Posted on 06/19/2011 2:22:55 AM PDT by tlb
The U.S. Navy has discovered "aggressive" corrosion in Austal Ltd.'s first new combat ship designed for operating close to shore.
The corrosion is in the propulsion areas of the USS Independence, the Littoral Combat Ship built by the Mobile, Alabama-based subsidiary of Australia's Austal and General Dynamics Corp.
"This could be a very serious setback," said Norman Polmar, an independent naval analyst and author in Alexandria, Virginia. "If the ship develops a serious flaw, you're not going to continue producing them."
Permanent repair will require drydocking the ship and removing its "water jets,".
Aluminum-hulled ships such as Austal's tend to rust faster than steel-hulled ships, Polmar said. "But I'm surprised it happened so early," he said. "This ship is brand new."
The corrosion discovery in a ship that was commissioned in January 2010 marks another blow to the Littoral Combat Ship program, planned to ultimately consist of 55 ships. In February, the Navy discovered another ship in the series, from another construction team, had a crack through the hull.
Austal won a $465 million contract that could reach as much as $3.78 billion if all options are exercised. Building all 55 ships will cost the Navy at least $37.4 billion.
Officials were concerned about the potential for corrosion during construction of the ship because of "dissimilar metals," particularly near the steel propulsion shafts, the Navy memo said.
(Excerpt) Read more at sfgate.com ...
Does aluminum rust?
It certainly oxidizes.
And people wonder why manufacturing is moving off-shore. We are exporting imagined pollution and real jobs.
I think the answer is, "It depends." It depends on the mission, for one thing. Once you've achieved air supremacy and run out of air targets, you may want to get some boots on the ground. One LCS can put a lot more boots on the ground than one CVN. I am skeptical that the U.S. will ever get involved in "Littoral" warfare, basically retaking the Arabian Penisula from the sea.
Which would we rather have? 55 LCSs or 6 aircraft carriers?
Non state actors like Hamas have sea-skimming ultra-fast anti-ship missiles. Mines are getting more intelligent and can be set to go after individual ships. The Chinese have repeatedly proven they can sneak into torpedo range of carriers. I think the era where carriers can safely move air power anywhere anytime are over. The next Pearl Harbor may take out all of our carriers or render them impotent by denying them access to where they need to be. (Each carrier has 5000 men and 90 aircraft. To put that into perspective Israel has 90 front-line planes and I think we have 13 carriers. Forgive me, Navy Freepers, if Im off on that count.)
The point is that asymmetric warfare has put the carriers at a huge disadvantage. They are for today what the battleship was in 1939.
I guess Im dumber than a box of rocks; wouldnt the engineers have known that partnering these metals in saltwater wouldve caused the accelerated corrosion or dont they test, or read of prior results, before going ahead and spending billions of tax dollars?
Having been involved in similar contractors design problems I can tell you that even 15 years ago this wouldnt have been an issue. The problem is the ultra-green military contracts. They forbid coatings like chromium and cadmium that would make the parts last forever. If youd buried a cadmium coated connector in the ground in 1950 and dug it up today you could still use it. But the environmental requirements of contracts have reached past ridiculous and are pegging the stupid meter. As a supplier, you cant even buy a product that uses a banned chemical or process in its manufacture, even if theres no trace of the chemical in the final article. These green requirements (eliminating lead from solder, for example) are building in failure mechanisms we havent seen since World War 2. The contractors are fully aware and theres nothing they can do about it.
Add vibration to give everything a nice added mechanical threat aimed at every new crevice and pit which is a new and upplanned "stress raiser" weak point. It's a friggin nightmare.
You must not try to invent this wheel, but try to learn as much as possible from the Aussies mainly, who have been building these as "fast transports" for a long time.
It was our experience supporting the East Timor situation that convinced our Navy we needed these types of high-speed ships. The Aussies were ferrying materiel from Oz to E.T. at a dizzying pace, leaving our big slow LPDs etc in the dust.
We must study those earlier Aussie ships, now pushing 20+ years old, to see what goes wrong and how they solved the problems.
But once the water jet tunnels etc begin to resemble swiss cheese, the boat is really screwed. That is the guts of the boat. To get access for a total replacement/rebuild of that area means removing engines, shafts, turbine blades, giant hydraulic actuators, etc etc.
Then there is corrosion in the hull framing and plating itself...another problem. If it has started, it becomes very problematic about the future of the hull itself.
See 28 please. Thoughts?
My fear is that our carriers could suffer the fate of the Prince of Wales and the Repulse after leaving Singapore.
The British Navy met the paradigm shift with guns blazing and went down to Davy Jones Locker in a hurry.
A new era was born. I hope we don’t suffer a similar rude awakening.
What kind of firepower would this have and at what cost compared to maintaining the Wisconsin, Iowa, etc. on the list of active (or reserve?) vessels. Yes, I know they’re museum pieces now, but I’m interested in the pro/con of pursuing that course of action. Is there anything like a 16” gun?
I have seen it here in Jax a couple of times. It was at the BAE ship fitters for some tower updates. When they said steel prop shafts in the article, I knew it was jet drive but they also have shafts for the jets. Whatever the case, have them changed out to composite and see how they perform. The first two were built to mainly test under operational conditions. Rarely does anyone get it 100% right the first time out.
Technically, it is a thing of beauty and I love that it essentially produces no bow wake and for that matter, not much of a wake at all.
You over look the salient fact.
The vessels were built to Navy specifications.
The aluminium hull isn’t as much of problem if it’s isolated from everything else on the ship. You drop a penny or a piece if electrical wire in the bilge of an aluminium hull, if there is even a little salt water around and it will eat right through the plate!
Yes, the goosenecks and elbows of turbine exhausts are a good example of the challenging environment. I worked on many older aluminum yachts and workboats as a welder, often in a boatyard or yacht facility situation. Hauled out, obviously. If alloy yachts are built scrupulously from the same alloys, with generous zincs (actually magnesium on alloy yachts), and good isolation of engines and electrics, they can last a long time, 20 years sure, 30 is pushing it.
I prepped some former Gulf oil platform delivery boats for resale to some South American client. 20 years old. The hull plates were a nightmare. Trying to weld on pipe stubs and donut rings for installing new specified internal piping, was almost futile. 20 year old aluminum is NOT like welding new aluminum, not when the aluminum has been in salt water with engines and gear running all the while. Aluminum and long hull life do not go well together.
The Scandinavians are leading the way in building ever longer and faster composite boats. No electrolysis between kevlar and carbon fiber in a glass matrix, right? It will be interesting to compare hulls after 20 years of service life.
I agree, the concept is “all there,” but the execution for long life in a salt water environment must be worked out.
The first thing I thought of was inferior materials. Some contractors cut corners to increase profit on gov. contracts.
Although classed as destroyers, these are large (stealthy) ships and many people consider them to be fulfilling a classic battleship function for the 21st century.
Originally, we wanted 32 Zumwalts. Cost was prohibitive, and we will end up with just 3. The first one should be commissioned in 2013 or 2015.
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