An excavator is provided, in which the excavator includes a head that is slidably mounted on a leader, and a position fixture assembly slidable along the leader via the head. The turbine is connected to a generator with a flexible drive shaft. The extruded elements are of the same width and along each of the longitudinal opposite sides of each of the extruded elements a profiled groove is provided so that the collateral grooves of the two joined bodies are the same, parallel, positioned on the same plane and made to receive the fixing brackets for at least one control actuator.