Rail Structural Drainage

Rail construction projects require structural drainage in a number of applications. Typical applications within the rail sector include bridge abutments, buried concrete structures, retaining walls and sprayed concrete walls. ABG design, manufacture and supply proven geosynthetic solutions which provide structural drainage as well as providing significant cost savings.

Traditionally, porous blocks, drainage aggregate or no fines concrete have been used to relieve hydrostatic pressures on structures in rail developments. As a RISQS Verified supplier ABG have developed our high-performance geosynthetic drainage systems which are used in place of theses traditional solutions. ABG Deckdrain is a BBA approved, UK manufactured drainage geocomposite, which provides factory consistent drainage performance along with a range of other benefits.

Typical applications

  • Rail Bridge Abutments
  • Buried Concrete Structures
  • Back of Wall Drainage
  • Station Wall Drainage
  • Retaining Walls
  • Cut and cover tunnels / green tunnels
  • Green bridges


  • Cost-effective alternative to granular gravel drainage
  • Horizontal or vertical drainage applications
  • Enhanced performance of waterproofing
  • Reduced delivery traffic volumes when compared with stone delivery vehicles
  • Very fast installation
  • BBA approved

Deckdrain drainage geocomposite provides structural drainage that is up to 50 times more effective than drainage stone at a fraction of the material and labour cost. This is achieved through the high-performance cuspated HDPE drainage core thermally bonded to geotextile filter element which acts to maintain a free-flowing drainage void. Deckdrain is light-weight yet robust drainage layer which also offers protection to the waterproofing for the lifetime of the structure.

Deckdrain is simple to install without specialist knowledge or equipment. It is supplied on easy to handle rolls making access and installation simple for areas with restricted access, such as bridge abutments, retaining walls, culverts, and cut and cover tunnels.

When compared to traditional permeable Type A filter gravel the same volume of drainage can be achieved with a significantly thinner layer. That means Deckdrain provides cost effective groundwater management for underground structures, and has uses in rail stations and tunnels where reducing the volume of dig out and import has huge finanacial benefits.

In certain applications, concrete can be cast directly into the back of Deckdrain making it ideal for an underground station slab, or to receive sprayed concrete. The unique cuspated profile of the back of Deckdrain is reported to reduce concrete rebound by up to 25%, meaning faster completion with reduced waste.

Using Deckdrain geocomposite can reduce the amount of excavation required on site and enables excavated material to be re-used as backfill. That means vastly reduced vehicle movements to and from site representing up to a 95% reduction on carbon emissions when compared to traditional methods.

ABG provide full technical support for the design of structural drainage within rail markets. Deckdrain is specified for use on rural lines, main lines and high speed rail lines as well as depot structures around the world.

Road under rail structure utilising Deckdrain to allow more site won fill to be used

Deckdrain drainage layer installed prior to bridge slide allows accelerated fill placement and reduced possession time.

Deckdrain is quickly and easily installed.

Shotcrete installation onto the Deckdrain retaining wall drainage composite

Tunnel Drainage – Cut & Cover

ABG Deckdrain is a high performance geocomposite drainage system, providing an effective and environmentally friendly alternative to traditional granular structural drainage for railway tunnels. ABG Deckdrain has a high flow capacity and provides added protection to the external walls of the tunnel.The HDPE cuspated core of the geocomposite provides a free flowing drainage void allowing water to flow in all directions, unlike linear or pipe systems. The cuspates are designed to support the stiffened filtration geotextile which is thermally bonded to the core. This ensures that the geotextile does not deform into the drainage void under the pressure of the backfill material. More information about flow testing.

ABG Deckdrain is durable and sufficiently robust to resist the mechanical stresses imposed during installation and then on throughout its design life. The use of ABG Deckdrain eliminates the need for further protection of the waterproofing system. Deckdrain has been creep tested at compressive loads of up to 1,000 kPa to give a design life of 120 years.

For cut and cover tunnels, Deckdrain can be used for the external drainage layer

For the internal and invert tunnel drainage our Cavidrain geocomposites should be considered.

RISQS Verified

ABG are RISQS Verified – (Railway Industry Supplier Qualification Scheme)

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Case studies

Additional information

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