Cathelco have won orders to supply equipment for two projects which are being undertaken by Keppel yards in Singapore. The first is to provide marine growth protection systems (MGPS) for a KFELS semi-submersible drilling tender (Project B374).
The Cathelco MGPS system will eliminate blockages in sea water pipework caused by the growth of barnacles and mussels. A total of four seachests will be protected, each with flow rates of 1,160 m3/hr. This involves fitting two copper anodes and one aluminium anode in each of the seachests which are wired to a control panel.
In operation, the copper anodes produce ions which create an environment where barnacles and mussel larvae do not settle or breed, but are carried through the system to discharge. At the same time, the aluminium anode produces ions which create an anti-corrosive coating on the internal surfaces of pipes.
The Cathelco MGPS system operates effectively with very small concentrations of copper, between 2- 24 parts per billion depending on the individual application. This discourages the organisms from settling in pipes but does not kill them which is better for the wider marine environment, resulting in a system that is environmentally benign.
Cathelco is one of the few manufacturers of MGPS systems conforming to Article 95 of the EU biocides Regulation (528/2012). They are listed as an Authorised Supplier of copper based anti-fouling systems for the marine and offshore market.
The second project in Singapore is to supply MGPS and hull corrosion protection equipment for an FPSO conversion which is being undertaken for Armada Madura EPC. Keppel Shipyard has already commenced work on the conversion which is scheduled for completion in the 3rd quarter of 2016. The FPSO will be deployed in the Madura Strait Block BD which is located 65km east of Surbaya and about 16km south of Madura Island, Indonesia.
The MGPS systems on the Armada Madura will protect pipework connected to the main seachests, fire water seachest and sea water lift seachest, the largest having flow rates of up to 1,300 m3/hr.
The Cathelco impressed current cathodic protection (ICCP) for the vessel will protect the hull against corrosion throughout its design life of 20 years. This is particularly important on FPSOs which remain on station for prolonged periods of time without drydocking.
As the Armada Madura has an overall length of 246.8 metres it will be installed with forward and aft ICCP systems. The 300 amp forward system consists of a two C-Max disc anodes mounted port and starboard and two reference electrodes connected to a thyristor control panel. C-Max disc anodes maintain a smooth hull profile and have the advantage of being diver changeable, enabling anode replacement to be carried out at sea, if necessary. The aft system, also 300 amps, utilises two linear loop anodes and two reference electrodes.
In operation, the reference electrodes measure the electrical potential at the hull/seawater interface and send a signal to the control panel which raises or lowers the output to the anodes. In this way, the hull receives the optimum level of corrosion protection at all times.
The Quantum control panels store data about the performance of the system which can be monitored through a series of displays. All of the data can be relayed to a control room or bridge computer system via an RS485 link.