One way to increase the Froude number for a hull is to rearrange displacement hulls into segments that have short lengths. SLICE™ employs such an arrangement.

When comparing vessels of equal displacement, a SLICE™ vessel's hulls are one quarter the length of SWATH hulls. The correspondingly larger diameter of SLICE™ hulls provides the required displacement. For the same operational speed, this innovation doubles the Froude number. For example, a 500-ton SWATH operating at 25 knots would be near its wave resistance hump, while a SLICE™ of equal displacement would be operating well beyond its hump--taking advantage of substantially reduced wave resistance.

A comparison of the resistance for these two vessels can be seen in the following illustrations:

The hump in the resistance still occurs at F = 0.5 ; however, due to the short lower hulls, this phenomenon occurs at low speeds, and SLICE's™ engine is able to power over the created hump and achieve the high design speed. By operating at high Froude numbers, SLICE's™ wave resistance is greatly reduced and SLICE™ outruns its own transverse wave pattern.

Summary

The improvements in SLICE's™ resistance characteristics translate into several quantified benefits. Since SLICE™ is based on the principles of SWATH technology, SLICE™ possesses all of a SWATH's advantages: smaller size, better seakeeping and cheaper acquisition and operating costs.

Adding to these benefits, SLICE™ has higher speed, reduced wake, better range, endurance and fuel consumption, and is built utilizing conventional shipyard practices, including design, construction, materials and equipment. Additional benefits are modular payload capability, simplified payload balancing (due to forward weight), large open deck space, unobstructed stern for loading and unloading, and propulsion amidships--which substantially reduced the chances of fouling and propeller damage. These factors combine to create an optimum small, affordable ship that operates at high speed in high seas.