Lateral characteristic evaluation for the continental 684N 'Flex-air' spring (TM-DOS-3)

The spring tested is incorporated in the C.M. & E.E. (B.R.B.) "Flex-air" designs for Mk III (BT 7) and GN electrification motored (BP 15) bogies. Although generally similar to the 67IN type previously tested (ref: R & D Divisional Internal Memorandum IMDA 109) the 684N is new to British...