Highland Railway Clan Class

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Highland Railway Clan class
Type and origin
Power type Steam
Designer Christopher Cumming
Builder Hawthorn Leslie and Company
Serial number 3329–3332, 3443–3446
Build date 1919 (4), 1921 (4)
Total produced 8
Specifications
Configuration 4-6-0
UIC classification 2′C h2
Gauge 4 ft 8 12 in (1,435 mm)
Leading wheel
diameter
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 9 316 in (1.453 m) diameter, with 1 18 in (29 mm) taper
Boiler pressure 175 psi (1.21 MPa)
Firegrate area 25.5 sq ft (2.37 m2)
Heating surface:
– Total
1,467 square feet (136.3 m2)
Superheater type Robinson
Superheater area 256 sq ft (23.8 m2)
Cylinders Two, outside
Cylinder size 21 in × 26 in (533 mm × 660 mm)
Valve gear Walschaerts
Valve type 10 in (254 mm) piston valves
Performance figures
Tractive effort 23,688 lbf (105.37 kN)
Career
Operator(s) HRLMSBR
Power class LMS/BR: 4P
Number(s) HR: 49, 51–57
LMS: 14762–14769
BR: 54767
Withdrawn 1943–1950
Disposition All scrapped

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. The first four were built in 1919, and the remaining four in 1921.

Dimensions[edit]

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).

Oil firing[edit]

Early in 1921 Clan Stewart was used for experiments with oil firing. This seems 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.

Transfer to LMS[edit]

The locomotives passed to the London, Midland and Scottish Railway (LMS) in 1923. The LMS classified them '4P'.

Transfer to BR[edit]

Two survived into British Railways (BR) hands in 1948, but only Clan Mackinnon received its BR number. Some of the Clan names were later reapplied to the BR Standard Class 6.

Numbering[edit]

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

References[edit]

  • 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) [1966]. Locomotives at the Grouping 3: London, Midland and Scottish Railway. Shepperton, Surrey: Ian Allan. p. 152. ISBN 0-7110-0554-0.