Highland Railway Clan Class
|Highland Railway Clan class|
|Builder||Hawthorn Leslie and Company|
|Serial number||3329–3332, 3443–3446|
|Build date||1919 (4), 1921 (4)|
|UIC classification||2′C h2|
|Gauge||4 ft 8 1⁄2 in (1,435 mm)|
|3 ft 0 in (0.914 m)|
|Driver diameter||6 ft 0 in (1.829 m)|
|Locomotive weight||63.25 long tons (64.26 t)|
|Tender weight||42 long tons (43 t)|
|Boiler||4 ft 9 3⁄16 in (1.453 m) diameter, with 1 1⁄8 in (29 mm) taper|
|Boiler pressure||175 psi (1.21 MPa)|
|Firegrate area||25.5 sq ft (2.37 m2)|
|1,467 square feet (136.3 m2)|
|Superheater area||256 sq ft (23.8 m2)|
|Cylinder size||21 in × 26 in (533 mm × 660 mm)|
|Valve type||10 in (254 mm) piston valves|
|Tractive effort||23,688 lbf (105.37 kN)|
|Operator(s)||HR → LMS → BR|
|Power class||LMS/BR: 4P|
|Number(s)||HR: 49, 51–57
The Highland Railway's Clan Class was a class of passenger 4-6-0 steam locomotives designed by Christopher Cumming. The design is derived from that of the slightly earlier Clan Goods although the similarity is more visual than real.
They had 21-by-26-inch (533 by 660 mm) cylinders outside with outside Walschaerts valve gear, 6 ft 0 in (1.83 m) driving wheels and a boiler pressured to 175 lbf/in² (1.2 MPa). Weight was 62 tons 5 cwt (63.25 t) for the locomotive and 42 tons (42.7 t) for the tender. Piston valve diameter is given as 10 inches (quite large for the period), but they had the conventional short lap, short travel valves. Bearing in mind that they probably spent a large part of their time slogging uphill or coasting down this was probably not too important.
Total evaporative heating surface is given as 1,467 sq ft (136.3 m2), plus 256 sq ft (23.8 m2) for the Robinson-type superheater, and grate area as 25.5 sq ft (2.37 m2). The first four were built in 1919, and the remaining four in 1921.
|HR Number||Name||Built||LMS Number||BR number||Withdrawn||Notes|
|49||Clan Campbell||1919||14762||—||June 1947|
|51||Clan Fraser||1919||14763||—||August 1944|
|52||Clan Munro||1919||14764||54764||February 1948||BR number not applied|
|53||Clan Stewart||1919||14765||—||February 1945|
|54||Clan Chattan||1921||14766||—||April 1944|
|55||Clan Mackinnon||1921||14767||54767||January 1950|
|56||Clan Mackenzie||1921||14768||—||March 1945|
|57||Clan Cameron||1921||14769||—||November 1943|
Two survived into British Railways hands, but only Clan Mackinnon received its BR number.
Early in 1921 Clan Stewart was used for experiments with oil firing. They seem to have been successful, but was not applied to any other locomotives. Just when Clan Stewart reverted to coal operation does not seem to be recorded.
The LMS classified them '4P'.
The Clan names were later reapplied to the BR Standard Class 6.
- Baxter, Bertram (1984). Baxter, David, ed. British Locomotive Catalogue 1825–1923, Volume 4: Scottish and remaining English Companies in the LMS Group. Ashbourne, Derbyshire: Moorland Publishing Company. p. 202.
- Casserley, H.C. & Johnston, Stuart W. (1974) . Locomotives at the Grouping 3: London, Midland and Scottish Railway. Shepperton, Surrey: Ian Allan. p. 152. ISBN 0-7110-0554-0.