US3768429A

US3768429A - Watercraft

Info

Publication number: US3768429A
Application number: US00231194A
Authority: US
Inventors: R Greer
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-03-02
Filing date: 1972-03-02
Publication date: 1973-10-30
Anticipated expiration: 1990-10-30
Also published as: GB1370273A

Abstract

An air supported watercraft for transporting cargo is disclosed. The watercraft is supported by lift generated by: a planar surface set at a given angle of attack with respect to the air stream, air foil surfaces, vanes within the water and to some extent by the displacement of water. The control system for maneuvering the watercraft interacts with the water through which the watercraft is traveling. The control system orients the watercraft with respect to the surface of the water, which orientation has the effect of altering the angle of attack of the planar surface and the air foils and thereby modifies their effectiveness. The watercraft employs a docking system extending from the sides thereof, which docking system cooperates with a pair of land based guide rails. On docking, the watercraft is ''''flown'''' onto these guide rails and then slowed down. As the watercraft slows down, the guide rails begin to support its weight. Similarly, when the watercraft departs from the dock and begins to accelerate, the surfaces interacting with the airstream begin to support the watercraft with less and less dependence on the guide rails for support.

Description

United- States Patent [1 1 Greer Oct. 30, 1973 1 WATERCRAFT Richard R. Greer, 6122 E. Indian School Rd., Scottsdale, Ariz. 85251 [76] Inventor:

[52] US. Cl. 114/435, 114/61, 114/665 H,

' 61/67 [51] Int. Cl B63b 35/44 [58] Field of Search 114/665 R, .5 R, 114/61, 43 S, 44; 61/67 [5 6] References Cited UNITED STATES PATENTS 3,354,857 11/1967 Hobday 114/66.5 H 3,648,640 3/1972 Granger 114/665 H 3,145,954 8/1964 Jenny et al 114/665 H 3,390,655 7/1968 Quady et al. 114/665 H 3,635,035 1/1972 Greer 114/66.5 H 3,139,059 6/1964 Hanford, Jr.. ll4/66.5 H 3,179,077 4/1965 Loo 114/665 H 3,532,067 10/1970 Baker 1l4/66.5 H

Primary Examiner-Allen N. Knowles Attorney-William C. Cahill et al.

[5 7] ABSTRACT An air supported watercraft for transporting cargo is disclosed. The watercraft is supported by lift generated by: a planar surface set at a given angle of attack with respect to the air stream, air foil surfaces, vanes within the water and to some extent by the displacement of water. The control system for maneuvering the watercraft interacts with the water through which the watercraft is traveling. The control system orients the watercraft with respect to the surface of the water, which orientation has the effect of altering the angle of attack of the planar surface and the air foils and thereby modifies their effectiveness. The watercraft employs a docking system extending from the sides thereof, which docking system cooperates with a pair of land based guide rails. On docking, the watercraft is flown onto these guide rails and then slowed down. As the watercraft slows down, the guide rails begin to support its weight. Similarly, when the watercraft departs from the dock and begins to accelerate, the surfaces interacting with the airstream begin to support the watercraft with less and less dependence on the guide rails for support.

18 Claims, 10 Drawing Figures WATERCRAFT The present invention relates to air supported watercraft and, more particularly, to air supported watercraft having vanes for controlling the angular relationship between the watercraft the the surface of the water.

It has long been recognized that the speed of watercraft is a function of whether they are displacement vessels, hydrofoil vessels, planing vessels, or air supported vessels.

The displacement vessels establish a wave at the bow of the vessel with the crest of the wave being at the bow. At low speeds, the second crest is generally at some point rearward of the bow but in front of the stern. As the speed of the vessel increases, the second crest of the wave moves rearwardly until it is at the stern of the vessel. At this particular speed, the vessel is supported only by the displacement of the bow in the first crest of the wave and the displacement of the stern in the second crest of the wave. Should the vessel attempt to travel faster, the support provided at the stern will disappear and the vessel will sink. Thus, the maximum speed for a displacement vessel is that speed equivalent to the velocity of a wave having a period equivalent to the length of the vessel. For extremely long tanker type vessels, the speed limitation due to the shifting crests of a wave is generally not the controlling factor limiting the speed. Instead, the speed limitation is primarily dependent upon the amount of frictional resistance generated by the vessel passing through the water.

