Patent Application
20070243774
1. Field of the Invention
The invention relates to water craft in general and to auxiliary vehicle driven water craft in particular.
2. Prior Art
Water craft powered by auxiliary vehicles are well known in the art. U.S. Pat. No. 1,568,307, for example, illustrates a propellor driven barge, in which the power for the propellor is provided by an auxiliary vehicle, namely a car. The car's wheels turn a set of rollers which impart motion to the propeller which in turn drives the vessel. The car acts as the engine for the vessel. However, in the prior art, the auxiliary vehicles are generally positioned quite high relative to the hull of the vessel. As a result, the vertical centers of gravity of the prior art vessels are high. Such vessels cannot be both fast and stable. A vessel moving at any substantial rate of speed—fast enough to be “on plane” for example—generally must roll or bank somewhat when making a turn. With a high center of gravity, the vessel can become unstable as the roll extends the center of gravity outward relative to the axis of rotation of the vessel. Acting across this moment arm, the distance between the center of gravity and the axis of rotation, the mass of the auxiliary vehicle can cause the vessel to overturn. Accordingly, the prior art vessels must either travel at relatively slow speeds to allow them to be maneuvered safely or the vessel operator must run great risks when turning the vessel. This poses no great problem when the vessel is primarily serving as a ferry, carrying the auxiliary vessel across a body of water. The operator can simply “go slow.” However, where any significant amount of travel is required of the vessel, greater speed and maneuverability than is available in the prior art is desirable. Therefore, an auxiliary powered vessel meeting the following objectives is desired.
It is an object of the invention to provide a vessel configured to carry an auxiliary vehicle.
It is another object of the invention to provide a vessel whose propulsion system is powered by an auxiliary vehicle.
It is still another object of the invention to provide an auxiliary vehicle powered vessel capable of operating at relatively high speeds.
It is yet another object of the invention to provide an auxiliary vehicle powered vessel capable of maneuvering safely at relatively high speeds.
It is still another object of the invention to provide an auxiliary vehicle powered vessel capable of operating in relatively shallow waters.
It is yet another object of the invention to provide an auxiliary vehicle powered vessel that can be steered like a conventional water craft.
An auxiliary vehicle powered vessel is disclosed. The vessel comprises a hull and a deck. The vessel is configured to carry an auxiliary vehicle, such as an all terrain vehicle or four wheeler, preferably on the deck. The all terrain vehicle can be driven onto and off of the vessel. When in the vessel, the auxiliary vehicle will engage a transmission such that the operation of the auxiliary vehicle will power the propulsion mechanism of the vessel. When the vessel reaches its destination, the auxiliary vehicle can be driven off the vessel and used at the destination. When the operator is ready to depart, the auxiliary vehicle can be returned to the vessel and used to power the vessel again. The preferred embodiment of the vessel is provided with a “mud boat” propulsion system to allow it to operate in shallow waters. The preferred embodiment of the vessel is also designed to overcome the stability challenges posed by the high center of gravity that will arise from carrying objects such the auxiliary vehicle in the vessel and particularly when such objects are transported on deck.
A vessel 1 is disclosed. Vessel 1 comprises a hull 101. Hull 101 further comprises a bow 102 and a stern 103. A bottom 104 extends from bow 102 to stern 103. A deck 105 is positioned opposite and generally parallel to bottom 104. Sidewalls 106 extend upward from bottom 104 toward deck 105. Vessel 1 also has a longitudinal centerline 107 extending from bow 102 to stern 103, though it will be appreciated that longitudinal centerline 107 is a line of reference rather than an actual physical component of vessel 1. In the preferred embodiment, longitudinal centerline 107 is positioned substantially equidistant from sidewalls 106. Longitudinal centerline 107 also has a mid-point 108.
In the preferred embodiment, vessel 1 is made from ⅛ inch thick aluminum plate, with ¼ inch aluminum used for critical components of the frame of vessel 1. In the preferred embodiment, vessel 1 is about 14 feet long, though longer embodiments are contemplated as well. Sidewalls 106 are preferably about fourteen inches wide and will preferably be provided with gunnel rails 55 at their upper edge.
