Navy: No risk from bad welds - Navy News | News from Afghanistan & Iraq - Navy Times

Navy: No risk from bad welds

Defective welding procedures discovered at Northrop Grumman’s Newport News Shipbuilding in late 2007 pose no significant danger to sailors or submarines, a recently completed Navy review of the situation concluded.

“The Navy conducted a 16-month in-depth review of the shipbuilders’ findings and is satisfied that our people and platforms are not at risk due to this issue,” the Naval Sea Systems Command (NAVSEA) said in a statement e-mailed Thursday to Defense News.

“Both Northrop Grumman Shipbuilding and General Dynamics Electric Boat have conducted exhaustive analysis and testing that demonstrates: the low probability of improper welds occurring aboard submarines; that improper welds are unlikely to fail during the ship’s operational life; and that should a weld fail it would leak but not break, thereby alerting the crew in time to address the issue before the weld degraded further.”

The problems were first reported in mid-November 2007, when the Navy discovered welding process weaknesses associated with some of the non-nuclear piping welds made on Virginia-class submarines at Newport News.

According to the Navy, “the failures during testing were caused by trace amounts of copper alloy weld filler material incorrectly welded into corrosion resistant steel (CRES) socket-welded joints. The copper alloy weld filler in CRES piping joints could potentially lead to premature cracking of the joints, which could result in leaks.”

Northrop Grumman Newport News and General Dynamics Electric Boat share equally in building Virginia-class submarines. Each shipyard has responsibility to build certain sections of each sub, and the yards alternate in assembling, launching and completing the vessels. The weld issues discovered in November 2007 were found only at the Newport News, Va., shipyard, where, at the beginning of a work shift, welders were handed different kinds of weld filler material to use on multiple work assignments. The bad welds resulted when some welders accidentally used the wrong kind of filler on a job.

Northrop has instituted a number of process changes and no longer issues more than one kind of weld filler at a time. Workers also have undergone an extensive retraining program.

The company provided the Navy with a full report on the problem in April 2008, but more time was taken by the Navy to complete its assessment and approve the findings and actions of both shipbuilders to address the issue.

Northrop’s Newport News shipyard also builds all of the nation’s aircraft carriers. A separate review of the aircraft carrier program is still ongoing, according to Katie Roberts, a NAVSEA spokesperson.

As part of the review, according to NAVSEA, Northrop Grumman Shipbuilding:

• Reviewed its welding procedures and inspection criteria to limit the issue to non-nuclear CRES pipes completed between January 2000 and January 2008.

• Conducted quality process reviews, weld record reviews and shipboard material verifications tests.

• Inspected CRES piping located within ship-critical systems. The inspections found a low number of copper-contaminated welds, which were replaced.

• Revised shipyard practices with regard to control of welding materials.

The shipbuilders and the Navy concluded that, while additional improper welds are possible, contaminated welds would likely not show any signs of failure during a submarine’s operational life and if they did, the pipe would leak rather than fail.

“The quality of our work is something we take very seriously,” Margaret Mitchell-Jones, a spokesperson for Northrop Grumman Shipbuilding, said in response to the NAVSEA statement. “We have a rigorous program in place that includes inspecting and evaluating our work to ensure it adheres to the Navy’s strict requirements. When issues arise, it’s something we address in an immediate and methodical way, in full communication with the U.S. Navy and our industrial partners.”

The Navy completed its assessment of Northrop’s inspection report and revised procedures on Aug. 7, a source said, but took more than a month to release the statement because of the need for multiple internal departments to provide their approval.