The Dundee and Newtyle Railway was built in the Scottish gauge of four foot six inches and operated three locomotives of an unusual design. They were among the first British locomotives to have a bogie, which in this case was located behind the driving axle. The cylinders were arranged vertically and transmitted the power to the connecting rods via L-shaped levers.

Two locomotives of this type were built by J. and C. Carmichael in Dundee. The “Lord Wharncliffe” differed from the first locomotive in that the cylinder diameter was 11.25 inches instead of 11 inches. A third, named “Trotter” with different dimensions came from James Stirling & Co.

After the Dundee and Perth Railway had taken over the Dundee and Newtyle, the locos were also converted to standard gauge in 1849 after the line was regauged. Both locomotives were in use until 1854. The “Earl of Airlie” was restored and photographed in 1863 but not preserved for posterity.