HIGH SPEED PLANING BOAT

Abstract: A pleasure boat having a rectangular passenger area for operation at high speeds in moderate seas, planes on ski-like planing surfaces (14) on the bottom of laterally spaced, knife edge hulls (6) located on the starboard and port sides of the craft and the stern end of a wedge shaped bottom (8) is rounded to assist in turns; the rounded bottom also having flutes (38) to improve tracking and strakes (36, 40) to assist in the lift and to divert spray from the craft; the two forward hulls terminating in tunnels (9) located along either side of the rounded bottom to reduce greatly the surface area in the water and to provide lift to assist in planing.

Description: HIGH SPEED PLANING BOAT BACKGROUND OF THE INVENTION The present invention relates to high-speed pleasure boats and more particularly to a stable, maneuvereable, high speed craft for operation in moderate seas and having a large rectangular passenger area. DESCRIPTION OF THE PRIOR ART High speed planing boats, hydroplanes, are well known for their ability to achieve combined high-speeds and maneuverability. The ride of these craft is quite uncomfortable, bouncing from wave to wave, skidding in turns and flipping over backwards if the lift on the forward part of the boat exceeds a predetermined design parameter. Also, the classic hydroplane provides a small passenger compartment. Attempts to improve the performance of the hydroplane have taken many routes, a number of which are discussed in the article "Supercritical Planing Hulls", Ocean Engineering, Vol. 11 No. 2 pp 129-184 by Peter R. Payne, one of the inventors of the present invention. Additional planing craft are found in U.S. patent Nos. 3,709,179 and 3,763,810 of Peter Payne. See also the article "Sea Knife Arriving" by John Stebbin, pp 113-118, Proceedings, U.S. Naval Institute, Feb. 1985, Vol. 111/2/984. Each of the craft described in the aforesaid literature and the literature including patents are constructed such that for the size of the craft, the passenger area is smal-1. The craft are designed primar- ily for speed and maneuverability, often for combat and/or racing and sacrifice passenger area and creature comfort to these ends. SUMMARY OF THE INVENTION It is an object of the present invention to provide a fuel efficient, high-speed, maneuverable, plea¬ sure craft for operation in light to moderate seas, having a large passenger area and providing a comfortable, stable ride. The craft of the present invention has a pair of laterally spaced symmetrical planing hulls located forward on the craft and a wedge shaped bottom having maximum width at the transom and providing a third planing surface. The forward planing hulls provide one planing surface (ski) each and have knife edge, leading edges to permit the craft to cut through waves to reduce drag; the front skis reducing the rise and fall of the craft and thus preventing the craft from falling out of equilibrium. The front hulls also carry S-shaped spray rails to direct spray from the passenger area. The S- shaped spray rail provides at its highest point near the front of the hulls, deflection of high waves and as it approaches the water line diverts waves of lesser height almost down to the planing surface of the skis. The spray rail carries to just above the planing surface and to the rear of the skis to reduce the wetted surface at planing and also breaks up the bow wave into two waves of lesser height than would otherwise be the case. A third planing surface is provided by a wedge shaped bottom of the boat with the craft planing on the tail end of such surface. Planing hulls are employed at the forward end of the craft as indicated above to decrease rocking of the craft in moderate seas and to prevent the craft from falling out of equilibrium. Further due to the use of a rectangular hull, a large proportion of the weight, one- third to one-half, is located forward of the transverse center of the craft and must be supported separately from the rear planing surface. Thus an added use of the forward planing hulls. A single forward hull is not employed since it would adversely effect the ability to plane on the rear planing surface. Thus the two widely separated forward hulls are employed. Symmetrical hulls are employed to prevent yawing of the craft in turns and in the presence of waves striking the boat at an angle to its centerline. The front hulls terminate in tunnels running down each side of the wedge which tunnels add lift to the craft when coming up to its planing position and during planing greatly reduce the wetted surface of the craft to only that required to produce planing. The rear of the forward planing surfaces of the hulls carry downwardly depending hooks to increase the lift of these surfaces. The distribution of the weight of the craft over three surfaces provides a very shallow draft even at low, non-planing, speeds; the draft at rest in one such craft being 10 inches for a 3000 lb. craft. The wedge shaped bottom of the craft is rounded to soften the ride, assist in lift and to prevent the chines of the wedge from digging into the water on turns and thus improving the ability of the craft to hold a turn. The- wedge is also provided with flutes to assist in holding a heading and strakes which assist in holding a turn, and add to the lift and assist in diverting spray away from the passenger area. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a bottom view of the boat of the present invention. Fig. 2 is a side view in elevation of the invention. Fig. 3 is a detailed side view of the hooks at the rear of the front skis. Fig. 4 is a rear view of starboard half of the boat of the present invention, Fig. 5 is a front view of the starboard half of the craft, Fig. 6 is a top plane view of the craft, Figs. 7-1 to 7-3 are a series of contour views illustrating the configuration of the boat at various locations rearward of the back of the front hulls; and Figs. 8-1 to 8-2 are a series of contour views illustrating the configuration of the craft at the back of and forward of the rear of the front hulls. DETAILED DESCRIPTION OF THE PRESENT INVENTION Referring now to Figures 1 and 2 of the accom¬ panying drawings, the craft 2 comprises an upper, generally rectangular part 4, a pair of laterally sepa- rated front hull members 6, and a rounded wedge 8 formed on the bottom 9 of the craft. The wedge 8 may be inclined between 2 • and 6 » to the line 10 drawn between the bottom of the wedge 8 at transom 12 and the bottom rear of the forward hulls 6. In the specific craft being considered the angle is 4'; the same angle the bottom of the hulls 6, hereinafter referred to as the skis 14, make with line 10. The hulls 6 are identical and thus only one is discussed. The hulls are symmetrical and have relatively sharp leading edges 16 which slope upwardly along a continuous curve 18 to a virtual point 20 at the prow of the craft. The hulls 6 are provided with both inner and outer spray deflectors 22 and 24, the inner deflector terminating at the front of the ski region and the outer deflector carrying to the end of the ski. Both sets of deflectors 22 and 24 are S-shaped and carry from near the top front of the hulls to near the bottom at the back of the skis; thus providing spray protection for both low and high waves. As previously indicated, the fact that the outer spray rails 24 provide, in effect, a notch 25 in the outer edge of the ski that serves the threefold purpose of a spray rail, a means of reducing the wetted surface of the ski and most importantly breaks up the bow wave thus reducing the height thereof. The rear of skis 14, and reference is made to Fig. 3 of the accompanying drawings, is curved to provide a relatively flat downward hook 26 which provides additional lift to the front skis. The craft has a flat bow transom 28 commencing rearwardly of the leading edge 20 of the hulls 6 by a short distance sufficient to permit the hulls 6 to knife into incoming waves before encountering the main body of• the boat. Thus a large dynamic force that would tend to lift the bow is substantially avoided. An additional reduction in lifting force is realized by sloping the bow transom down and to the rear at about a 45'- angle relative to upper chines 30; the transom terminating at the bottom 9 of the boat. This sloping surface provides the additional function of preventing swamping of the craft in heavy seas. If wave is encountered it will serve to raise the bow, permitting the wave to pass under the craft and down through the tunnels. The wedge 8 commences at the intersection of the bow transom and the bottom 9 of the craft. The wedge tapers outwardly to the rear at an angle determined by the width of the craft and the width of tunnels to be described subsequently. In the particular realization of the invention illustrated, the outward taper of each side of the wedge relative to the centerline of the craft is 7 1/2' , going from a virtual point 32 to about 52" at the stern transom 12. The stern of the craft in question is about 87" wide. The wedge is rounded in the vertical back to front view as illustrated in Fig. 4 of the accompanying drawings. The radius of curvature of the bottom of the wedge, is about 92" for this particular craft. The bottom of the wedge is provided with six longitudinally extending strakes, three, numbers 34, 36 and 38 on each side of the centerline of the craft with the innermost strake spaced apart a sufficient distance so as not to introduce significant amounts of air bubbles to the propeller which in this embodiment is intended to be a surface piercing propeller. Located between strakes 38 and 40 on both sides of the centerline of the wedge 8 are longitudinally extending grooves 40 which help reduce yawing of the craft and hold it on course while producing some lift. The strakes provide some lift during rise to planing and while on plane operate as spray diverters. The rounded bottom of the wedge 8 prevent chines 42 of the wedge from digging into the water on -turns, reducing drag and helping to hold the turn. Specifically, the rounded bottom reduces shock and allows banking to provide better turning at slow speeds; behaving like a flat bottom at high speeds. The sides 44 of the wedge rearward of the hulls 6, rise sharply and terminate in a surface of large radius, in the embodiment illustrated, a radius of about 12". These surfaces define tunnels 46 extending from the rear of the hulls 6 to the stern transom, greatly reducing the area of the craft engaging