[1]Utuoted States Patent Office 3@450@084 3,450,084 BOAT HULL CONSTRUCTION WITH OUTRIGGER PONTOON ASSEMBLY Fred Gerbracht, 2325 Seidenberg Ave., Key West, Fla. 33040 Filed Apr. 13, 1967, Ser. No. 630,629 Int. Cl. B63b 1/10 U.S. Cl. 114-66.5 7 Claims ABSTRACT OF THE DISCLOSURE A boat construction in the form of a hull coop@-rating with removable outri.-.-er pontoons associated with transverse frame members in the boat hull to provide adequate support for the outri.-,-er pontoons and longitudinal trusses co-joined with the transverse frame members to provide support to an impermeable covering fixedly attached thereto. The hull is substantially parallelopiped in configuration and provided with a pair of parallel sl)aced keels merging into a complexly curved bow. The present invention generally relates to improved and novel structure in boat construction generally in the form of a runabout hull having a novel cooperative relation with removable outrigger pontoons. As is well known, boating for pleasure, fishing, cruising and when in en.-a.-ement in various water sports is becoming inereasin-ly popular. Boats generally are constructed in a manner which renders them hi.-hly efficient for a specialized @purpose while being unacceptable for other purposes. For example, a boat which is adapted especially for fishin@ or skin diving would be relatively inefficient for use for towing water skiers. Attention is directed to mv prior U.S. Patent No. 3,061,845 and other prior art for recitation of the advantages offered by catamaran-type boats. It is therefore, one object of this invention to provide a boat hull construction which may be combined with outrigger pontoons to provide a catamaran-type of boat or employed without the outri,@.'er -pontoons so that the hull may be used for runabout service. The hull is substantially parallelopiped in form thereby eliminatina the single conventional pointed bow that rides high in the air rather than in the water and is primarily for the purpose of maintaining the itraditional image of a boat. With rny construction and with given over-all dirnensions, considerably rnore usable space is available than would be found in a like-size conventional hull bounded by curved surfaces. The specific construction of the boat hull of this invention provides for substantially minimal but tiniform freeboard for a - iven volume which renders it easy and safe for swimmers to enter the water and return to the boat without requiring the use of a boat ladder and also provides for a level decking, which taken with the floor or sole makes the entire area of the boat tiseful, or in other words, approximately doubles the useful area in cornparison to conventional runabout design. Another object of the present invention is to provide a boat hull which is strona but simply built and which depends upon two parallel longitudinal trusses positioned vertically in the sides of the hull so as to resist concentrated and reversing stresses that are created by altematively ho-gin- over a wave and then slammin.- down on the far side thereof and wallowing in the trou,-h and also will resist similar stresses that occur wh-.n launcbing and retrieving the boat hull and trailing it over rough roads. A further object of the present invention is to provide a boat hull construction consistin.- of two parallel longitudinal triisses positioned vertically in the sides of the hull Patented June 17, 1969 2 which are joined to and interconnected by a plurality of transverse frames with the transverse frames being joined by employing longitudinal stringers with the entire hull being covered with an exterior skin to provide a strong, water-tight strlicture built from simply shaped and simply joined pieces, more numerous but shorter spanned then are found in a conventional hull and thus requiring less costly materials and less skilled labor in its manufacture. 10 Still another object of the present invention is to provide a boat hull having a prismatic stern se ction with a narrow horizontal planing surface which is quite efficient for lightly loaded high speed operation with the horizontal planing surface being bounded on both sides by 15 upwardly inclined planes which extend to the chines so that with heavier loading, the hull assumes an increasing V-bottom characteristics, namely, an ability to plow through rough water with a heavy load with quasiplaning dynamics and without excessive pounding. The 20 forward end of the hull is a complexly curved section at least two sharply pointed bows that will cut into low waves and in combination with the outri.