How Does H.A.R.T.H.tm Work?
High Aspect Ratio Twin Hull
QUESTIONS MOST COMMONLY ASKED REGARDING THE HYDRO LANCEtm AND H.A.R.T.H.tm TECHNOLOGIES:
1. What keeps it up, or how does it float?
Hydro-Lance (H.E.A.R.T.H.) is new, but is still a basic displacement hull. It does not use horsepower to lift or raise it above the waves. It does not have gyros or trim tabs to make it ride level and remain straight and true. Buoyancy holds it up and the well understood physics of hydro-static pressure keeps the hull straight and true. If the power is lost at sea in rough water, the Hydro-Lance design is formulated for stability with a geometry that assures dynamic wave averaging.
2. What kind of engine does it use?
Hydro-Lance can utilize any or multiple types of propulsion. Because of the small cross-section in its rails (hulls), smaller boats will have their engines built under the main deck in the root section of the two rear or front legs. Power plants may be located in the hulls of larger ships which have a larger hull cross-section.
For slow harbor speeds, propulsion can be hydraulic, electric or directly driven 360 degree water jets allowing for maneuvering in any direction, including sideways and 'cater pillaring' in its own length. High-speeds in open-ocean may be handled by aircraft propeller ducted air drive, jet drive in water, electric drive or by a pair of direct cavitating screws. Engines can be gasoline, diesel, piston, rotary, steam, Opus or turbine, whichever offers the best performance and cost-effective trade-off for the owner. Combinations of prime power can be utilized.
3. How fast will it go? Graph
Speed is a function of horsepower. Horsepower is a function of platform size, range desired, hull cross-section, bow point, and structural ability to deal with rough water slamming. Hydro-Lance reduces frontal wave-making drag up to 85 percent. It pierces the wave so that the rails (hulls) always ride in a flat horizontal position with no slamming. The vessel's geometry averages the ocean surface contours, reducing overall structural stress at all speeds. Graph
Hydro-Lance recognizes that sea water is nearly 800 times more dense than air. It is fundamental that boats should be more streamlined than airplanes, given that air weights 2.2 pounds per cubic yard vrs. over 1,700 pounds for water. In order to achieve 60 MPH (economic cruising speed when measured against a 15 MPH traditional displacement monohull of equal weight) Hydro-Lance became a "no compromise" and "no foolishness" design...a technology built on physics.
No one yet knows the upper limits of speed in rough water, except that it is well over 60 MPH. With specific designs for higher speeds, theoretical bow wave resistance can be pushed out to over 165 MPH. Larger vessels offer higher speeds and range potential because of their economy of scale. The inventor believes that with certain modifications in basic design, speeds in excess of 100 MPH, in relatively high seas, can be economically maintained for trans-Atlantic runs, as well as operations in the North Seas.
4. How about beam seas? (Graph) Beaufort #6 Sea State
All vessels are at their worst in beam seas, high winds and waves. Some craft such as catamarans are even susceptible to roll-over (axial rotation) when placed on the slope of a large wave. Hydro-Lance is designed to eliminate this problem with basic geometry. First is by rating the new vessel with sea-state operational parameters.
Careful study of the Hydro-Lance proportions will reveal that in proportion to its weight and size, it has a very large stable base. Short wave lengths contain the most energy, yet Hydro-Lance operating in the sea-state rating, will never produce more than a five (5) degree roll. This is even while standing dead in the water without speed or power. Obviously the captain can eliminate even the five (5) degree roll by starting the engines and steering on a heading a few degrees away from beam conditions. Conclusion: Hydro-Lance handles very well in beam seas. Axial rotation is not a problem, because of the wide geometry, and the reserve buoyancy in each hull (rail) is sufficient to carry the vessel entirely on one rail (if vessel was tipped) without going neutral. Other proprietary means are employed to eliminate all roll on open-ocean class vessels.
5. What about draft?
Because of the extreme length-to-diameter ratios utilized in Hydro-Lance, draft is kept to a minimum. These vessels measure draft in inches, not feet. A small 100 ton vessel, for example, might have a draft of 18-20 inches (and a 1,500 ton vessel will have only five or six feet of draft), making it possible to cross over reefs at high-tide or pass through shoal water that only small boats might otherwise venture. This feature makes Hydro-Lance a good candidate for super tanker and bulk cargo design where shallow-draft is essential for entry into shallow harbors.
6. What about safety?
The extremely long rails naturally make newcomers nervous about everything from hitting semi-submerged logs, or flotsam and jetsam, to hitting whales. Others ask what happens if you hit a rock wall or lose a rail on one side; will the upper body float long enough to get rescued?