Deck 105 is configured to allow an auxiliary vehicle 7 such as an all terrain vehicle or four wheeler to be driven onto deck 105. Vessel 1 is preferably provided with a ramp 111 to facilitate the ingress and egress of an auxiliary vehicle 7, such as an all terrain vehicle. Auxiliary vehicle 7 will typically have a wheel base 110 (the distance between the wheels) of about forty-eight inches or less.
In the preferred embodiment, ramp 111 is comprised of a port arm 111A and a starboard arm 111B. Each arm 111A, 111B preferably comprises an aluminum ladder type frame with a ⅛ inch aluminum checker plate covering over each frame. Each arm 111A, 111B is preferably mounted to deck 105 proximate to the bow on a double hinge 501. Each arm 111A, 111B is preferably provided with a rod 502 at one end. Rod 502 is preferably positioned within a cylinder 503 forming part of double hinge 501. Rod 502 and attached arm 111A or 111B can rotate within cylinder 503. Typically only about ninety degrees or less of rotation will be needed between rod 502 and cylinder 503. Cylinder 503 is preferably secured to deck 105 by a shaft 504 positioned within a ring 505 that is mounted to deck 105 and which together form the other half of the preferred embodiment of double hinge 501.
When not in use, each arm 111A, 111B of the preferred embodiment of ramp 111 will be positioned atop and substantially parallel to one of side walls 106. The outward facing side 509 of each arm 111A, 111B will preferably be provided with the aluminum checker plate covering mentioned above. A first end of each arm 111A, 111B is secured to a double hinge 501. The opposite end of each arm 111A, 111B is releasably secured to one of sidewalls 106 with a pin, clasp or other conventional means. When it is time to use ramp 111, each arm 111A, 111B will be released at the end opposite double hinge 501. Each arm 111A, 111B will then be swivelled on the shaft 504 and ring 505 portion of double hinge 501 until the end of each arm 111A, 111B opposite double hinge 501 hits the ground or such structure to which auxiliary vehicle 7 is to be off loaded. Each arm 111A, 111B will then be turned on rod 502 and cylinder 503 until outward facing side 509 of each arm 111A, 111B is facing up and one edge of each arm 111A, 111B is resting on deck 105 on at least two points. It will then be possible to drive auxiliary vehicle 7 down ramp 111 and off vessel 1 and to return auxiliary vehicle 7 to vessel 1 in the same manner. Once auxiliary vehicle 7 is returned to vessel 1, ramp 111 can be stowed in its prior position.
Deck 105 is configured to secure auxiliary vehicle 7, most preferably directly over longitudinal centerline 107. In the preferred embodiment, deck 105 is further provided with a seat 112 forward of the position where auxiliary vehicle 7 will be secured. A cargo area 113 is preferably provided aft of the position where auxiliary vehicle 7 will be secured. Other cargo areas, such as lockers 113A may be provided along sidewalls 106 near the bow. Cargo area 113 and seat 112 will both preferably be positioned over the longitudinal center line 107 of vessel 1. When seat 112 is placed forward of auxiliary vehicle 7, seat 112 will need to be removable or otherwise configured to allow auxiliary vehicle 7 to pass as it enters and exits vessel 1. The inventors contemplate using a pedestal-type seat 112, and providing multiple receivers in deck 105 to allow easy placement and removal of seat 112, as desired.
The inventors contemplate configuring vessel 1 so that auxiliary vehicle 7 can also be loaded into and removed from vessel 1 from the stern. This would generally not be the preferred way of loading auxiliary vehicle 7 during operation of vessel 1. However, loading auxiliary vehicle 7 onto vessel 1 via the stern would be desirable when vessel 1 was on a trailer, where the tongue of the trailer could impede loading vessel 1 from the bow. Loading vessel 1 in this fashion would preferably be accomplished using a ramp such as those disclosed and discussed in U.S. Pat. No. 6,059,344, which is hereby incorporated by reference in its entirety. Such ramps are commonly used to load all terrain vehicles into the beds of pick-up trucks. Being able to load or unload auxiliary vehicle 7 into vessel 1 in this fashion is expected to be particularly useful when loading or unloading vessel 1 at a user's home, prior to and after taking vessel 1 to the water.
