Some data from Traite pratique de la machine locomotive ... By Maurice Demoulin, 1898
Librairie polytechnique, Baudry et Cie, p 404-405; and "Heavy 12-Wheel Locomotive: Great Northern Railway, USA", Railway Engineer, Volume 19, No 4 (April 1898), table, p. 113. Works numbers were 4523-4526 in 1897.
These Twelve-wheelers were delivered as compounds in 1897 and intended, said Demoulin, for the Helena-Missoula section. This portion of the NP had a ruling grade of 2.2% that covered almost 17 miles (27 km). The writer noted a horsepower output of 1,300 continuous over a three-hour period. Although regarded as mammoths of their day when they first appeared, this quartet would soon be outstripped in their dimensions on the NP by Schenectady-built Ten-wheelers (Locobase 9542).
Firebox heating surface area included 15.3 sq ft () of water tubes.
Rebuilt 1917 with two 20" x 30" cylinders and a superheater, TE of 32,454. See Locobase 6561.
NB: The evaporative heating surface is an estimate calculated by adding the calculated tube heating surface to the reported firebox heating surface.
Data from NP 1 - 1929 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange collection. Stanley later added the NP Locomotive Cards scan in August 2013.
Locobase is intrigued by all this attention paid to a rarely used wheel arrangement originally delivered as compounds in 1897 (Locobase 929): superheater, piston valves, new valve gear, new tubes and flues ... The later diagram describes the Xs as "switchers" and it's possible that they filled a key niche in short-haul freight.
In September 1936, the NP sold the 14 to the Cowlitz, Chehalis & Cascade Railroad. 13 and 15 were dismantled in March 1940 with the 16 going under the torch in April.
Principal Dimensions by Steve Llanso of Middle Run Media | ||
---|---|---|
Class | X | X - superheated |
Locobase ID | 929 | 6561 |
Railroad | Northern Pacific (NP) | Northern Pacific (NP) |
Country | USA | USA |
Whyte | 4-8-0 | 4-8-0 |
Number in Class | 4 | 4 |
Road Numbers | 13-16 | 13-16 |
Gauge | Std | Std |
Number Built | 4 | |
Builder | Schenectady | NP |
Year | 1897 | 1917 |
Valve Gear | Stephenson | Walschaert |
Locomotive Length and Weight | ||
Driver Wheelbase (ft / m) | 15.50 / 4.72 | 15.50 / 4.72 |
Engine Wheelbase (ft / m) | 26.33 / 8.03 | 26.33 / 8.03 |
Ratio of driving wheelbase to overall engine wheelbase | 0.59 | 0.59 |
Overall Wheelbase (engine & tender) (ft / m) | ||
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 40,900 / 18,552 | |
Weight on Drivers (lbs / kg) | 150,000 / 68,039 | 146,200 / 66,315 |
Engine Weight (lbs / kg) | 186,000 / 84,368 | 184,200 / 83,552 |
Tender Loaded Weight (lbs / kg) | 94,000 / 42,638 | 94,000 / 42,638 |
Total Engine and Tender Weight (lbs / kg) | 280,000 / 127,006 | 278,200 / 126,190 |
Tender Water Capacity (gals / ML) | 4350 / 16.48 | 4350 / 16.48 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 9 / 8 | 9 / 8 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 63 / 31.50 | 61 / 30.50 |
Geometry Relating to Tractive Effort | ||
Driver Diameter (in / mm) | 55 / 1397 | 55 / 1397 |
Boiler Pressure (psi / kPa) | 200 / 1380 | 175 / 1210 |
High Pressure Cylinders (dia x stroke) (in / mm) | 23" x 30" / 584x762 (1) | 20" x 30" / 508x762 |
Low Pressure Cylinders (dia x stroke) (in / mm) | 34" x 30" / 864x762 (1) | |
Tractive Effort (lbs / kg) | 33,653 / 15264.76 | 32,455 / 14721.36 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.46 | 4.50 |
Heating Ability | ||
Tubes (number - dia) (in / mm) | 332 - 2.25" / 57 | 206 - 2" / 51 |
Flues (number - dia) (in / mm) | 32 - 5.5" / 140 | |
Flue/Tube length (ft / m) | 13.92 / 4.24 | 13.08 / 3.99 |
Firebox Area (sq ft / m2) | 221.80 / 20.61 | 206.50 / 19.19 |
Grate Area (sq ft / m2) | 35 / 3.25 | 35.05 / 3.26 |
Evaporative Heating Surface (sq ft / m2) | 2943 / 273.41 | 2234 / 207.62 |
Superheating Surface (sq ft / m2) | 468 / 43.49 | |
Combined Heating Surface (sq ft / m2) | 2943 / 273.41 | 2702 / 251.11 |
Evaporative Heating Surface/Cylinder Volume | 407.76 | 204.77 |
Computations Relating to Power Output (More Information) | ||
Robert LeMassena's Power Computation | 7000 | 6134 |
Same as above plus superheater percentage | 7000 | 7176 |
Same as above but substitute firebox area for grate area | 44,360 | 42,281 |
Power L1 | 4713 | 10,996 |
Power MT | 277.08 | 663.26 |