The planing vessels do not suffer from the same speed limitations as the displacement vessels. However, other limitations are present. The planing vessels are basically displacement vessels at low speed. Their hulls, however, are designed such that they interact with the water to lift the vessel to the surface of the water at high speed. There are several disadvantages associated with the planing vessel. First, the hull configuration is not designed to pass through the water in the nature of a displacement vessel with minimum disturbance of the water, and thus requires a great amount of power to being the vessel to. the minimum planing speed. Second, the planing-vessel in planing position has a strong tendency to capsize due to normal wave action at the water surface. Thus, planing vessels are primarily limited to sporting or racing watercraft rather than acting as utilitarian cargo carriers.

The hydrofoil vessel is basically a combination of the displacement vessel and the planing vessel. At rest and at low speed, the hull of the hydrofoil vessel acts as a displacement hull and may be configured to offer minimum resistance to the water through which it passes. One or more hydrofoils are attached to each of a plurality of struts extending downwardly from the hull. At high speed, the water interacting with the hydrofoil creates a force tending to raise the hull out of the water. When this force is great enough, the hydrofoils will in fact lift the hull of the vessel clear of the water and thereafter continue to support the vessel. The hydrofoil fect of the hydrofoil. These forces impose structural limitations upon the length of the strut and the distance between adjacent struts. For these reasons, hydrofoils are generally limited to vessels designed to operate along the coastline or within inland lakes.

The air supported vessels are primarily designed to take advantage of the reduced resistance in traveling through the atmosphere compared to that of traveling through water. However, a vessel which is transformed from a displacement vessel to an air supported vessel at a specified speed suffers from several disadvantages. First, such a vessel is primarily dependent upon a smooth air stream adjacent the water surface, and a smooth air surface is almost never realized if there is any appreciable wind.'The control systems for these vessels interact with the air stream, not the water, to stabilize the vessel. However, some maneuvers may be required which would inherently cause a section of the airborne portion of the vessel to contact the water surface. If such contact is made, the increased resistance of the water may produce disastrous results. Second, the majority of the air supported vessels generate air lift through employment of airfoil surfaces exterior to the hull and interacting with the air stream. The amount of lift generated by these surfaces is a function of the speed of the airfoil through the air stream. Thus, if the vessel were to travel upwind, a given speed, with respect to the water surface, might produce sufficient lift. However, where the vessel travels downwind, a substantial increase in speed, with respect to the water surface, would be required to generate the same lift. For these reasons, the requirements placed upon the power plant, the latter being the only portion of the vessel engaging the water, are extreme. A third disadvantage of the airborne vessel is that of the space requirements for an airfoil of sufficient area to provide the required support. The disadvantage is particularly acute for cargo carrying vessels where the docking space is at a premium.

It is therefore a primary object of the present invention to provide an air supported watercraft having the hull of the vessel act as the lift generating surface.

Another object of the present invention is to provide a plurality of lift generating surfaces.

Yet another object of the present invention is to provide control of the lift generating surface from members disposed below the water line.

A further object of the present invention is to provide stability for an air supported watercraft by having a portion of the hull extend below the surface of the water.

A still further object of the present invention is to provide an airborne watercraft to a plurality of propulsion systems.

Yet another object of the present invention is to provide a docking system which permits the watercraft to effect a transition from operating speed to docking speed without acting as a displacement vessel.

These and other objects of the present invention will become apparent to those skilled in the art as the description thereof proceeds.

An air supported watercraft is disclosed which incorporates the speed advantages of a hydrofoil vessel and yet retains the inherent stability of a displacement vessel. The watercraft is primarily supported by the lift generated by the hull as it passes through the air. Additional air foil surfaces extending across the bow and stern of the watercraft generate lift and operate as stabilizing members. A side depends from each of the longitudinal edges of the hull of the watercraft and extends below the surface of the water. A plurality of vanes extend below the water line at the bow and stem from each of the sides. These vanes act as control members for controlling the longitudinal angular relationship between the hull of the vessel and the air stream. In addition, they can be adjusted to provide a certain amount of lift for the vessel.

