Class 104 (12 vehicles)
Built by the Birmingham Railway Carriage & Wagon Co in 1957/1958, 13 Class 104 vehicles were initially preserved by the same two private owners, who saved 12 vehicles in a bulk bid from British Rail who had a puzzling reluctance to sell sets individually. A thirteenth vehicle joined following an extended period in departmental service and unusually no other groups or individuals saved any further vehicles of the class.
The large size of the newly formed collection meant that loan agreements were required for many of the vehicles. The Llangollen Railway took three on a long term loan and quickly returned a power twin set to service in 1993 that ran very successfully until 2025.
Four vehicles were stored elsewhere until being gathered together at the Telford Steam Railway, who repaired and ran a 2-car set from 1999-2004. Sadly over 25 years all the vehicles there fell into decline and the loans terminated, with the four affected vehicles having to be either scrapped or rehoused elsewhere, with the last vehicle bringing down the curtain in 2023.
The original headquarters of the group however was at the Churnet Valley Railway where six vehicles were located in the 1990's. By 2004 a 2-car set had been steadily restored and put into service there following an extensive 12 year rebuild. Before any further vehicles could be completed however, the group moved the collection in 2014 to the East Lancashire Railway, where the 2-car set continues to operate whilst the rest of the collection there remains stored awaiting future restoration and eventual service.
The next railway to accept a Class 104, from 2015 onwards, was the North Norfolk Railway where members previously active at the Churnet Valley relocated a 2-car set, newly formed from displaced vehicles from the Churnet Valley and Telford. The first half of the set was returned to traffic in 2023 with the remaing half now undergoing an equally major overhaul following years of dereliction.
The final railway to join the Class 104 party was the Great Central Railway in 2026, who took on the set originally hired to Llangollen.
In total, four sets remain in preservation (two 3-car sets and two 2-car sets) following the loss of a set to provide spare parts, with two and a half sets operational, just under half the overall collection. DMBS 50479 at the North Norfolkis currently the only member of the class under restoration, although it is hoped that the stalled rebuild of TCL 59137 at the East Lancs can be resumed soon. Immediate plans include finishing these two which will bring the number of restored 104's to a record high with three sets in traffic including a much awaited original 3-car formation.
Now Scrapped
| Number | Type | Last Location |
| 50556 | DMCL | East Lancashire Railway |