16 JUNE 2017 • FOGHORN FOGHORNFOCUS: OPERATIONS Complete control and steering systems for vessels of all types and sizes. +1 (604)572-3935 • Surrey, BC, Canada sales@kobelt.com • www.kobelt.com KOBELT MANUFACTURING CO.LTD. • 100% Furuno designed Linux software improves stability & reduces virus risk • Fully compliant IMO systems (19" & 23.1" LCD) or Black Box ECDIS with user supplied wide glass bridge monitors are available • Simple Ethernet connection to FAR2xx7 Radars, saving thousands over complex interface kits www.FurunoUSA.com www.Facebook.com/Furuno ECDIS Electronic Chart Display and Information System ECDIS Electronic Chart Display and Information System EDITOR’S NOTE: The May 2017 FOGHORN (page 32) included a warning from the U.S. Coast Guard about the effects of corrosion on metal vessels if par- ticular care is not taken by vessel operators. FOGHORN reached out PVA Associate members Metal Shark, Jeanerette, LA, and DeJong & Lebet, Inc., Jacksonville, FL, to offer expert guidance on the proper care and maintenance of metal vessels. Chemical Spills Harm All Metal Vessels By Andy Lebet, P.E., DeJong & Lebet T he article in the May 2017 issue of FOGHORN regarding corrosion from a chemical spill discussed an aluminum vessel specifically. The main point of the article was about chemical spills and their potential health risks and potential damage to the vessel structure. The issue under discussion is equally applicable to steel vessels. Certainly, aluminum vessels are more sensitive to corrosion issues. These can be related to stray currents, dissimilar metals, proper anode selection (zinc, aluminum and magnesium), shore power isolation, etc. But the issue in the article was not related to any of these common aluminum vessel corrosion issues. The issue was related to having a corrosive substance trapped under a covering over the deck. While the specific case was related to an aluminum crew boat, that substance would have been equally destructive to a steel deck boat with a wood planking protective deck. Given all the different corrosive cargoes that might be found on an aluminum crew boat, this situation is not a far reach. But the steel supply vessels probably carry even more destructive chemicals on similar wood covered decks. The real issue here is corrosive liquids being un- detected in hidden spaces. On passenger vessels, both steel and aluminum, you can find a similar situation where the metal in a concealed space can deteriorate. Some examples of this are: • Tiles in a galley floor Given the uneven metal deck surfaces, From the Pros: How to Properly Maintain Metal Vessels to Keep them Free of Corrosion