These types of questions are reminiscent of those faced by the first airplane. "If those long things you call wings should happen to come off the airplane, what happens then?" Fortunately, Hydro-Lance is not as vulnerable as it may appear. For example, flooded buoyancy is assured by 100% ship displacement, foam back-filled hull walls, in each hull or rail; the same for the legs and the house. The speed assures the ship's ability to outrun hurricanes. The hull design allows for the over-ride of logs and such and satellite linked electronics assure precise navigation..and much more;
The extreme shallow draft and the bow point design are more likely to ride up and over low floating objects at or below the water line. Floating objects are also going to be pushed down as well as Hydro-Lance being lifted. The likelihood of center-punching a whale is very remote, since whales hear things (sub-surface signal horns incorporated) at long distances. Those creatures, dropping a few feet below the surface, will then avoid any collision of the ship with these 'intelligent' creatures. Hydro-Lance does not have exposed propellers below the hull bottom, which could otherwise destroy or chop up marine animals.
The long tapered bow-points pass over kelp and floating nets, etc. Even here, design provisions are incorporated to help cut away such occurrence. What happens if you hit a sailboat or power vessel while traveling at 60 MPH? Have you ever seen the picture of the straw driven through the telephone pole during a hurricane? Arrows, harpoons, spears, etc. are stronger along their length. A close examination of Hydro-Lance's front legs may reveal their cutting slope where they fasten to the hull.
We're hoping that pilot competence, long range radar and the new starlight night vision equipment will prevent the test of such collisions.
7. What keeps the rails running straight?
Almost everyone worries about the rails going their own separate ways. I believe a simple comparison would be water skies, ice skates, snow skies, etc. How strong are your ankles compared to your body weight. The plain facts are that the water itself demands that the rails travel in a path of least resistance. As a matter of interest, it takes more energy to turn them than it does to make them go straight. When standing still, wave action might create minor pressures to create lateral forces. Under way, these forces work back-and-forth to cancel each other. At high-speed, the water has only enough time to move a very short distance until the rail feels pressures of it going the other way. The higher the speed of Hydro-Lance, the closer these forces equate to zero. Remember, 60 MPH is 88 feet per second. To understand the subtleness of the Hydro-Lance design, you must do a velocity time vector analysis of waves. Amazing, isn't it? Time and dwell for averaging wave forces is important.
8. Where do you park it?
Any place in sheltered or unsheltered water. You don't need a snug harbor when your boat rides flat, parked in the HIGH surf. In the real world, this is a stable platform at sea making the vessel a stable pier as well. When the hulls are beached at the bow, even with large waves rolling in, it is stable. Consider that conventional vessels are built for the convenience of harbors, while the Hydro Lance is designed and build for the ocean. When airplanes were finally accepted as viable, airplane landing strips were built as airports. Hydro Lance can accommodate open beaches, shallow waters and can accommodate some existing port facilities, however there will be modifications for this high speed transport capability to each.
It's true that the relatively large footprint, for its weight and house size, does not conform with traditional ships. Hydro-Lance is a complete opposite; designed on the basis of physics. It performs well at sea, but never fits in compact slips at the small boat marina. On the other hand, traditional boats berth well, and do poorly at sea. At least we will now have an option on what we buy a boat or ship to do.
9. How expensive is it?
Hydro-Lance should not cost much more than ordinary vessels, once they are repeatedly produced. Hydro-Lance has approximately 30 percent more surface area, which means more skin and ribs, etc. But measured against weight, it has double the living or cargo area; a relatively small Hydro-Lance will offer more space and luxury than a traditional boat twice its weight. The twin-hull geometry and limited free-board makes the difference.
10. How about fuel consumption? See Ferry Study Summary
Because Hydro-Lance is over 80 percent efficient in the amount of water disturbed per mile, fuel consumption and horsepower are kept at a minimum. Compared to a standard mono-hull displacement vessel, or even a catamaran, SWATH, Hydrofoil Hovercraft, etc, Hydro-Lance will either double or triple your speed for the same fuel and horsepower consumption...or reduce fuel consumption by several times when compared to other vessels operated at 10-30 MPH speeds (hull shapes and bow points are relative to snow plows in water).
11. What about heave?
Heave is negligible. Consider a draft of three feet; then free-board would be a maximum of three feet, with buoyancy established by the length of the hull. The draft is the buoyancy and the free-board is the reserve buoyancy. By design, that reserve is limited, not infinite as with conventional designs. Within any total wave length, there is 50% of rising water and 50% of falling water. The Hydro Lance design averages this forces to zero. Waves roll over each hull. The length of the hulls is usually a minimum of one and one-half full wave lengths. As speed is increased, the effective wave length is shortened. The forces of heave become averaged to zero.
11. What about turning at high-speed?
Turning a Hydro-Lance may be as fast as any large ship in the water. The new methods used are proprietary and are part of the overall patent process. Many new innovations had to be developed to make Hydro-Lance a total working system. Features such as wetted-surface drag reduction systems, variable displacement, high/low decks and tail gates, walk-ashore rails that eliminate shore boat transfer problems, no rudders and many other unique features were designed to make Hydro-Lance a true contender for global marine improvement.
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