HDS-jet equipped with a combination of water- and sand-blasting technology. The new process amazed the professionals at the ENTSORGA show in 2009. This apparatus, registered with the German patent office under the name HDS-jet, is equipped with 2 water/sand blasting nozzles. Operation is as the TSSR.

The array rotates through 360º on its own axis and is raised and lowered by winch. Working on the venturi principle, the high pressure water pump creates a strong vacuum which in turn draws the blasting sand out of the container.

The sand is then accelerated so powerfully through the nozzle that it keys or prepares tiles, new concrete surfaces or synthetic surfaces so that the new ERGELIT coating makes a permanent bond. Thanks to the short, uniform and easily adjustable distance between the nozzle and the shaft wall, the blasting sand, with carefully selected grain size, gives very even results. The speed at which the HDS-jet cleans is around 15mins per metre. That is, it normally takes 1 hour to complete the cleaning and preparation of a standard 4m deep shaft with these problematic shaft walls. In exceptional cases the procedure can be repeated several times, depending on the sandblasting finish required.