High speed screws extend from the stern of the sides to provide propulsion force for the vessel. Rudders attached to the stern of the sides and disposed below the water line provide lateral control. Each of the sides also includes an airfoil surface extending outwardly from the fore and aft upper portions of the sides. A plurality of horizontally and vertically oriented wheels are disposed at the extremities of these airfoils. These wheels cooperate with guide rails at the docking facility to support the watercraft. In operation, the vessel is initially supported by the guide rails at the docking facility. On departure, the watercraft moves along the guide rails and as it picks up speed, generates sufficient lift to become self supporting. Similarly, the vessel, on docking, engages the rails and thereafter slows down. As the lift decreases due to the slower speed, the rails aupport more and more of the weight of the watercraft until the full weight is supported thereby.

The present invention may be understood with more specificity and clarity with reference to the following figures, in which:

FIGS. I and la illustrate a watercraft incorporating the teachings of the present invention.

FIG. 2 illustrates a cross section of the lifting surfaces shown in FIG. 1.

FIG. 3 illustrates a modification of the central lifting surface.

FIG. 4 illustrates a further modification of the central lifting surface.

FIG. 5 illustrates a frontal view of the present invention as shown in FIGS. 1 and 2.

FIG. 6 illustrates a docking system for the present invention.

FIG. 7 illustrates the relationship between the docking system ofFIG. 6 and the water surface.

FIG. 8 illustrates the means for supporting the watercraft on the docking system.

Referring to FIG. 1, there is shown an overall view of the watercraft l as taught by the present invention. The body 2 of the watercraft 1 has a dual function. It serves as the hold for the cargo, and it serves as the main lift generating surface, as will be explained in more detail. A pair of

sides

3 and 4 extend upwardly and downwardly from the respective longitudinal sides of body 2.

A bridge 12 intraconnects the upper portions of

sides

3 and 4. The bridge 12 serves as the control center for operating the watercraft 1. In addition, it contains quarters for the crew. Windows 28 extend along the frontal portion of bridge 12 and along the outer sides of

sides

3 and 4. An antenna 13, including a radome (a housing for a radar unit), extends upwardly from bridge 12. The antenna 13 serves as part of the communication link with other vessels and land based installations.

A pair of wings or airfoils 5 and 8 extend outwardly from

sides

4 and 3, respectively, in proximity to the bow and in approximate alignment with body 2. These winds serve two primary functions. The first function is that of providing a lifting surface for the watercraft l. The second function is that of providing means for docking the watercraft 1. Similar airfoils, 6 and 7, extend in proximity to the stern of

sides

4 and 3, respectively. These airfoils, 6 and 7, also provide lift and a means for docking the craft, but also carry out a third function. The third function is that of acting as a base for mounting

vertical stabilizers

9 and 10.

These

vertical stabilizers

9 and 10 interact with the air stream to provide stability in the lateral axis while the watercraft l is underway. A horizontal stabilizer 11 is disposed between

vertical stabilizers

9 and 10. The angle of attack of the horizontal stabilizer 11 is controllable and provides stability in the pitch axis while watercraft l is underway.

The lower portions, keels 35 and 36, of

sides

4 and 3, respectively, extend beneath the surface of the water to

water lines

26 and 27, respectively. A plurality of adjustable vanes, shown in FIG. 1 as

vanes

15 and 16 and 17, are disposed beneath the surface of the water and operate as control members for orienting watercraft l in the pitch axis. Although not fully shown in FIG. I, a set of vanes are disposed on either side of

sides

3 and 4 in proximity to the bow and stem.

Propulsion for watercraft I is obtained from any one of several different types of propulsion units. The type shown in FIG. 1 includes a high speed screw 24 disposed at the stern of each of the

sides

3 and 4. A cavitation plate 37 is disposed above screw 24 to prevent cavitation and loss of power during high speed operation. One of a pair of rudders 25 also disposed at the stern of each of the

sides

3 and 4 to provide control in the lateral axis. It is to be understood, however, that propulsion units such as jet engines or turbine driven air screws can be readily incorporated into the present invention.

