Jack is a front loader who works for The Crotoonian Construction Co.
Jack is a very friendly front loader, who started off on Sodor with the Sodor Construction Company, until the company formed with Bob's building team to form the Crotoonian Construction Company. He's brave, doesn't take any hassle, and loves his work with the whole team. However, he's so eager to please sometimes that he jumps in where he doesn't belong!
It is unclear what type of vehicle Jack is based on, he seems to resemble a Nuffield tractor with an added front loader.
Jack was painted red with the top half of his cab and his wheels painted cream. He had the number 11 painted in cream on his sides.
- Unlike in Crotoonia, Jack doesn't keep the design with a rounded face, instead he has a design more like his possible basis including the square face.