The Rhymney Railway S class was a class of 0-6-0T steam locomotives introduced into traffic in 1908 designed by the railway's engineer Hurry Riches . There were initially four locos in the class. A further 4 ‘S1’ locomotives with a larger boiler and higher tractive effort were built in 1920.
Rhymney Railway Class S1 0-6-0T No. at Cardiff 1950
Type and origin Power type Steam Designer C. T. Hurry Riches Build date 1908–1920 Total produced 7 4(S), 3(S1)
Specifications Configuration: • Whyte 0-6-0T Gauge 4 ft 8+ 1 ⁄2 in (1,435 mm ) standard gauge Driver dia.4 ft 6 in (1.372 m) Loco weight S 55.06–66.95 long tons (55.94–68.02 t); S1 56.08–66.95 long tons (56.98–68.02 t) Fuel type Coal Boiler pressure 175 lbf/in2 (1.21 MPa);2 (1.38 MPa) Cylinders Two, inside Cylinder size 18 in × 26 in (457 mm × 660 mm)
Performance figures Tractive effort S 23,870 lbf (106.2 kN);
Career Operators RR , GWR , BR Class RR: S & S1 Power class BR: 4F Numbers RR: 32-4, 111–4 Withdrawn 1954–5 Disposition All scrapped
Casserley, H. C. & Johnston, Stuart W. (1966). Locomotives at the Grouping 4: Great Western Railway . Shepperton, Middlesex: Ian Allan Limited. p. 9-6. 
