Original: It incorporated three sets of modified Caprotti valve gear, relatively new to British locomotive engineering, and more efficient than Walschaerts or Stephenson valve gear.
Simplified: British Railways standard 3 cylinder 4-6-2 express passenger steam locomotive No. 71000 (HMSO, British Transport Commission: London, 1957), p. 58 (Performance and efficiency tests, Bulletin No. 15)