Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of two leading wheels, six coupled driving wheels and two trailing wheels. This arrangement is commonly called a Prairie.
Overview
The majority of American 2-6-2s were tender locomotives, but in Europe tank locomotives, described as , were more common. The first 2-6-2 tender locomotives for a North American customer were built by Brooks Locomotive Works in 1900 for the Chicago, Burlington and Quincy Railroad, for use on the Midwestern prairies. The type was thus nicknamed the Prairie in North American practice. This name was often also used for British locomotives with this wheel arrangement.
As with the 2-10-2, the major problem with the 2-6-2 is that these engines have a symmetrical wheel layout, with the centre of gravity almost over the centre driving wheel. The reciprocation rods, when working near the centre of gravity, induce severe side-to-side nosing which results in intense instability if unrestrained either by a long wheelbase or by the leading and trailing trucks. Though some engines, like the Chicago and Great Western of 1903, had the connecting rod aligned onto the third driver, most examples were powered via the second driver and were prone to the nosing problem.
Usage
Australia
Queensland Railways operated one 2-6-2 tender engine of the B16 1/2 class. It was built in August 1918 by the North Ipswich Railway Workshops as an experimental engine burning coke instead of coal. After nearly 9 years burning coke, it was converted to coal in 1927. The engine spent its working life on the Brisbane to Ipswich line working coal trains. It was withdrawn in February 1950.
In New South Wales a class of twenty engines, the Z26 class, formerly the (I)17 class, entered service in 1892 and operated until the end of steam. Two are preserved, no. 2606 at the Rail Transport Museum at Thirlmere and no. 2605 at the State Mine Museum in Lithgow.
The Silverton Tramway operated two locomotives from 1891, both of which are preserved in South Australia.
The principal 2-6-2T locomotives which were built for the narrow gauge system of the Victorian Railways (VR), are the now famous "Puffing Billy" engines. Two of these little locomotives arrived from Baldwin Locomotive works in 1898 and a total of seventeen saw service throughout the state on the various narrow gauge timber and gold lines, including the Wangaratta and Walhalla. When the VR determined to close the Upper Ferntree Gully to Gembrook narrow gauge route in the mid-1950s, the Victorian community refused to let the train die. Today, the Puffing Billy Railway has a fleet of saved and modified 2-6-2T engines on active steam roster and is one of Victoria's main tourist attractions.
Belgium
The Belgian State Railways ordered 91 inside-cylinder 2-6-2 tank engines between 1878 and 1881 (Belgian State Railways Type 4) with large drivers and side tanks longer than the boiler. They hauled commuter trains and fast trains on short lines. Some of them survived the war and were used on local trains until 1930.
After World War I, the Belgian State Railways were desperately needing new engines in order to replace the ones that were lost or damaged during the war. They purchased 63 2-6-2 Saddle tank engines from the Railway Operating Division (Belgian State Railways Type 22, later SNCB Type 57) and used them for switching and light freight trains until the 1960s.