Lankhorst KLP® Rail Sleepers installed in Rotterdam Willemsspoortunnel

Single largest European installation of composite sleepers so far

In what is believed to be the single largest European installation of composite sleepers, Lankhorst Rail has supplied 6000 KLP® Hybrid Polymer Sleepers as part of the Rotterdam Willemsspoortunnel upgrade, via its Dutch distributor Voestalpine Track Solutions Netherlands B.V. The KLP® sleepers replace wooden sleepers where there is a risk of subsidence.

Dutch rail network operator, ProRail, is upgrading the infrastructure within the Willemsspoortunnel. The damp environmental conditions in the tunnel, together with exposure to waste from passenger toilets, have significantly reduced the service life of the tunnel’s wooden sleepers. Many of the wooden sleepers have been replaced by concrete. However, a disadvantage of concrete sleepers is that they are considerably heavier than wooden sleepers.

In those parts of the tunnel where subsidence, due to the total weight of the tunnel construction, is a risk or has already occurred, KLP® Hybrid Polymer Sleepers are now being used. As Bernard Huitema, sales manager at Lankhorst Rail, explains. “A concrete sleeper is typically larger and up to three times heavier than a Hybrid Polymer Sleeper, and so requires more ballast. If the subsoil is weak, such as a peaty soil with potentially poor drainage, the KLP® Hybrid Polymer Sleepers allows you to use less ballast, thereby reducing the load on the subsoil."

The first 1500 sleepers were installed in the Willemsspoortunnel in 2021 and the remaining 4500 sleepers installed in 2023.

Automated Sleeper Installation

KLP® Hybrid Polymer Sleepers are resistant to the effects of damp and toilet waste and offer a maintenance free service life of up to 50 years. They are the same size as an average wooden sleeper, allowing the use of automated track lay systems such as the RUS 1000 S in the Willemsspoortunnel. As the wooden sleepers were removed, they were replaced by KLP® Hybrid Polymer Sleepers with the rail fixtures already fitted.

In those tunnels, where height restrictions prevent the use of concrete as an alternative to replacing wooden sleepers, KLP® Hybrid Polymer sleeper can also be used. The lower height and lighter KLP® sleepers provide engineers with a more cost-effective alternative to undertaking time consuming and costly tunnel re-engineering.

KLP® Hybrid Polymer Sleepers

The KLP Hybrid Polymer Sleeper comprises a ductile polymer combined with steel rebars, resulting in a sustainable and long-lasting, maintenance free track sleeper with high bending stiffness and low thermal expansion. In effect, it combines the best performance attributes of wooden and concrete sleepers. KLP® Hybrid Polymer Sleepers are available for specific applications such as main track, turnouts, bridges and tunnels.