The ex-BR class 04 is currently the rescue locomotive for the railway, and is in full working order, although when the Class 14 is returned to service it will be due for an overhaul. When built in 1952 by Vulcan / Drewry, the intended use was as a shunting locomotive for BR on the Wisbech and Upwell Tramway, which it fulfilled. It is now the last surviving loco to have worked on the tramway. It was Drewry No. 2400, and Vulcan Foundry No. 145, as well as being BR 11103, and later D.2203 which is the identity it currently supports, devoid of sideplates and cowcatchers.

The 0-6-0 DM was sold into industrial service to Hemel Concrete Company, before coming to the railway. It has a 204hp Gardener engine which required some attention initially, but has since been very useful for the railway.

As an interesting point, during its life it was fitted with sideplates and cowcatchers to work the Wisbech and Upwell Tramway - becoming the last locomotive to do so. This loco was almost certainly the basis for 'Mavis' from the Thomas series, and some thoughts are being given to returning it to that form when its overhaul takes place! One lasting trace of its tramway guise is that the rear steps are still plated over to prevent feet getting through to the rods. This can just about be seen in the right hand photo at the top of the page, although it isn't clear.

Despite grave concerns as to its ability to act as a rescue loco, the 04 was pressed into service during the 2003 Harvest of Steam to haul the Stately Trains' 6-wheelers - a role it performed faultlessly, and looked the part. Since then it has been fully repainted, had considerable attention paid to the bodywork and had the gearbox mounting bolts replaced.