In addition, it is feasible to mount a

plurality ofjet engines

80, 81 and 82 along the outside of

sides

3 and 4, which engines serve two functions, as shown in FIG. la. First, they serve as a basic means for propelling the watercraft 1. Second, by mounting the engines on a pivot, the direction thrust can be varied from a horizontal to vertical thrust line. In this manner, the thrust can be used to augment theother lift producing elements at low speed and aid in low speed maneuverability.

FIG. 2 illustrates a cross section of the major lift generating surfaces of the present invention. The cross section of bridge 12 is shaped as a semi-symmetrical airfoil. That is, the top surface 33 is convex shaped, having its high point at approximately 40 percent of the chord. The lower surface 34 is also convex shaped, having its high point similarly positioned to the high point of surface 33. However, the curvature of the upper surface 33 is greater than the curvature of the lower surface 34. As is well known to those skilled in the aerodynamic art, such a cross section, when placed in an air stream, will produce a lifting force. In this manner, the bridge 12 functions as a lifting surface for watercraft l.

The horizontal stabilizer 11 disposed between and connected to

rudders

9 and 10 is symmetrical; that is, the curvature of the upper surface is equal to the curvature of the lower surface. Therefore, the lift produced by stabilizer 11, when at a zero degree angle of attack, will be zero. However, if the angle of attack is varied positively or negatively, a corresponding force will be generated perpendicular to the air stream. In this manner, a force is generated to permit positioning of the watercraft 1 in the pitch axis.

The main lifting surface of watercraft 1 is that of the hull 2 itself. The deck 30 is generally parallel to the water line. The lower surface 31 of hull 2 is at a positive angle of attack with respect to the forward movement of watercraft 1. The effect of lower surface 31, when the watercraft 1 moves forward, is that of striking the air stream at an angle and deflecting the air stream to produce a lifting force. The total lifting force is a function of both speed and angle of attack. Thus, it is possible to obtain a wide speed range by simply varying the angle of attack to obtain the requisite lifting force.

The amount of lifting force and drag produced by a planar surface set at an angle of 8 with respect to the air stream may be shown by the following calculations:

The lift and drag characteristics of a flat plate, the equivalent of lower surface 31 of watercraft 1, may be computed by the following formulae: The drag, or force (F), exerted on a free standing flat plate perpendicular to an airstream is obtained by:

F 1.28 P /2 V where 1.28 a constant representing the turbulence about the free edges of the flat plate. It will be disregarded in this analysis because the edges of lower surface 31 are not free.

p density of air at sea level (0.002378 slugs, or lbs sec )/ft 4 a area of flat plate (ft V velocity (ft/sec) Where the flat plate is at an angle other than perpendicular to the airstream, the force (F') acting upon the flat plate may be separated into a lift and a drag component by the following formulae after multiplying the force (F) by the sine of the angle (sin 0), or F sin 0 F Lift (L) F cos 6, or F sin 0 cos 0 Drag (D) F sin 0, or F sin 0 Where 0 8",

L= l/2 p V a cos 8 sin 8 and D= l/2 p Va sin 8 If one assumes the speed of watercraft 1 to be 120 mph, or V 176 ft/sec, then L (0.5) (2.378 X 10 (1.76 X 10 (0.988) (0.139) a 5.05 a lbs and D (0.5) (2.378 X 10 (1.76 X 10 (0.139) (0.139) a 0.710 a lbs The power required to overcome the drag (D) is Power [(Drag) (a) (Velocity)]/550 [(0.710) (176) a]/550 0.227 a 111. Where the watercraft 1 has a lower surface area of 60 X 4.00 ft the power required is:

Power (0.227) (2.4 X 10 I-I.P.

= 5,450 I-I.P.

and it will generate a lift equal to:

Lift (5.05) (2.4 X 10) lbs 12.1 X 10 lbs or= (12.1 X 10 /2 X 10 tons 60.5 tons A lifting surface which is wedge shaped in cross section, as shown in FIG. 2, will have a tendency to orient itself with respect to the air stream whereby the upper and lower surfaces (deck 30 and lower surface 31) are each at opposite but equivalent angles of attack with respect to the air stream. Should this be permitted to occur, the total lift produced by the wedge shaped lifting surface will necessarily diminish to zero.

