Railway.

The pumping action generated by the passing of railway traffic over the track can cause the rapid deterioration of the ballast and the breakdown of the granular support given by the ballast to the sleepers.
In these applications Heavyweight NW geotextiles have many years of proven performance as a filtration/separation layer to help reduce track failure from pumping.
Installed between the ballast and underlying soil, the key properties of the geotextile include good puncture resistance and a small characteristic opening size.