Metal plate deterioration resulting from corrosion has reached serious proportions in many Type T-2 Tankers built during the war years and in other older vessels. Consequently, ship owners and the various regulatory bodies are concerned as to the condition of the vessels and extensive thickness measurements of internal bulkhead and hull plates are in order. Regulatory bodies, such as the American Bureau of Shipping and the U. S. Coast Guard, required periodic measurement of plate thickness, the time limit being governed by the type and variety of cargoes carried and frequency of tank cleaning. Although the corrosion rate in other types of ships usually is much less than that in tankers, periodic thickness measurements also are required for these vessels.
For many years, corrosion losses and rate of corrosion were determined by means of drilling holes, calipering and re-welding. Obviously, a ship must be in drydock in order to drill...