There are several methods by which the angle of attack of the lower surface 31 may be maintained. One such method is to provide an additional balancing lifting surface. The configuration of bridge 12 serves this function in that the lift generated by bridge 12 is substantially in front of the center of lift of hull 2. Another method for controlling the angle of attack of the lower surface 31 is that of rotating horizontal stabilizer 11 to provide an equal and opposite force movement to maintain lower surface 31 at the desired angle of attack. Yet another method for controlling and maintaining the angle of attack of lower surface 31 is by the use of

vanes

15, 16 and 17 (as shown in FIG. 1). These vanes interact with the water through which the watercraft 1 is traveling. By rotating each of the sets of vanes to an appropriate angle, control of the watercraft 1 in the pitch axis is obtained. Because water is very dense with respect to air, the amount of angular orientation of the sets of vanes need be relatively small while still obtaining the requisite force to maintain watercraft 1, and therefore lower surface 31, at the desired angle of attack. By integrating the movement of the movable surfaces (horizontal stabilizer 11 and

vanes

15, 16 and 17), precise control of the angle of attack of lower surface 31 for various air speeds may be achieved.

For maximum efficiency in traveling through the combined mediums of air and water, the watercraft 1 should have as few surfaces not parallel to the air stream or water flow as possible. This desired condition is generally not optimum with the use of the control system illustrated in FIG. 2 due to the negative forces necessary to maintain lower surface 31 at the preferred angle of attack. In order to rely to a minimum extent upon the horizontal stabilizer 11 and the

vanes

15, 16 and 17 for positional control in the pitch axis, the configuration of the lower surface 31 may be altered.

Referring to FIG. 3, there is shown a watercraft 1 having an altered lower surface of hull 2 shown as

surfaces

40 and 41. The angle of attack of lower surface 40, with respect to the air stream, is approximately 3. The length of the lower surface 40 is approximately one-third the total length of the lower surface ofthe hull 2. The angle of attack of lower surface 41 with respect to the air stream is approximately 8. The length of the lower surface 41 is approximately two-thirds the total length of the total surface of hull 2.

The total effect of

lower surfaces

40 and 41 upon the pitch stability of watercraft 1 may be explained as follows. As the watercraft 1 travels forward at operating speed, the lower surface 41 will generate a predetermined amount of lift. Similarly, the lower surface 40 will generate a predetermined amount of lift. Assuming for the moment that horizontal stabilizer 11 and

vanes

15, 16 and 17 (see FIG. I) are set at a neutral angle, the stern of the watercraft 1 will tend to rise because the friction due to water acting upon the keels 35 an 36 of

sides

4 and 3, respectively, is greater than the air resistance presented by the watercraft 1 above the center of gravity causing the watercraft 1 to rotate counterclockwise about its center of gravity. As the stern begins to rise, the effective angle of attack of lower surface 40 decreases from three degrees to a lesser value. The decreased angle of attack of lower surface 40 results in a smaller lift component attributable thereto. At come value of angle of attack of lower surface 40, the lift produced thereby is equal to the difference between the weight at the stern and the rotational force tending to rotate the watercraft 1 in a counterclockwise direction. At that position, the watercraft 1 becomes stable in the pitch axis without additional aid from control surfaces, such as horizontal stabilizer l1 and vanes l5, l6 and 17 (See FIG. 1). Rotation of watercraft 1 in the counterclockwise direction will necessarily reduce the angle of attack of lower surface 41 as well. However, the angle of attack of lower surface 41 is substantially greater than the angle of attack of lower surface 40 and therefore lower surface 41 will continue to provide lift for watercraft 1 even though the lift provided by lower surface 40 is zero or minimal.

Referring to FIG. 4, there is shown yet another modification of the hull 2 of the present invention. A hull 2, shown in cross section, illustrates the two distinctly angled

lower surfaces

40 and 41, as described above. In addition, the upper surface 30 of body 2 includes a plurality of convex sections 52 transverse the longitudinal axis of watercraft 1. These sections 52 are similar in curvature to the upper surface of an airfoil. The purpose of these sections is to generate an additional lift component in the same manner as the upper surface of an airfoil generates lift. The number and chord of sections 52 and their position along deck 30 is dependent upon the size of the additional lift component desired and the positional relationship of the resultant lift generated by the sections 52 with respect to the other lift surfaces present.

