With Special Equipment for Installation Above and Under Water Ships with bigger propulsion travelling at higher speeds require revetments employing larger rock dimensions (size III or IV) or thinner and therefore interlocked revetments. A technique especially developed for underwater installation makes it possible to apply a pre-defined amount of the Hydrocrete® grouting mortar to a pre-defined area of the revetment. The consistency and the grain size of the aggregate are tailored to allow the mortar to interlock not only the top rock-layer but also the second and the third layer. This way, a two-dimensional interlock is obtained - while at the same time the permeability of the revetment is maintained. Both, the Hydrocrete® and the installation technique have been checked for compliance with the German Code of Practice for the Application of Grouting Materials (MAV) by the Federal Waterways Engineering and Research Institute in Karlsruhe. Impermeable revetments for sealing purposes or at high water velocities can be built with the Hydrocrete® System using the full grouting technique. Depending on the consistency the mortar allows it to completely fill out pores in the revetment. Drill core from a revetment that has been fully grouted with Hydrocrete®. Hydrocrete® can be produced in any ready-mix plant. Our two inland waterway vessels fitted with concrete mixing equipment are available for the on-water production of Hydrocrete® mortar. In addition to that, the vessels are equipped with tanks for cement and aggregates as well as concrete pumps and conveying boams. The installation of Hydrocrete® interlock concrete can also be performed by divers. Long-time experience of more than 25 years and staff that has worked with us since the company was founded guarantee optimal results for every grouting and concreting task. gewatech works according to the quality assurance standard DIN ISO 9001 Installing Hydrocrete® grouting mortar on a permeable revetment using an automatically underwater working device Grouted revetment maintaining permeability. Scour protection of bridge piers at the Schlei firth in Kappeln, Germany. Grouting works on a floor revetment at the dock gate in Oslebshausen, Germany. Grouting of a stilling pool at the Iffezheim weir in Germany.