Central RR of New Jersey 4-6-4 "Hudson" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class H-1 / SU-31 (Locobase 6530)

Data from 1944 locomotive diagram supplied by Allen Stanley in May 2005 from his extensive Rail Data Exchange. See also DeGolyer, Vol 69, pp. 18+. Works numbers were 57387-57390 in October 1923, 57533-57534 in November.

Anthracite road historian Marty Feldner told Locobase in March 2003 that this big tank was ".. a surprisingly modern loco, and well-proportioned. Wooton firebox over the last driver, Elesco feedwater heater, Walschaerts gear ..." Locobase had uncovered his part in a discussion over proper terminology for a tank locomotive like this. Feldner didn't think "Baltic" or "Hudson" properly described it, preferring 4-6-0+4t instead.

The National Park Service's Steamtown study on the Grand Trunk Western's X-10 class (see Locobase 2454) includes discussion of the H-1s, which the NPS notes were very similar. It notes that the piston valves measured 11" [279 mm] in diameter, a generous proportion. The NPS quotes Paul Warner's report in the Baldwin house organ in 1926: "While the greater part of the suburban traffic on the New Jersey Central [sic] is now being worked by locomotives with separate tenders, the double-ender tank locomotives have proved practically indispensable on certain short runs where facilities for turning the engines are lacking. The locomotives operate in either direction with equal facility, and are well liked by the enginemen."

Reverse gear was Alco Type E.

The running gear was designed for a line with tight curves: in addition to the relatively small drivers (which also aided acceleration), the two swing-bolster trucks were designed to take curves of up to 20 degrees. Unlike the X-10s, the CNJ engines had equally spaced driving axles.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassH-1 / SU-31
Locobase ID6530
RailroadCentral RR of New Jersey
Number in Class6
Road Numbers225-230
Number Built6
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.75 / 4.19
Engine Wheelbase (ft / m)39.25 / 11.96
Ratio of driving wheelbase to overall engine wheelbase 0.35
Overall Wheelbase (engine & tender) (ft / m)39.25 / 11.96
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)163,500 / 74,162
Engine Weight (lbs / kg)291,700 / 132,313
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)291,700
Tender Water Capacity (gals / ML)4000 / 15.15
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)6 / 6
Minimum weight of rail (calculated) (lb/yd / kg/m)91 / 45.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)63 / 1600
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)21" x 26" / 533x660
Tractive Effort (lbs / kg)30,940 / 14034.16
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.28
Heating Ability
Tubes (number - dia) (in / mm)202 - 2" / 51
Flues (number - dia) (in / mm)32 - 5.375" / 137
Flue/Tube length (ft / m)11.75 / 3.58
Firebox Area (sq ft / m2)164 / 15.24
Grate Area (sq ft / m2)68.26 / 6.34
Evaporative Heating Surface (sq ft / m2)1923 / 178.72
Superheating Surface (sq ft / m2)430 / 39.96
Combined Heating Surface (sq ft / m2)2353 / 218.68
Evaporative Heating Surface/Cylinder Volume184.55
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation13,652
Same as above plus superheater percentage16,109
Same as above but substitute firebox area for grate area38,704
Power L113,328
Power MT539.14

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