Caledonian Railway 72 Class

Caledonian Railway 72 Class
113 class No. 54471 at Dingwall in 1957
Type and origin
Power typeSteam
DesignerWilliam Pickersgill
BuilderSt. Rollox Works (10)
Armstrong Whitworth (10)
North British Locomotive Co. (12)
Build dateMay 1920 to December 1922
Total produced32
Specifications
Configuration:
 • Whyte4-4-0
 • UIC2′B h2
Gauge4 ft 8+12 in (1,435 mm) standard gauge
Leading dia.3 ft 6 in (1.067 m)
Driver dia.6 ft 6 in (1,981 mm)
Wheelbase46 ft 10+34 in (14.29 m)
Length56 ft 4+12 in (17.18 m)
Height12 ft 10+12 in (3,924 mm)
Axle load19 long tons 18 cwt (44,600 lb or 20.2 t)
Adhesive weight39 long tons 15 cwt (89,000 lb or 40.4 t)
Loco weight61 long tons 5 cwt (137,200 lb or 62.2 t)
Tender weight46 long tons 10 cwt (104,200 lb or 47.2 t)
Total weight107 long tons 15 cwt (241,400 lb or 109.5 t)
Fuel typeCoal
Fuel capacity6 long tons 12 cwt (14,800 lb or 6.7 t)
Water cap.4,200 imp gal (19,000 L; 5,000 US gal)
Firebox:
 • Grate area17 sq ft (1.6 m2)
Boiler pressure180 psi (1.24 MPa)
Heating surface:
 • Firebox144 sq ft (13.4 m2)
 • Total surface1,529 sq ft (142.0 m2)
Superheater:
 • Heating area200 sq ft (19 m2)
CylindersTwo, inside
Cylinder size20.5 in × 26 in (521 mm × 660 mm)
Valve gearStephenson
Valve typePiston valves
Valve travel9 in (229 mm)
Train brakesWestinghouse air brake
Performance figures
Tractive effort21,435 lbf (95.35 kN)
Factor of adh.4.15
Career
OperatorsCR • LMS
ClassCR: 72
Power classLMS: 3P
Number in class32
NumbersCR: 72-91, 66-71, 92-97
LMS: 14477-14508
BR: 54477-54508
Nicknames"Pickersgill Bogies"
First runMay 1920
Last runOctober 1, 1962
Withdrawn1953 (1), 1959-1962 (31)
DispositionAll scrapped
'72' class No. 14493 at Inverness Depot in 1948

The Caledonian Railway 72 Class was a class of 4-4-0 steam locomotives introduced by William Pickersgill for the Caledonian Railway (CR) in 1920. Thirty-two locomotives were built and all survived to be taken over by the London, Midland and Scottish Railway (LMS) in 1923 and by British Railways (BR) in 1948. The earlier 113 Class (introduced in 1916), of which 16 were produced, were similar but slightly smaller. These were the Caledonian's last express passenger locomotives, and technically, the last of the Dunalastair series, and were unofficially dubbed, Dunalastair V.[citation needed]