The Hudson came into being because the existing 4-6-2 Pacific power was not able to keep up with the demands of longer, heavier trains and higher speeds. Given NYC’s axle load limits, Pacific could not be made any larger; a new locomotive type would be required to carry the larger boilers. Lima Locomotive Works’ conception of superpower steam as realized in the 2-8-4 Berkshire type was the predecessor to the Hudson. The 2-8-4’s 4-wheel trailing truck permitted a huge firebox to be located after the boiler. The resulting greater steaming rate ensured that such a locomotive would never run out of power at speed — a common failing of older locomotives. Applying the ideas of the freight-minded Berkshire type to the Pacific resulted in a 4-6-4 locomotive
NYC ordered prototype #5200 from Alco, and subjected it to intensive testing. A fleet of 205 J-1 class Hudson’s were later built, including 30 for the Michigan Central Railroad and the Cleveland, Cincinnati, Chicago & St. Louis Railway (“Big Four”) apiece. In addition, NYC subsidiary Boston & Albany Railroad ordered 20 J-2 class, 10 from Lima Locomotive Works (all other NYC Hudson’s were built by Alco’s Schenectady works). A later development were 50 J-3a class Super Hudson’s in 1937–1938, with many modern appliances and innovations.
The Hudson’s were of excellent quality. Locomotive #5344 had streamlining applied and named Commodore Vanderbilt. The streamlining was later replaced to match the last ten J-3a locomotives that had been built with streamlining designed by Henry Dreyfuss. Two more J-3a locomotives had streamlining fitted in 1941 for Empire State Express service. The streamlined locomotives featured prominently on NYC advertising.
The forte of all Hudson’s was power at top speed. They were poor performers at low speed and the presence of a booster engine on the trailing truck was an absolute necessity for starting. For this reason, they were generally favored by railroads with flat terrain and straight routes. After the NYC, the Milwaukee Road was also fond of the Hudson’s, acquiring 22 class F6 and six streamlined class F7s. The Atchison, Topeka & Santa Fe Railway also had 16, while the New York, New Haven & Hartford Railroad had 10 (#1400-1409) streamlined I-5 4-6-4s built by Baldwin in 1937 (nicknamed “Shoreliners”). Few railroads with hilly terrain acquired any.
A booster was prone to troubles, however, and gradually fell out of favor. Instead of a complicated booster, it was deemed preferential to have an extra pair of driving wheels, and thus better traction.
Trials of dual-purpose 4-8-2 Mohawks sealed the Hudson’s fate. The Mohawk was nice, but it was still more suited to lower-speed hauling than high-speed power. In 1944, NYC received permission from the War Production Board to build a new, high-speed locomotive of the 4-8-4 type, combining all the advantages of the Hudson with those of the Mohawk. Many other railroads had taken to the 4-8-4 in the 1930s, generally calling them Northerns after the Northern Pacific Railway, which had first adopted them. By being a late adopter, the NYC had the chance to build on everyone else’s experience. That locomotive proved to be exceptional, and the type on the NYC was named the Niagara. Since only 27 were built, however, they only took over the heaviest and most-prestigious trains; most Hudson’s labored until the end of steam on NYC.
None of the NYC Hudson units survive; all were scrapped when the railroad dieselized.