-gers will breast a higher wave, to disperse the water, generate spray, utilize some of the spray to decrease skin resistance and reduce 25 the impact of the water against the underbody and insure smoother and faster passage of the hull. Still a further object of the invention is to provide a boat hull having outrigger pontoons thereon including the provision of support arms to position the outrigger 30 pontoons in parallel spaced relationship to the center hull. The support arrns cooperate with transverse frames or trusses to transmit stresses thereto in which the position of the outrigaer pontoons may be adjusted and also oriented in an operative position or folded into a vertically 35 extending position to reduce the over-all width of the boat, The outri.-ger pontoons are specifically shaped and oriented intelation to the center hull to generate dynamic lift and thrust to counteract the plunging and yawing effect produced on the craft by driving a pontoon into 40 a wave. To reduce the sudden increase in dra.- when a pontoon is submerging, the cross-section of the bow portion is made triangtilar with the vertex downward so that buoyant lift increases about twice as fast as frictional drag with the bottom surface widening aft to form a hori45 zontal planing surface that terminates in a step slightly forwardly and above the transom chine of the center hull to make auxiliary planing and stabilizing sponsons that become more effective as load increases and the sea gets rougher. By extending the pontoon Tearwardly of the 50 transom and by rounding the stern end of the pontoons upwardly, the pontoon will provide dynamic and buoyant lift when overtaken by a following sea. Basically, the outriggers add dynamic lift and stability at planing speeds, add buoyancy for heavier loading and serves to initiate a 55 quick, easy roll away from the sea regardless of the direction the wave approaches the craft. These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter de60 scribed and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which: FIGURE I is a perspective view with decking removed 65 illustrating the boat hull construction and outrigger pontoons associated therewith; FIGURE 2 is a perspective view with exterior skin thereof Temoved to illustrate the structure thereof; FIGURE 3 is a fraginental perspective view taken from 70 under the bow end of the boat hull; FIGURE 4 is a longitudinal, sectional view taken substantially upon a plane passing along section line 4-4 of
[2]3)4501084 4 FIGURE I illustrating further specific structural details of the boat hull; FIGURE 5 is an end view from the stem illustrating the outrigger @pontoons disposed in ingperative relation; FIGURE 6 is a detailed plan view of the mounting structure for one of the outriger pontoon supporting arms; FIGURE 7 is a longitudinal, sectional view taken substantially upon a plane passing along section line 7-7 of FIGURE 6 illustrating the further structural details 10 thereof; FIGURE 8 is a plan view of one of the outrigger pontoons; and FIGURE 9 is a diagrammatic view showing the transverse configuration of the pontoons at the various 1,5 static)ns. Referring now specifically to the drawings the boat hull construction of the present invention is generally designated by the numeral 10 and a pair of outrig,-er pontoons, each being substantially identical in construction, 20 are designated by reference numeral 12 with the - pontoons being disposed in substantially borizontal spaced - relation to the side surfaces of the boat hull 10. Referring specifically to FIGURE 2, the boat hull includes basically two parallel longitudinal trusses 14 and 25 @16 which are vertically disposed and longitudinally elongated and may be considered separated into panels with panel points being generally designated in FIGURE 2 at 18, 20, 22, 24 and 26. The composition of the trusses or box beams may vary provided that the materials 30 chosen provide strength adequate to cope with the stresses encountered in use with each truss including a top chord member 28 and a bottom chord 30. The truss may be stren-,thened by crossed bracing as at 32 which may be provided between soine of the panel points or 35 between all of the panel points thus providing - strength and rigidity to the longitudinal trusses 14 and 16. At the five panel points 18-26, five transverse trusses, frame members or bulkheads 34, 36, 38, 40 and 42 are fixedly attached with knees or gussets 44 provided where- 40 ever desired and reinforcement members 4,6 are - provided for sustaining the supporting structure for the outrigger pontoons 12 in a manner described hereinafter. The rearmost transverse truss 34 is constructed to provide for mountin-, an outboard motor (not shown) there- 45 on with a cut-out 48 being provided in the top edge thereof. It