The rail infrastructure suffers problems in various locations where minute particles of metal are produced by the abrasion of wheels on the rails, particularly on the outside of tight radius curves.
This collection of metallic particles around insulated block joints (which separate track circuits) can lead to a bridge in the insulation. This bridge causes a short circuit resulting in a track circuit failure which puts the signals to red and delays trains until staff have cleared the excess detritus material. Historically there has been no solution to this problem other than by manual intervention, which has often failed to prevent the track circuit failures.
The patented Permanent Particle Rail Magnet (PPRM) provides an innovative solution to this problem. The magnet is fitted to the rail at a position either side of the insulated joint and collects the metal dust that would otherwise have caused the short circuit across the joint. Magnets are available to suit most Rail section sizes
The magnets are 'cleaned' by a magnetic wand and the particles disposed of in an environmentally friendly way as part of normal maintenance activities staff undertake whilst on site for other work.
Successful trials of the patented PPRM’s were carried out during 2010, at three Network Rail sites, the first being in the London Bridge Station area. Track circuit failures in such a busy area cause significant problems! The PPRM’s have full Network Rail product acceptance and more than 7,000 units have been installed across Network Rail and London Underground Infrastructure, since product approval.