A History
of the Castle Class
The origins of this highly successful design date back to Mr.
G. J. Churchward’s famous ‘Star’ Class of 1907. These 4 cylinder 4-6-0s
with long travel valves, and belpaire fireboxes were an immediate success
on the GWR’s top-link express duties to the west of England. However,
with increasing loads the Stars had little in reserve to maintain the
restored pre- World War One timings. Mr. C.B. Collett succeeded
Churchward as Chief Mechanical Engineer in 1922 and faced an immediate
task of providing more power with little ability to increase axle weight.
Thus, the Castle class was born. When introduced they were heralded as
Britain’s most powerful express passenger locomotive being some 10% more
powerful than the Stars. The Castle class locomotives had a larger boiler
and cylinders bores were increased from the 15 to 16 inch diameter. The
first, No 4073 ‘Caerphilly Castle’, made its debut at Paddington station
on August 23, 1923.
During 1924, ‘Caerphilly Castle’ was exhibited at The British
Empire Exhibition, Wembley alongside Sir Nigel Gresley’s ‘Flying
Scotsman’. The Great Western engine was declared to be more powerful than
its bigger LNER rival. During the subsequent ‘Locomotive Interchange
Trials’ between the GWR and LNER No. 4079 ‘Pendenis Castle’ operated on
the East Coast Main line alongside Gresley Pacifics; while LNER 4474
‘Victor Wild’ was sent to work between Paddington and Plymouth alongside
No. 4074 ‘Caldicot Castle’. All locomotives acquitted themselves well but
the compact Castle class demonstrated their superior fuel and water
efficiency.
So successful was the Castle class design that construction
continued at intervals until 1950 by which time 171 has been built. This
included 15 converted from the Stars class plus the rebuilding of the ‘The
Great Bear’, the Great Western’s only Pacific locomotive.
In 1946 Mr. F. W. Hawksworth, Charles Collett’s successor,
introduced a higher degree of superheat to the Castle boiler with
resulting increased economy in water consumption. From 1956, the fitting
of double chimneys to selected engines, combined with larger superheaters
further enhanced their capacity to sustained high speed performance. In
1958, No. 7018 ‘Drysllyan Castle’ fitted with a double chimney and a four
row superheater ran ‘The Bristolian’ express reaching 100 mph. at
Somerford.
The Castles handled all but the heaviest loads, these being
entrusted to the thirty strong ‘King’ class (modeled by Aster in 1990).
The King class were themselves a development of the Castle class with a
larger boiler and slightly smaller wheels for increased tractive effort.
The final Castle to be run in British Railways service was No.
7029 ‘Clun Castle’, which worked the last steam train out of Paddington in
1965. However, that was not the end of the story for this long lived and
popular class of express locomotives.
Preservation
Eight Castles have been preserved. The pioneer No. 4073
‘Caerphilly Castle’ lies at the Swindon GWR Museum. No.7029 ‘Clun Castle’
built in 1950 and fitted with a double chimney represents the final
development of the class. No. 4079 ‘Pendennis Castle’, which scored a
triumph for the GWR in the locomotive interchange trials of 1925, is still
with us having been repatriated in 2000 from a 23 year sojourn in
Australia by the Great Western Society. Five others were rescued after
languishing for years in a South Wales scrapyard and four have already
been restored to working condition including the popular 5029 ‘Nunney
Castle’.
UK Postage Stamp
The Aster
Model
No. 5015 ‘Kingswear Castle’ was named after the fortification
built in 1502 to assist in the protection of Dartmouth harbor, the
locomotive entered service in 1932 as one of the first of the ‘5013’
Castle series. Furthermore, Kingswear Castle was one of just a few to
retain its tapered front buffers, inside cab sandbox fillers and tall
chimney into British Railway days. It was withdrawn in April 1963.
So today Great Western Castle class locomotives with their
beautiful green lined orange / black livery and polished brass and copper
fittings delight and thrill enthusiasts with their majestic beauty and
exhilarating performance! Long may they steam!