To facilitate the use of such a ramp to load or unload vessel 1, deck 105 in the vicinity of the stern should preferably be substantially free from obstacles. To this end, cargo area 113 is preferably provided with a removable cover 401. Cover 401 will preferably allow auxiliary vehicle to pass over cargo area 113 when cover 401 is in place. Cover 401 will help secure any cargo stored in cargo area 113, but may be removed after auxiliary vehicle 7 is in place if the cargo is too bulky to fit in cargo area 113 with cover 401 in place.
Vessel 1 is provided with a means of propulsion 2. Means of propulsion 2 is a mechanical device used to propel vessel 1 through the water. Means of propulsion 2 may be a propellor 3 or an impeller. Propellor 3 may be a water propellor 3A or an air propellor 3B, such as those used in air boats. Impellers are commonly used in “jet boats” to impel water and thus provide impetus to the vessel. The foregoing propulsion means 2 are well known to those skilled in the art and a detailed explanation of their operation is not intended here.
Vessel 1 is further provided with a steering mechanism 4. Steering mechanism 4 may comprise a rudder or air-rudder (collectively, rudder 5), or propellor 3 may be movable to vary the direction of thrust to vessel 1. In the preferred embodiment, rudder 5 is mounted at the top and partially positioned within propellor channel 29 (discussed below). In the preferred embodiment, rudder 5 is mounted at the bottom to skid plate 301 (also discussed below).
In many prior art vessels, the front wheels of the auxiliary vehicle 7 are used to control the steering mechanism. The regular steering system of auxiliary vehicle 7 is used to control the steering mechanism of the vessel, and such a system could certainly be utilized in the present invention. However, in the preferred embodiment, more conventional water craft controls 8 are provided. Rudder 5 is preferably mounted on a cable or linking rod 9. Where propellor 3 is moveable, it could also be mounted on cable or linking rod 9. Controls 8 will cause cable or linking rod 9 to move the steering mechanism 4 as desired.
Typically, controls 8 will comprise a steering wheel or a steering shaft 10. Steering shaft 10 will comprise a pivotable rod rising perpendicular to the deck 105 of vessel 1 adjacent to the vessel operator. By moving steering shaft 10 toward the bow 12 of vessel 1, vessel 1 will be directed to the right or starboard. Similarly, by directing steering shaft 10 toward the stern 13 of vessel 1, vessel 1 will be directed to the left or port. When steering shaft 10 is vertically positioned, vessel 1 will advance directly ahead. Of course, all of the foregoing applies to forward motion of vessel 1. Where vessel 1 is operating in reverse, the effect of steering shaft 10 on the motion of vessel 1 will be the opposite of that described above.
In the preferred embodiment, steering shaft 10 will pivot between the starboard and port sides of vessel 1 as well as between the bow and stern. This will allow steering shaft 10 to be positioned well away from the path auxiliary vehicle 7 will travel as it enters and exits vessel 1, and then repositioned so that the upper end of steering shaft 10 is within easy reach of the operator sitting atop auxiliary vehicle 7 after auxiliary vehicle 7 is in its traveling position in vessel 1.
Steering shaft 10 is the most preferred control 8 because a steering shaft does not require much space on or over deck 14. However, the use of conventional controls 8 will also make vessel 1 easier to operate insofar as doing so will not require operators to learn a new steering system or adapt the steering system of auxiliary vehicle 7 to the steering of vessel 1. Were the steering system of auxiliary vehicle 7 used to control steering mechanism 4 of vessel 1, vessel 1 would be unlikely to respond to impetus from the operator in the same manner as auxiliary vehicle 7 would respond to the same impetus on land. Using one set of controls for two different vehicles that are likely to respond differently to identical impetuses, unnecessarily creates the potential for confusion and operator error. That is not to say that using steering vessel 1 with the steering system of auxiliary vehicle 7 is outside the intended scope of the present invention; quite the contrary. However, there are advantages to providing an independent steering system for vessel 1.
