Jack is a brave, friendly and enthusiastic front loader. He will not take any hassle, as seen whenever he stands up to Max and Monty when they are bullying him and Alfie. When Jack first arrived, he always wanted to be the one with a job but soon learned his lesson about not jumping in where you shouldn't be. Jack has also helped with the restorations of Great Waterton and Ulfstead Castle, and helped build the Harwick Branch Line.
It is unclear what Jack is based off of, but he resembles an International 454 tractor.
- Two Left Buffers (cameo)