Under the Whyte notation, a 2-8-4 is a steam locomotive that has two unpowered leading wheels, followed by eight coupled and powered driving wheels, and four trailing wheels. This locomotive type is most often referred to as a Berkshire, though the Chesapeake and Ohio Railway used the name Kanawha for their 2-8-4s. In Europe, this wheel arrangement was mostly seen in mainline passenger express locomotives and, in certain countries, in tank locomotives.

Overview

In the United States of America, the 2-8-4 wheel arrangement was a further development of the enormously successful 2-8-2 Mikado. It resulted from the requirement for a freight locomotive with even greater steam heating capacity. To produce more steam, a solution was to increase the size of the locomotive's firebox, though the 2-8-2 wheel arrangement, with its single axle trailing truck, limited the permissible increased axle loading from a larger firebox. The most practical solution was to add a second trailing axle to spread the increased weight of a larger firebox.

2-8-4

The first American 2-8-4s were built for the Boston and Albany Railroad in 1925 by Lima Locomotive Works. The railroad's route across the Berkshire mountains was a substantial test for the new locomotives and, as a result, the name Berkshire was adopted for the locomotive type.

2-8-4

In Europe, 2-8-4 tender locomotives were designed mainly for passenger express trains, but they also hauled long distance express freights to increase utilisation. European 2-8-4 tank locomotives were a logical transition from the 2-8-2T locomotive types, allowing larger fireboxes and larger coal bunkers. They were mainly used for busy suburban services in heavily populated suburban areas of big cities, but infrequently also for sparsely populated rural areas or long distance lines.

2-8-4

Usage

Australia

The Western Australian K-class was a class of 2-8-4T steam locomotives of the Western Australian Government Railways (WAGR). Between 1893 and 1898, the WAGR took delivery of 24 of these locomotives from Neilson and Company. They entered service on the Eastern Railway between Midland Junction and Northam. In 1900, during the Second Boer War, the Imperial Military Railways experienced a shortage of locomotives and six more new K class locomotives destined for the WAGR were diverted to South Africa, where they were known as the Western Australians.

The South Australian Railways also operated 2-8-4s. Fleet construction commenced in 1930 and by the end of 1943, seventeen locomotives were in service on the gauge system. The design of these locomotives was based on American practices. After they were withdrawn from service by 1958, they were all scrapped.

Austria

The heavy Class 214 1’D2′ (2-8-4) two-cylinder simple expansion express passenger locomotive was developed in Austria in 1927. It was designed by engineers of the Floridsdorf Werke and was the largest Austrian steam locomotive and the most powerful Berkshire type to run in Europe. Designed for the West railway express train service, they were to be used to haul 580-ton express trains from Wien Westbahnhof in Vienna over to Salzburg. This mainline has three approximately banks with gradients between 1 in 91 and 1 in 125.

Two prototypes were built, a two-cylinder and three-cylinder version. When tested, the two-cylinder version proved to be superior to the three-cylinder Class 114 version, and eventually twelve more two-cylinder Class 214 locomotives were built. In 1936, No. 214.13 reached a speed of , the highest speed ever attained by an Austrian steam locomotive. The regular speed limit was .

From 1938, the Deutsche Reichsbahn (DRB) designated the locomotive class 12.0. In the mid-1939, they hauled 600 tons express trains out of Vienna over Wienerwald at a speed of , reaching over level stretches.

In 1945, seven of these locomotives were taken over by the Soviet Military Administration when they occupied the Russian Zone in Austria. These locomotives had "T" (Trofya) painted before their running numbers and were marked "CCCP". The Russians did not transfer these locomotives out of Austria and, when they withdrew their occupying forces in September 1955, the locomotives were returned to the Austrian Federal Railways (ÖBB).

When the mainline west of Vienna was electrified, all the ÖBB 1’D2’ locomotives were taken out of service and written off. On 15 February 1962, locomotive No. 12.10, built by Floridsdorf in 1936, was preserved as museum locomotive at the Eisenbahnmuseum Strasshof.

Brazil

Beyer Peacock delivered four 2-8-4T locomotives to Minas & Rio Railway (gauge 1000mm) in 1890, and one more in 1894.