Welding in hyperbaric chamber helps keep aluminum-hulled ships afloat...
PRACTICAL WELDING TODAY® MAY/JUNE 2013
May 3, 2013
The U.S. Navy has been searching for new weld-repair methods on its aluminum-hulled ships beyond dry docking, which is impractical and costly. Phoenix Intl., an underwater services company that has held the Navy’s Diving Services contract for the past 15 years, may have found one: underwater aluminum GMAW in a hyperbaric chamber.
It's too bad that they didn't show actual welding being performed in the hyperbaric "Dry" chamber or the resulting welds as they look after being deposited because the only welds I observed were done and shown being performed outside the actual chamber which is somewhere inside the water tower that Phoenix Intl. uses to perform these underwater dry welds on Aluminum... Did I miss something? I don't think so after looking @ the video 3 times...
Here's the url address on the bottom of your post that wouldn't function as a direct link in your post so I took the liberty to add this link as well. In case anyone is wondering, this is basically the same url and the only difference are the extra numbers, letters, symbols, slashes included in the address.
I think at around 1:14 to 1:43 is in a habit in the tower, As the diver was wearing an AGA mask that he place a welding hood on. The AGA mask is usually used in the habitats.
You're right but, they were only test welds plus a practice joint being welded inside the chamber and not on an actual submerged structure where the dry chamber is attached to... I'm not so sure the finished joint was actually done in the chamber or not yet I'll have to take their word that it was since the welder was shown climbing down into the water of the tank...
I wonder if the test piece was "new" aluminum or a piece that had been exposed to salt water. I've welded a few pieces of aluminum in a hyperbaric chamber just to see if I could do it, new stuff was fairly straight forward. The thing to remember is that you're in a closed room and aluminum makes a lot of smoke. Interesting piece.
I was thinking about you regarding this thread and you answered my question as to whether or not you had such experience... it doesn't surprise me that you have some...
And I was wondering if it was new metal or exposed to sea water aluminum also... I believe you can see that it's dry, unexposed to seawater metal in some of the pics which is what I was previously asking also, and you "hit the nail on the head" regarding the fumes generated when GMA Welding Aluminum... I would hope that they consider this since it is considered a confined space and if you have experience working in them then you would know that some form of ventilation is required... Unless that is if the welder has a full face mask pumping in some clean and cool air. Good to see you posting again Chuck! One of our resident underwater welding experts (My favorite).
You can make all the decisions you want Metrinka... It still doesn't change the fact that "it is what it isn't..." And you are also responsible for the decisions you make so let's not forget about that!
"I'm an engineer now, I don't have time to read or respond to your RFI's. Listen Buddy, I make decisions and YOU have to live with them... sorry I missed that...."
Where is this coming from - Left field? And just who are you directing this to?
All the hyperbaric chambers in the water and on land that I've been in we vented them very well, easier to do in the field than in the "safer environment". Never did try a piece that was exposed to salt water, and the deepest I tried was about 75 foot of sea water. To do any of that type of welding you'll have to wear a full face mask with supplied air. With the increased pressure of the hyperbaric environment the toxicity of the fumes increases.
I know a lot of lads over there at Phoenix, and those boys don't leave anything to chance about their health.
I'm glad to see that someone is trying to get a procedure for that application, the company that I was working for at the time didn't see a need for it. Then again we never worked for the Navy, only the petroleum companies.
SSBN727 and other Ladies and Gentlemen AWS, Been into underwater welding plus 20 years / five patents. Have chamber and I can come up with surface quality. Some chambers underwater were design to and delivered helium – oxygen environments below one atmosphere underwater ! My focus is wet welding and I believe a 4043 stick weld could be done with my system noted below on 4043 aluminum shallow i.e. less than 3 msw. Like to chase such! Out of work and looking for work ! Sincerely Len Andersen weld@spemail.org 914-536-7101 www.lenandersen.com Attachment: AWSwetweldingsystems.pptx - Len Andersen 914-536-7101 Wet Welding February Power Point Presentation www-lenandersen.com (267k)
Henry, Hyperbaric works. Bet my engineering / CWI way to make a living on hi we can , no. Fill in a lot of details and figure can I give them the ship for time to be neat and nice! Len
I get that Joseph but, my concern was the fact that no actual field welds were shown in the video whereby previously exposed metal was used in showing the actual welds performed from the chamber also... And the fact that all of the qualification testing was done without using any aluminum material that was actually exposed to sea water... Such material would have already been exposed to the sea water for quite some time before any attempt to repair was even considered in a dry chamber (Hyperbaric real world conditions)... Ad therein lies the rub a dub-dub! In other words lab conditions are NOT the same as in the real world...
So all of the testing so far has been successful to prove that the process works as planned but, the metal used was virgin metal and NOT the actually exposed Aluminum found on the LCS's... which would mean that much more consideration to removal of contaminants from surface & joint preparation (grinding and burring in the chamber with appropriate controls to filter out any grinding dust/contaminants coming from the removal of the surface condition/layer already exposed to the seawater) issues that will arise in the field before anyone can tell me that this process of achieving consistent class 1 X-ray quality welds regardless of the actual material conditions has been worked out from every angle... Because in this paper they didn't go that far as of yet when this was published...
Nonetheless, it was a well written report which coming from the USN isn't something that happens all the time...
Interesting read. But like you would like to see what they come up with with exposed metal. The only way that I welded it was TIG, the office types wouldn't let me set up the wire feed for it. I know that there are techniques topside for welding contaminated aluminum, (TIG wise), I would think that those techniques would work for the hyperbaric. I'm still can't go into specific techniques due to contractual obligations, those won't run out for another couple of years.
You know you do something because someone says that you can't or it can't be done that way. That was the only reason that I was welding aluminum in the hyperbaric setting. Learned a tonne of info doing that and some unconventional ways of underwater welding. My hats off to someone that is looking into it.