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The Highland Railway Drummond 0-6-4T or X class were large tank engines originally intended for banking duty. They were designed by Peter Drummond.
Construction
The first four were built by the North British Locomotive Company and delivered in 1909. A second batch of four was delivered in 1911.
Design
The design was derived from that of the class K (0-6-0) tender engines and leading dimensions were very similar although the boiler and firebox are recorded as being 'larger' but by an unspecified amount.
Reputation
They were not popular with their crews, many thought them heavy and clumsy, and several crews had problems with water capacity. It seems their axleboxes were not well-proportioned either as there are reports of consistent hot box problems.
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. 200.
Haresnape, Brian; Rowledge, Peter (1982). Drummond Locomotives, a pictorial history. Shepperton, Surrey: Ian Allan Limited. ISBN0-7110-1206-7.