Earl of Airlie

Earl of Airlie was a locomotive of the Dundee and Newtyle Railway, a pioneer Scottish railway opened in 1831 that ran from Dundee northward to Newtyle in Angus, crossing the Sidlaw Hills by means of three rope-worked inclined planes. The railway was notable as one of the earliest in Scotland and for using an unusual combination of stationary winding engines on the inclines and locomotive haulage on the level or gently graded sections between them — a mixed-mode operation that was common on early railways before steam locomotive technology was sufficiently reliable and powerful for the full range of gradients encountered.

The Dundee and Newtyle Railway was opened with horse traction, but in 1833 it introduced steam locomotives for the level sections, of which Earl of Airlie was one of the early examples. The locomotive was named after David Ogilvy, the 6th Earl of Airlie, who was a prominent supporter and director of the railway. The 0-2-4 wheel arrangement — no leading wheels under the front of the engine, two coupled driving wheels, and four trailing wheels — was unusual and reflected the experimental nature of very early locomotive design, when engineers had not yet settled on the configurations that would become standard.

The Dundee and Newtyle Railway was eventually absorbed into the Caledonian Railway system and its early locomotives were scrapped without preservation. Earl of Airlie survives only in railway records and contemporary accounts as a representative of the experimental phase of Scottish railway development in the 1830s.