EN
Upgrading a vessel to the Impressed Current Cathodic Protection (ICCP) system is one of the most technically challenging and significant installations the vessel owner can make during a dry dock window. Unlike the sacrificial anode, which is bolted to the hull, an ICCP retrofit must be carefully planned, precisely engineered and coordinated between the electrical and mechanical teams. Every hour is valuable and the dry dock period is costly. A detailed checklist will help make the installation go more smoothly, on time and on budget. With more than 20 years’ experience and hundreds of completed projects, SME has created an ICCP retrofit framework that will help shipowners and superintendents navigate through all of the key stages of an ICCP retrofit.
Phase 1: Pre-Docking Engineering and System Design
The key to a successful retrofit starts well before a vessel is in the dry dock. This stage involves collecting detailed data and developing a system that will work with the specific hull shape and usage of the vessel. The first task on the checklist is to review the original drawings of the vessel, such as the general arrangement, shell expansion plans and existing cathodic protection plans. This enables the engineering team to decide the best position for the new reference electrodes and permanent anodes so as to distribute the current evenly throughout the entire submerged hull.
A thorough hull resistance survey is then required. This includes determining the current demand needed to attain the protective potential and measuring the existing coating condition. The system will be unnecessarily expensive to oversize and will corrode too fast to undersize. Our technical support engineers are responsible for finalizing the cabling routes from the anodes to the new control panel in consultation with the shipyard, ensuring all penetrations through watertight bulkheads as per the class societies requirements. The engineering phase before docking should end with a detailed installation manual, along with a material list that includes all of the cables, glands and mounting brackets.
Phase 2: Material Inspection and Workshop Preparation
Once the vessel is in dry dock, time is of the essence. But, until all materials are properly examined, installation can't begin. The checklist requires the complete physical examination of the ICCP anodes, reference electrodes, junction boxes and the main control panel. Preliminary checks confirm that anode dimensions match approved drawings, reference electrode resistance is within specification, and the cabling is appropriately rated for the marine environment.
At the same time, the workshop set-up should be completed. This includes making the mounting brackets and support structures in the shipyard's workshop and not on the ship's hull. Whether in confined spaces or at height, prefabrication decreases working time. Cable Termination Kits should be set up and the control panel should be turned on on bench for a basic check of function. With a 5,000 m² workshop facility owned by us in Nantong City, SME ensures that all the pre-assembly work is done under controlled conditions, thus ensuring that the materials on the dock side are ready for immediate installation.
Phase 3: Hull Mounting and Mechanical Installation
Once all preparation steps are complete, the actual installation of the system can be done. First, the surface of the hull where the anodes and reference electrodes are to be installed is treated mechanically. This includes grit blasting to bare metal, the application of a specified primer, and making sure that the surface is flat and clean for best electrical contact. All mounting brackets shall be welded or bolted to the vessel in strict adherence to the approved drawings and care shall be taken to ensure that all anodes are mounted in a way that will not conflict with the sea chests or water jets.
At the same time, mechanical crew needs to install the cable trunking and conduits to ensure that the anode cables will be protected when they lead from the mounting point to the control room. These should be properly clamped and kept clear of hot work areas or moving equipment. All mechanical installations shall be completed with a qualified surveyor's signature at each stage of installation. Mechanical technicians at SME are trained to work in coordination with shipyard production schedule and welding and bolting are done efficiently without affecting the integrity of the hull structure.
Phase 4: Electrical Wiring and Control Panel Integration
After mechanical fixings, the electrical installation comes to the fore. This checklist concentrates on the end connections of all anode and reference electrode cables on the junction boxes and then to the main control panel. To ensure that there is no cross-connection, each cable should be clearly identified with the schematic diagram. The reference electrode cables that transmit the millivolt signals must be handled specially: They should not come into contact with power lines due to potential electromagnetic interference.
The control panel should be installed in a dry, well-ventilated and easily accessible area, usually close to the engine control area. Connections from the ship's main switchboard to the power supply are then completed in such a way that the ICCP system is properly fused and protected. This also involves the installation of earth leakage monitoring devices and over-current protection devices. Stray current corrosion is a problem that can be caused by a poor earth connection, which is why our electrical technicians pay careful attention to the earthing arrangements.
Phase 5: System Commissioning, Calibration, and Sea Trials
Once all cables are terminated and the panel is powered, the next step is commissioning. This is not something that needs to be taken hurriedly. The checklist calls for a progressive energisation process that begins with the measurement of the hull's natural energisation. Then the reference electrodes are calibrated for accurate readings. The system is set in auto mode and the output of the system is slowly raised and the potential reading is observed on various locations around the hull.
After your initial calibration procedure has been followed the vessel has to pass its sea trials and check the system is behaving as intended on dynamic movement. The following points need checking: is the system automatically making compensations for speed, water temp, salinity? A final report confirming all settings, curves and recorded protection potentials will be supplied. At SME, we support every ICCP retrofit by offering you an extensive 12-month warranty on the scope of work, ensuring that operators will have the necessary peace of mind for their asset. If you employ the below stringent checklist your next dry-dock project is the transition from a risk in the schedule to a beneficial contribution to the asset for years.