Means of propulsion 2 is powered by auxiliary vehicle 7. A transmission 15 is provided between auxiliary vehicle 7 and means of propulsion 2. Transmission 15 will simply transfer mechanical energy from auxiliary vehicle 7 to means of propulsion 2, and a great variety of systems may be used to accomplish this task. Where auxiliary vehicle 7 is provided with a power take-off (PTO), transmission 15 will preferably engage the PTO directly. Where auxiliary vehicle 7 is not provided with a PTO, transmission 15 will engage one or more of the drive wheels 16 of auxiliary vehicle 7, assuming auxiliary vehicle 7 has wheels 16.
Transmission 15 will preferably drive means of propulsion 2 in one direction (clockwise for propellor 3) when auxiliary vehicle 7 is operated in forward and in the opposite direction (counter-clockwise for propellor 3) when auxiliary vehicle 7 is in reverse. Thus, the operator will be able to place vessel 1 into reverse simply by putting auxiliary vehicle 7 in reverse. Similarly, the speed at which means of propulsion 2 operates will vary directly with the rate at which auxiliary vehicle 7 is operated. Accordingly, the operator will be able to accelerate vessel 1 by engaging the accelerator on auxiliary vehicle 7.
In the preferred embodiment, a plurality of rollers 17 and a belt 17A are provided. One or more sets of rollers 17 and belt 17A will engage the drive wheel(s) 16 of auxiliary vehicle 7. As drive wheels 16 rotate, rollers 17 and belt 17A will rotate as well. Belt 17A will drive a pulley 17C which will drive gears 18 which, in turn, will drive means of propulsion 2.
Auxiliary vehicle 7 should be well secured to ensure that it cannot move. Preferably, a strong locking arm will be provided to engage the trailer ball present on most all terrain vehicles and thereby secure the all terrain vehicle to deck 105. Similar locking devices can be found in U.S. Pat. No. 6,063,417 (device for securing all terrain vehicles to truck beds) which is hereby incorporated by reference. If any of the drive wheels 16 of auxiliary vehicle 7 are not engaged to transmission 15, wheels 16 should preferably be free to rotate. Such drive wheels 16 may be engaged to dumb rollers 17 that do not connect to means of propulsion 2. Alternatively, one end of auxiliary vehicle 7 may be securely supported with a jack so that unengaged drive wheels 16 can spin freely.
In the preferred embodiment, a track 201 will be provided in deck 105. Track 201 will guide auxiliary vehicle 7 to the proper location in deck 7. However, the size of tires commonly used on all terrain vehicle varies. The inventors contemplate a track width of sixteen inches, which will be wider than most common tires. Belt 17A will also preferably be sixteen inches in width.
Although it is desirable that auxiliary vehicle 7 not move at all during operation of vessel 1, some shifting is anticipated. Should the tires of auxiliary vehicle 7 rub against the walls of track 201 during operation, damage to tires 201 could result. The inventors propose addressing this problem by providing the sides of track 201 with upright rollers 202 to protect the tires from damage.
Hub locks 21 provide one alternative to rollers 17 and belt 17A. In this embodiment, hub locks 21 can be used to engage the drive wheels 16 of auxiliary vehicle 7. Hub locks 21 will preferably be configured to engage a shaft 22 positioned to share an axis of rotation with drive wheels 16. When hub locks 21 are engaged with both drive wheels 16 and shaft 22, shaft 22 will be turned by drive wheels 16 as they rotate. Shaft 22 can then engage gears 18, discussed below.
Rollers 17 or hub locks 21 will preferably drive a plurality of gears 18. Gears 18 may be connected to means of propulsion 2 in a variety of ways. One of gears 18 may turn a shaft that directly powers propulsion means 2. Gears 18 may turn a chain or a pulley and cable that power propulsion means 2. In general, any conventional mechanical means of conveying the rotational power generated by auxiliary vehicle 2 to propulsion means 2 may be used for transmission 15.
