A Brake Standard Open (Micro-Buffet), often abbreviated to BSOT or BSO(T), is a type of railway carriage used by British Rail.
| British Rail Brake Standard Open (Micro-Buffet) | |
|---|---|
 BR Mk 1 BSOT, no. 9015 at Swanage on 13 April 2006. This coach is preserved on the Swanage Railway and is painted in Southern Region malachite green. It was converted from BSO 9229. | |
| In service | 1952– |
| Manufacturer | Mark 1: BR Doncaster & Wolverton, Mark 2: BR Derby |
| Number built | Mark 1: 18, Mark 2: 8 |
| Fleet numbers | Mark 1: 9500-9017, Mark 2: 9100-9107 |
| Capacity | Mark 1: 31 seats, Mark 2: 23 seats |
| Operators | British Rail |
| Specifications | |
| Car length | 64 ft 6 in (19.66 m) |
| Width | 9 ft 3 in (2.82 m) |
| Height | 12 ft 9 1⁄2 in (3.90 m) |
| Maximum speed | 90 or 100 mph (145 or 161 km/h) |
| Weight | 34 long tons (35 t; 38 short tons) |
| HVAC | Steam, electric, or dual heating, ETH index (Mk1 3, Mk2 4) |
| Bogies | Mark 1: BR1 or Commonwealth, Mark 2: B4 |
| Braking system(s) | Vacuum, air, or both |
| Coupling system | Drop-head knuckle coupler on draw-hook (dual) |
| Track gauge | 4 ft 8 1⁄2 in (1,435 mm) standard gauge |
These coaches were converted from a Brake Standard Open (BSO), by replacing one passenger seating bay with a counter for serving food, and space for a trolley for light refreshments. The toilet was removed and the space converted to a steward's prep-room and store.
Two batches of coaches were converted, as shown below.
| Number range | Type |
|---|---|
| 9500-9017 | Mark 1 |
| 9100-9107 | Mark 2 |
These coaches are no longer in scheduled main-line services, the last being withdrawn in the mid-1990s. However, several coaches from both Mk1 and Mk2 types have been preserved on heritage railways, or are used by charter companies. These are detailed below:
| Numbers | Built | Location | Condition | |
|---|---|---|---|---|
| BSOT | BSO | |||
| 9500 | 9276 | 1956 Doncaster | Gloucestershire Warwickshire Railway | In service |
| 9001 | 9275 | 1956 Doncaster | Paignton and Dartmouth Steam Railway | In service |
| 9002 | 9372 | 1963 Wolverton | Scrapped | |
| 9003 | 9377 | 1963 Wolverton | Dean Forest Railway | In service |
| 9004 | 9379 | 1963 Wolverton | Scrapped | |
| 9005 | 9373 | 1963 Wolverton | Scrapped | |
| 9006 | 9365 | 1963 Wolverton | Scrapped | |
| 9007 | 9374 | 1963 Wolverton | Scrapped | |
| 9008 | 9367 | 1963 Wolverton | Scrapped | |
| 9009 | 9378 | 1963 Wolverton | Scrapped | |
| 9010 | 9369 | 1963 Wolverton | Mid Norfolk Railway | In service |
| 9011 | 9370 | 1963 Wolverton | Embsay and Bolton Abbey Steam Railway | In service |
| 9012 | 9371 | 1963 Wolverton | Scrapped | |
| 9013 | 9368 | 1963 Wolverton | Scrapped | |
| 9014 | 9380 | 1963 Wolverton | West Somerset Railway | In service |
| 9015 | 9229 | 1955 Doncaster | Swanage Railway | In service |
| 9016 | 9237 | 1956 Doncaster | Bo'ness and Kinneil Railway | In service |
| 9017 | 9375 | 1963 Wolverton | Scrapped | |
| 9100 | 9405 | 1966 Derby | Royal Deeside Railway | Static use as a visitor centre |
| 9101 | 9398 | 1966 Derby | Vintage Trains | Mainline charter service |
| 9102 | 9383 | 1966 Derby | Northampton & Lamport Railway | In service |
| 9103 | 9389 | 1966 Derby | Nottingham Heritage Centre | In service |
| 9104 | 9401 | 1966 Derby | West Coast Railways | Mainline charter service |
| 9105 | 9404 | 1966 Derby | Peak Rail | In service |
| 9106 | 9406 | 1966 Derby | Telford Steam Railway | Under Restoration |
| 9107 | 9407 | 1966 Derby | Scrapped | |