the water, providing lift when in the water with the craft rising to the planing position and serve as spray diverters when planing. The sharp rise along the sides of the planing wedge also serves to reduce the dynamic forces acting on the bottom of the craft to only those required for planing and thus do not produce excess forces that would produce unnecessary rocking of the craft. The craft described above has a rectangular upper shape much like a house boat and is intended for pleasure use in moderate seas but may be adapted to other uses where high speed, maneuverability and a large passenger area are desired. The length to width ratio, ideally 2:1 to 3:1 is, in this rendition, 2:68:1 and is 21 ft. long. In test of this craft using a 115 horsepower outboard engine with a submerged propeller, speeds of slightly over 51 miles per hour were attained. The craft is capable of carrying a 200 horsepower outboard engine and may be adapted to an inboard engine with a submerged propeller. In the tests conducted on the craft, which weighed about 3000 pounds with one person and all equipment aboard, and in waves of 1.5 feet, the craft experienced no loss of speed or efficiency. Based on these tests, it has been calculated that with a Mercedes 5 cyl. engine of 130 shaft horsepower, the craft will attain a speed of approximately 50 MPH and a fuel efficiency of 10 miles/gal. at wide open throttle and 15 + MPG at cruise speeds of approximately 35-40 MPH. it was found that only about the last four feet of the wedge 8 and one foot each of skis 6 were in water and the front skis rode on the surface of the water. The skis in this rendition were about 16" wide. It is apparent that the wetted surface of the craft was quite small and thus the high efficiency. The very small area of wetted surface, less than 14 square feet for a 3000 lb craft in this rendition, results from the use of the tunnels to reduce the wetted surface of the wedge; the height of the tunnel being effective to minimize wetting along the sides of the wedge and adjacent surfaces of the bottom of the boat. The length of the wedge in water when planing is defined also to a great extent by the placement and angle of the front skis. In waves, the front edges of the hulls which hold the wedge at the proper angle of attack cut through the waves permitting the skis to ride the surface of the waves; the rear of the wedge following whereby to reduce rocking and slapping along the bottom of the boat to relatively comfortable levels even in seas of up to three feet. It has been found that the rear of the skis should be no greater than 50% of the length of the boat from the bow thereof; specifically 10'4" in a boat of 20'll"in length. In summary, the craft planes on three surfaces such that the bow of the craft can be quite wide; the weight thereof being carried by the narrow front skis which also serve to maintain the rear .planing surface at the proper angle of attack. The front of the forward hulls are knife edged to permit the craft to knife through waves instead of riding the crests and this together with the sloping forward transom maintains rocking in moderate seas at relatively low levels. Tunnels to the rear of the skis and along the sides of the wedge, reduce the surface in contact with water to the minimum required to support the fully loaded craft, thus minimizing drag to a level far below that found even in the deep-V high performance hulls. The three surfaces of support permit an unusually shallow draft -for a boat of such size and weight; only 10 inches in the boat that was built and tested. The craft maintains close to maximum speed in waves up to three feet. Maneuverability and turning is enhanced by the use of a rounded bottom on the wedge and the use of strakes and flutes. Depending upon desired end use of the craft, angles of attack, radius of curvature of the bottom of the wedge, flat surface area of the skis and the like may be varied to accomodate specific needs. Thus it is apparent that minor variations in design are possible without violating the teachings or spirit of the present invention. The passenger area can be configured as desired with stark or luxurious fittings and controls, deck covering structures, sleeping accommodations and the like. The craft, due to its shallow draft, is ideal for lake fishing or because of speed and maneuverability for racing or warfare. For instance the ride can be softened by increasing the dead rise of the skis and/or making the front transom and planing surface in a V-shape. The former modification will reduce the speed of the craft and the latter modification will reduce its efficiency but both reductions will not be great and the ride will be noticeably smoother. Although not illustrated, since it forms no part of the present invention, the cockpit area in one form will be about 101 square feet, leaving free space of 63 sq. feet in a 21 foot long craft; thus comparing favorably with craft of 30 feet or more in length. Other improvements, modifications and embodiments will become apparent to one of ordinary skill in the art upon review of this disclosure. Such improvements, modifications, and embodiments are considered to be within the scope of this invention as defined by the following claims.