One preferred embodiment of transmission 15 comprises hydraulic pump 19 and hydraulic motor 20. In this embodiment, rollers 17 or hub locks 21 will drive a shaft 23 that powers hydraulic pump 19. Hydraulic pump 19 will pull hydraulic fluid from a hydraulic tank 24 and pump it through hydraulic motor 20 and back to hydraulic tank 24. Hydraulic motor 20 will power propulsion means 2. For example, where propulsion means 2 comprises a propellor 3A, propellor 3A may be mounted on a drive shaft 25. In this embodiment, hydraulic motor 20 will drive shaft 25.
An hydraulic drive offers many advantages over some of the more conventional embodiments of transmission 15 described above. Hydraulic systems have a small number of moving parts and these can usually be enclosed within protective housings. As a result, hydraulic systems are generally more reliable and durable than their conventional counterparts. To transfer power from wherever drive wheels 16 may be located on vessel 1 to propulsion means 2, hydraulic pump 19 may be located adjacent to drive wheels 16 and hydraulic motor 20 may be located adjacent propulsion means 2. Only a hydraulic line 26 need connect hydraulic pump 19 and motor 20. No exposed moving parts are required between hydraulic pump 19 and motor 20.
When transmission 15 comprises an hydraulic drive, a switch will preferably be provided to allow the operator to reverse the flow of hydraulic fluid through hydraulic motor 20. This will allow the operator to place vessel 1 in reverse while keeping auxiliary vehicle 7 in forward. This will preferable in this embodiment because in most configurations, hydraulic pump 19 should continue to operate in the same direction regardless of whether vessel 1 is in forward or reverse.
Hydraulic tank 24 will preferably be located on or just above bottom 104. Hydraulic tank 24 will preferably be elongated in shape and will have a longitudinal axis 27. Hydraulic tank 24 will preferably be positioned so that longitudinal axis 27 of tank 24 is substantially parallel to and vertically aligned with the longitudinal center line 107 of vessel 1. Positioning tank 24 in this fashion will help keep vessel 1 balanced and limit the effect of any weight shift caused by the movement of hydraulic fluid within tank 24 during operation of vessel 1. For the same reason, hydraulic tank 24 should be kept as full as consistent with efficient operation of hydraulic pump 19 and motor 20.
In one preferred embodiment, vessel 1 is configured to operate as a “mud boat.” In this configuration, propulsion means 2 comprises a propellor 3A mounted on a drive shaft 25. Bottom 104 of vessel 1 is provided with a propellor channel 29. In the preferred embodiment, propellor channel 29 comprises an indentation in bottom 104, concave when viewed from below vessel 1. Drive shaft 25 will pass through bottom 104 near the narrow end of propellor channel 29. Packing such as that typically used with inboard watercraft will be appropriate to ensure that the point where shaft 25 passes through bottom 104 is water tight.
Propellor 3A will be mounted near the end of propellor channel 29, but within propellor channel 29. Propellor channel 29 will preferably be deep enough to contain half or more of propellor 3A within channel 29. In this configuration, less than half of propellor 3A will ever extend below bottom 104. Thus, for example, if propellor 3A were six inches in diameter, vessel 1 would require less than three inches of water above the amount required to float vessel 1 to allow propulsion means 2 to be operated. Where vessel 1 is configured as a mud boat, a skid plate 301 may be shipped below propellor 3A. Skid plate 301 will protect shaft 25 and propellor 3A from objects that may be encountered during operation of vessel 1.
The preferred design of vessel 1 creates certain challenges. Vessel 1 is designed to be a personal watercraft. It will ideally hold an operator and one to two passengers, an all terrain vehicle, and a certain amount of gear. In particular, it is anticipated that vessel 1 will be used for hunting. Thus, in addition to the operator, passenger(s), and all terrain vehicle, vessel 1 might be expected to carry firearms, ammunition, decoys when waterfowling, and one to two dogs or when deer hunting, might be expected to carry a bagged deer. Loading all of the foregoing equipment on deck 105 will give vessel 1 a relatively high center of gravity CG, a condition which often adversely affects the stability of vessels, in general. Other uses of vessel 1, such as camping, military, police or rescue operations or commercial operations such as land management are likely to require operators to carry a substantial amount of gear and will also likely result in an equally high center of gravity CG.
