GWR Route: Banbury to Wolverhampton

Warwick Station: gwrw398

GWR 4-6-0 No 6015 'King Richard III is seen passing through the station at speed at the head of an up express to Paddington circa 1930s. Built at Swindon works to Lot 243 in June 1928 No 6015 remained in service until September 1962 when it was withdrawn from Stafford Road shed in Wolverhampton to be scrapped during April 1963 by Cox & Danks of Langley Green near Oldbury. The King class was the final and most powerful development of the GWR's 4 cylinder designs and were frequently seen on the Paddington to Birkenhead services.

GWR CME (Chief Mechanical Engineer) Charles Collett's Castles were arguably the GWR's finest passenger engine design, and on a tractive effort basis, had proved themselves more powerful than LNER's Flying Scotsman. Nevertheless, the advent of the Southern Railway's King Lord Nelson class as the new leader in British express steam tractive effort (33,500lbs) pushed the GWR's publicity office to push for one greater engine class, with a nominal tractive effort of 40,000lbs.

Collett opted for smaller wheels on the King than his Castles, after casting aside the conventional wisdom that large wheel diameter was needed for the greatest speed. He had observed an express train being overhauled by a mineral train hauled by a close-coupled GWR 4-8-0 with small wheels. When compared with the Castle class, the slightly smaller wheels adopted for the King Class allowed more space above them for a fatter boiler to be built, as little extra engine height was available for expansion.

Nevertheless, such a reduction in wheel size was not without its corresponding problems. A long standing Swindon design constraint imposed by former CME George Jackson Churchward, was that the pistons would be level and not slanted. This meant the centre height of the pistons would be the same as the driving wheel axles. The smaller wheels thereby lowered the height of the pistons. At the same time, to achieve the 40,000lb tractive effort, the pistons were enlarged to 16¼” bore and 28” stroke. The outer pair of pistons, acting on the centre wheels, needed to hang either side of the rear wheels of the front bogie. The hidden inner pair of pistons, acting on the front set of driving wheels, hung low between the front wheels of the bogie. Both factors meant a traditional springing arrangement for the bogie was impossible. A compromise design with the front wheels sprung on the outside and the back wheels of the bogie sprung on the inside, produced the distinctive and decidedly odd-looking long front bogie of the Kings. Courtesy of 6023 King Edward II Project.

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