Construction; repair in the field of the laying, maintenance and repair of cables, pipes and conduits; installation services by laying and burial of cable, pipes, flexible and rigid rod materials in soil; laying, maintenance and repair of cables, pipes and conduits, in particular trenchless, mechanical pipe and cable laying; drilling, in particular horizontal drilling; machinery installation, maintenance and repair; sludge dewatering works; rental of construction machines, especially machines and equipment, such as ploughs, for laying cables, pipes and conduits; underground civil engineering services.