Great Western 2-6-0 Locomotives in Great_Britain

Class 43XX (Locobase 2743)

John Daniel's Great Western Railway site -- [], last accessed 28 May 2007 for details on this class, including all names. See also "Great Western Railway", The Locomotive, Volume 17, No 228 (15 August 1911), p. 169; and "2-6-0 Locomotives", Railway Engineer, Volume 32, No 11 (November 1911), p. 345

Note that Locomotive Magazine's writeup gave the following dimensions; 209 fire tubes amassing 1,228 sq ft (114.1 sq m), evaporative heating surface area of 1,567 sq ft (145.6 sq m), and 215.8 sq ft (20.5 sq m) superheater surface area. All later sources give the figures as shown in Locobase's specs.

According to the writeup accompanying a model on [] (visited 30 Dec 2003), When H. Holcroft, one of Churchward's assistants, toured the US in the early 1900s, he came away most impressed with the 2-6-0 arrangement. In part this appreciation was due to a need on the GWR to increase tractive power beyond the two-coupled-axle engines then prevalent.

The result was a design that became the standard, especially in Cornwall, where they were responsible " for practically the entire main-line work ...both passenger and goods," according to OS Nock (RWC IV, pl 117). Nock notes the tapered boiler barrel "very carefully developed at Swindon" and a Belpaire firebox "also of a highly specialized and successful design."

Several hundred were built with numbers in the 53xx, 63xx, and 73xx series.

Class Aberdare (Locobase 3479)

See John Daniel's excellent Great Western Railway site -- [], last accessed 28 May 2007 -- for history and data.

Although nominally produced under William Dean and bearing many of his design features, this is one of the first Great Western locomotives to have GJ Churchward's tapered boiler, this one mated to a Belpaire firebox. They were double-framed.

Their class name comes from Abedare, the departure point in the coal fields from which the engines hauled trains to Swindon. The numbering order reflects the continuation of the Kruger class, which originally owned 2601-2620, and later the supplanting of those 20 engines after the Kruger design manifested several serious shortcomings (Locobase 15915).

Delivery occurred over seven years (1900-1907), completion of which was almost immediately followed by the first superheater installations in November 1908. Churchwrd's top-feed feedwater system was fitted in its first Abedares in 1911.

Class Kruger (Locobase 15916)

Data from G J Churchward, "Large Locomotive Boilers" [read before the Institution of Mechanical Engineers, 16 February 1906], The Railway Engineer (11 April 1906), pp. 116, 118 and George Montagu, MP, Ten Years of Locomotive Progress (London: Alston Rivers, Ltd, 1907) , p. 152. History from Wikipedia's "GWR 2602 class" at [], last accessed 23 October 2014; and Brewer, F W Brewer, "Modern Locomotive Practice on the Great Western-No V", Railway Magazine, Volume LXII [62] (January-June 1928), pp. 450-451. 2602 appeared in 1899 while 2603-2610 entered service by 1903.

Based on F W Dean's 1899 4-6-0 goods locomotive described in Lcobase 21247, this nonet of Moguls differed primarily in replacing the leading bogie with a single leading truck axle. Wikipedia's author describes this Dean/Churchward prototype as "ungainly" with good reason. Its drivers were enclosed by a heavy plate frame while the lead truck used inside bearings. All of the motion lay inside the frames as well. But the Belpaire firebox bulked large and square, filling the loading gauge and masking the driver's forward vision.

A larger boiler and firebox served more cylinder volume. The cylinders, in combination with the relatively high boiler pressure, meant higher tractive effort but a low factor of adhesion.

Wikipedia asserts that a 3 ft 6 in (1,067 mm) long combustion chamber gave trouble, but Churchward's diagram of his own boiler shows no such installation. Another reported problem was the excessive force applied by the 28" stroke on the crank axle of the middle driver. Churchward may have signalled his own disappointment with the 2602's design when he commented on a general trend toward wide fireboxes that put too much of the fire too close to the tubesheet and encouraged too many tubes to allow proper circulation.

Churchward's embarrassment at the class's early retirement in 1906 is best indicated by the reuse of the road numbers 2601-2610 in a later Aberdare batch (Locobase 3479).