HARTH and SLICE Boats and Ships

The Cutting Edge of Boat/Ship-Building Technology

May 28, 2007 John Crandall

HARTH and SLICE technologies are SWATH modifications that reduce "drag" in order to increase speeds or reduce horsepower or fuel requirements for boats.

Both SLICE and HARTH are modifications of the SWATH concept. Slice uses four pontoons two at the rear corners and two slightly drawn in towards the centerline from the front corners. The use of four smaller pontoons reduces drag, and allows for higher speeds without sacrificing the stability of a SWATH design in rough seas. HARTH stands for High Aspect Ratio Twin Hull, and has two long thin streamlined SWATH type twin hulls. HARTH boats can achieve amazing speeds without amazing horsepower, and are about as stable as SWATH. However, beneath the waterline the hulls are larger than the boat. This can be a problem in maneuvering, and turning into a dock. Such problems can be easily overcome either by experienced operators, or more probably in the modern world by sensor technology that tells the steersman or captain where the pods are relative to the dock or other craft. SLICE boats do not have this problem, and are far faster than SWATH, but not as fast or hydro-dynamically efficient as HARTH.

It is very likely that one or both of these advanced submerged hull technologies will be the primary boat building paradigms of the future. Compared to either of these conventional hulls are terribly inefficient. It is like the difference between pushing a bathtub through the water with a propeller and pushing a streamlined torpedo through the water. Either of these hull designs will go faster with less horsepower than any conventional hull. Both are far more stable in rough seas than conventional boats just like the original SWATH, and both are current technical realities.

Neither design needs gyros or other advanced stabilization, although the SLICE does employ underwater canards. Neither will become unstable with the loss of power like some hydrofoils. Both are buoyant hulls that will float and right themselves like a conventional boat whether powered or un-powered. More powering options are available. Standard gas or diesel with propellers, hydro-jets, aircraft engines of all types, or forced air will work. In fact, almost any technology ever employed to induce motion will power these craft, even sail. Some of the technologies can be mounted for 360 degrees or steering either below or above water promising new levels of the possible in boat maneuverability. Weather and storms that have been the bane of mariners for centuries untold may soon be safe even for novice pleasure boaters. The next few decades will be exiting and interesting times. I believe a nautical transportation revolution is upon us.

The copyright of the article HARTH and SLICE Boats and Ships in Boats is owned by John Crandall. Permission to republish HARTH and SLICE Boats and Ships in print or online must be granted by the author in writing.