is pointed out that other types of propulsion may be employed for the boat as desired. The transverse trusses 38 and 40 are also provided with recesses 50 and 52 to provide a passageway along the center line of the hull 50 ]LO. As illustrated in FIGURE 2, the trusses 34, 36, 38 and 40 have bottom chords 54, 56, 58 and 60 and the bridging of the three spans between the bottom chords is accomplished with longitudinal stringers as at 62 with the stringers being disposed in pairs on opposite sides of 55 the center line of the hull with the skin engaging the bottom of the stringers and the floor or sole engaging the top surface thereof. A central area of the hullmay be left free of stringers to provide for a glass viewing -port, a live well or a beverage cooler. 60 The underside of the hull defined generally by the bottom surface of the strin.-ers 62 and the bottom - surfaces of the chords 54, 56, 58 and 60 is substantially planar and is desi.-nated by the numeral 64 and an up@vardly - inclined segment 66 is disposed along one side of the planar surface 65 64 and a similar upwardly inclined segment 68 is disposed along the other side thereof. The hull - segments 64, 66 and 68 may be fabricated from any readily available planar material such as laminated material including marine plywood or equivalent material. 70 While a flat bottom hull planes efficiently, its action becomes quite rough in a rising sea so a bow section -,encrally design,,ited by the numeral 70 is provided forwardly of the planat segments 64, 66 and 68. The bow section 70 is a complexly curved structure which may be con- 75 structed of fiber reinforced plastic or other moldable material and which is fixedly adhered by bolts, rivets, cement or the like between the forward portions of the longitudinal triisses 14 and 16 and likewise adhered totransverse truss 40 and the planar segments 64, 66 and 68. The bow section 70 is provided with a concave central area 72 which extends between a pair of parallel bows 74 and 76 which bows are relatively sharp and deep and carried forward to a point 78 and then rise sharply to m,rge with the leading ed.-e @80 of -the bow section 70. Thus, when the hull is making headway there is formed somewhat of a funnel-shaped cavity between the bows 74 and 76, concavity 72 and the surface of the water. The bows 74 and 76 form a spray which entrains air and more or less compresses this air and spray -mixture as the hull moves forward. While this function is known in socalled "gull wing" hulls and single hull catamarans, this structure provides the additional feature in that the dynamic compression just described is suddenly relieved by a transversely disposed s@tep 82 which allows considerable expansion of the entrapped air under the forward part of planar segments 64. As is well known, in a planing hull, much of the shock originates where a line across the bottom near the forward edge of the planing surface first strikes the water and the upward dynarnic force that supports the boat, imparting a downward velocity to that water, instantaneously increases from zero to some finite value. However, in this construction, air is first entrained and compressed, then released into this area where upward thrust is instantaneously applied, and air being a compressible medium, absorbs more of the inidal shock in this hull than in any other planing hull configuration thus far proposed. Depending on the characteristics desired bows 74 and 76 can be made sharper and deeper and can be continued aft by fastening keelsons to the stern sections of the hull if desired. While the Ion.-itudinal trusses in FIGURE 2 are il-. lustrated as open frameworks, in FIGURE 1, the lon-ltudinal trusses are illustrated as solid bodies with it being pointed out that the trusses are either filled with buoyant material such as foam plastic or covered with an impermeable membrane such as plywood or fiber reinforced plastic thus defining side surfaces 84 to complete the hull. By providing buoyant bodies, a righting ingment will be exerted in case of swamping - and rolling thus resisting capsize until the hull has been rolled substantially to perpendicular relation to the water surface, Also, as illustrated in FIGURE 4, sole or floor panels 86 have been provided between the transverse trusses 34, 36, 38, 40 and 42 and in the interest @of safety the space between the sole 86 and the bottom se.-ments 64, 66 and 68 should be sealed or preferably filled with buoyant @material. As illustrated specifically in FIGURES 6 and 7, mounting structures or sockets 88 are provided for each of the supporting arms or struts 90 for the pontoons 12 and which also form part @of the joint between the longitudinal trusses 14 and 16 and the transverse trusses 34 and 42 whereby the resistance to vertical as well as longitudinal flexure that is developed by the framework of the center hull is imparted to the struts Gr arms 90 to en.