Lankhorst's recessed KLP hybrid plastic sleeper was chosen together with five other alternative sleepers for the test installation near Kalmar.

The hybrid sleeper is reinforced with two steel bars using a patented production process to achieve the required rigidity and strength.

According to Lankhorst the sleeper has lifespan of more than 50 years, compared to just 10 years for untreated oak sleepers while offering the same level of damping and continuous track stiffness.

The sleeper was developed in response to the European ban on the use of creosote in railway sleepers and the restricted availability of hardwood.

KLP sleepers are already in use in the Netherlands, France, and Germany with applications including conventional plain track, bridges, and switches.