The Highland Railway Drummond 0-6-4T or X class were large

tank engine A tank locomotive or tank engine is a steam locomotive that carries its water in one or more on-board water tanks, instead of a more traditional tender. Most tank engines also have bunkers (or fuel tanks) to hold fuel; in a tender-tank locomo ...

s originally intended for

banking A bank is a financial institution that accepts deposits from the public and creates a demand deposit while simultaneously making loans. Lending activities can be directly performed by the bank or indirectly through capital markets. Becau ...

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 A boiler is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, centr ...

and

firebox Firebox may refer to: *Firebox (steam engine), the area where the fuel is burned in a steam engine *Firebox (architecture), the part of a fireplace where fuel is combusted *Firebox Records Firebox Records was a Finnish record label based in S ...

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.

Numbering

Transfer to LMS

They all survived to be taken over by the London, Midland and Scottish Railway (LMS) at the 1923 Grouping. The last was withdrawn in 1936.

References

* * X 0-6-4T locomotives NBL locomotives Railway locomotives introduced in 1909 Scrapped locomotives Standard gauge steam locomotives of Great Britain {{Scotland-steam-loco-stub