Integrity measures protect Polarcus seismic vessels

Cathelco is supplying hull corrosion protection systems and marine pipework anti-fouling systems for two new Ulstein X-Bow vessels under construction in Norway for Polarcus.

Offshore staff

CHESTERFIELD, UK – Cathelco is supplying hull corrosion protection systems and marine pipework anti-fouling systems for two new Ulstein X-Bow vessels under construction in Norway for Polarcus.

This follows installation of similar equipment for the geophysical contractor on the Polarcus Asima and Polarcus Alima, both launched in 2010.

Throughout their operational life, the hulls of the new NB292 and NB293 vessels will be protected from corrosion by Cathelco’s 200A impressed current cathodic protection (ICCP) systems.

These will comprise four elliptical anodes mounted port and starboard and two reference electrodes connected to a control panel.

In operation, the reference electrodes measure the electrical potential at the hull/seawater interface and relay a signal to the control panel. This raises or lowers the anode output to provide optimum corrosion protection at all times.

The two vessels will also be supplied with shaft earthing systems to protect against spark erosion to the bearings and potential damage to the propellers; and marine pipework anti-fouling systems to protect four seachests against blockages caused by build-up of mussels and barnacles.

The engine room and auxiliary seachests will be fitted with copper and ferrous anodes wired to a control panel. In operation, the copper anodes produce ions that are carried through the seawater pipework system, forming an environment where mussels and barnacles do not settle or breed.

At the same time, the ferrous anodes generate ions which help to maintain a protective oxide layer on the internal surfaces of the cupro-nickel pipework to counter corrosion.

09/02/2011

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