TERRAM Hydrotex

Application Function

Filter separators

Market Sectors


Traditionally a sub-ballast and/or a graded-sand blanket layer has been used in rail trackbed applications to prevent the upward movement of fine sub-grade particles, whilst allowing effective drainage and dissipation of pore water pressure. 

TERRAM Hyrdotex now offers this solution in one geocomposite.

TERRAM Hydrotex is a geocomposite solution, for fine soil trackbed stability applications, that acts as a filter/separator, removing the need for a sand blanket.

TERRAM Hydrotex is a nonwoven geocomposite consisting of a central filter media thermally bonded to two opposing needlepunched nonwovens Robust Geotextile filter layers, to create a geocomposite with sufficient strength and protection to be durable to the abrasion and point loading of ballast.

TERRAM Hydrotex is strong but flexible allowing the composite to conform to the excavated formation, so that no voids exist below the filter media for the development of pockets of slurry resulting in an unstable trackbed.

• Prevents upwards particle passage smaller than 0.002mm
• Permeable filter, allowing upward and downward water transmission
• Replaces the requirement for a sand blanket
• Quickly and easily installed, no specialist plant is required
• Functions under ballast without any reduction in performance
• Approved by Network Rail 
• Residual slurry becomes desiccated as any pore water is dissipated 
• Supplied on standard rolls of 3.9m x 50m
(other sizes available on request)

Environmental Benefits:
TERRAM Hydrotex composite reduces the depth of excavation that would be required with a traditional sand blanket. The result is a decrease in the amount of spoil being taken away for landfill and a reduction of vehicles required to deliver materials.


TERRAM Railways