Articles in Virginia and Connecticut newspapers discuss the root cause of the problem -- welders at Newport News being allowed to carry filler material for more than one weld type. As a result, the probe is being extended to all ships worked on recently at Newport News:
An investigation of faulty pipe welds on Virginia-class submarines assembled at Northrop Grumman Newport News has been broadened to include aircraft carriers and another class of submarines.The problem came to light when a couple of welds on PCU New Hampshire failed hydrostatic tests at EB; basically, welders at Newport News used copper alloy filler on CRES (corrosion-resistant stainles steel) socket welds. Having only been at EB myself, I know that it was always a big deal if we saw some welder carrying around more than one type of filler (it normally happened on the night shift). The articles don't say how long Newport News welders have been allowed to carry more than one type of filler -- does anyone know if they've always done it that way?
The assessment will cover non-nuclear piping systems on carriers and subs repaired and built by shipyard workers in recent years, shipyard and Navy officials said Monday.
A shipyard spokeswoman described it as a precautionary move after the discovery in recent weeks of contaminated welds on some of the Virginia-class submarines the yard has assembled. It's possible that welders made the same mistake on other vessels - using the wrong type of metal weld filler to join non-nuclear piping systems...
...The internal piping systems under review carry such things as oil, air and water.
So far, seven ships beyond the Virginia-class subs have been targeted for an assessment, Dellapenta said. Four are carriers - the George H.W. Bush, the Carl Vinson, the Enterprise and the George Washington. The other three are Los Angeles-class attack submarines - the Toledo, the Newport News and the Oklahoma City.
Update 0858 20 Dec: Springbored and Galrahn have more on the issue.
