Caledonian Railway 721 Class

Specifications
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

Type and origin
Type and origin
Power type	Steam
Designer	John F. McIntosh
Builder	St. Rollox Works
Build date	1896
Total produced	15

Caledonian Railway 721 Class
"Dunalastair"
For variations see Table 1 below
Caledonian Railway 721 Class; "Dunalastair"; For variations see Table 1 below
Power type
Type and origin
Power type	Steam
Designer	John F. McIntosh
Builder	St. Rollox Works
Build date	1896
Total produced	15
Configuration:;
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
Tractive effort
Performance figures
Tractive effort	15,100 lbf (67 kN)
Operators
Career
Operators	CR • LMS • British Railways
Class	CR: 721
Power class	LMS: 2P
Withdrawn	1930–1958
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. 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.