Data from "South Eastern Ry Passenger Engines "259" Class," The Locomotive Magazine, Vol VIII (21 March 1903), p. 192. See also [WL] "SER Express Engines", English Mechanic and World of Science, Volume 26, No 671 (1 February 1878), pp. 510-511.
Glover (1967) says this class was modelled on the London & North Western's "Precedents." The LM article explains that in 1875 Cudworth, then locomotive superintendent, locked horns with the SER's directors over what designs to build or procure. In what was an intolerable breach of authority, the board arranged for the L & NWR's Ramsbottom to design a new class of passenger engines without consulting Cudworth. He naturally quit and was replaced by Watkin pro tem.
Sharp, Stewart's works numbers 2610-2619 were the first ten engines to arrive in 1876; Avonside contributed 10 more (works numbers 1147-1156). They turned out to be "somewhat of a disappointment," and not too long after their introduction were relegated to branch traffic.
These J.I. Cudworth engines were built in two sub-classes, in which the early group had fireboxes measuring 7' 6" and had 140.75 sq ft heating surface. Later engines had a firebox cut back to 6' 6" (113.7 sq ft), which reduced grate area to 19.8 sq ft and total evaporative heating surface to 938.7 sq ft. See Ahrons (1927) for data and an early photograph that shows a long, straight boiler, unsheltered footplate, brass steam dome well forward, open splasher on the lead driver and boxed in splasher on the trailing driver, outside springs, and a tall stack and safety valve stand.
Principal Dimensions by Steve Llanso of Middle Run Media | ||
---|---|---|
Class | 259 / Ironclads | unknown |
Locobase ID | 3001 | 2927 |
Railroad | South Eastern | South Eastern |
Country | Great Britain | Great Britain |
Whyte | 2-4-0 | 2-4-0 |
Number in Class | 20 | 100 |
Road Numbers | 259-278 | |
Gauge | Std | Std |
Number Built | 20 | 100 |
Builder | several | EB Wilson |
Year | 1875 | 1856 |
Valve Gear | Stephenson | |
Locomotive Length and Weight | ||
Driver Wheelbase (ft / m) | 7.42 / 2.26 | 7.42 / 2.26 |
Engine Wheelbase (ft / m) | 14.83 / 4.52 | 14.83 / 4.52 |
Ratio of driving wheelbase to overall engine wheelbase | 0.50 | 0.50 |
Overall Wheelbase (engine & tender) (ft / m) | ||
Axle Loading (Maximum Weight per Axle) (lbs / kg) | ||
Weight on Drivers (lbs / kg) | 47,040 / 21,337 | |
Engine Weight (lbs / kg) | 73,920 / 33,530 | 68,320 / 30,989 |
Tender Loaded Weight (lbs / kg) | 68,880 / 31,243 | |
Total Engine and Tender Weight (lbs / kg) | 142,800 / 64,773 | |
Tender Water Capacity (gals / ML) | 3000 / 11.36 | |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 3.30 / 3 | |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 39 / 19.50 | |
Geometry Relating to Tractive Effort | ||
Driver Diameter (in / mm) | 78 / 1981 | 72 / 1829 |
Boiler Pressure (psi / kPa) | 140 / 970 | 120 / 830 |
High Pressure Cylinders (dia x stroke) (in / mm) | 17" x 24" / 432x610 | 16" x 24" / 406x610 |
Tractive Effort (lbs / kg) | 10,582 / 4799.92 | 8704 / 3948.07 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 5.40 | |
Heating Ability | ||
Tubes (number - dia) (in / mm) | 208 - 1.75" / 44 | |
Flues (number - dia) (in / mm) | ||
Flue/Tube length (ft / m) | 10.50 / 3.20 | |
Firebox Area (sq ft / m2) | 102 / 9.48 | 140.75 / 13.08 |
Grate Area (sq ft / m2) | 16.15 / 1.50 | 22.40 / 2.08 |
Evaporative Heating Surface (sq ft / m2) | 1104 / 102.57 | 950 / 88.29 |
Superheating Surface (sq ft / m2) | ||
Combined Heating Surface (sq ft / m2) | 1104 / 102.57 | 950 / 88.29 |
Evaporative Heating Surface/Cylinder Volume | 175.10 | 170.10 |
Computations Relating to Power Output (More Information) | ||
Robert LeMassena's Power Computation | 2261 | 2688 |
Same as above plus superheater percentage | 2261 | 2688 |
Same as above but substitute firebox area for grate area | 14,280 | 16,890 |
Power L1 | 4659 | 4264 |
Power MT | 399.68 |