LSWR K10 class

LSWR/SR K10

K10 number 386 at Eastleigh, 1950

Type and origin Power type Steam Designer Dugald Drummond Builder LSWR Nine Elms Works Build date 1901-1902 Total produced 40

Specifications Configuration: ​  • Whyte 4-4-0 Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Leading dia. 3 ft 7 in (1.092 m) Driver dia. 5 ft 7 in (1.702 m) Length ? ft ? in (? m) Loco weight 46 long tons 14 cwt (104,600 lb or 47.4 t) Fuel type Coal Fuel capacity 5 long tons 0 cwt (11,200 lb or 5.1 t) Water cap 4,000 imp gal (18,000 l; 4,800 US gal) Boiler pressure 175 lbf/in2 (1,210 kPa; 12.3 kgf/cm2) Cylinders 2 Cylinder size 18.5 in × 26 in (470 mm × 660 mm)

Performance figures Tractive effort 19,755 lbf (87,870 N)

Career Operators London and South Western Railway, Southern Railway (Great Britain), Southern Region of British Railways Locale Great Britain

The London and South Western Railway K10 Class was a class of 40 4-4-0 steam locomotives designed for mixed traffic work. They were introduced on the London and South Western Railway in 1901 and 1902 to the design of Dugald Drummond, where they earned the nickname "Small Hoppers".

In order to satisfy a pressing requirement for mixed-traffic locomotives, Drummond adopted the solution of a small-wheeled 4-4-0 he had previously employed on the Caledonian Railway. The resulting K10 had the same 5 ft 7 in (1.702 m) diameter coupled wheels as the M7 and the boiler was interchangeable with the M7, 700 and C8 classes

Forty of the class were subsequently outshopped from the LSWR's Nine Elms Locomotive Works. They were generally paired with a 6-wheel tender because of their intended short journey lengths, which included local stopping trains and medium-level freight haulage, but as with the later L11 class, some could occasionally be seen with a 4,000-imperial-gallon (18,000 l; 4,800 US gal) "watercart" tender for longer trips.

Livery under the LSWR was Drummond's LSWR Passenger Sage Green, with purple-brown edging and black and white lining. Under Southern Railway ownership from grouping in 1923, the locomotives were outshopped in Richard Maunsell's darker version of the LSWR Sage Green with yellow lettering on the tender, with black and white lining. This livery was continued under Oliver Bulleid despite his experimentations with Malachite green, though the 'Southern' lettering on the tender was changed to the 'Sunshine Yellow' style. During the Second World War, members of the class outshopped form overhaul were turned out in wartime black. The class was haphazardly numbered by the LSWR. Numbering under the Southern retained the LSWR allocations.