-age similar socket means incorporated in and forming part of the framework of the pontoons 12. The pontoons are light in weight and are filled or covered to insure their buoyancy so that a stress inflicted by the sea is dissipated through the center hull and both pontoons, fore and aft, which greatly improves the riding qualities of the craft. The stern sockets ;88 also streiigthen the transverse frame or truss 34 which forms the transom to better withstand eithet anoutboard motor or other propulsion system such as an inboard-outboard drive and with four sockets serving to strengthen and rigidify the htill at both the bow and stern areas. As illustrated each of the pontoons 12 includes an elongated buoyant body 92 having relatively @slim bows
[3]3)450,084 5 94 which are disposed ahead of and well outboard of the center hull to provide levera.-e so that when one of them strikes a wave, a quick, easy pitch and TOII iS started rather than the dead, sudden movement characteristic of a single hull in a heavy sea. Likewise, wben r) a pontoon crosses the crest of a wave, it will start a downward movement soon enou.-h to avoid the rending crash ncpted in the action of many boats, and will itself receive and -distribute the first shock of the downward pitch. FIGURE 4 illustrates the relationship of the 10 lengths of the pontoon to the center hull and the stern end 96 of the pontoon body 92 is broad and rather voluminous and -the bottom surface of the stern end 96 ,of the pontoon body 12 is downwardly and forwardly curved as at 98 to impart lift when overtaken by a fol- 15 lowing sea. This lift force is leveraged by the distance aft and outboard from the center of gravity of craft and starts a quick and easy roll and lessens the chance that a wave will break over the transom top edges surface 48 of the hull. 20 The struts or arms 90 are in the form of hollow or tub.ular members having ed.-e flanges and which are generally Tectan-ular in section and are connected to the inboard surface of the pontoon body 92 by a socket structure 100 similar to sockets 88 but somewhat lighter 25 in construction to cope with the lesser forces encountered by the outboard end. If desired, the space between the hull 10 and the pontoons 12 be closed with fabric material to reduce spray otherwise thrown into the center hull or a net may be 30 rigged for the benefit Df personnel or gear to prevent such gear or personnel from falling overboard from the boat hull. Holes or hardware may be provided in the ponioon 12 for docking and the flat top surface of the pontoon body 92 is useful for boardin.- the craft or to 35 move around the center hull in lieu of the side decks. Also, one pontoon 12 may be removed and the struts or arms 90 may be used to tie up beneath the edge of a pier or the craft may be employed with a single <)utrigger thus introducing the useful features and versatility of the 40 pontoon structure. The socket structure 88 or 100 is in the form of a boxlike enclosure of plates 104 welded or otherwise permanently fixed to each other and fixed to the reinforce-ment 46 and to the corresponding transverse truss 34 4,5 or 42. The sockets 88 and 100 must be sufficiently strong to transmit forces directly and effectively to the transverse trusses in particular and to the hull framework in ,-eneral. A transversely extending solid pin 106 extends through .50 the box-like socket 104 and extends through a tubular sleeve 108 that is fixed horizontally through the end of the strut or arm 90 with both of its extremities protruding -as illustrated in FIGURE 6. The strut 90 is restricted in regard to its upward and 5,5 downward flexure by means of tubular stops 110 wbich may be cylindrical or any other shape and each st<)p 110 is provided with an inserted rubber snubber 112 whfch is exposed throu,,h a cutaway or slotted portion 114 of the stop 110. 60 The rubber snubbers 112 are disposed in opposed @facing relation and en.