H.M.C.S. “New Liskeard,” an Algerine Class minesweeper (length 225 ft., beam 351/2 ft., underwater area 7500 sq. ft., 960 displacement tons) on active duty with the Royal Canadian Navy, has been fitted with a cathodic protection system using magnesium alloy anodes.
In June, 1949, ten magnesium alloy anodes, 3″ × 7″ × 60″ weighing about 80 lbs. each, were secured to the bilge keels but insulated from the steel of the hull.
Hull potential readings with respect to a silver-silver chloride electrode in sea water show that the hull is protected while at rest. Underway the degree of polarization decreases slightly.
By securing the anodes on the bilge keel there appears to have been a loss in effectiveness caused by uneven distribution of current with varying distance from the anode.
Results to date indicate cathodic protection of an active ship of this size is economically practical.
