Rockdelta RB

Vibration control for ballasted tracks

High-performance, dual density Rockdelta RB solution with a composite geotextile-geogrid. Dual density – high density top layer and low density bottom layer design – ensures that static and dynamic loads from gravel, stone, soil and other covering materials do not result in deterioration of the stone wool fibre material thus helping to provide the exceptional long product life cycle, e.g. as documented by the Technical University of Munich in approved test according to DIN 45673-5.

Sophisticated Three-Stage Anti-Vibration Solution For Ballasted Tracks

Providing for decades of stable, predictable and highest vibration isolation even in the most demanding applications the Rockdelta anti-vibration solution for ballasted railway tracks is based on a sophisticated three-stage approach using high-efficiency Rockdelta RB as the core element.

The solution consists of a unique dual-density sub-ballast mat with;

  • a low-damping, soft resilient layer – designed, tested and manufactured to have an extended lifetime with retained functional performance even under harsh climatic conditions
  • a force distributing high-density top layer, and finally
  • the sub ballast mats fibres are being protected from potential impairment by the ballast stones with a geocomposite product – with excellent resistance to stretching and tearing – that deforms under the load of the ballast and enables easy replacement of the ballast.

The Rockdelta geocomposite is a high-quality composite product comprising two membranes of non-woven geotextile and a load-distributing core. This solution can also be designed to act as a drainage system.

Selected Features Of A Rockdelta RB Solution

  • Excellent dynamic properties with inherent, first-rate volume compressibility
  • Unique dual density design with hard layer upper surface and soft layer core
  • Outstanding functional performance under any climatic conditions
  • Fully documented specifications based upon exhaustive tests
  • Exceptional life-span with virtually no change in functional performance
  • Maintenance free solution
  • Highly cost-effective
  • Short installation time with easy-to-handle mats and no need for gluing
  • No functional performance changes at sub-zero temperatures
  • All products artificially aged to ensure outstanding long-term stability
  • Excellent references
  • Designed to work with geocomposite
Tracks, Rockdelta, Rockdelta RB, ballasted tracks, vibration, structure protection, stone wool, tunnel, lapinus


Installation of a Rockdelta RB solution is easy and swift. As installation is performed with easy-to-cut and easy-to-handle mats – and without the use of glue – man power and time required for the installation is minimal at all times, even for a curved track.

Easy and safe installation is an advantage, especially in tunnels, where accessibility with heavy large cumbersome machinery and lifting devices can be difficult to manoeuvre. - Welding and grinding can be done without risk of fire.