LSWR F13 class

LSWR/SR F13

F13 class 330, circa. 1907

Type and origin Power type Steam Designer Dugald Drummond Builder LSWR Nine Elms Works Build date 1905 Total produced 5

Specifications Configuration 4-6-0 Gauge 4 ft 8 1⁄2 in (1,435 mm) Leading dia. 3 ft 7 in (1.092 m) Driver dia. 6 ft 0 in (1.829 m) Length 63 ft 11 in (19.48 m) Loco weight 76.65 tons (77.9 tonnes) Fuel type Coal Fuel capacity 5 tons (5.1 tonnes) Water cap 5,800 imp gal (26,000 l) Boiler pressure 175 psi (1.21 MPa) Cylinders Four Cylinder size 16 × 24 in (406 × 610 mm) Valve gear Stephenson (inside) Walschaerts (outside)

Performance figures Tractive effort 25,387 lbf (112.93 kN)

Career Operators London and South Western Railway, Southern Railway (Great Britain) Class F13 Locale Great Britain Retired 1924 Disposition All rebuilt to H15 class

The London and South Western Railway F13 class was a class of 4-6-0 locomotives designed by Dugald Drummond for the London and South Western Railway (LSWR).

Whilst Dugald Drummond's success with his previous 4-4-0 designs meant that the LSWR's immediate traffic needs were covered in 1905, he began to undertake a new project that would help solve a new problem. This problem rested in fact that the timetables were continually accelerated because of this success, especially in the case of boat trains to the South Coast ports.

It soon became clear that faster passenger locomotives with a better power-to-weight ratio than the 4-4-0 designs were needed, in order to keep pace with the LSWR's passenger requirements increasing due to lengthened, heavier rolling stock that needed to keep up with faster point-to-point schedules.

As a result, Drummond believed that a new wheel arrangement (for the LSWR) was required in order to support such power, which in turn was provided by a multiple-cylinder layout. The resultant design was to become the F13 Class.

Drummond had settled on the 4-6-0 wheel arrangement in anticipation of further increases in speed and length of trains, a concept that had many advantages. A longer, larger boiler could therefore be utilised, therefore generating the steam needed to power a four-cylinder front end, and 6 feet 0 inches (1.829 m) wheels were utilised. In terms of the cylinder arrangement, Drummond's first foray into 4-6-0 locomotive design was highly unusual.

The new design was equipped with Stephenson valve gear for the inside cylinders and Walschaerts valve gear for the outside, therefore creating an overly complex design in respect to spare parts required during overhauls. This factor also created a heavy locomotive, though route availability was not a high consideration in terms of their intended role to ply their trade on the LSWR mainline.

Full-scale construction was undertaken at Nine Elms, with the first of five F13s being outshopped in 1905, and the class was married to a Drummond 'watercart' eight-wheeled tender in an attempt to provide adequate provision of coal and water for long journeys.

Under the LSWR, the F13s were outshopped in the LSWR Passenger Sage Green livery with purple-brown edging, creating panels of green. This was further lined in white and black with 'LSWR' in gilt on the tender tank sides.