Delaware & Hudson 4-6-6-4 "Challenger" Locomotives of the USA

The Delaware & Hudson Railroad recieved its first "Challengers" in 1940 from the American Locomotive Company with the delivery of twenty of the 4-6-6-4s. These locomotives were designated Class J and assigned road numbers 1500 through 1519. They had four 20.5 x 32 cylinders, 69" drivers, a boiler pressure of 285 psi, exerted 94,000 lbs of tractive effort and weighed 597,000 pounds.

In 1943, fifteen more Class J "Challengers" arrived from ALCO and were given road numbers 1520 through 1534. these locomotives were similar to the Class Js received in 1940 except for a small increase in weight.

In 1945 and 1946, five more Class Js (road numbers 1535 through 1539) came from ALCO. These last five differred very little from the other "Challengers".

All 40 of the D&H "Challengers" were scrapped in 1952 and 1953. The tender used with number 1508 did survive the scrapper and is now in Binghamton, NY.

Roster by Richard Duley

ClassQty.Road NumberYear Built Builder Notes
J201500-15191940ALCONumbers 1500-1519 scrapped in 1952-1953
J151520-15341943ALCONumbers 1520-1534 scrapped in 1952-1953
J 41535-15381945ALCONumbers 1535-1538 scrapped in 1952-1953
J 115391946ALCONumber 1539 scrapped in 1953

Class Details by Steve Llanso of Sweat House Media

Class J-95 (Locobase 338)

Data from tables in 1947 Locomotive Cyclopedia. See also D&H 1 - 1946 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection.

Firebox heating surface included five thermic syphons of 77 sq ft (7.15 sq m) total. Forty engines -- 1500-1519 purchased in 1940 (builder's numbers 69297-69316), 1520-1534 (70006-70020) over next 2 years, and 1535-1539 (74666-74670) procured in 1946.

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, " 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 by Steve Llanso of Sweat House Media
Locobase ID338
RailroadDelaware & Hudson
Number in Class40
Road Numbers1500-1539
Number Built40
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase12.17'
Engine Wheelbase59.92'
Ratio of driving wheelbase to overall engine wheebase 0.20
Overall Wheelbase (engine & tender)
Axle Loading (Maximum Weight per Axle)
Weight on Drivers406500 lbs
Engine Weight597000 lbs
Tender Light Weight311800 lbs
Total Engine and Tender Weight908800 lbs
Tender Water Capacity22500 gals
Tender Fuel Capacity (oil/coal)26 tons
Minimum weight of rail (calculated)113 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter69"
Boiler Pressure285 psi
Cylinders (dia x stroke)20.5" x 32"
Tractive Effort94428 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.30
Heating Ability
Firebox Area633 sq. ft
Grate Area108.20 sq. ft
Evaporative Heating Surface5389 sq. ft
Superheating Surface1681 sq. ft
Combined Heating Surface7070 sq. ft
Evaporative Heating Surface/Cylinder Volume220.42
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation30837
Same as above plus superheater percentage38238
Same as above but substitute firebox area for grate area223702
Power L131748
Power MT1033.10



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