Railroad History

Passenger and Commuter Rail

Railroading Today

Rolling Stock

Infrastructure and Terms

Museums and Tourism

Miscellaneous

About The Site

[?] Subscribe To This Site

The 4-6-2 Pacific Type Steam Locomotive

The Pacific Type became one of the most prolific steam locomotive designs to ever grace the rails and was by far the most widely used for passenger service, where it was most often intended for operation. The Pacific's large drivers (of at least 70 inches) and high tractive efforts (of at least 40,000 pounds) made them ideal for passenger service where they could regularly cruise at speeds of over 70 mph.

The Pacific was originally developed in 1902 and was built through 1930 with nearly 7,000 units manufactured by the time production ended among all classes! The Pacifics, as a type were perhaps the most aesthetically pleasing steam locomotive of any ever developed, which were not streamlined in any way (take for example those operated by the Southern Railway). Virtually every well-remembered Class I of the time owned some type of the 4-6-2 wheel arrangement with those of the Pennsylvania Railroad, Class K-4, considered the most famous, as they pulled double-duty hauling both passengers and freight (the PRR also owned the most Pacifics of any railroad, rostering well over 500), and the Southern Railway’s Class Ps4 arguably the most beautiful painted in regal deep green with gold trim.

Because so many K-4s of the Pacific Type were built by the PRR it’s not surprising that they became commonplace across the system from the early 20th century practically all the way through the transition to diesels, beginning in the late 1930s through the 1940s.

The Class K-4 Pacific is undoubtedly the most popular Pacific design ever built. In all the Pennsylvania Railroad would come to own 424 of these masterfully crafted machines (the Juniata shops built 349 of the locomotives with the Baldwin Locomotive Works chipping in another 75) and they would carry everything from freight to the railroad’s most well-known passenger trains.

The Ps4 Pacific Type was originally constructed by the American Locomotive Company (Alco) in the early 1920s with an updated version arriving to the railroad later that decade. Like the Baltimore & Ohio’s magnificent EM-1 locomotive class the Ps4s did not have a considerably long lifespan for a steam locomotive. After Alco delivered the last Ps4s in the late 1920s they survived less than thirty years before being retired in 1952 and replaced by the Electro-Motive Division’s (EMD) E7 diesel-electric locomotive to pull the Southern’s premier passenger trains.

The Southern Railway Ps4, being built for passenger service, also did an excellent job in what was required of them. With their larger driving wheels they were capable of speeds approaching 80 mph with nearly 1000 tons in tow and regularly cruised the Southern’s Washington to Atlanta main line at nearly 60 mph.

While the Southern and Pennsylvania’s 4-6-2s were perhaps the two most celebrated classes there were dozens of others. For much, much more information on the Pacific Type please click here to visit SteamLocomotive.com.

For more information on the Pacific Type steam locomotive consider How a Steam Locomotive Works by author Karen Parker, which explores in great detail how exactly each component of a steam locomotive works but is also easy enough to read for anyone to understand. The book has received excellent reviews and is a great resource on steam locomotives and a fine reference tool; you should find it very useful.

Also, consider the book American Steam Locomotives from author Brian Solomon. While this publication does not include quite as much technical data as Parker's book, How a Steam Locomotive Works, it is still a very good resource with lots of information covering many of the most popular steam designs such as Pacifics, Ten Wheelers, Berkshires, and Hudsons and best of all, is loaded with photographs! If you're interested in perhaps purchasing either (or both) of these books please visit the links below which will take you to ordering information through Amazon.com, the trusted online shopping network.

footer for pacific type page