2-6-2

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, a 2-6-2 has two leading wheels, six coupled driving wheels, and two trailing wheels.

Other equivalent classifications are:
UIC classification
(also known as German classification and Italian classification): 1C1,French classification: 131,Turkish classification: 35,Swiss classification: 3/5.

The majority of American 2-6-2s were tender locomotives but, in Europe, tank locomotives (classified 2-6-2T) were more common.

United States

2-6-2T tank locomotives were built in the 1880s for the Central Pacific Railroad, and the earliest 2-6-2 tender locomotives were built in 1885 by Baldwin for the New Zealand Railways Department as the NZR N class. In 1891, Baldwin supplied two more N class locomotives to New Zealand, this time to the private Wellington and Manawatu Railway Company. One of these 1891 locomotives, WMR No. 10 and later NZR N 454, set a new world speed record for the 1,067mm (3'6") narrow gauge on 20 July 1892 when it hit 103.6 km/h (64.4mph) across the coastal plains of Horowhenua between Levin and Shannon.

The first 2-6-2 tender locomotives built for a North American customer were built by Brooks 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 used in British practice as well.

In the USA the type evolved from the 2-6-0 configuration. The ATSF became one of the largest fleet users of the type and intitially had tandem compound cylinders. However, tandem compounds and fast running are by definition incompatible. In 1902 the ATSF had a 2-6-2 with a boiler pressure of a huge (for those days) 220 p.s.i mounted on a large 41 square feet fire grate.(Swengel, p.78.)

Tha major problem with the 2-6-2 as with the 2-10-2 is that these engines have a symmetrical layout, wherein the 'centre of gravity' is almost over the center driving wheel. The reciprocation rods, when working near the center of gravity, induce severe 'side to side' nosing, which if can't be restrained either by a long wheel base or by the leading and trailing trucks results in 'severe instability'. Though some engines had the connecting rod aligned onto the third driver (like the Chicago and Great Western of 1903) most examples were powered via the second driver, hence the nosing problems remained with the type.(Swengel, p.79.) In the USA, over 1,000 examples existed of which 100 were high wheeled engines; larger than 69 inches. The Lake Shore & Michigan Southern operated 80 inch drivers but this did not overcome their inherent instability. The class was not suited to passenger workings because of the nosing problems. (Swengel, p.80.)

Australia

In Australia, no tender versions of the 2-6-2 operated on any system. However, three classes of 2-6-2T did. In New South Wales a class of 20 engines (Class 26) entered service in 1892 and operated until the end of steam. Two are preserved, 2606 at the Rail Transport Museum at Thirlmere and 2605 at the State Mine Museum in Lithgow. The Silverton Tramway operated two 2-6-2T from 1891 and both are preserved in South Australia.

The main 2-6-2T which were built for the Victora's narrow gauge system are the now famous "Puffing Billy" engines. These little locomotives arrived in 1898 from Baldwin Locomotive works and a total of 17 saw service through out the state on the various narrow gauge timber and gold lines, including 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 on active steam roster, a fleet of saved and modified 2-6-2T engines and is one of Victoria's main tourist attractions.

Russia/Soviet Union

In Russia the 2-6-2 was the standard passenger locomotive. They were represented by the pre revolutionary design, the S(С)(Sormovskij) and the Su (Су)series locomotives which appeared in 1928. The pre-revolutionary S-series locomotive has the characteristic pointed nose, absent on the Su locomotive. The suffix 'u' means 'usilenny' which translates as strengthened or uprated. Several are preserved- several Su-series locomotives are even preserved in working order! However, only one pre-revolutionary S-series locomotive is still around - S68. It is located in the Saint Peterburg railway museum.

The Su was the main standard passenger engine on most routes and it was only on the key trunk lines that the IS class 2-8-4 or later the P36 4-8-4 would be used. Therefore the majority of passenger miles were hauled by an Su (Су). Visually the Su was the last true ‘Russian’ looking design before the American influence of high running boards, bar frames and ‘boxpok’ wheels became the norm. The Su retains such features as a clerestory sky light in the cab roof and handrails on the outside of the running board. The handrails were a result of the harsh Russian winters. Ice would build up on running boards making them highly dangerous, enginemen had fallen to their death from moving trains and the fitting of ‘promenade deck’ style handrails was a safety measure ordered by the Tsar (pre revolutionary times). These features, combined with the high (17-foot) loading gauge combine to give the uniquely Russian look. ("Russian Steam Locomotives", LeFleming/Price)("Locomotives of Russia 1845 - 1955", V.A.Rakov).

United Kingdom

In the UK, 2-6-2 tender locomotives were rare but two examples were LNER Class V2 and LNER Class V4. In contrast, 2-6-2 tank locomotives were very widely used, e.g. GWR 2-6-2T.

Narrow gauge

The 2-6-2T layout was popular for large narrow gauge engines but the design was modified to allow the use of a firebox much wider than the track gauge. A standard gauge 2-6-2T normally has inside frames and the firebox is placed between the second and third coupled axles. A narrow gauge one has outside frames and the firebox is placed behind the third coupled axle and clear of the wheels. To minimise the rear overhang, the fuel is carried in side-bunkers (alongside the firebox) instead of a rear bunker. Preserved examples include the Welsh Highland Railway's "Russell", the Vale of Rheidol Railway locomotives and the Victorian Railways class NA 2-6-2 tank locomotives on the Puffing Billy Railway.

References

*Swengel, F.M. "The American Steam Locomotive, Vol. 1, The Evolution of the Steam Locomotive", MidWest Rail Publications, Davenport, 1967.
*Oberg, Leon. "Railways of Australia", Reed, Sydney, 1975.(plus subsequent editions)