Wednesday, June 22, 2011

Austal's LCS Corrosion Problem

It started when Bloomberg reported the Navy had discovered “aggressive” corrosion on the USS Independence (LCS 2). There weren't many details in the original report, so I initially chalked this up to part of the learning curve both the Navy and Austal will suffer through with a new ship type built completely of aluminum. The story became more interesting to me as an observer when I saw the way Austal Chief executive Andrew Bellamy responded to the news.

Chief executive Andrew Bellamy said any corrosion on the vessel, known as a ''littoral combat ship'' for its ability to hug the shore, would be the fault of the operator or maintainer.

''We have built 230 vessels of this type that have not suffered from this type of problem … where the operator and the maintainer of the ship have followed the procedures in a thorough way,'' Mr Bellamy said. ''I suspect there is a problem in the area of operational maintenance if there is a galvanic corrosion issue.''

The rust claim comes weeks after the Perth-based Austal said it would sharpen its focus on the defence sector amid weakening demand for commercial boats.
Blame the Navy for poor maintenance because Austals first big warship runs into a problem none of their simple commercial ferry designs ever had? That seems like a really poor way to respond to problems encountered. My impression at the time this article was released is that the Navy was dealing with a rust problem, so to me this article was nothing more than a good laugh at the hubris of Austal.

But it turns out this isn't a simple rust problem, which was my mistake in following this story. Check out this remarkable press statement sales pitch by Austal.
Galvanic corrosion is an issue that has challenged U.S. warships since 1844, when the USS Michigan, the first iron-hulled Navy ship, entered service. Today, two common and robust solutions, impressed current cathodic protection systems and the use of strategically-placed sacrificial anodes, are in wide use throughout the world, particularly in ships where two different metals such as steel and aluminum are utilised in the one vessel.

As a specialist in aluminum shipbuilding, having built over 220 aluminum vessels for defence forces and commercial clients around the world since its formation in 1988, Austal is intimately familiar with the management of galvanic corrosion. An electrochemical process, galvanic corrosion occurs when two dissimilar metals, after being in electrical contact with one another, corrode at different rates.

According to company records, galvanic corrosion has not been a factor on any Austal built and fully maintained vessel, and our technical experts are eager to support any request to identify root causes of any corrosion issue in any aluminum naval vessel in service today. The Westpac Express, an Austal-built and fully maintained high-speed catamaran, has shuttled U.S. Marines throughout the Pacific Basin continuously for ten years, with a 99.7% availability over that period.

As Prime Contractor for Jackson, the third Independence-variant Littoral Combat Ship (LCS-6), Austal has a well-developed methodology for the management of galvanic corrosion, which it has deployed globally on behalf of its defense and commercial clients. If selected to provide post-delivery support for the Littoral Combat Ship (LCS) Class Services program, it is a straight forward process for Austal engineers to regularly conduct systematic reviews of the electrical grounding throughout each Austal-built vessel to detect and eliminate stray currents that might cause electrolysis between the stainless steel impeller housing and of the adjacent aluminum structure.

An integral part of any post-delivery support program for a high-performance, high-speed vessel such as the Independence-variant LCS is to provide a cadre of qualified maintainers who can help our Navy partners to deploy temporary sacrificial anodes every time the vessel is moored, and ensure that high-voltage maintenance equipment is properly grounded before use aboard ship. These are services that Austal’s skilled aluminum specialists, operating from six maintenance hubs in the Asia-Pacific, North America, South America, Europe and the Middle East, offer Austal customers every day.

With almost 2,200 current employees at Austal’s USA shipyard, with a future workforce planned of over 4,000, each and every Austal employee is committed to making the Littoral Combat Ship a success. Awarded a ten-ship contract in December 2010, Austal has eagerly assumed the role of Prime Contractor for the Independence-variant Littoral Combat Ships awarded under the 10 ship block buy contract, and, as a Prime Contractor for those 10 ships, Austal will always stand by its products and our Navy partners.
It turns out this is not rust, rather an electrolysis issue between the stainless steel waterjet parts and the aluminum hulls, and when the Navy calls an electrolysis problem “aggressive corrosion" that suggests to me the metal is completely gone - not rusted. In the case of LCS-2, the problem was apparently accelerated by stray currents in the hull from the electrical distribution system problems the ship has been having since it was turned over to the Navy. Normally an electrolysis problem would be prevented by the use of a Cathodic Protection System (CPS), but wouldn't you know it - USS Independence (LCS 2) doesn't have a CPS.

LCS-4 doesn't have one either, but apparently CPS is part of the lessons learned process and was included in the fixed-price contracts for Austal versions of the LCS beginning with LCS-6. LCS-2 will have the CPS installed at the next drydock period, while Austal has said a CPS will be added to LCS-4 before the ship is turned over to the Navy.

The question everyone seems to be asking is whether the JHSV could suffer the same issue. With all due respect to the Austal press statement, vessels built for Navy purposes have a great deal more technology potentially running electrical currents through the ships than commercial ferry's do, and Austal isn't exactly a world wide expert on building frigate sized navy ships. The stray currents in USS Independence (LCS 2) could easily reoccur in the JHSV creating similar problems if prevention isn't built into the design. The Westpac Express is a commercial design and the charter did not significantly add technology nor were changes made to Westpac Express that runs electrical power throughout the ferry, so Austal is making an apples to oranges comparison suggesting their immune from criticism because their simple commercial vessels don't have this problem.

I've heard from a few unofficial but relatively informed folks the JHSV does not have a cathodic protection system, and if that turns out to be true we could see the Navy move to address that issue before JHSV-1 conducts sea trials later this year. I'd be curious to know if Westpac Express has a CPS installed, or some other form of prevention is used at all.

I tend to think of this problem as the first public problem that is part of a steep learning curve process both the Navy and Austal were bound to run into with the Austal version of the Littoral Combat Ships, indeed I suspect there will be other public problems revealed over time that will require relatively simple, albeit costly, solutions. Is this a big deal? Hard to tell, but given both the problem and solution is well understood, in the context of unknowns yet to be discovered with LCS - to me this isn't really that big of a deal as long as the long term solutions effectively work as intended.

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