An excavating machine includes an actuation unit for moving the excavator, a main winch and secondary winch for lifting and lowering the actuation unit. A closed hydraulic circuit or an electric circuit drives the main winch. An open hydraulic circuit drives the secondary winch. A first pressure or current sensor measures fluid pressure or, electric current intensity in the hydraulic or electric driving circuit. A second pressure sensor measures fluid pressure in the open hydraulic circuit. A pressure regulator regulates fluid pressure in the open hydraulic circuit. A control unit executes a combined operating condition with the winches applying a force simultaneously and based on values sensed, controls the pressure regulator so the fluid pressure in the open hydraulic circuit, during the combined operating condition, has a target value that is a function of: the fluid pressure in the closed hydraulic circuit or the current in the electric circuit.