Norfolk & Western Other Articulated Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class X1 (Locobase 13802)

Data from "Articulated Compound Locomotive," American Engineer & Railroad Journal, Volume 84, No 10 (September 1910), pp. 341-342. See also N&W 12-1929 Locomotive Diagrams supplied in May 2005 by Allen Stanley. (Thanks to Chris Hohl for supplying the valve gear ID.)

In the same year that Baldwin delivered its Y-1 2-8-8-2 locomotives, Alco produced this pair of all-adhesion pushers. The AERJ report notes that the two builders differed in their approaches with these two orders displaying three main areas of differences: "...wheel arrangement, boiler construction and system of compounding."

The absence of a leading truck meant that these would remain unique on the N & W - all of their other large articulateds had at least two auxiliary axles.

Contrasting the two boilers reveals that Baldwin's interest in its own style of large feedwater heater (such as fitted to most Santa Fe articulateds at this time, for example) and Baldwin reheater ahead of the boiler proper stood in stark relief against Schenectady's provision of "...simply and entirely a steam generator." Tube length was 3 feet longer, reaching the maximum extent any articulated would ever deploy. Even with so long a boiler and the lack of a leading truck, the smokebox door opening was above the space between the first and second driving axles.

Schenectady's use of the Mellin compounding system meant the inclusion of an automatic intercepting valve (as opposed to the much simpler, nonadjustable valve used in the Y1s) that admitted steam " a reduced pressure to the receiver as soon as the throttle is opened and automatically closes when the exhaust from the high-pressure cylinders builds up the receiver pressure to the proper point."

Locobase observes that both had very small fireboxes for the boiler.

Which design better suited the purpose of moving freight over the road? Well, according to Drury (1993), "Tests showed the X1 was the better performer, but the leading and trailing trucks of the Y1 gave it better riding stability." He also points out that the Y1s were retired first because of their complicated separable boilers, while the N & W superheated the X1s and raised their boiler pressures to 230 psi.

They ended their days as hump switchers before being retired in 1934.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID13,802
RailroadNorfolk & Western (N&W)
Number in Class5
Road Numbers990-994
Number Built5
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)15.50 / 4.72
Engine Wheelbase (ft / m)41.17 / 12.55
Ratio of driving wheelbase to overall engine wheebase 0.38
Overall Wheelbase (engine & tender) (ft / m)72.83 / 22.20
Axle Loading (Maximum Weight per Axle) (lbs / kg)49,800 / 22,589
Weight on Drivers (lbs / kg)376,800 / 170,914
Engine Weight (lbs / kg)376,800 / 170,914
Tender Loaded Weight (lbs / kg)167,500 / 75,977
Total Engine and Tender Weight (lbs / kg)544,300 / 246,891
Tender Water Capacity (gals / ML)9000 / 34.09
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)14 / 12.70
Minimum weight of rail (calculated) (lb/yd / kg/m)79 / 39.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)56 / 1422
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)24.5" x 30" / 622x762
Low Pressure Cylinders (dia x stroke) (in / mm)39" x 30" / 991x762
Tractive Effort (lbs / kg)78,394 / 35558.96
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.81
Heating Ability
Firebox Area (sq ft / m2)212 / 19.70
Grate Area (sq ft / m2)75.30 / 7
Evaporative Heating Surface (sq ft / m2)5379 / 499.72
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)5379 / 499.72
Evaporative Heating Surface/Cylinder Volume328.60
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation15,060
Same as above plus superheater percentage15,060
Same as above but substitute firebox area for grate area42,400
Power L12898
Power MT135.65

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