Data from The English Mechanic and World of Science, 1 February 1884, p. 480.
Possibly predecessors to the Mail engines described in Locobase 2210 or simply variants from the same class, the singles shown here were a bit smaller and lighter. They had the tall drivers and the midfeather firebox preferred by Cudworth for his engines. Some were built at Ashford, others at Vulcan Foundry. Many were rebuilt in 1877 by Watkin.
Data from Ahrons (1927), pp. 145, 147.
Designed by J.I. Cudworth, who used outside frames and outside bearings on all axles. They worked 135-140 ton Dover Mail expresses for 24 years. Ahrons notes that its route went over "...a road by no means easy in regard to gradients ..."
NB: Tube length is estimated based on subtracting the stated firebox area from the stated total evaporative heating surface and comparing that to a calculated area of the given number and diameter of tubes.
| Principal Dimensions by Steve Llanso of Middle Run Media | ||
|---|---|---|
| Class | 81 | |
| Locobase ID | 9907 | 2210 |
| Railroad | South Eastern | South Eastern |
| Country | Great Britain | Great Britain |
| Whyte | 2-2-2 | 2-2-2 |
| Number in Class | ||
| Road Numbers | ||
| Gauge | Std | Std |
| Number Built | ||
| Builder | several | |
| Year | 1861 | 1861 |
| Valve Gear | ||
| Locomotive Length and Weight | ||
| Driver Wheelbase (ft / m) | ||
| Engine Wheelbase (ft / m) | 17.25 / 5.26 | 17.25 / 5.26 |
| Ratio of driving wheelbase to overall engine wheelbase | ||
| Overall Wheelbase (engine & tender) (ft / m) | ||
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 27,888 / 12,650 | 28,224 / 12,802 |
| Weight on Drivers (lbs / kg) | 27,888 / 12,650 | 28,224 / 12,802 |
| Engine Weight (lbs / kg) | 71,120 / 32,260 | 74,144 / 33,631 |
| Tender Loaded Weight (lbs / kg) | ||
| Total Engine and Tender Weight (lbs / kg) | ||
| Tender Water Capacity (gals / ML) | 3000 / 11.36 | |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | ||
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 46 / 23 | 47 / 23.50 |
| Geometry Relating to Tractive Effort | ||
| Driver Diameter (in / mm) | 84 / 2134 | 84 / 2134 |
| Boiler Pressure (psi / kPa) | 130 / 900 | 130 / 900 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 16" x 22" / 406x559 | 17" x 22" / 432x559 |
| Tractive Effort (lbs / kg) | 7409 / 3360.67 | 8364 / 3793.85 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.76 | 3.37 |
| Heating Ability | ||
| Tubes (number - dia) (in / mm) | 170 - 2" / 51 | |
| Flues (number - dia) (in / mm) | ||
| Flue/Tube length (ft / m) | 11 | |
| Firebox Area (sq ft / m2) | 132.50 / 12.31 | 163 / 15.15 |
| Grate Area (sq ft / m2) | 21 / 1.95 | 21.20 / 1.97 |
| Evaporative Heating Surface (sq ft / m2) | 1105 / 102.70 | 1138 / 105.76 |
| Superheating Surface (sq ft / m2) | ||
| Combined Heating Surface (sq ft / m2) | 1105 / 102.70 | 1138 / 105.76 |
| Evaporative Heating Surface/Cylinder Volume | 215.84 | 196.90 |
| Computations Relating to Power Output (More Information) | ||
| Robert LeMassena's Power Computation | 2730 | 2756 |
| Same as above plus superheater percentage | 2730 | 2756 |
| Same as above but substitute firebox area for grate area | 17,225 | 21,190 |
| Power L1 | 6283 | 6150 |
| Power MT | 496.69 | 480.39 |