"Advanced Metalworking Solutions for
Naval Systems that Go in Harm's Way"
Improved Pipe Processing Methods Expected to Save $590K per VCS Hull
NMC developed pipe fixturing and welding process improvements for large diameter pipes that are expected to save $590K per VCS hull. Electric Boat photo
Current Virginia (SSN 774) Class submarines (VCS) contain off-hull new construction pipe detail fabrication processes that involve various complex configurations for large diameter pipe (3"-12" diameters) for preparation, fixturing, positioning, fit-up, and welding methods. Current applied fabrication techniques and weld processes require excessive labor in set-up and handling times, which reduces work cell process flow output and efficiencies. This Navy Metalworking Center (NMC) project developed improved and automated construction processes to reduce labor hours in VCS construction.
The NMC-led project team investigated methods for improving the efficiency of specific areas of pipe preparation including fixturing, positioning, and fitting; automation of welding and drilling pipe bosses; pipe purging methods; and the use of internal pipe joint blending tools and applications to reduce pipe section cutting, rework, and pipe material scrap. The NMC project team developed several large diameter pipe process tool concepts, executed first-article prototype demonstrations, conducted feasibility studies based on projected man-hour and material cost savings, and performed demonstration testing and validation at both VCS shipyards.
Implementation and Technology Transfer:
Testing and validation of prototype process improvements were completed in the fall of 2011 at General Dynamics Electric Boat and Newport News Shipbuilding. The prototype tools were transitioned to the shipyards in April of 2012. Full implementation is expected in both VCS pipe shops for the SSN 788 hull in the fall of 2012.
The current projected savings are 8,500 man-hours per hull in manual labor. The reduction in man-hours results in a projected $590K savings per hull and $5.9M savings over the next five years based on the VCS production build schedule of two hulls per year.
For more information, contact:
Dr. Daniel L. Winterscheidt
NMC Senior Program Director