The Gotlandia II, operated by Destination Gotland, was built by Fincantieri in 2006 and has the capacity to carry 900 passengers and 160 cars.
Water jets on high speed ferries can be vulnerable to corrosion as a result of their construction. In the case of the Gotlandia II, the body of the duct is made from high tensile steel, whereas the impellor and shaft are made from stainless steel.
When the craft is in operation there is a difference in the electrical potential between the two types of materials and this can lead to corrosion. The rate of corrosion is increased because of the high levels of turbulence within the water jet.
The purpose of the Cathelco Jettek impressed current cathodic protection system (ICCP) is to suppress corrosion occurring at the interface between the different materials.
The Jettek system consists of anodes which are flush mounted within the water jet tunnel and reference electrodes which constantly monitor the electrical potential.
The reference electrodes send a signal to the control panel which automatically raises or lowers the output to the anodes so that the optimum level of protection is achieved at all times.
The installation of the Jettek system was carried out at the Oresund Heavy Industries yard by Marinprodukter AB, Cathelco’s well established Swedish agent.
The steel hull of the Gotlandia II is already protected with a Cathelco ICCP system which was installed in the then newbuild in 2006. The system consists of four 25 amp elliptical anodes mounted port and starboard in pairs, with one reference electrode mounted port and starboard, all connected to a 100 amp thyristor control panel.
Cathelco has considerable experience in the design and manufacture of corrosion protection systems for fast ferries. Their customer reference list includes Sea Containers, Color Line Marine, Nordic Jetline, Tirrenia, British Columbia Ferries, New World Ferries and ASDP (Indonesia).
