| Present Location | NRM York |
| County Location | York |
| Designed For | NER |
| Build Location | Darlington |
| Diagram number | 101a |
| Type | SPEC |
| First Number | 3591 |
| Later Numbers | 23591, DE902502 |
| Present Number | 902502 |
| Current Livery | LNER - Teak |
| Gauge | 4ft 8 1/2in |
| Wheel Arrangement | 4-w bogies |
| Original Underframe | Yes |
| Original Bogies/Wheelsets | Yes |
| Additional Notes | Clerestory Dynamometer Car, most famous for the record-breaking run behind 'Mallard'. Replacement finally delivered 1951, so honourably retired and preserved by BTC. (NER Carriage Register says built March 1906) (as does NRM). |
| Owner | National Railway Museum |
| External Structural Condition | Good |
| Internal Structural Condition | Good |
| Underframe Condition | Good |
| External Finish | Satisfactory |
| Internal Finish | Satisfactory |
| Degree of External Originality | As built/last Passenger rebuild (BR or before) |
| Degree of Internal Originality | As built/last Passenger rebuild (BR or before) |
| Degree of Underframe/Running Gear Originality | As built/last Passenger rebuild (BR or before) |
| Degree of External Authenticity | Very Good |
| Degree of Internal Authenticity | Very Good |
| Degree of Underframe Authenticity | Very Good |
| Rarity | Unique |
| Historical Importance | Exceptionally Important |
| Storage | Secure Building |
| Operating | No |
| Survey Date | 06/09/1998 |
| Surveyor | Ian Smith |
| Photo Date | 18/08/2023 |
| Photo by | Paul Holroyd |
| At Risk | No |
| Date Record Last Updated | 09/09/2023 |
