Data from "Tank Locomotive for the Cliffe Hill Granite Co's 2-ft Gauge Ry.", Locomotive Magazine, Volume 18 (15 October 1912), p. 211. For the quarry, see "A Leicestershire Granite Quarry", The Surveyor and Municipal and County Engineer, Volume 25 (13 May 1904), p.612.
A 3-mile (4.8 km) road with steep gradients and light rail, the Cliffe Hill line moved granite from its quarry to Bardon Hill Station on the Midland Railway's Leicester and Burton line. The details highlight the challenge. Pulling the 42-ton (47 short tons) load in 14 wagons meant scaling a 3% grade while returning light traveled up an even steeper 1 in 22 (4 1/2%). At the time of "Mary's" arrival, much of the rail was still 24 lb/yard (12 kg/metre), but was being replaced by 40 lb/yard (20 kg/metre).
In response, Bagnall reproduced a "very useful and well-proportioned" locomotive fitted with a boiler of "very liberal proportions" that would "make the engine an excellent steamer and very economical."
The Mary operated for over 40 years before being scrapped in 1957.
A typical day for the Mary consisted of six round trip that included 15 minutes to Bardon Hill, followed by switching at the station, a return trip, and further shunting back at the quarry. That segment took 60 minutes, 620 Imp gallons (744 US gallons), and 9 cwt (1,008 lb).
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Mary |
| Locobase ID | 20047 |
| Railroad | Cliffe Hill Granite Company |
| Country | Great Britain |
| Whyte | 0-4-2T |
| Number in Class | 1 |
| Road Numbers | |
| Gauge | 2' |
| Number Built | 1 |
| Builder | WG Bagnall |
| Year | 1912 |
| Valve Gear | Bagnall Price |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 3.58 / 1.09 |
| Engine Wheelbase (ft / m) | 9.08 / 2.77 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.39 |
| Overall Wheelbase (engine & tender) (ft / m) | 9.08 / 2.77 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 10,640 / 4826 |
| Weight on Drivers (lbs / kg) | 21,280 / 9652 |
| Engine Weight (lbs / kg) | 25,200 / 11,431 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | 25,200 / 11,431 |
| Tender Water Capacity (gals / ML) | 240 / 0.91 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 0.55 / 1 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 18 / 9 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 24.50 / 622 |
| Boiler Pressure (psi / kPa) | 160 / 1100 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 8" x 12" / 203x305 |
| Tractive Effort (lbs / kg) | 4263 / 1933.67 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.99 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 58 - 1.75" / 44 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 6.25 / 1.90 |
| Firebox Area (sq ft / m2) | 32 / 2.97 |
| Grate Area (sq ft / m2) | 6.66 / 0.62 |
| Evaporative Heating Surface (sq ft / m2) | 197 / 18.30 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 197 / 18.30 |
| Evaporative Heating Surface/Cylinder Volume | 282.18 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 1066 |
| Same as above plus superheater percentage | 1066 |
| Same as above but substitute firebox area for grate area | 5120 |
| Power L1 | 3341 |
| Power MT | 692.26 |