Coconut mats KGW stabilize railroad tracks around Amsterdam

Knipscheer Rail-Infra B.V. and TEFAB are reinforcing more than 30 thousand square meters of embankments around the railroad tracks in the municipality of Amsterdam. At three locations, improvements are being made to the embankments near the tracks, prompted by subsidence in the embankments. Meanwhile, the subsoil in Riekenpolder, Sloterdijk and Diemen has been backfilled and covered with our anti-erosion coir mats.

A solid surface with biodegradable coir mats from TEFAB

To prevent shearing soil on the renovated embankments, Knipscheer was looking for an interlayer that automatically decomposes and prevents erosion. TEFAB's coir mats act as a natural interlayer. They separate the clay topsoil from the underlying sand and are designed to prevent leaching.

In total, the Knipscheer professionals are covering 16 km of railroad embankment with coir matting to restore the embankments. Rudy Ekelschot of contracting firm Knipscheer explains: ''We remove the top layer of vegetation from the embankment and re-profile that embankment to create a neat, taut surface again. Then we roll the TEFAB coir mats over it and secure them with wooden pegs. The wooden pegs we used in this project were also supplied by TEFAB.

Why a KGW coir mat?

From the client ProRail, there was no way plastic was allowed to be present in the project. Rudy notes, ''Coco is pretty much our only option, it decomposes at some point. Plastic doesn't decompose and you have more work later on with excavation and recycling.''

The 450-gram KGW Kokos mat used is one of the heavier variants in the range to prevent subsidence in the future. An additional advantage is that the standard 50 m x 2 m rolls are highly permeable to water. The biodegradable properties of this product mean that there is one less worry, especially in hard-to-reach areas near railroads.

Working late into the night

In addition to limited accessibility, there were several issues at play. In Riekenpolder, Sloterdijk and Diemen, work was mainly done at night. The planned duration for the 3 locations is 1 year in total. Rudy Ekelschot reveals that more than a handful of nights were scheduled. ''The biggest challenge is getting to the hard-to-reach places with the materials and machines. Logistically that is difficult to plan, supply is only via rail and that is why we make optimal use of service interruptions to efficiently carry out our work in a short time.''

Slow-growing herbal mixture

Minimal maintenance is a priority in this project. Knowledge is plentiful and consideration is given to the awkward location, even years after completion. As a result, the nature-friendly coir mats were sown with a slow-growing herb mixture as a requirement of ProRail. This means less frequent mowing in awkward spots and a green view for train passengers. At the same time, insects and birds enjoy increased biodiversity.

A sustainable partnership

Meanwhile, Knipscheer has been working with ProRail for 15 years, Rudy adds. The contact with TEFAB is also excellent. In advising the project manager and work planners of contracting company Knipscheer, TEFAB's advisors put in a lot of time. The wishes and requirements of ProRail were also carefully considered in order to unburden both organizations. Far into the future, TEFAB coir mats also save valuable time because no plastic materials are left behind during repair work. Rudy expects several projects to come up for stabilizing embankments. For these, Knipscheer turns to TEFAB again.

An overly sagging track bed will be a thing of the past after completion of this project in late summer 2022. Soon the routes will be able to tolerate higher frequencies of train traffic. Esther IJzer and Ron van Gestel, owners of TEFAB, are pleased with the contribution to making Dutch transportation more sustainable.