There are six old tenders found on the North Western Railway. They are described as being very old, dirty and filled with boiler sludge.
The tenders were seen being shunted by Diesel on the other railway.
Two tenders were once seen on a flatbed being pulled by Harvey.
Two of the tenders somehow ended up at Great Waterton with one sitting in the station when Thomas discovered the town.
The old tenders are based on the LMS Fowler 3500-gallon tender and LNER J39 4200 gallon tenders.
The old tenders appear to be painted NE wartime black and LMS black, however given their age they appear faded and rusty.
- Series 3 - Tender Engines and Escape
- Series 4 - Trucks (Two only), Rusty to the Rescue (Two only) and Toad Stands By (Two only)
- Series 5 - Thomas, Percy and Old Slow Coach
- Series 6 - Middle Engine (one only)
- Series 7 - Fergus Breaks the Rules (two only)
- Series 8 - Halloween (one only)
- Series 12 - Steady Eddie
- Series 6 - Boo! Boo! Choo-Choo (three only)
- Series 7 - Five New Engines in the Shed (two only)
- The Great Discovery - Where, oh Where is Thomas? (two only)
- Sludge tenders were a genuine practice on the railways, particularly when the diesel era started and more LNER locomotives were scrapped leaving their tenders available for different usage.
- One of the old tenders has "LMS" on the side, a possible reference to Henry's basis; the LMS Black 5 Class. Some of the other tenders have "NE" on the sides, indicating that they are North Eastern Railway tenders.
- Since the tenders appeared all together in "Escape" after "Tender Engines", it can be assumed that they were sent for scrap after the events of the latter episode.
- One of the old tenders were used for the Halloween Engine's tender.
- It also gained a tail lamp.