Claims: WE CLAIM: 1. A high speed, high efficiency planing boat comprising: a passenger compartment, having a bottom, a pair of forward hulls depending downwardly from said bottom of said passenger compartment, said hulls being spaced apart and lying on opposite sides of the longitudinal centerline of said boat, each said hull having a ski-like surface toward the rear thereof, a wedge-shaped member extending downwardly along said bottom of said passenger compartment with its apex lying between said hulls along the longitudinal centerline of the boat and extending to the stern of the boat. 2. A high speed, high efficiency planing boat according to claim 1, wherein said passenger compartment is generally rectangular. 3. A high speed, high efficiency planing boat according to claim 1, wherein said ski-like surfaces and said wedge-shaped member are inclined upwardly from stem to bow relative to said bottom of said boat. 4. A high speed, high efficiency planing boat according to claim 3 wherein said angle of inclination is in the range of approximately 2' - 6' . 5. A high speed, high efficiency planing boat according to claim 1 or claim 3, wherein said hulls are tapered to a generally sharp downwardly and rearwardly curved leading edge. said leading edges tapering., into said ski-like surfaces. 6. A high speed, high efficiency planing boat according to claim 5, wherein said boat has a forward transom extending between said hulls and sloping downwardly and rearwardly. 7. A high speed, high efficiency planing boat according to claim 6, wherein said apex lies at the intersection of said bottom and said forward transom. 8. A high speed, high efficiency planing boat according to claim 5, wherein said wedge-shaped member has sides rising sharply toward said bottom of said passenger compartment. 9. A high speed, high efficiency planing boat according to claim 5, wherein said hulls include spray deflectors. 10. A high speed, high efficiency planing boat according to claim 9, wherein said hulls each have along their outer surfaces an S-shaped notch having its highest point adjacent the bow thereof and extending to the rear of each said hull in a generally smooth curve to a short distance above said ski-like surface. 11. A high speed, high efficiency planing boat according to claim 8, wherein said sides are curved out- wardly adjacent said bottom and merge into a continuous curve terminating in a downwardly depending region to provide spray deflectors along the two sides of the boat. 12. A high speed, high efficiency planing boat according to claim 1, wherein said wedge-shaped member further includes a bottom surface having longitudinally extending strakes symmetrically disposed relative to the centerline of said boat. 13. A high speed, high efficiency planing boat according to claim 1 or claim 12, wherein said wedge- shaped member includes a bottom surface having a plurality of longitudinally extending flutes dispersed symmetrically with respect to the centerline thereof. 14. A high speed, high efficiency planing boat: according to claim 1 or claim 12, wherein said wedge shaped member has a rounded bottom in transverse section. 15. A high speed, high efficiency planing boat according to claim 1, wherein said ski-like surfaces are positioned to carry at least approximately one-third the weight of said boat. 16. A high speed, high efficiency planing boat according to claim 1, wherein said ski-like surfaces ter¬ minate at their stern end a distance from the bow of said hulls of not greater than 50% of the distance from said bow to the stern of said boat. 17. A high speed, high efficiency planing boat according to claim 1, and claim 15, wherein said ski-like surfaces have a shallow downward curve at their stern ends.

Inventors: PAYNE PETER R, SAPP SAMUEL C, PAYNE, PETER, R., SAPP, SAMUEL, C.
Applicants: MARINE TECHNOLOGICAL EXCHANGE, MARINE TECHNOLOGICAL EXCHANGE, INC.
Application year: 1986
Main classification: B63B1
IPC codes: B63B1