In the construction of DDG 1000, a prototype system has been implemented that will minimize manual grinding of plate edges for weld preparation, which is slow and physically taxing work. General Dynamics Bath Iron Works photo
In order to improve the plate edge preparation process, a prototype tool is being developed to increase the production rate and reduce injury claims.
During ship fabrication, rust and primer must be removed from the weld joint areas of steel plates prior to welding. Currently, edge preparation is done manually using a pneumatic stone grinder or sander. This is a slow, labor-intensive process causing numerous vibratory and carpal tunnel injuries. The typical production rate in shipyards is approximately 12 feet per hour. There are several thousand plates on a typical naval surface combatant ship, with several edges per plate requiring preparation. A slight improvement in production could provide a substantial labor savings.
This will be accomplished by developing appropriate surface preparation and manipulation equipment, integrating the two technologies into a prototype system, and utilizing the prototype for production of DDG 1000.
The Navy Metalworking Center project team estimates a 200 percent increase in production rate is possible with the potential of saving several million dollars on the cost of a typical surface combatant. The extent of savings will ultimately be determined by when the mechanized plate edge preparation system is introduced into the production cycle. Furthermore, the technology has been shown to reduce vibration levels by 70 percent compared to conventional hand-held tool, which should greatly reduce injuries. This technology can readily be implemented on virtually any ship type, not limited to surface combatants. Savings will be proportional to the amount of edge preparation required.
Prototype operation has been demonstrated at Bath Iron Works (BIW), Ingalls Shipbuilding and Newport News Shipbuilding. Partial implementation of a modified alpha prototype began in fourth quarter FY12. Full implementation of technology using commercially produced units is anticipated in 2013.
Bath Iron Works
Naval Surface Warfare Center, Carderock Division
PMS 500 DDG 1000 Program Office