Caledonian Railway 72 Class

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.

Caledonian Railway 72 Class
113 class No. 54471 at Dingwall in 1957
Type and origin Power type Steam Designer William Pickersgill Builder St. Rollox Works (10) Armstrong Whitworth (10) North British Locomotive Co. (12) Build date May 1920 to December 1922 Total produced 32
Specifications Configuration: ​  • Whyte 4-4-0  • UIC 2′B h2 Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Leading dia. 3 ft 6 in (1.067 m) Driver dia. 6 ft 6 in (1,981 mm) Wheelbase 46 ft 10+3⁄4 in (14.29 m) Length 56 ft 4+1⁄2 in (17.18 m) Height 12 ft 10+1⁄2 in (3,924 mm) Axle load 19 long tons 18 cwt (44,600 lb or 20.2 t) Adhesive weight 39 long tons 15 cwt (89,000 lb or 40.4 t) Loco weight 61 long tons 5 cwt (137,200 lb or 62.2 t) Tender weight 46 long tons 10 cwt (104,200 lb or 47.2 t) Total weight 107 long tons 15 cwt (241,400 lb or 109.5 t) Fuel type Coal Fuel capacity 6 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 area 17 sq ft (1.6 m2) Boiler pressure 180 psi (1.24 MPa) Heating surface: ​  • Firebox 144 sq ft (13.4 m2)  • Total surface 1,529 sq ft (142.0 m2) Superheater: ​  • Heating area 200 sq ft (19 m2) Cylinders Two, inside Cylinder size 20.5 in × 26 in (521 mm × 660 mm) Valve gear Stephenson Valve type Piston valves Valve travel 9 in (229 mm) Train brakes Westinghouse air brake
Performance figures Tractive effort 21,435 lbf (95.35 kN) Factor of adh. 4.15
Career Operators CR • LMS Class CR: 72 Power class LMS: 3P Number in class 32 Numbers CR: 72-91, 66-71, 92-97 LMS: 14477-14508 BR: 54477-54508 Nicknames "Pickersgill Bogies" First run May 1920 Last run October 1, 1962 Withdrawn 1953 (1), 1959-1962 (31) Disposition All scrapped, replica planned

'72' class No. 14493 at Inverness Depot in 1948

Numbering

Year	Quantity	Manufacturer	Class	CR nos.	LMS nos.	BR nos.
1916	6	St. Rollox Works	113	113–116, 121, 124	14461–14466	54461–54466
1916	10	North British Locomotive Co. 21442–21451	113	928–937	14467–14476	54467–54476
1920	10	St. Rollox Works	72	72–81	14477–14486	54477–54486
1921	10	Armstrong Whitworth 111–120	72	82–91	14487–14496	54487–54496
1922	12	North British Locomotive Co. 22943–22954	72	66–71, 92–97	14497–14508	54497–54508

The two classes together totalled 48 locomotives. No. 54481 was scrapped after an accident at Gollafield Junction in 1953, the remainder were withdrawn between 1959 and 1962.

Dimensions

Figures given in this section are from BR Database. Figures given by Rail UK are slightly different.

72 Class

See box, top right.

113 Class

See table below.

Introduced: 1916 
Total produced: 16
Locomotive weight: 61.25 long tons (62.23 t)
Boiler pressure: 175 psi (1.21 MPa)
Superheater: Yes
Cylinders: 20 in × 26 in (508 mm × 660 mm)
Driving wheel diameter: 6 ft 6 in (1,981 mm)
Valve gear: Stephenson
LMS/BR Power classification: 3P
Tractive effort: 19,833 lbf (88.22 kN)

Preservation

Although no members of the class have been preserved, there are plans to construct a replica.

See also

• Locomotives of the Caledonian Railway
• Locomotives of the London, Midland and Scottish Railway