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 They had cylinders outside with outside Walschaerts valve gear, driving wheels and a boiler pressured to . Weight was for the locomotive and for the tender. Piston valve diameter is given as (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 , plus for the Robinson type superheater, and grate area as .
Oil firing 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 The locomotives passed to the London, Midland and Scottish Railway (LMS) in 1923. The LMS classified them '4P'.
Transfer to BR 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Numbering HR Number Name Built LMS Number BR number Withdrawn Notes 49 Clan Campbell 1919 14762 — 51 Clan Fraser 1919 14763 — 52 Clan Munro 1919 14764 54764 BR number not applied 53 Clan Stewart 1919 14765 — 54 Clan Chattan 1921 14766 — 55 Clan Mackinnon 1921 14767 54767 56 Clan Mackenzie 1921 14768 — 57 Clan Cameron 1921 14769 —
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