Class 108 Derby 2,3 & 4-car DMUs
Diagrams
Vehicles were given a diagram number to identify its design. They would later be replaced by design codes.
They are sorted here by vehicle type. The power cars seemed to justify a variation based on whether it carried the two-digit route indicator or four-character headcode on the cab front.
Driving Motor Brake Second (DMBS)
| Diagram | Page | Lot Number | Design Code |
|---|---|---|---|
| 543 |
 |
30406 30407 30460 30465 |
DQ212 |
| There was an alternative version of 543, on this the tare weight is show as 27 tons, it is 29 tons on the other. | |||
| 543 alternative |
 |
30406 30407 30460 30465 |
DQ212 |
| There was an ammended version of 543 where a twin seat was turned 90% to allow heating ducting to be fitted when the intake grille was added to the bodyside. | |||
| 543A |
 |
30406 | DQ231 |
| 634 |
 |
30498 30601 |
DQ213 |
Driving Motor Composite Lavatory (DMCL)
There were two versions for the two-character vehicles, those for the ER had luggage area replacing two seats opposite the toilet.
| Diagram | Page | Lot Number / Batch |
Design Code |
|---|---|---|---|
| 544 |  |
30408 | DP219 (DTS) DP310 (DTC) |
| 609 |  |
30461 | DP226 (DTS) DP311 (DTC) |
| 638 |  |
30660 | DP227 (DTS) DP312 (DTC) |
Driving Trailer Composite Lavatory (DTCL)
| Diagram | Page | Lot Number / Batch |
Design Code |
|---|---|---|---|
| 640 |
 |
30409 30410 30466 |
DS207 (DTS) DS310 (DTC) |
| 640 with note |
 |
30409 30410 30466 |
DS207 (DTS) DS310 (DTC) |
| There was an ammended version of 640 where a twin seat was turned 90% to allow heating ducting to be fitted when the intake grille was added to the bodyside | |||
| 640A |
 |
30409 | DS314 (DTC) |
| 646 |
 |
30499 30602 |
DS311 (DTC) |
Trailer Second Lavatory (TSL)
There seems to be little difference between these two - on one the centre saloon is non-smoking and the tare weight is one ton lighter, 22 tons rather than 23. Did 33 ashtrays weigh one ton?
I have also come across alternative versions of both types, and these show the tare weight as 21 tons.
| Diagram | Page | Lot Number / Batch |
Design Code |
|---|---|---|---|
| 545 |
 |
30493 | DT206 |
| 545 Alternative |
 |
30493 | DT206 |
| 547 |
 |
30411 | DT205 |
| 547 Alternative |
 |
30411 | DT205 |
Trailer Brake Second Lavatory (TBSL)
The first version shows the tare weight as 23 tons, the alternative version lists it as 21 tons.
| Diagram | Page | Lot Number / Batch |
Design Code |
|---|---|---|---|
| 546 |
 |
30412 | DU201 |
| 546 Alternative |
 |
30412 | DU201 |