O.J.'s Windmill is a TUGS parody of the Thomas The Tank Engine And Friends episode "Toby's Windmill".
One of O.J.'s favorite places in Bigg City Port is the windmill that resides up river, but it is very old and can't make as much flower as it used to. One day, O.J. is going to collect a barge of flour from the windmill for a tramp steamer to take away, but he is distracted by the windmill and accidentally sinks the barge. When he comes back with Little Ditcher to rescue the barge, The Fuel Depot is upset, as the accident risks putting him out of business.
Later that night, O.J. feels sad about what he did and cannot sleep thinking about it. On that same night, a storm came to Bigg City Port and causes lots of damage to everything. The windmill is struck by lightning and set on fire.
The next morning, O.J. sees that the windmill was destroyed, making him upset. The Fuel Depot says that he can't afford to make the repairs and decides to shut down his business. Feeling sad, O.J. leaves, feeling like his carelessness is what caused it. Later, he sees a fallen tree that Little Ditcher and Coast Guard's Messenger were trying to clear out of the canal. O.J. asks Captain Star if he can use the tree to make the repairs, and he says yes. Feeling happy, O.J. takes the tree to the windmill, making The Fuel Depot very happy. After many days, the windmill is repaired and makes more flour than ever, and The Fuel Depot now calls it O.J.'s Windmill.