A 4-4-6-2 was an oddity on any railroad, although less so for one as adventurous in locomotive design as was the Santa Fe in the early 20th Century. Locobase 420 describes the articulated original and its short career.

The Atchison, Topeka & Santa Fe bought ten 4-6-4s (road number 3450 through 3459) from the Baldwin Locomotive Works in 1927. Curiously, Santa Fe did not refer to these locomotives as Hudsons. Instead, the Santa Fe classified them as an extension of the 3400 class of Pacifics.

The 256 class, Worley wrote, "gave the Santa Fe, for the first time, a capable, high-speed 4-4-2." With passenger-train weights increasing every year, this inherently limited arrangement enjoyed only short-term success and the class operated only until 1925-1927.

These were the most seriously single-purposed 4-6-0s, their small-diameter drivers connoting their drag-freight role. Most of the class served the Santa Fe for over 35 years and seventeen reached 40 years or more.

But when converted to 4-6-2s in August and October 1915, respectively, along much more conventional lines, the pair served for decades (see Locobase 8274). Principal Dimensions by Steve Llanso of Middle Run Media

Of the class, #1051 and 1125 supplied engine sets for a home-built 2-6-6-2 (1157). Sylvan Wood reported that twelve of the 1014 and 1050 classes (1020, 1027, 1127, 1087, and 1070, inter alia) were equipped with Hobart Allfree cylinders.

The diagram shows the long profile with a joint made of plates that linked the two 2-6-2 boilers as well as the surprisingly high drivers. In 1924, the 1051 was allowed to reclaim its identity as the 1157 was broken up.

Kiefer's design looked much like a Class K-5, Pacific. It was only 5 inches longer and had the same cylinders (25 X 28) and drivers (79") as the 4-6-2's, but the boiler pressure was increased to 225 psi. The new 4-6-4 locomotive had a slightly larger boiler evaporative heating surface, 24 sq. ft. more of firebox and 14 sq. ft. more of grate area.

New York, Chicago & St Louis 4-6-2 "Pacific" Locomotives in the USA The New York, Chicago & St. Louis was not a major passenger carrier. Its major passenger corridor was from Buffalo to Chicago.

Starting in 1946, the Chesapeake & Ohio took five of its Class F-19 Pacific 4-6-2 locomotives and converted them into Class L-1 Hudsons. This rework was done in its Huntington Shops and was completed in 1947.