A Rapid and Cost Effective Method for Performing Topside Coatings Assessments on US Navy Ships

Current methods for performing assessments of topside coatings are slow, labor intensive and subjective.  These assessments require significant pull tests, dry film thickness measurements, and color meter measurements as well as inspector based assessments of corrosion damage, coatings delamination and blistering.  NRL has shown that inspector's results can vary by over 500 % when assessing shipboard tank coating's condition.  It is likely that topside coatings assessment are additionally impacted by the subjective nature of manual inspections.   Further, it takes 3 months or more to perform an assessment on a carrier's topside coatings.

In 2009, NRL performed an inspection of the USS NIMITZ.  In less than 4 days, using digital handheld cameras, over 3000 images depicting the ship's complete topside surfaces were collected.  These images were analyzed using automated algorithms that quantified the corrosion damage and coatings color variation.  NRL is currently finalizing the inspection protocols for collecting topside image sets.  A suite of algorithms referred to as the Automated Freeboard Topside Coatings Assessment Toolkit (AFTCAT) is also under development for quantifying the corrosion damage, the color variation(including pinking, fading and an aesthetics assessment), the extent of coatings delamination and blistering in these image sets.  These algorithms will also automatically generate reports of inspection results.  The inspection protocols and AFTCAT should allow the complete topside coatings of a carrier to be assessed in approximately one week, thereby allowing improved allocation of limited maintenance in light of a condition based assessment of the topside condition.