Data from E L Ahrons, The British Steam Locomotive from 1825 to 1925 (London: Ian Allan, 1926). See also Clement E Stretton, "The New Express Engines Upon the Glasgow and South Western Railway," English Mechanic and World of Science, No. 819 (3 December 1880), p. 301; and Graham Glover, British Locomotive Design 1825-1960 (London: George Allen & Unwin Ltd, 1967).
A Hugh Smellie design that Glover commented deserve the palm for Scottish 2-4-0s, although he's not certain why they were called the "Apostles."
"Certainly, " says Glover, "-- like all of this designer's productions -- they were exemplary locomotives -- fast, powerful, and economical."
At the time of their introduction, Clement Stretton provided detailed support for a positive view of this design: "The distance from Glasgow to Cirlisle is 115 miles 36 chains, and from the working time-tables I find that 2h. 43m. is the time allowed to perform the journey, including 10 minutes' standing at Kilmaruock, and Dumfries stations.
"When the gradients are taken into consideration it will be seen that the work performed by the Glasgow and South-Western engines is very good indeed, and, if it were necessary, the journey could be accomplished in less time by them."
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Twelve Apostles |
| Locobase ID | 2996 |
| Railroad | Glasgow & South Western |
| Country | Great Britain |
| Whyte | 2-4-0 |
| Number in Class | 12 |
| Road Numbers | |
| Gauge | Std |
| Number Built | 12 |
| Builder | Kilmarnock |
| Year | 1879 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | |
| Engine Wheelbase (ft / m) | 16.25 |
| Ratio of driving wheelbase to overall engine wheelbase | |
| Overall Wheelbase (engine & tender) (ft / m) | |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 31,360 |
| Weight on Drivers (lbs / kg) | 65,184 / 29,567 |
| Engine Weight (lbs / kg) | 86,240 / 39,118 |
| Tender Loaded Weight (lbs / kg) | 61,824 / 28,043 |
| Total Engine and Tender Weight (lbs / kg) | 148,064 / 67,161 |
| Tender Water Capacity (gals / ML) | 2520 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 3.30 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 54 / 27 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 81.50 / 2070 |
| Boiler Pressure (psi / kPa) | 140 / 970 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 18" x 26" / 457x660 |
| Tractive Effort (lbs / kg) | 12,300 / 5579.19 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 5.30 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 240 - 1.625" / 41 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | |
| Firebox Area (sq ft / m2) | 101 / 9.39 |
| Grate Area (sq ft / m2) | 16 / 1.49 |
| Evaporative Heating Surface (sq ft / m2) | 1206 / 112.08 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1206 / 112.08 |
| Evaporative Heating Surface/Cylinder Volume | 157.49 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 2240 |
| Same as above plus superheater percentage | 2240 |
| Same as above but substitute firebox area for grate area | 14,140 |
| Power L1 | 4249 |
| Power MT | 287.42 |