- GWR 4073 Class
Infobox Locomotive
name = GWR 4073 "Castle" class
powertype=Steam
caption=5034 "Corfe Castle" fresh fromSwindon Works , 1954.
designer=Charles Collett
builder=GWR / BRSwindon Works
builddate=1923–1950
totalproduction = 171
gauge=RailGauge|ussg|lk=on
whytetype =4-6-0
uicclass = 2'Ch4
driversize = convert|6|ft|8+1/2|in|m|3|abbr=on
cylindercount=Four
cylindersize = convert|16|x|26|mm|abbr=on
valvegear = Inside cylinders: Walschaerts
Outside cylinders: derived from inside cylinders via rocking bars.
valvetype = Piston valves
boilerpressure = convert|225|psi|MPa|2|abbr=on|lk=on
tractiveeffort = convert|31625|lbf|kN|2|abbr=on|lk=on
weight = convert|79.85|LT
tenderweight = convert|46.70|LT
railroad =Great Western Railway British Railways
roadnumber = 4073–4099; 5000–5099; 7000–7037.
powerclass = GWR: D
BR: 7P
axleloadclass = GWR: RedThe GWR 4073 Class or Castle class locomotives were a group of
4-6-0 steam locomotive s of theGreat Western Railway .cite book| pages=p 21| title=The ABC of Great Western Locomotives| month=March| year=1944| author=Ian Allan, compiler| publisher=Ian Allan| location=Staines, Middlesex| ] They were originally designed by the railway's Chief Mechanical Engineer, Charles Collett, for working the company's express passenger trains.History
A development of the earlier Star Class, one hundred and seventy-one (171) were built, over a 25 year span from August 1923 to August 1950. They were numbered 4073–4099; 5000–5099; 7000–7037.
Although most were built new, sixteen locos were rebuilt from older locomotives—fifteen Star Class locomotives; and the
Great Western Railway 's sole4-6-2 locomotive, number 111 "The Great Bear".The Castle class was noted for superb performance on the "Cheltenham Flyer" during the 1930s: on
6 June 1932 , pulled by 5006 "Tregenna Castle", the train covered 77 miles (124 km) fromSwindon toPaddington at an average speed of 81.68 miles per hour (131.45 km/h). This world record for steam traction was widely regarded as an astonishing feat.In 1926, number 5000 "Launceston Castle" was loaned to the
London, Midland and Scottish Railway where it ran trials between London to Carlisle. It was rumoured that LMS tried to persuade GWR to build a batch of Castles for use on the West Coast Main Line.Withdrawal started in the 1950s; the last to be withdrawn was "Clun Castle" at the end of 1965.
pecifications
Cylinders: 4; 16 in (406 mm) diameter, 26 in (660 mm) stroke
Valve gear: inside cylinders –Walschaert 's; outside cylinders – derived from inside cylinders via rocking bars.
Valves: piston valves
Boiler pressure: 225 lbf/in² (1.55 MPa)
Driving wheel diameter: 6 ft 8.5 in (2.04 m)
Tractive Effort: 31,625 lbf (140.675 kN)
Engine weight: 79 tons 17 cwt (81.1 Mg)
Tender weight: 46 tons 14 cwt (47.44 Mg)List of locomotives
See
List of GWR 4073 Class locomotives Preservation
Eight Castles survive in preservation:
References
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External links
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