Cathelco will supply equipment for two force projection and command vessels, BPC Mistral Class, which are being built in France for the Russian Navy. DCNS will act as the prime contractor for the warships to be constructed at St -Nazaire, the first ship due for delivery in 2014. With a displacement of 22,000 tonnes and a speed in excess of 18 knots, the BPC multi-role vessels are also known as landing helicopter docks (LHD).
Throughout their operational life, the underwater hull surfaces of the two ships will be protected against corrosion by Cathelco impressed current cathodic protection (ICCP) systems.
As the vessels are 199 metres in length, they will be installed with independent forward and aft ICCP systems to achieve the necessary levels of corrosion protection.
The 100 amp forward systems will consist of an arrangement of reference electrodes and anodes (mounted port and starboard) wired to a thyristor control panel. The reference electrodes measure the electrical potential at the hull/seawater interface and send a signal to the control panel which automatically raises or lowers the output to the anodes.
The ships will have more powerful 200 amp aft systems to counteract the effects of turbulence and the proximity of dissimilar metals in propulsion systems at the stern of the vessel. In this way, the vessels receive the optimum level of protection at all times.
Cathelco will also be supplying seawater pipework anti-fouling systems for the vessels. These are designed to prevent blockages in seawater cooling lines caused by the growth of barnacles and mussels.
The cross-over seachests serving the main engine, auxiliary engine and fire fighting pumps will be fitted with pairs of copper and aluminium anodes wired to a control panel. A similar system will also protect seachests serving the heating, ventilating and air conditioning equipment.
In operation, the copper anode produces ions which are carried throughout the system by the flow of seawater and create conditions where barnacle and mussel larvae do not settle or breed. At the same time, the aluminium anode produces ions which create a cupro-aluminium film on the internal surfaces of pipes to suppress corrosion.
The latest orders follow the successful installation of similar equipment on the BPC Dixmude, the third Mistral class vessel, which was delivered to the French Navy by DCNS and STX France in January 2012.
Cathelco’s systems are supplied to over 40 navies around the world for vessels ranging from frigates and aircraft carriers to fast patrol craft.
Shipbuilding Tribune Staff, February 29, 2012; Image: cathelco