GWR 3252 Class
|GWR Duke class|
No. 9083 Comet at Didcot in 1948
|Type and origin|
|Builder||GWR Swindon Works|
|UIC classification||2'B ht|
|Gauge||4 ft 8 1⁄2 in (1,435 mm)|
|3 ft 8 in (1.118 m)|
|Driver diameter||5 ft 8 in (1.727 m)|
|Axle load||15 long tons 7 cwt (34,400 lb or 15.6 t) full|
|Locomotive weight||46 long tons 0 cwt (103,000 lb or 46.7 t) full|
|Tender weight||24 long tons 0 cwt (53,800 lb or 24.4 t) full|
|Locomotive and tender
|70 long tons 0 cwt (156,800 lb or 71.1 t) full|
|Boiler pressure||160 lbf/in2 (1.1 MPa)|
|1,285.58 sq ft (119.434 m2)|
|– Firebox||115.27 sq ft (10.709 m2)|
|Cylinder size||18 in × 26 in (457 mm × 660 mm)|
|Operator(s)||GWR » BR|
The Great Western Railway 3252 or Duke Class were 4-4-0 steam locomotives with outside frames and parallel domed boilers. They were built in five batches between 1895 and 1899 for express passenger train work in Devon and Cornwall. William Dean was their designer, possibly with the collaboration of his assistant, George Jackson Churchward. Four prototype 4-4-0s, of the Armstrong Class, had already been built in 1894.
Frames and wheels
The outside frames of the Dukes were curved upwards over each pair of driving wheels. Inner and outer frames were 3⁄4 in (1.9 cm) thick. The first 40 members of the class were fitted with Mansell pattern bogie wheels with wooden centres. The first 25 tenders built also had Mansell pattern wheels, and a shorter than normal wheelbase of 11 ft (3.4 m) so that the locomotives would fit on the smaller turntables then in use west of Newton Abbot. The engine bogie was of a centre-less type designed by Dean.
The majority of the class were fitted with round-topped fireboxes of the same diameter as the boiler. The last four were fitted with Belpaire fireboxes, raised a few inches above the boilers. Eighteen of the Duke class were later rebuilt with domeless tapered boilers and Belpaire fireboxes between October 1906 and January 1909. They were reclassified as members of the Bulldog Class. A further Duke, no. 3273 Armorel, had been fitted with a parallel domeless boiler in February 1902, converting it to a Camel Class locomotive. It was fitted with a Bulldog-type boiler in October 1910. By December 1923 all remaining Dukes had been fitted with flush-topped Belpaire fireboxes and domed boilers pressed to 180 lbf/in2 (1.2 MPa). Duke no. 3258, King Arthur, built August 1895, was fitted with a superheater in December 1896. The rest of the class, with the exception of two locomotives, were fitted with superheaters between August 1911 and September 1946. The class had distinctive long smokeboxes, extended to hold a diaphragm plate and net for spark prevention.
Cylinders and valves
Slide valves were fitted underneath the cylinders, and were driven directly by eccentrics on the leading driving axle through Stephenson valve gear. This position had the advantage that, when the regulator was closed and steam pressure shut off, the valves would drop away from the steam ports, thus reducing wear on the valves and port faces. Dean's earlier designs had used slide valves mounted vertically between the cylinders; the new position allowed an increase in cylinder diameter from 17 in (43.2 cm) to 20 in (50.8 cm) in the Armstrong Class. The Dukes had 18 in (45.7 cm) diameter cylinders, possibly due to permanent way weight restrictions and a reduced supply of steam from the Dukes' smaller boilers.
The Dukes were subject to the 1912 renumbering of GWR 4-4-0 locomotives. Those Dukes rebuilt as Bulldogs were renumbered as members of that class in the series 3300-3455. The remaining Dukes were renumbered consecutively as 3252-3291, this block of numbers having previously been allocated to the first batch of Duke Class locomotives.
By the 1930s many of the Duke class were becoming uneconomical to repair, particularly with regard to the curved outside frames, which were weaker than the later straight-topped version. A number of the class had been transferred to the ex-Cambrian Railways main line, where permanent way restrictions debarred the use of heavier locomotives.
In December 1929, no. 3265, Tre Pol and Pen, was withdrawn, and the cylinders and motion, together with a spare Duke boiler and smokebox, were fitted to the straight-topped frames and cab of Bulldog no. 3365 Charles Grey Mott. The rebuilt locomotive retained the name and number of the Duke. The reduction in axle weight, as compared to the Bulldogs, allowed for working over the Cambrian section.
From 1936 a further twenty-nine of the Dukes were withdrawn and replaced by Bulldogs fitted with Duke boilers and motion, reclassified as Earl Class locomotives. The onset of World War II brought a halt to the program, the last replacement being in November 1939, leaving ten Dukes to pass into British Railways ownership. These were scrapped between June 1949 and July 1951, the last survivor being No. 9089, formerly no. 3289 St Austell of July 1899.
|3252||3252||Earl 3214||Duke of Cornwall|
|3253||Bulldog 3300||Pendennis Castle|
|3258||3257||Earl 3213||King Arthur||Denamed in 1927|
|3259||3258||Earl 3217||Lizard||The Lizard|
|3261||3260||Earl 3219||Mount Edgcumbe|
|3263||Bulldog 3302||Sir Lancelot|
|3264||Bulldog 3303||St. Anthony|
|3265||3261||Earl 3212||St. Germans|
|3266||3262||Earl 3215||St. Ives|
|3267||3263||Earl 3201||St. Michael|
|3268||Bulldog 3304||Tamar||River Tamar|
|3271||3265||Earl 3265||Tre Pol and Pen|
|3277||3270||Earl 3226||Earl of Devon||Denamed in 1930|
|3281||3272||9072||Fowey||Denamed in 1930|
|3284||3274||Earl 3207||Newquay||Denamed in 1930|
|3285||3275||Earl 3203||St. Erth||Denamed in 1930|
|3286||Bulldog 3310||St. Just|
|3287||3276||9076||St. Agnes||Denamed in 1930|
|3288||3277||Earl 3209||Tresco||Isle of Tresco|
|3290||3279||Earl 3220||Torbay||Tor Bay|
|3291||3280||Earl 3227||Tregenna||Denamed in 1930|
|3314||3282||Earl 3216||Chepstow Castle||Denamed in 1930|
|3316||Bulldog 3312||Guernsey||Isle of Guernsey|
|3317||3284||9084||Jersey||Isle of Jersey|
|3325||Bulldog 3316||St. Columb|
|3326||3289||9089||St Austell||Denamed in 1930|