The Caledonian Railway 264 and 611 classes were 0-4-0 saddle tank locomotives designed by Dugald Drummond and built by Neilson and Company in 1885. Later examples were built at St. Rollox railway works under the direction of John F. McIntosh in 1895, 1900, 1902 and 1908.These small shunters remained in long service under the LMS (who designated all Neilson saddle locomotives as Class 0F) and British Railways, with the last of the class withdrawn in 1962.