Embedded rail slab track offers tempting advantages

Deterioration of track geometry, mainly by settlement of the substructure and ballast, is the main cause of the need for track maintenance. The mechanism that causes ballast deterioration is outlined. Tamping to restore track geometry can cause further ballast breakdown. Two types of cost-effective railway track construction methods to reduce the burden of maintaining ballast are described. The first uses a polymer reinforcement in the ballast layer to improve its durability and reduce long-term maintenance costs. The XiTrack GeoComposite treatment modifies ballast behaviour without altering ballast drainage. The second is a ballastless track form that can change the maintenance requirements. Slab track is still perceived as more expensive than ballasted track, but there is evidence that slab track using embedded rail technology can be cheaper. Most existing embedded rail installations use conventional Vignoles or grooved rail profiles. The option to improve ballast can be used to upgrade existing track. Slab track is more appropriate for new track.