This advanced Cathodic Protection design spreadsheet allows the user to design an optimal cathodic protection system for steel marine infrastructure such as steel piled quays, steel retaining structures and steel pontoons and vessels. The steel structure can be either coated or uncoated, and can be situated in a variety of water conditions. The spreadsheet includes unique tools allowing the user to optimise the anode design quickly.
First the user calculates the surface area of steel to be protected. This can either be input directly, or calculated using the steel area calculator included with the spreadsheet. Next the user specifies the water and tidal conditions including the water resistivity. Finally the user specifies the anode number, type, performance, an estimate of the anode dimensions and the system design life.
For coated steel surfaces the user inputs the coating breakdown factors, and the spreadsheet includes these factors in the calculation of the current densities required over the design life specified.
The spreadsheet then calculates the design current densities from the British Standards and DNVGL-RP-B401 (2017). The spreadsheet calculates the required total mass of anodic material and shows the user how this will change with a change in the design life. It also shows the user how altering the anode length affects the required anode dimensions.
Then the spreadsheet calculates the required Initial and Final Current Demand. The spreadsheet then calculates the minimum anode length required to meet the Initial and Final Current Demand requirements.
The spreadsheet allows the user to optimise the anode design using a quick iterative process. First the user estimates the number of anodes required until the Final and Initial Current Demand graphs show anode lengths within the normal range. Then an anode length is selected, usually fewer longer anodes are more cost effective. Then the anode depth and width can be optimised using the Total Maintenance Current Demand graphs.