Cathelco have supplied seawater pipework anti-fouling equipment for the Berge Stahl, the world’s second largest ore carrier which has recently been refitted in Singapore.
With a length of 343 metres and a capacity of 364,767 dwt the Norwegian vessel owned by Berge Bulk was the largest bulk carrier in existence until the launch of the Vale Brasil in 2011.
The Cathelco system will protect seawater pipework connected to the scoop of the Berge Stahl which has a flow rate of 4,500 cubic metres per hour. A system is also being supplied to protect a strainer serving two ballast water pumps with a flow rate of 600 cubic metres per hour.
Designed to prevent blockages in pipework caused by the growth of barnacles and mussels, Cathelco systems consist of copper and aluminium anodes which are fed with an electric current from a control panel.
In operation, the copper anode releases ions which create an environment where barnacles and mussels do not settle or breed. At the same time, the aluminium anode produces ions which suppress corrosion by forming an anti-corrosive coating on the internal surfaces of pipes.
In the case of the Berge Stahl, four copper anodes and two aluminium anodes will be installed in pipework upstream of the scoop using pipe upstands. Cathelco are also providing two cathodes for the scoop installation which provide a dedicated earth return for current from the anodes, avoiding any problems with uneven anode wear.
The strainer installation serving the ballast water pumps will consist of two copper anodes and two aluminium anodes connect to a control panel. The system has also been designed with two cathodes, providing a dedicated earth return and preventing any ‘stray current’ issues with the strainer basket.
The Cathelco system is ideally suited to the treatment of large volumes of seawater and has been chosen for installation on a number of the world’s largest ships.
In total, systems have been installed on more than 30,000 ships over a period of 50 years. These range from ocean going vessels such as cruise and commercial ships using large, multi-anode systems to tugs and workboats which can be installed with miniaturised anodes and compact control panels.
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Source: Cathelco, November 14, 2011