To prevent corrosion of the circular bottom of a storage tank, several
small cylindrical anodes are placed beneath and parallel to the tank
bottom, and parallel to each other. A design strategy is presented for
determining the anode spacing and depth for proper cathodic protectio
n. For a uniform flux density of oxygen to the tank bottom, the maximu
m potential variation on the tank bottom (made dimensionless with the
average cathode current density, the soil conductivity, and the anode
spacing) is reported along with estimates of the potential drop in the
soil between the cathode and the anodes and the potential drop within
the anodes themselves.