Rail Fastenings Systems

Bonded DFF

The Bonded DFF system has been developed for plain line and turnout applications to directly combat corrugation and vibration problems caused by major dynamic forces generated from passing trains.

The DFF system is suitable for use on slab tracks, concrete ties, steel bridges, ballasted tracks and turnouts. The fastening system has two system variations available; a standard model for plain line tracks and customized models for turnout applications. The DFF system can be constructed by either the top-down method or bottom-up construction and is adaptable to all types of slab.

Technical Features

  • Different anchor configurations are available utilising plastic dowel or cast inserts subject to operational requirements
  • Special variants for turnout areas such as for switches and crossings
  • Vibration isolation can be provided in a range of stiffness down to 60 lbs/inch although a typical standard stiffness configuration would be around 220 lbs/inch
  • The bonded resilience provides longitudinal, vertical and lateral stiffness
  • The system is adjustable laterally and vertically, typically +/- 12 mm laterally per rail seat and + 30 mm vertically


  • The one piece bonded system comprises a top and bottom plate factory assembled by bonding using vulcanized rubber which provides very high levels of electrical resistance, long electrical leakage path and the lateral resilience which can minimise corrugation propagation
  • The complete factory-assembled baseplate in the DFF system provides the opportunity to attach the system directly to the bridge superstructure or to the timber, concrete or steel bearer and provide a high level of adjustment to suit
  • Depending on the type of rail clip used on the DFF system, structure interaction between the rail and the structure can be managed by low toe load and/or zero longitudinal restraint (ZLR) fastening options
Rail Fastenings Systems

Bonded DFF