An on-site low-cost friction stir welding machine would save costs and improve aluminum panel quality in the construction of the Joint High Speed Vessel. NMC image
A low-cost FSW system was developed and demonstrated for Freedom Class LCS applications during a previous Navy Metalworking Center (NMC) project (S2100). This NMC-led project team developed a detailed design for an expanded capabilities low-cost FSW machine, developed processes and tooling for JHSV products, and was prepared to assist in startup and training of the new system at Austal USA
The Joint High Speed Vessel (JHSV) design incorporates the use of large integrally stiffened aluminum panels produced via friction stir welding (FSW). If panels are produced by off-site FSW vendors, the sizes of the panels are limited due to shipping constraints. Assembling smaller panels via conventional welding methods is costly and frequently results in excessive distortion and other quality issues.
A low-cost friction stir welding (LC-FSW) system was developed and demonstrated for Freedom Class LCS applications during a previous Navy Metalworking Center (NMC) project (S2100). That machine design is being modified for application in JHSV construction. This project will develop a detailed design for an extended capabilities LC-FSW machine, develop optimal processes and tooling for JHSV products, and assist in startup and training of the new system at Austal USA.
This project was executed to enhance the producibility of lightweight aluminum structures on JHSV, and to provide expected benefits such as reduced ship costs, improved welded joint quality, and decreased vessel weight. A cost saving of $1.8M per year to the JHSV Program was projected if the technical results of the effort were implemented. In addition, the technical developments could potentially be leveraged for application to other platforms with aluminum structures.
NAVSEA and the American Bureau of Shipping are addressing updated inspection requirements. It’s expected that the new requirements will be issued in late 2012 and that Austal will decide whether or not to procure the extended capabilities FSW system shortly after that.
American Bureau of Shipping