Structural Composites teamed up with industry partners Interplastic Corporation and BASF to develop the resin and coating technologies required to commercially produce CoCure, making it available for use in the Navy project. CoCure 20 was applied to the corners and radiuses of the 7ACC’s console, since that’s where gel coat cracking generally starts. In other sections, the project team used CoCure 15, since it didn’t need as much stretching capability.
Improvements were made to the new craft’s engine, too. The Navy typically uses inboard diesel technology to combat the risk of fire. As the 7ACC project evolved, however, engine manufacturers, including Mercury and BRP-Evinrude, began making outboard diesels. That eliminated the need for an engine-support structure, further reducing the boat’s weight. The 7ACC at CAMX, built by Willard Marine, included two BRP lightweight two-stroke, spark-fired, multi-fuel outboard engines.
With all these enhancements, the change in weight has been significant. When the project started, the 7M Navy standard rigid inflatable boat (a predecessor of the 7ACC) with an inboard diesel weighed about 5,600 pounds. Today, the latest model – the 7ACC powered with twin BRP multi-fuel engines – weighs approximately 3,500 pounds. This boat is set for fleet trials after instrumentation and offshore testing and evaluations.
In the meantime, the technology developed for the 7ACC project has benefited other applications. Wabash uses CoCure for its growing fleet of Molded Structural Composite (MSC) trailers, and Interplastic Corporation introduced new CoCure coatings to the recreational boating industry in October. Lewit hopes to see boat designs that use PRISMA components, a suspended deck and thinner hulls adopted as well. He says a combination of CoCure materials and new designs could contribute to a boat that’s up to 30 percent lighter with reduced engine sizes at costs less than current models.
The composites industry could use a breakthrough like this for the marine industry. “Other industries, like electronics, have made these great advances,” says Lewit. “It would be nice to be able to say that we’ve made boats 30 percent lighter so you don’t need as big an engine. You could actually talk miles per gallon instead of gallons per mile.”