The Gulf Coast Region Maritime Technology Center issued a request for proposals to provide technical assistance with Cutting and Welding Systems for Rapid Fabrication of Erection Joints. Shipyards indicate that completion of erection joints used to join ship modules during final construction is a major cost factor and bottleneck. Thousands of these joints must be manually cut, welded, and inspected during the fabrication of a ship structure.
Erection joints are typically butt joints between steel Tís, angles, or bulb flats. Fitting a neat-cut erection beam with a manually cut erection beam from the stock side makes the erection joints. Gaps, mismatch, and irregular weld joint surfaces promote a high incidence of weld defects. Defective welds must be ground out and repair welded. It is estimated that repair costs increase the cost of erection beam fabrication by an order of magnitude.
Erection beam welding is now a bottleneck for shipyard production. Shipyard costs are increasing on erection beam applications due to the primitive cutting and welding procedures, along with increased inspection requirements. Portable robots have been considered for erection beam welding, but many believe that they may not be sufficiently robust for rapid welding in a construction environment. A semi-automatic or mechanized approach to neat cutting and welding may prove to be the quickest route to implementation for erection beam fabrication. This project is focused on developing innovative in-situ semi-automatic and/or mechanized cutting technology and tools. Robust methods of welding joints will also be developed.
The objective of this project is to develop practical cutting and welding systems that can be widely used in shipyards for rapid fabrication of erection joints. The project will focus on developing a range of tools and techniques for both manual and mechanized operation.