Abstract: An anti-fouling arrangement in a marine vessel with a marine propulsion system, the propulsion system comprising at least one driveline housing, a torque transmitting drive shaft extending out of the driveline housing, and at least one propeller mounted on the drive shaft. The at least one propeller is electrically isolated from its drive shaft, wherein each electrically isolated propeller is connected to a positive terminal of a direct current power source, and each metallic component to be protected against fouling is connected to a negative terminal of the direct current power source. A control unit is arranged to regulate the voltage and current output from the direct current power source.

Abstract: A marine ICCP system includes an electrical circuit comprising a primary and a secondary circuit. The primary circuit comprises a first electrode connected to a positive terminal of a power source to act as an active anode; and a second electrode connected to a negative terminal of the power source. The secondary circuit comprises a passive electrode normally disconnected from the electrical circuit and arranged to act as back-up protection, wherein the second electrode connectable to the passive electrode. The passive electrode is arranged to be connected to the power source if a detected output voltage in the primary circuit reaches a maximum value and if a determined polarization potential for the cathode is insufficient. The control unit is operable to control the output voltage supplied to the primary and secondary circuits separately in order to supply an individual output voltage to each circuit.

Abstract: The invention relates to a propeller arrangement in a cathodic protection system for a marine vessel with a marine propulsion system, which cathodic protection system comprises a direct current power source with a positive terminal. The propulsion system comprises at least one driveline housing at least partially submerged in water; a torque transmitting drive shaft extending out of the driveline housing; and at least one propeller mounted on the drive shaft. According to the invention, the at least one propeller is electrically isolated from its drive shaft. Each electrically isolated propeller is electrically connected to a slip ring connector, which slip ring connector is in electrical connection with the positive terminal. The invention further relates to a vessel provided with such a propeller arrangement.

Abstract: An anti-fouling arrangement in a marine vessel with a marine propulsion system, the propulsion system comprising at least one driveline housing, a torque transmitting drive shaft extending out of the driveline housing, and at least one propeller mounted on the drive shaft. The at least one propeller is electrically isolated from its drive shaft, wherein each electrically isolated propeller is connected to a positive terminal of a direct current power source, and each metallic component to be protected against fouling is connected to a negative terminal of the direct current power source. A control unit is arranged to regulate the voltage and current output from the direct current power source.

Abstract: The invention relates to an arrangement for measuring salinity in water, which arrangement is part of an impressed current cathodic protection system having an electrical circuit comprising a source of electrical power (310); at least one first electrode (315) connected to a positive pole of the power source (310); at least one second electrode (317) connected to a negative pole of the power source (310); a voltage sensor (341); a current sensor (342); and a control unit (313).

Abstract: A portable unit is arranged to measure a value for polarized potential in a corrosion protection system comprising a protected structure, an anode and a reference electrode, which portable unit is connectable to the protected structure and to the reference electrode. The portable unit is arranged toperform voltage measurements to detect and monitor an instant-off sequence, wherein the corrosion protection system is turned off for a predetermined time period during normal operation. If an instant-off sequence is detected, then a voltage measurement is performed to measure a voltage signal representing a direct current potential curve for the corrosion protection system during the instant-off sequence. A step response detected in the voltage signal during an initial IR drop and a subsequent voltage decay are analysed. An initial value for the voltage signal at the time of the step response is determined and displayed as a value for polarized potential.