Data from "Tank Locomotive for the West Chase Colliery", Locomotive Magazine, Volume XXIX [29], No 365 (15 January 1923), p. 24. See also Spa Valley Railway - 75F Loco Department, "Bagnall 0-6-0ST No. 2193 'Topham', Locomotive Biography Number 12, Spa Valley Railway, posted 12 July 2020, last accessed 16 November 2021.
LM's report noted several unusual features for a colliery locomotive including the outside radial Walschaert's valve gear and a Wakefield twelve-feed mechanical lubricator. The latter's feeds were distributed six to the axleboxes, two to the cylinders barrels. Two more went to the steam chests (each of these was divided into a further two) and two, also divided into four outlets, to each slide bar.
Spa Valley's account offers all kinds of interesting history for this well-publicized saddle tank, beginning with a hybrid payment arrangement. West Cannock and Bagnall's agreed that West Cannock would cover the 3,600 PS cost for this one-off engine by paying 600 PS and sending 3,000 PS in coal to Bagnall's Castle Works. "This was beneficial," the biography states '[owing] to the fact Bagnall's electricity generating plant at the Castle works was coal fired and there was a lower supply in coal production post World War One, caused by a post war trade depression."
West Cannock was very pleased with the power increment offered by the Topham and Bagnall's was delighted to showcase this reliable locomotive. See the account for the details of Topham's career, which was set to end twice before it completed a major coal shift to a new generating station. After this finished in midsummer 1970, the Topham was retired.
Topham soon entered excursion service in 1973 and ran for successive owners until its boiler ticket expired. Although the will was there to restore the engine to active service, funding the Topham hadn't proved possible as late as 2020.
An update viewed on 5 October 2024 said the following:" Being owned by the volunteer Society behind the railway, many of the volunteers have a soft spot for the engine and it is an aspiration the loco will get overhauled in the future"
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Topham |
| Locobase ID | 20951 |
| Railroad | West Cannock Colliery |
| Country | Great Britain |
| Whyte | 0-6-0ST |
| Number in Class | 1 |
| Road Numbers | |
| Gauge | Std |
| Number Built | 1 |
| Builder | WG Bagnall |
| Year | 1922 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 12 / 3.66 |
| Engine Wheelbase (ft / m) | 12 / 3.66 |
| Ratio of driving wheelbase to overall engine wheelbase | 1 |
| Overall Wheelbase (engine & tender) (ft / m) | 12 / 3.66 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 100,800 / 45,722 |
| Engine Weight (lbs / kg) | 100,800 / 45,722 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 1200 / 4.55 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 1.65 / 1.50 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 56 / 28 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 45 / 1143 |
| Boiler Pressure (psi / kPa) | 160 / 1100 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 17" x 24" / 432x610 |
| Tractive Effort (lbs / kg) | 20,962 / 9508.21 |
| Booster (lbs) | 2 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.81 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 177 - 1.75" / 44 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 10.50 / 3.20 |
| Firebox Area (sq ft / m2) | 81 / 7.53 |
| Grate Area (sq ft / m2) | 15 / 1.39 |
| Evaporative Heating Surface (sq ft / m2) | 936 / 86.96 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 936 / 86.96 |
| Evaporative Heating Surface/Cylinder Volume | 148.45 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 2400 |
| Same as above plus superheater percentage | 2400 |
| Same as above but substitute firebox area for grate area | 12,960 |
| Power L1 | 2552 |
| Power MT | 167.45 |