US Government 2-4-4 Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class General Rodman (Locobase 11497)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 26, p. 255; Record of Recent Construction No 48, pp.24-25. See also "Fort Hancock and Sandy Hook Proving Grounds", Military Railroads of the New York Area website at http://members.trainweb.com/bedt/milrr/fthancock.html, last accessed 5 February 2017; and Randall Gabrielan, Images of America--Sandy Hook (Arcadia Publishing 1999), p. 67. .(Thanks to Chris Hohl for his 4 December 2017 email noting the coal bunker's capacity.) Works number was 23969 in March 1904.

The Military Railroad's website shows a photo of the General Rodman at the head of a two-car train. Its profile is deceptive at first, seeming to show a tender-engine layout with a very short tender. The unusual wheel arrangement is explained by weight-distribution requirements and curve radii as tight as 200 feet (61.0 m).

Baldwin's optimistic weight estimates have been noted before and here Baldwin itself showed the disparity. The original specs called for weights distributed as follows: 12,000 lb (5,442 kg) on the lead, single-axle truck, "about" 55,000 lb (24,948 kg) on the drivers, and 32,000 lb (14,515 kg) on the bogie for a total of "about" 100,000 lb (45,359 kg) (The math calculated an engine total of 103,000 lb (46,720 kg) The Record of Recent Construction showed instead 13,520 lb (6,133 kg) on the front truck, 58,420 lb on the drivers, and 40,000 (18,144 kg) on the rear bogie for an overshoot of 11,940 lb.

According to Gabrielan, the Sandy Hook Proving Ground ran a passenger train each day to Highland Beach station in Sea Bright, where it picked up the facility's civilian employees. Because the same train took the employees home each night, the line was sooned called the "BNF Line" to represent the railroad's "Back n Forth" travel.

After working at the Sandy Hook Proving Ground, the 4 was transferred during World War One to the Aberdeen Proving Grounds as their #11.

Principal Dimensions by Steve Llanso of Sweat House Media
ClassGeneral Rodman
Locobase ID11,497
RailroadUS Government (Sandy Hook)
CountryUSA
Whyte2-4-4T
Number in Class1
Road Numbers4
GaugeStd
Number Built1
BuilderBurnham, Williams & Co
Year1904
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)7 / 2.13
Engine Wheelbase (ft / m)28.50 / 8.69
Ratio of driving wheelbase to overall engine wheebase 0.25
Overall Wheelbase (engine & tender) (ft / m)28.50 / 8.69
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)58,420 / 26,499
Engine Weight (lbs / kg)111,940 / 50,775
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)111,940
Tender Water Capacity (gals / ML)1500 / 5.68
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT) 2.50 / 2.30
Minimum weight of rail (calculated) (lb/yd / kg/m)49 / 24.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)54 / 1372
Boiler Pressure (psi / kPa)160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)15" x 22" / 381x559
Tractive Effort (lbs / kg)12,467 / 5654.94
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.69
Heating Ability
Firebox Area (sq ft / m2)108 / 10.03
Grate Area (sq ft / m2)19.50 / 1.81
Evaporative Heating Surface (sq ft / m2)896 / 83.24
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)896 / 83.24
Evaporative Heating Surface/Cylinder Volume199.13
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation3120
Same as above plus superheater percentage3120
Same as above but substitute firebox area for grate area17,280
Power L14596
Power MT346.88