4-8-4 "Northern" Type Locomotives

The 4-8-4 was the ultimate wheel configuration for the modern passenger and fast freight steam locomotive. The eight driver arrangement was usable on almost every main line in North America and with drivers up to 80 inches in diameter allowed any reasonable speed that the railroad could handle. The four wheel trailing truck supported a larger firebox for maximum steam levels allowing for extra boiler capacity. The four wheel leading (or pony) truck completed the best combination for riding and tracking.

With the surge in passenger business in the 1920's most railroads were being forced to operate extra trains or run their scheduled trains in sections simply because the locomotives in use could only haul about 12 cars. It was out of this need that the "super powered" locomotives were developed and of them the 4-8-4 was the most numerous and widely used.

The first 4-8-4 was built by the American Locomotive Company, in January, 1927, for the Northern Pacific. This locomotive was basically the 4-8-2 modified to accommodate a large grate area and a very deep firebox which was required to burn the very low grade of bituminous coal that the Northern Pacific produced from its own mines. This new wheel arrangement was dubbed "Northern Pacific", which was quickly shortened to "Northern".

There were 36 North American Railroads that owned and operated a total of 1,126 "Northern" type locomotives.

Some railroads, particularly the southern ones, rejected the "Northern" name and used names with a more regional connection. The C&O called them "Greenbriers"; the Delaware, Lackawanna & Western used the name "Poconos"; the Lehigh Valley came up with "Wyoming"; the Nashville, Chattanooga & St.Louis named them "Dixies"; the New York Central chose "Niagaras"; the Richmond, Fredericksburg & Potomac named each of its 27, 4-8-4s after southern generals, governors and statesmen; the Southern Pacific used the name "Golden State"; the Western Maryland dubbed them "Potomacs" and in Canada, the CNR named them "Confederations" while the Nacionale de Mexico called them "Niagras".

The Timken Demonstrator

In 1930, the Timken Company took delivery of its own 4-8-4 Northern locomotive from the American Locomotive Company. Timken wanted to demonstrate the advantages of roller bearings on steam locomotives and thus became one of the very few private owners of a main line locomotive.

This locomotive carried road number 1111 and the Timken name and became known as "four aces" on the many railroads that tested it. In the two years it traveled the country it ran up an impressive record in both passenger and freight operation.

Designed for fast freight and passenger service, this locomotive was tested in drag freight operation and consistently did well without helpers. On one occasion it started a 132 car freight train of 9,864 tons.

Timken had "four aces" built so that the boiler pressure could be varied between 235 and 250 psi and its weight could be shifted between the drivers and trucks thus allowing the demonstrator to have a tractive effort of 59,900 lbs at 235 psi and 63,700 lbs at 250 psi. The locomotive weighed 417,500 lbs, had 73" drivers and 27 x 30 cylinders.

While being tested on the Northern Pacific, number 1111 suffered crown sheet damage. Timken was essentially finished with it and did not want a damaged locomotive and NP did not want to repair a locomotive it did not own. In order to resolve this stand-off, NP bought the locomotive, repaired it, numbered it 2626 and used it until 1955.

• Northern Pacific's "Four Aces"
• Four Aces Photographs

Information for this introduction to Northerns provided by Richard Duley.