A Floating Production, Storage and Offloading vessel (FPSO) or a Floating Storage and Offloading (FSO) vessel requires a specially designed Impressed Current Cathodic Protection (ICCP) hull corrosion protection system because periods between drydocking are significantly longer than for normal vessels. Other factors such as "current creep" on anchor chains also have to be taken into consideration.

On a conventional ship, there may be a 15% paint loss over a 5-year period, but on an FPSO paint loss may exceed 80% after a 20-year operational period at sea. Therefore, the skill in designing an ICCP system for an FPSO relies on understanding these differences and using equipment which meets the demand for long lasting reliability.

Cathelco Ltd. ICCP uses diver-change anodes and reference electrodes which can be changed from the outside of the hull, simplifying replacement. There is also the option of using Jotun diver-change circular anodes and reference electrodes, which are designed with vulcanized rubber coatings to create a watertight seal with the cofferdam for easy installation and replacement.

As FPSOs are stationary in the field, they are fitted with forward and aft systems, providing a 50/50 current output, unlike conventional vessels, which have higher current demand around the stern. As with all offshore facilities demanding the highest levels of performance, reliability and safety, Cathelco Ltd. hull protection systems have a minimum 1.5 times redundancy factor built into the design, subject to specification.

Through a comprehensive understanding of cathodic protection and technical innovation in equipment design, Cathelco Ltd. are maintaining their position as leaders in hull protection for this fast developing area of offshore production.