By Geoff Fein
The investigation into welding issues at Northrop Grumman‘s [NOC] Newport News (NGNN) shipyard that initially led to the tying up of the first three Virginia-class submarines earlier this month has been expanded to include other subs and aircraft carriers, the Navy said.
The Navy, NGNN, and General Dynamics [GD] Electric Boat are conducting a detailed assessment of completed welds through record reviews and additional inspections.
The discovery of the weld weaknesses and the resulting inspections have impacted operational testing of the USS Virginia (SSN-774) and pre-commissioned unit North Carolina Sea Trials (Defense Daily, Dec. 10). The USS Texas (SSN-775) was in port at the time.
The scope of the long-term investigation includes Virginia-class submarines, Los Angeles-class submarines, aircraft carriers and in-service surface ships built or maintained by NGNN from 2000 to 2007, according to Naval Sea Systems Command (NAVSEA).
“In the aircraft carrier business, this is a very important finding. NGNN knows they have to understand what this means to the aircraft carriers, ” Rear Adm. William Hilarides, program executive officer submarines, said in an interview with Defense Daily earlier this month.
“We are currently in the process of assessing what ships could be potentially affected, and we anticipate completing our assessment in early January,” Jennifer Dellapenta, an NGNN spokeswoman, said yesterday.
The investigation is the result of a process deficiency at NGNN, which potentially enabled improper weld filler metal to be used on non-nuclear piping systems over an extended period of time, the Navy said. NGNN has revised its procedures and is retraining its workforce on the new procedure. Both NGNN and the Navy are providing additional deckplate oversight to monitor the revised process, the Navy added.
“The Navy continues to work closely with NGNN to ensure that Navy vessels are built to the highest technical and safety standards. All vessels constructed by or maintained by NGNN since 2000 will undergo a technical assessment of non-nuclear piping systems,” according to NAVSEA.
The internal piping systems under review transport air, water and hydraulic fluid inside the hull of the vessel. Neither the hull nor any nuclear components are affected, the Navy said.
The Navy will complete an initial assessment of near-term concerns regarding critical welds in late December. The Navy is committed to ensuring the safety of our crews and ships.
In spring 2008 the Navy and NGNN will complete an analysis of the long-term effects of the weld problem and identify the specific steps to be taken to address the issue. Specific actions may include reworking some welds and conducting routine monitoring or testing of the welds, the Navy said.
“The Navy will better understand the long-term effects of this problem and associated costs when the investigation is complete,” NAVSEA said. “This issue and resulting investigation has had minimal impact to naval operations.”