Advanced Metalworking Solutions for
Naval Systems that Go in Harm's Way

Hull Fabrication Improvement

A mechanized backgouging system will improve weld joint quality and reduce construction costs for the Virginia Class Submarine.


This project will develop a portable, production-hardened, track-based plasma arc backgouging system for VIRGINIA Class submarine (VCS) hull butt joints.


The Navy Metalworking Center (NMC) is conducting a Navy ManTech project that is developing an improved backgouging system for hull butt weld joints, which will reduce labor hours in the construction of Virginia Class Submarines (VCS).

Technical Approach

This system design will be an extension of the robotic welding technology that was successfully demonstrated in Phase II of a prior ManTech project (S2197) executed by the Navy Joining Center and will use the same track from that mechanized welding system. Phase III will focus on hardening the backgouging system components against electromagnetic noise and physical hazards and integrating these components with a simpler control system on a dedicated carriage. The system will be tested on a hull butt weld joint, production schedule permitting.


As a result of implementing this technology for backgouging the hull weld joints, General Dynamics Electric Boat (GDEB) estimates a three percent savings in overall welding labor hours is possible. This savings is a result of an overall increase in efficiency of the backgouging method, consistent backgouge profile allowing for more efficient welding, reduced grinding time, and reduced set-up time. A small compression in schedule (approximately 14 days) also allows other trades to begin their work earlier. The net impact is a total labor reduction of 910 man-hours per ship.


The prototype system is expected to be available for training or as a back-up system at GDEB Quonset Point by early 2014. GDEB will procure two production backgouging systems from the commercialization partner, Servo-Robot, for use in its Quonset Point assembly plant for preparing VCS hull butt joints, starting in the spring of 2014.




Charles McNamara
Asst. Program Manager for Virginia Class Development and Modernization
Naval Sea Systems Command, PMS 450D


General Dynamics Electric Boat Corporation
Naval Surface Warfare Center, Carderock Division
PMS 450 Virginia Class Program Office