1 is thus provided with a connecting device 15 onto which a separate water supply line can be connected a distributor 17 which divides the flow of water supplied into several streams of water and conducts them to a corresponding number of connecting elements 16 is disposed inside the retaining device 1 in addition the retaining device 1 is provided with a valve 44 for regulating the water pressure the conduction of the water from the connecting elements 16 to the water lance 18 is done by a flexible hose system 21 the retaining device 1 is configured with different control indicators 20 and operating elements 24 with the aid of which the operational behavior of the water lance blower can be observed and possibly be influenced steering elements 19 disposed in the retaining device 1 can be influenced by the operating elements 24 the steering elements monitor and regulate at least one motor 3 of a drive unit 2 and or the formation of a water jet the connectors 23 enable transmission of the data that describe the operating behavior of the water lance blower to a not illustrated remote diagnostic unit fig2 shows a detailed perspective and diagramatic view of an embodiment of a drive unit 2 it shows a configuration of the components of a spindle.