Coast Guard identifies causes of Stratton corrosion

MAY 6, 2013 — The U.S. Coast Guard announced the results of an Engineering Analysis Board convened to identify factors associated with corrosion observed on the Coast Guard’s National Security Cutter Stratton (see earlier story).

The Engineering Analysis Board concluded that the unusual pattern of corrosion observed on the Stratton was caused by damage to the hull coating, caused by below-the-waterline welding, coupled with a cathodic protection system that was operating in an “underprotect” configuration contributed to the corrosion on Stratton’s hull. Additionally, stray current corrosion from the welding was also identified as a contributing factor.

Although the corrosion issues were only limited to the Stratton, the Coast Guard conducted visual inspections on both the Bertholf and Waesche. These inspections provided indication that the corrosion seen on the Stratton was an isolated incident and not a class-wide issue.

In addition to determining contributing factors, the Engineering Analysis Board provided several recommendations to prevent future occurrences of the type of corrosion experienced on Stratton, including better training on the use of cathodic protection systems and avoiding welding on wetted hull surfaces.

The Stratton has been fully repaired and has been fully operational since March.