Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 27, pp. 39 and 108; and "Sentetsu Purei-class locomotives" in Wikipedia at [], last accessed 24 May 2024. (Thanks to Ivo Rutishauser for his email noting the earlier set of works numbers.) See also "The Seoul-Wiju Railway, Far East Economic Review, Volume III [3], No 11 (April 1907), pp. 347-348. (Thanks to Ivo Rutishauser for his email supplying the earlier specification page and noting the works numbers for the first eight locomotives.) Works numbers were 24028, 24036, 24079-24081, 24160-24161 in April 1904; 24179, 24185-24186, 24191-24194, 24206-24208 in May
This class, bought by Frazar & Company,repeated the design of 1901 Seoul-Chemulpo locomotives (Locobase 12495) under its new name. The latter seven were later assigned to the Japanese-controlled Seoul Government Military Railway (aka Shin Gishu Military Railway or Temporary Military Railway). In the specs, the tank's mark for all 20 read "I G R", presumably for "Imperial Government Railways."
Wikipedia says the locomotive class was named Pure, presumably because it had the nearest pronunciation to the original "Prairie" by which the wheel arrangement was known in the US.
FEER's 1904 report noted the 310-mile (500 km) Seoul-Wiju had been built in less than a year during wartime (i.e. the Russo-Japanese War of 1904-1905). This section would complete the Korean trunk line from Fusan in the extreme southeast to Wiju, just outide of the far northwestern port of Antung Scarcity of both coal and water supplies imposed a significant constraint on operations.
FEER's description of the initial construction notes the builders' adoption of relatively steep grades, wooden trestles, and light, though standard-gauge, track consisting of 30-ft sections weighing 60 lb/yard (30 kg/metre). By the middle of 1907, reconstruction of the railway reduced the maximum ruling grades to 1% and gentled the curves to a minimum of 40 metres. New rail sections measured 33 ft and weighed 75 lb/yard (37.5 kg/metre). "All of the steel girders, road metals and rolling stock, " the report added", are imported from the United States.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | Purei |
| Locobase ID | 13638 |
| Railroad | Seoul-Wiju |
| Country | Korea |
| Whyte | 2-6-2T |
| Number in Class | 20 |
| Road Numbers | 1-20 |
| Gauge | Std |
| Number Built | 20 |
| Builder | Burnham, Williams & Co |
| Year | 1904 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 11.33 / 3.45 |
| Engine Wheelbase (ft / m) | 25.17 / 7.67 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.45 |
| Overall Wheelbase (engine & tender) (ft / m) | 25.17 / 7.67 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 75,000 / 34,019 |
| Engine Weight (lbs / kg) | 105,000 / 47,627 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 1500 / 5.68 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 2 / 1.80 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 42 / 21 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 54 / 1372 |
| Boiler Pressure (psi / kPa) | 160 / 1100 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 16" x 24" / 406x610 |
| Tractive Effort (lbs / kg) | 15,474 / 7018.90 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.85 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 176 - 2" / 51 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 10.50 / 3.20 |
| Firebox Area (sq ft / m2) | 107 / 9.94 |
| Grate Area (sq ft / m2) | 18.20 / 1.69 |
| Evaporative Heating Surface (sq ft / m2) | 1067 / 99.13 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1067 / 99.13 |
| Evaporative Heating Surface/Cylinder Volume | 191.05 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 2912 |
| Same as above plus superheater percentage | 2912 |
| Same as above but substitute firebox area for grate area | 17,120 |
| Power L1 | 4130 |
| Power MT | 364.20 |