Headcheck Detection

The new rail steels are of such high quality and are so resistant to abrasion that material wear is no longer sufficient to prevent the growth of cracks appearing in the rail surface such as "head checks" (defects occurring at the gauge corner of the rail).

Head checks initially run into the interior of the rail at a very shallow angle of 15–30°. They are typically spaced between 2 and 7 mm apart but the crack spacing may decrease to as little as 0.5 mm in rails in which the head of the rail has been hardened.

If the head checks are not removed by processing the surface of the rail, for example by re-grinding, they will often grow to cause shelling at and around the gauge corner. In cases of strong growth, head checks may undergo a sudden change of orientation after which they grow vertically down into the rail inevitably leading to rail breakage.

MERMEC Group Head Check Detection System allows automatic detection and precise localization of 0,1 mm headcheck defects at 120 km/h (75 mph) enabling early-stage detection of gage corner cracking when grinding is still a possible solution.

High Speed

Main & Regional

Mass Transit & Light

Heavy-Haul