Caledonian Railway 721 Class

Caledonian Railway 721 Class "Dunalastair" For variations see Table 1 below
Type and origin Power type Steam Designer John F. McIntosh Builder St. Rollox Works Build date 1896 Total produced 15
Specifications Configuration: ​  • Whyte 4-4-0 Gauge 4 ft 8+1⁄2 in (1,435 mm) Driver dia. 6 ft 6 in (1.98 m) Loco weight 47 long tons (48 t) Fuel type coal Water cap. 4,125 imp gal (18,750 L; 4,954 US gal) Boiler pressure 160 psi (1,100 kPa) Cylinders Two, inside Cylinder size 18.25 in × 26 in (464 mm × 660 mm) Valve gear Stephenson Valve type Slide valves
Performance figures Tractive effort 15,100 lbf (67 kN)
Career Operators CR • LMS • British Railways Class CR: 721 Power class LMS: 2P Withdrawn 1930–48 Disposition All scrapped

The Caledonian Railway 721 Class (known as the "Dunalastair" class) was a class of 4-4-0 steam locomotives designed by John F. McIntosh for the Caledonian Railway (CR) and introduced in 1896.^[1] Taking their name from the estate in Perthshire owned by the Caledonian’s then deputy chairman, J.C.Bunten, all survived to be absorbed by the London, Midland and Scottish Railway (LMS) in 1923 and a few survived into British Railways (BR) ownership in 1948.