A newly conciliatory Austal USA says it is working “very closely” with the U.S. Navy to address aggressive galvanic corrosion that is bedeviling a new combat ship.
With coatings, cathodic protection systems and possibly other measures, the shipbuilder and its client are mapping out a “comprehensive corrosion management solution” for the 11 Independence-variant ships in the Littoral Combat Ship (LCS) class. Austal USA has a $3.6 billion contract to build the entire class.
|The ship underwent Builder’s Sea Trials in the Gulf of Mexico in July 2009, six months before commissioning.|
The effort includes remediating the corrosion now plaguing the $432 million aluminum LCS-2, the first in its class.
‘Unpredictable, Irregular War’
Austal USA says it is not responsible for the aggressive corrosion near the steel impeller within the ship's water jet propulsion system.
Earlier this week, Andrew Bellamy, chief executive of parent company Austal, put the blame squarely on Navy operations and maintenance and dismissed the problem as a “storm in a teapot.”
On Wednesday, however, the company struck a different tone, saying it was working with the Navy to devise a solution.
"The Navy and Austal team have a solid understanding of corrosion mitigating measures," Austal USA's President and Chief Operating Officer Joe Rella said in a prepared statement that did not address responsibility for the problem.
"It's often an unpredictable and irregular war that is fought every single day on the waterfront…..”
Corrosion Management Measures
The plan for the Independence class includes a mix of active and passive anti-corrosion measures.
For LCS-2, the ship now in service, “doubler plates” will be installed next month around parts of the propulsion system as a short-term fix. Long-term repairs will require installing a cathodic protection system next year when the ship is dry-docked, a Navy spokesman has said.
|Corrosion was spotted in the USS Independence (LCS-2), shown under construction in 2006, before the Navy took delivery of the ship, a contractor says.|
The Coronado (LCS-4), the next ship in the class, will get “new anti-corrosion surface treatments to better protect the water jet tunnels and associated structure from galvanic corrosion,” as well as a cathodic protection system, Austal USA said.
Beginning with the Jackson (LCS-6), the class will get impressed current cathodic protection systems now in place on the Westpac Express and due to be tested in the coming months for use on the Independence class. The U.S. Marine Corps has been using the Austal-built civilian Westpac for a decade, the company said.
‘Corrosion is Always a Problem’
"Not only do the active systems help eliminate the stray currents that cause galvanic corrosion," said Rella. "They can also alert the operators and maintainers if the ship is at risk of accelerated corrosion."
He added: "Corrosion is always a factor, but with Jackson (LCS-6), we will deliver to the Navy an array of tested corrosion-management tools and processes—tools and processes that will allow our Navy partners to get these innovative, versatile platforms out into the field and completing vital national security missions."
Austal USA “looks forward to deepening its collaboration with the Navy in fielding cutting-edge, labor-saving solutions for the Navy's ongoing battle with the elements,” Rella said.
The Navy has not commented on the corrosion issue recently, but records show that the service expressed concern during the design stage about galvanic corrosion, which occurs when dissimilar conducting materials are connected electrically.
Austal has not said why cathodic protection systems were not installed in the ships in the first place. But maritime writer and contractor Paul Bruno says the systems were omitted to save money.
Blogging on maritime.about.com, Bruno, a U.S. Coast Guard-licensed Ship Master with Passenger Certification, said Austal USA skipped the systems “in a move to save on costs.” He did not cite a source for the conclusion.
A spokesman for Bath Iron Works, which partnered on construction of the LCS-2, has said that the corrosion was spotted before the Navy took delivery of the 417-foot-long ship in January 2009.
Austal Ltd., parent company of Austal USA, and General Dynamics make up one of two teams building the new ship. The other team, which is building a very different version of the ship, is composed of FMG's Marinette Marine Corp. and Lockheed-Martin.
The first Marinette Marine ship (LCS-1) developed a six-inch hull crack below the waterline earlier this year and began taking on water. It was forced to abort sea-keeping trials and return to its homeport for repairs, the Navy said.