The Cube System is based on traditional diaphragm walling (slurry wall) excavation principles but the cutting equipment is encased in a container-sized cube system which obviates the need for a crane-mounted cutter. All the electrically-powered cutter components are housed within a compact steel cube frame which is lowered underground through a comparatively small access shaft into an existing tunnel. The frame comes in two parts mounted above the trench prior to the cutting process. And the complete set-up comes in a 2.9m cube which can fit in tunnels with diameters as low as 3.8m. Slurry wall construction can therefore take place in small tunnels which, it is claimed, has hitherto not been possible.

Bauer CEO Dr Rudiger Kaub said: “The system can be used to build subway stations exactly where they are needed: underground below existing buildings. The technology allows working in very confined spaces, such as underground parking lots and even microtunnels, and allows a completely safe working environment. The system can also be operated remotely.”

Claimed benefits of the system include minimal transport requirements, a reduced job site area, and lower neighbourhood impacts.

The first successful tests of the prototype have been undertaken at the Bauer plant in Aresing, Germany. This testing will continue for the next four to six months, and a practical application could happen towards the end of 2021.

The Bauer Cube System was developed in conjunction with Belgian tunnel construction firm Denys.