Considered by many observers to be the handsomest of the Challenger type. More important, it was this class that introduced flat bearing surfaces on the front boiler supports. Alfred Bruce acknowledged in 1952 (p. 327): "The flat bearing-plate surfaces required careful alignment on the erecting floor, but they were well worth the effort."
Why? This modification in how the front engine was allowed to move under the boiler was combined with a new limitation on how much was allowed in the articulation pin's vertical clearance. Now the front engine moved only as much what its springs would allow, said Bruce, "..as in the case of the rigid-chassis engine."
The payoff in productivity was especially noticeable where the trackbed and alignment would allow it: "The result is the most stable-riding articulated engine ever built and one that is safely operated at speeds up to 60 or 70 miles per hour." At those speeds, Bruce declared, "[t]here are no smoother riding articulated steam locomotives today."
All were disposed off in 10 months from October 1952 to August 1953.
| Specifications | |
|---|---|
| Class | J-95 |
| Locobase ID | 338 |
| Railroad | Delaware & Hudson |
| Whyte | 4-6-6-4 |
| Road Numbers | 1500-1539 |
| Gauge | Std |
| Builder | Alco-Schenectady |
| Year | 1940 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase | 12.17' |
| Engine Wheelbase | 59.92' |
| Ratio of driving wheelbase to overall engine wheebase | 0.20 |
| Overall Wheelbase (engine & tender) | |
| Axle Loading (Maximum Weight per Axle) | |
| Weight on Drivers | 406500 lbs |
| Engine Weight | 597000 lbs |
| Tender Light Weight | 311800 lbs |
| Total Engine and Tender Weight | 908800 lbs |
| Tender Water Capacity | 22500 gals |
| Tender Fuel Capacity (oil/coal) | 26 tons |
| Minimum weight per yard of rail on which locomotive could run | 113 lb rail |
| Geometry Relating to Tractive Effort | |
| Driver Diameter | 69" |
| Boiler Pressure | 285 psi |
| Cylinders (dia x stroke) | 20.5" x 32" (4) |
| Tractive Effort | 94428 lbs |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.30 |
| Heating Ability | |
| Firebox Area | 633 sq. ft |
| Grate Area | 108.20 sq. ft |
| Evaporative Heating Surface | 5389 |
| Superheating Surface | 1681 |
| Combined Heating Surface | 7070 |
| Evaporative Heating Surface/Cylinder Volume | 220.42 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 30837 |
| Same as above plus superheater percentage | 38238 |
| Same as above but substitute firebox area for grate area | 223702 |
| Power L1 | 31748 |
| Power MT | 1033.10 |
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