Empirical studies of head check propagation on the DB network

• We present empirical findings relating to both head check growth and wear development.
• We discuss key factors influencing head check development.
• The results have been used to derive head check propagation rates for R260 and R350HT rail steels.
• The propagation rates are used to determine the optimum time for preventive rail grinding.
• Advanced analysis of head check growth is necessary when planning and carrying out rail grinding work.

This article presents empirical findings relating to both head check growth and wear development and discusses a number of studies that have examined key factors influencing head check development. Advanced analysis of head check growth is necessary in order to determine the optimum time for preventive rail grinding and to enable crack propagation rates to be taken into account when planning and carrying out rail grinding work. The results have been used to derive head check propagation rates for R260 and R350HT rail steels. These empirically derived growth rates are used to specify the amount of metal that has to be removed from the rail surface in a particular grinding interval or by a particular grinding time-limit, either as part of DB's cyclical preventive maintenance scheme or its fault-based, corrective maintenance programme.