The traditional option of dealing with the stability issues caused by a high center of gravity is to design the vessel in question so that the weight it will carry will ride as close to its bottom as practical. Unfortunately, that solution is not feasible in the present design. First, vessel 1 is designed to carry an all terrain vehicle. Even if the all terrain vehicle were to rest directly on bottom 104, the heavier components of the all terrain vehicle, such as its motor, gas tank, and etc., would still be substantially above bottom 104 of vessel 1, and the operator atop the all terrain vehicle would be higher still. Thus, high center of gravity issues would likely persist, though they could, of course, be lessened by lowering the all terrain vehicle within the vessel. Still, other difficulties would remain.
The all terrain vehicle is intended to be able to enter and exit vessel 1 easily. If the all terrain vehicle were to ride on bottom 104, the all terrain vehicle would either have to go over the bow as it entered and left vessel 1 or a Higgins boat type bow would have to be adopted. While the Higgins boat type bow is a feasible solution to the loading problem, it requires the vessel to be landed in a completely dry environment before the all terrain vehicle can be unloaded. Off loading an all terrain vehicle into three or four inches of water will seldom pose a problem for the four wheeler. However, opening a Higgins type bow in three or four inches of water could allow a significant amount of water to enter the vessel. Yet for many landings, the water will be too shallow for too long to allow vessel 1 to reach a point where a completely dry landing is possible, something that is not necessary if the all terrain vehicle can enter and exit the vessel from the deck. The inventors' design is able to solve the stability issues and allow the all terrain vehicle and other cargo to be stowed on deck 105.
The foregoing should not be considered to be a disclaimer of the use of a Higgins boat type bow or a configuration where auxiliary vessel 7 rests on or near bottom 104. Such a configuration could certainly be used with the inventors' preferred design. This would allow the center of gravity to be lowered and the stability of vessel 1 to be further enhanced. However, a Higgins-type bow would, for most applications, be unnecessary in view of the present design.
Configuring the design to allow the all terrain vehicle, passengers, and cargo to be stored on deck 105 is desirable as it will make loading and unloading easier. It will also provide a convenient space below deck 105 for the various components of transmission 15 and means of propulsion 2.
The inventors' design addresses the stability issues that arise from the high center of gravity CG by providing a design for hull 101 that will displace very little water when vessel 1 is fully loaded. The preferred embodiment of vessel 1 will be about fourteen feet long, though shorter, and certainly longer, embodiments are feasible. Typical fourteen foot jon boats have bottom widths of about forty-eight to fifty inches. In the preferred embodiment, bottom 104 will have a width of at least about sixty-six inches, and more preferably will have a width between about seventy-two and eighty-four inches. Although a still wider bottom 104 could be useful from a performance and stability standpoint, it would begin to pose problems for vessel 1 with respect to trailering. Trailers in excess of eight feet in width are considered oversize loads on U.S. highways. To the extent that vessel 1 is to be conveniently trailered, it should be loadable on a trailer that has a total outside width of no more than eight feet. As such, a width of bottom 104 of about seven feet (eighty-four inches) is the practical upper limit.
Assuming auxiliary vessel 7 weighs about seven hundred twenty pounds, a weight near the upper end of standard four wheel all terrain vehicles, and that vessel 1 carries the operator and one passenger, who each weigh one hundred ninety-pounds and that they have another one hundred fifty pounds of gear, dog, or game, vessel 1 will have a total loaded weight of about 1900 pounds. With all of the foregoing items on deck 105, vessel l's center of gravity will be positioned about two feet above bottom 104, substantially above deck 105.
However, as configured, vessel 1 will have a draft of only about five inches of water. This will make vessel 1 very stable in a roll, meaning that if vessel 1 is rotated about its longitudinal axis by as much as ten degrees—that is, so that vessel 1 is listing as much as ten degrees to port or starboard—it will be strongly inclined to return to an upright position.
