Rail Fastenings Systems

ADH System (Bonded DFF)

Pandrol’s ADH System limits corrugation and vibration problems caused by the major dynamic forces generated by passing trains.

This versatile system can be used on both standard track and turnouts. A single fastening system can be used for the whole track system as the standard model is designed for running track and customised models are designed for switching zones.

The ADH System provides both vertical and lateral stiffness via two independent cast baseplates. A one-piece bonded system (comprised of a top and bottom plate) is factory assembled by bonding with vulcanised rubber. This provides high levels of electrical resistance, long electrical leakage path and lateral resilience.

Technical Features

  • The ADH system is available in two- and four-hole offset and two-hole line footprint configurations. This gives the best possible solution for new build, track renewal and retrofit applications.
  • To meet specification requirements, the ADH System is available with a variety of clip types, including e-clip, SD, SLK, Nabla and FE.
  • The system’s unique bonding process achieves very high levels of electrical resistance and long electrical leakage paths. Tests against EN Standards have shown electrical insulation performance several times higher than the minimum required.


  • The ADH System has particularly high corrosion resistance because the plate is covered with rubber, which acts as a protective barrier between the baseplate and the atmosphere.
  • The system provides a specifi c longitudinal restraint, good track elasticity, and reduced stress in the rail when exposed to high temperatures.
  • The system provides electrical insulation for the rail, isolating it from the track bed and avoiding electrical leakage into the ground. In addition to this, the system has a high level of stray current protection.
Rail Fastenings Systems

ADH System (Bonded DFF)