The 'Strath' class of 4-4-0 passenger locomotives were built for the Highland Railway by Neilson Reid & Co. of Glasgow in 1892. They were built to the design of David Jones, the company's locomotive superintendent, and were similar in design to his other locomotives, with the exception of having larger boilers. The twelve locomotives were numbered 89 to 100 and six of them passed into LMS ownership in 1923.