Thomas & Friends' sister show, TUGS, as they are more detailed than most of the other vehicle props, and were possibly made shortly before TUGS' cancellation.