Service trials of concret sleeper assemblies - an up-date on previous observations on F27A & F27BS concrete sleepered lenghts laid 1978-1980, following the deliberatins of the Concrete Sleeper Working Party (TM-CES-108)

A number of lengths of track were relaid with F27A (D912) and F27BS sleepers in the period 1978-1980, these two designs being evolved by the Concrete Sleeper Working Party to overcome some deficiencies experienced with the earlier F27 sleepers, notably cracking across the top near the rail seats at track...