Because the draft of vessel 1 is so small, a list by vessel 1 will substantially reposition the center of buoyancy of vessel 1 toward sidewalls 106. This is illustrated in
The foregoing is significant because water acts upwardly on the vessel through all of the vessels' wetted surfaces. The combination of these upward buoyancy forces can be thought of as the center of buoyancy. When the area of the vessel that is wetted changes, the location of the center of buoyancy changes. The degree of the shift of the center of buoyancy is largely a function of how much of the vessel's surface is wetted and becomes dry when the vessel lists as compared to the total wetted surface area of the vessel. The greater this percentage is, the more the center of buoyancy will shift during a list, and vice versa.
Assuming the cargo of vessel 1 remains fixed in place during a list, the center of gravity CG will remain fixed relative to hull 101 of the vessel. Thus, as hull 101 rolls, the center of gravity will roll through a corresponding arc. The higher the center of gravity, the longer the arc and the greater the displacement of the center of gravity in a roll.
This is illustrated in
The force of gravity acting downward on the vessel can be thought of as acting downward through the center of gravity. As noted above, the buoyant force of the water acts upward through the center of buoyancy. These forces are, by definition, equal. When the vessel is upright, the center of gravity, CG, and the center of buoyancy, B, are aligned and they cancel each other, as illustrated in
However, if the center of gravity moves to the outside of the center of buoyancy, instead of causing the vessel to right itself, the resulting torque will tend to cause the vessel to capsize. This is illustrated in
Vessel 1 has a very small draft, about five inches when fully loaded, in the preferred embodiment. As a result, when vessel 1 lists its center of buoyancy will shift substantially toward sidewalls 106. The difference between the repositioned center of buoyancy, B1, and the repositioned center of gravity, CG, when the preferred embodiment of vessel 1 lists ten degrees will result in a righting arm of about fifteen and a half inches. The foregoing is based on a width of bottom 104 of about eighty-four inches. When vessel 1 has a bottom width of about seventy-two inches, its righting arm will be about eleven and a half inches.
As should be apparent from the foregoing, all other things being equal, the size of the righting arm will diminish as the draft of the vessel increases. In the preferred embodiment of vessel 1, with a width of bottom 104 of about eighty-four inches, the righting arm of vessel 1 will fall to zero when the draft of vessel 1 reaches about eleven and a half inches. Similarly, in a another preferred embodiment wherein the width of bottom 104 is about seventy-two inches, the righting arm of vessel 1 will fall to zero when the draft of vessel 1 reaches about eight and a half inches. The sizes of the righting arm of various configurations of vessel 1 are given in the chart shown in
The bottom 104 of vessel 1 is preferably relatively wide and relatively flat. In the preferred embodiment, bottom 104 has a slight “V” of about two inches across about three feet.
It is important to keep water out of the hull of a vessel for many reasons, not the least of which is to prevent the vessel from sinking. However, water within the hull of a vessel can also adversely affect its stability. In particular, if a significant amount of water is present in the hull of a vessel, turning the vessel can cause the water to move within the hull. This can shift the center of gravity toward the sidewalls of the vessel. As discussed above, moving the center of gravity outside the center of buoyancy can cause the vessel to capsize, so anything that move the center of gravity CG toward sidewalls 106 of vessel 1 is to be avoided, whenever possible. To this end, the inventor contemplates filling the unused void spaces of vessel 1 with foam, such as 2.2 pound density pour foam available from Brenton Industries of 12360 Leisure Road in Baton Rouge, La. This will help prevent water from entering hull 101 in the event of any minor punctures of hull 101. Also, in the event that vessel 1 should take on water or even capsize, the foam can help keep vessel 1 afloat.
Although the invention has been described in terms of its preferred embodiment, other embodiments will be apparent to those of skill in the art from a review of the foregoing. Those embodiments as well as the preferred embodiments are intended to be encompassed by the scope and spirit of the following claims.
