Since 1998, the M Ship Company's executive director and co-founder, Bill Burns, has made a business of thinking outside the realm of conventional marine design. Genesis of the company: when living in Venice, Italy, business partner Charles Robinson, a former shipping and mining executive, observed damage to buildings caused by the wakes of boats on the city's vast network of canals.
M Ship didn't stop experimenting with Stiletto. Searching for a way to evaluate new designs and concepts more quickly, and less expensively, than in a tow tank, it built a 20' (6.1m) trimaran platform equipped with multiple computer stations and "various adaptable structures" to accommodate different models. Dubbed FLOWT - for fast, low-cost, open-water testing - the platform is a key part of M Ship's Rapid Empirical Innovation (REI) program.
Burns says that REI's significant advantage is its ability to test and compare two models at the same time in the same conditions, whether lake or ocean. Models are outfitted with "identical high-frequency 6-DoF [degrees of freedom] accelerometers that provide comprehensive motion and acceleration comparisons" and analyze power, speed, payload, fuel efficiency, range capability, and ride quality. The company has applied REI to displacement monohulls, multihulls, planing hullforms, and submersibles, and claims that it can save a builder or designer 50% - 80% of the cost of tow tank tests. The rising accuracy of computational fluid dynamics (CFD) has prompted many designers/builders to forgo tank-testing, but not without some reservations. Burns says REI gives them an affordable means of validating CFD and "untested claims."
Burns realized, of course, that to sell clients on REI, he needed to validate their open-water system, which he did at the U.S. Navy's David Taylor Model Basin in Maryland. Burns says the results exceeded their 95% threshold. Calm-water resistance measurements showed accuracy of 4% at 5 knots model scale and 3% at 15 knots model scale.
One client is Tim Kernan of Kernan Yacht Design (Long Beach, California), who tested a model for a sailboat/powerboat hybrid. For such a craft to plane in powerboat mode, the challenge is generating lift. Kernan developed two sets of chines to avoid sinkage of the stern sections. "It worked," he said, "but the drag increased." So with the help of feedback from REI, he pursued another, more successful solution. He said tests of his model took place in nearly calm waters, but since that time M Ship has incorporated sea state corrections into its software.
M Ship touts REI as a fast, affordable way to "quickly and accurately evaluate valuable design concept, and compare different designs, with instant results." Kernan concurs, "For the money, it's a good way to confirm your predictions, and we'll be using it again."