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

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 Rail Data Exchange collection; Alfred Bruce, The Steam Locomotive in America (New York: Bonanza Books, 1952); Jim Shaughnessy, Delaware and Hudson (Syracuse University Press, 1997 [originally Howell-North Books, 1982]), pp. 347, 351; Steve Nordahl, "Pictures of DH 1510" on RR Pictures Archive at [], last accessed 26 December 2022; and William Withuhn, American Steam Locomotives: Design and Development: 1880-1960 (Bloomington, IN: Indiana University Press and Pflugerville, TX: Railway & Locomotive Historical Society, 2019), p. 302-303. (Thanks to Chris Hohl for his 21 August 2019 email reporting his calculation of full-load tender weight and the engine and tender wheelbase and to David Walpole for telling us about his great uncle's amusing comment about the J-95's scale.) Works numbers were 69297-69316 in June 1940, 1520-1534 in 1942, and 1535-1539 in 1946.

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 two years, and 1535-1539 (74666-74670) procured in 1946.

Considered by many observers to be the handsomest of the Challenger type. David Walpole's granfather once described his brother-in-law Edward Short's appearance when at the throttle of the massive J-95: "He said that when Uncle Ed was in the engineer's seat of a Challenger, he looked like a flea sitting on a dog's back.

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."

Jim Shaughnessey limned an appreciation of what the Js contributed to D&H's war effort: "Day and night they raced between Binghamton and Mechanicville with trainloads of export goods and arms bound for the New England ports of Boston and Portland, with the deep-toned notes of their steamboat-type whistles echoing and re-echoing through the rolling confines of the Susquehanna valley en route."

Chris Hohl noted that the tender capacity shown in the D&H diagrams gave a loaded tender weight assuming the tender's coal and water were at 2/3s full capacity. That figure was 311,800 lb (141,430 kg). Hohl and Locobase agree that the full-load weight is approximately 195 short ton, although they used different methods to derive it.

Jim Shaugnessey's roster compilations noted that the 1510's boiler exploded on 15 July 1941 at "Warnerville (about 2 miles south of Cobleskill) while pulling symbol freight MB-2." Steve Nordahl, quoting pp. 380-381 of Jim Shaugnessy's book, gave more details of the tragic outcome in his post on the RR Picture Archives website: " 4-6-6-4 No. 1510 as it was starting to climb Richmondville Hill in July 1941 ... The explosion was blamed on low water in the boiler and [caused the] deaths of three men.. Surprisingly, #1510 was rebuilt and placed back in service by the end of 1941."

Luria, a well-known scrap dealer, bought all of the class in 10 months from October 1952 to August 1953.