LNWR Samson Class

The LNWR Samson Class was a class of ninety 2-4-0 steam locomotives[1] built by the London and North Western Railway at their Crewe Works between 1863 and 1879.

LNWR Samson Class
2154 Loadstone at Monument Lane locomotive depot
Type and origin Power type Steam Designer John Ramsbottom Builder Crewe Works Serial number 624–633, 680–689, 730–739, 780–789, 880–889, 1692–1701, 1842–1861, 2279–2288 Build date May 1863 – May 1879 Total produced 90
Specifications Configuration: ​  • Whyte 2-4-0  • UIC 1B n2 Gauge 4 ft 8+1⁄2 in (1,435 mm) Leading dia. 3 ft 6 in (1.067 m) Driver dia. 6 ft 3 in (1.905 m) Wheelbase:  • Engine 14 ft 7 in (4.445 m)  • Leading 7 ft 5 in (2.261 m)  • Coupled 7 ft 2 in (2.184 m) Loco weight 26 long tons 2 cwt (26.5 t) Water cap. 1,500 imp gal (6,800 L; 1,800 US gal) Boiler: ​  • Diameter 3 ft 9+1⁄8 in (1.146 m)  • Tube plates 9 ft 8+3⁄8 in (2.956 m) Boiler pressure 140 lbf/in2 (970 kPa; 9.8 kgf/cm2) Heating surface 1,083 sq ft (100.6 m2) Cylinders Two, inside Cylinder size 16 in × 20 in (406 mm × 508 mm) Valve gear Stephenson
Performance figures Tractive effort 8,700 lbf (38.70 kN)
Career Operators London and North Western Railway Withdrawn September 1889 – November 1894, 1914 - 1925 Disposition All scrapped

They were officially designated "Curved Link 6-ft Passenger" due to the use of Stephenson valve gear which included a curved expansion link between the fore and back eccentric rods (earlier LNWR designs had used the Allan valve gear which had a straight expansion link) and the use of 6-foot (1.829 m) diameter wheel centres, which, together with 1+1⁄2-inch (38 mm) thick tyres gave a driving wheel diameter of 6 feet 3 inches (1.905 m).[2]

Ostensibly a mixed traffic design, they were the first locomotives with coupled driving wheels to be allocated for passenger duties on the LNWR.

They were designed by John Ramsbottom who had fifty built, all without cabs and with pierced driving wheel splashers. Ramsbottom's successor F. W. Webb, built forty more, all with cabs. The earlier locomotives also gained cabs, and all eventually had their splashers filled in.

All ninety locomotives were 'renewed' (replaced) by a like number of Waterloo Class locomotives between 1889 and 1905, but only eighty were scrapped quickly. The ten exceptions were transferred to the Civil Engineer's list, and these were withdrawn between 1914 and 1925.[3] No examples have been preserved.