-age the outer inclined surface of oppositely disposed wedges 116 which are clamped to the top and bottom surfaces of the strut or arm 9,0 by means of a through bolt 118 extending through the strut 6,5 oT arm 90 and extending through a longitudinal slot 120 in each of the wedges 116. As illustrated, the center part of the wedges has the exterior surface thereof hollowed out as at 122 to enable the head and nut ()f the bolt 11.8 to engage flat parallel surfaces thus enabling 70 the wedges to slide longitudinally in relation to the strut 90 and by selectively sliding the wedges 116 and cla@mping them in position, the range of upward or downward movement of the strut 90 may be adjusted so that the position of the strtits 90 may be varied with the rubber 75 6 snubbers allowing resilient limited movement!of the struts 90 even after they have been positioned by selective movement of the wedges 116. If desired, an elastic boot to exclude water, together with a water-tight bottom and a drain hole may be provided to combat corrosion. By retracting pin 106 and removing it, the strut 90 can be withdrawn completely outwardly and pivoted and when forced back into the socket it wi@ll assume its established position. Since the optimurn position deperids on loading, roughness or water, and desired speed for economy, it will be necessary to be able to duplicate a previously determined position. When it is desired to rotate the pontoons 12, for instance to rotate them upward and inward and secure them over the top of the craft as illustrated in FIGURE 5 in order to trail it on the highway, pin 106 is withdrawn at both ends of the pontoon and the struts 90 are pulled out until the protruding ends of the sleeve 108 are retained by the inturned ears 124 which prevent the structure from falling to pieces after the pins 106 are withdrawn and the operator is maniptilating the pontoons into the @desired position. The pin 106 is then inserted through the sleeve 108 and the holes 126 to enable the struts 92 to swing iipwardly to a vertical position as illustrated in FIGURE 5. The pontoons -12 may swing into overlying and supported relation to a superstructure or cabin generally designated by the numeral 128 or any suitable interconnecting structtire may be provided to retain the pontoons in the inoperative position during over-the-ro;ad transport. The upper surfare,of the lips 124 have a notch to enable complete removal of the inner ends of the struts 90 from the sockets 88 when it is desired to completely remove the pontoons as for transport resting directly on the center hull. FIGURES 1, 4, 8,and 9 illustrate the starboard pontoon and in FIGURES 8 and 9, station numbers are assigned for reference between the vertical ;and horizontal projections and the cross-section with the structure being approximately a typical configuration for a 26-foot pontoon for use with a 17-foot center hull and is not to be construed as limiting the invention. It is pointed out that the other pontoon or port pontoon is related by bi-planar symmetry, or in other words, in a transverse section is a mirror image of the corresponding section in the other pontoon. The bow 130 at station O' is narrow and sharp to literally cut the water with a minimum of shock but abruptly deepens to provide for an internal structure sufficiently resistant to serve -for anchoring, docking,or beaching with the keel portion 132 of the forward end of the pontoon being reinforced to resist abrasion. The keel continues narrow to about station 6' but the top of the pontoon widens to produce a concave flaring section as ;at 134 wbich has the novel and specific function of lifting and thrusting to the left as it is driven into a wave thus counteracting the tendency to bury itself downward and pull to the right when considering the pontoon in FGURE 8 which is a starboard pontoon. Moreover, this tendency is lessened in this invention by a cross-sectional shape of bow portion, which is a scalene triangle with the vertex downward as most clearly seen at station 6'. This crosssection is one whose buoyancy increases about twice as fast as its skin @friction or drag increases upon being subme@ged, thus cooperating -with the flaring surface just des,-ribed, both factors acting well ahead of the center of resistance of the whole cra-ft to minimize yawing and pitching in rough water. The chine line 136 departs -from the inboard butt plane and merges with the widest portion of the pontoon around station 21', or stated differently, the bottom of the pontoon widens to its maximum abead of the step 133 to make a planing surface that cooperates with the planing surface of the main hull, thus increasing its load carrying ability and providing increased lift with increased sub-
[4]31450,084 7 mergence, thereby tending to keep the craft on an even keel. The stern end surface 140 is relatively broad and blunt and forward from station 26' labruptly deepens in a short radius curve as at 98 to provide dynamic lift and form a buoyant stern section aft of station 21' which will rise quickly when overtaken by a following sea. For clarity, stations 21' and 26' are shown in FIGURE 10 to the le@ft of the inner surface in order to illustrate the step or abrupt change,at 21'. What is
