Project Number: S2911

Project Title: Robotic Blending of Large Diameter Internal Piping

Period of Performance: JUL21 – MAY25

Final installation of large diameter shipboard pipe assemblies presents a scenario known as “closure joints”, where welding technicians complete the last weld assemblies in a pipe system. Weld joints completed before closure preserve a degree of access to the interior diameter (ID) of the pipe, allowing shipbuilders to perform rework – if warranted by inspection – on the ID of pipe joints. By contrast, closure joints eliminate the usual access. If rework is required, the lack of access results in numerous delays and additional labor costs to complete the joint to acceptable quality standards. The combination of material type, application, closure joint scenario and required quality make this situation unique to submarine construction at General Dynamics Electric Boat (GDEB).

The objective of this Center for Naval Metalworking (CNM) project is to utilize robotic and video technology to provide access to internal pipe locations to perform work typically conducted when access is available. GDEB seeks to develop a means for a small device to enter small access points, expand to the working pipe diameter, navigate to the intended work location, and perform minor blending and grinding operations. A high degree of system cleanliness must be maintained throughout the operation. This solution would provide an alternative to the current practice of removing critical equipment by making smaller access points associated with valves/bosses viable entry points. The solution would also provide a means to enter non-closure joints in the event ID access is still problematic due to configuration or length.

GDEB expects the results of this project will reduce the man-hours required in the repair of weld defects and reduce the overall number of internal piping weld defects. This CNM project is expected to provide an estimated savings of $400K per VCS hull, $493K per VPM, and $789K per CLB hull for combined five-year estimated savings of $6.81M across all platforms.

Upon successful and timely completion of the CNM project, the results will be implemented at the GDEB facility. GDEB anticipates implementation in the first quarter of fiscal year 2026.