Locomotive test report, London Midland & Scottish Railway Report, locomotive class 2P 4-4-0

Locomotive test report, London Midland & Scottish Railway Report, locomotive class 2P 4-4-0 No. 587 (with double exhaust piston valves) and No. 609 (with standard piston valves), performance and efficiency: "To determine saving in fuel to be obtained by fitting double exhaust piston valves", November and December 1929, Derby, 9 pages of text, 1 diagram, 8 graphs. (NRM Technical Archive reference TEST/LMS/10)