Railway permanent way construction - involves synthetic woven material covering to hinder plant growth

摘要

The permanentway construction esp. has ballast as bedding material for rails, and a material, covering the ballast surface, to inhibit plant growth. The material may consist of synthetic film, and closemesh woven materials, e.g. those containing bitumen or tar. The materials may be deformed by heat radiation, and there are surface drainage devices in the track centre.