Class 121 Pressed Steel Single / 2-car DMUs
Numbering
The original TOPS classification for the DTS vehicles was Class 149.
| Type | Seats | Lot No. | Diagram No. | Design Code | Weight | ||
|---|---|---|---|---|---|---|---|
| 55020 - 55035 | DMBS | 65 2nd | 30518 | 512 | DQ221 | 37t 8cwt | |
| 56280 - 56289 | DTS | 93 2nd | 30519 | 513 | DS201 | 29t 7cwt | |
| 89 2nd (gangwayed) | 513A (gangwayed) | - |
Only the DTS vehicles were gangwayed, they couldn't use the gangway working with a bubble car but could be used with other classes.
The DTS vehicles were renumbered to 54280-9 circa 1983.
Why were the DTS vehicles numbered lower than the 122 DTSs which had been ordered earlier? There had originally been an order for 70 63' 6" 2-car sets for the ER, lots 30366 (50938-51007) and 30367 (56221-56290). These were cancelled on 2/5/57 leaving the number gaps, the latter being filled by Class 108s (56221-56279) and the 121 DTS (56280-56289), with 56290 unused.
Names
Three vehicles were named while in the care of Silverlink:
- 55027 - Bletchley TMD
- 55029 - Marston Vale
- 55031 - Leslie Crabbe
Above the Leslie Crabbe name was a smaller plate that read 1926-1996 Railwayman and friend of the Marston Vale line".
55027 had a naming ceremony at Bletchley TMD on 17/11/98.
55029/31 had the names applied in January 1999 without ceremony — the names being transferred from Class 117 power cars 51332/58 when they were withdrawn from Bedford-Bletchley duties. The pair are seen in the image at Bletchley in August 1999 - photo by Lewis Bevan.
The Marston Vale name would later be used on Class 150 set 150131.
Worksplates
Worksplates were carried on the vehicle solebars to identify the builder and lot number. Many of the worksplate images on the website are from the collections of Simeon Gaskell, John Horne and Tony Spencer.
Driving Instructions
Many earlier DMU types had a booklet from the 33003 series issued specifically for them, none have been found for these vehicles.
This March 1961 editon covered all Blue Square vehicles - BR 33003-92. A companion to this was a "Preparation and Disposal" booklet BR 33003/211.
In 1968 the booklets were replaced by a three part set for Blue Square vehicles Mechanical Transmission):
BR 33003/247 1 - General Data And Equipment
BR 33003/248 2 - Driving Instructions Including Standard Preparation and Disposal Duties
BR 33003/249 3 - Fault Finding Data and Charts
In the early seventies the 33003 series was replaced by the more generic 33056 series of drivers manuals, no longer specific to any coupling code.