FIG. is a frontal view of the watercraft as shown in FIG. 2. In order to avoid the problems mentioned above with respect to the rotation of the wedge shaped hull 2, the distribution of the area of lower surface 31 is modified. Instead of lower surface 31 being essentially rectangular, the trailing edge 50 is narrower than the leading edge 51, thereby producing a generally trapezoid shaped lower surface 31. To compensate for the narrower trailing edge 50 without modifying the

sides

3 and 4, a fillet 5 3 and 54 is formed between the generally longitudinal sides of lower surface 31 and the

respective sides

4 and 3. In this manner, the resultant lift force generated by lower surface 31 is not positioned at the geometrical center oflower surface 31 but is moved forward therefrom. Thus, the resultant lift acts through a point forward of the center of gravity of watercraft 1 and inhibits the tendency of the watercraft to rotate in a counterclockwise direction. The

fillets

53 and 54 serve also to streamline the junction of lower surface 31 and

sides

3 and 4 to reduce induced drag.

The reduced cross sectional area at the stern with respect to thrust at the bow brings about a tendency to create an air cushion beneath the lower surface 31. As it well known in the art, such an air cushion will contribute to the total lift generated by watercraft 1. Additional lift is also available by increasing the density of the air beneath the lower surface 31. An increase in density can be effected by injecting a mist of water vapor from the nozzles disposed along the inner sides of

sides

3 and 4, as shown in FIG. 5a. In operation, the injected water mist will mix with the air forced between the

sides

3 and 4 and the lower surface 31 as the watercraft travels forward. The mixture of water mist and air will be more dense than air along and thereby cause an increase in the total lift of lower surface 31.

FIG. 5 also illustrates the pairs of

vanes

15 and 17 extending from either side of the bow of

sides

4 and 3, respectively. These vanes, while watercraft l is in operation, are positioned below the

waterline

26 and 27 of

sides

4 and 3 to control the pitch angle of watercraft 1.

In order to reduce the parasitic air drag at the stern of the watercraft, a system of vents (not shown) may be used. The use of such vents reduces the low pressure area created immediately astern any vessel. By reducing the low pressure area, the parasitic drag is diminished.

As may be deduced from studying FIGS. 1 5, the

sides

3 and 4 being positioned beneath the surface of the water have two primary stabilizing effects on watercraft 1. First, the

sides

3 and 4 are disposed at the outermost edges of hull 2. As such, they act as outriggers to prevent rotation about the longitudinal axis. The effect of

keels

35, 36 stabilizes the watercraft l in the lateral axis.

Sides

3 and 4, extending along the full length of watercraft 1, provides a stabilizing force in the pitch axis by reducing the effect of rolling seas. A yet further benefit of the

sides

3 and 4 is that of providing a lift force, due to displacement lift, uniformly extending for the full length of the watercraft 1.

One of the major disadvantages of hydrofoil vessels is that of size limitation. It is well known that the struts extending downwardly at the approximate four corners of the vessel may be separated from one another by no more than a given distance without causing undue strain on the structure of the vessel between the fore and aft pairs of struts. A criteria generally used by the United States Navy is that of limiting hydrofoil vessels to 1,000 tons or smaller. In situations where a semiairborne vessel is to be used as a cargo carrier in view of the wekk-known high speed possibilities, the limitation in size for hydrofoil vessels, due to the concentrated lift forces, practically preclude their efficient use.

In the present invention, the

sides

3 and 4, extending for the complete length of the watercraft 1, may easily be configured by those skilled in the art to provide the requisite rigidity between the bow and the stern regardless of the size of the watercraft 1. In addition, the lifting force is distributed along the length of the hull 2. Thus, the present invention avoids the structural limitations placed upon hydrofoils and yet achieves the benefits of the small wetted area of hydrofoil vessels.

In the figures, the means for propulsion is shown as high speed screws. Recent developments of high speed screws have made feasible the use of such screws for high speed operations of large vessels. However, there may be reasons dictating against the use of screws, and a change in propulsion system from a screw to a water stream, jet engines, or some other high speed propulsion unit is deemed to be a feasible method for powering the present invention.

The horizontally and vertically oriented wheels, 18, 18' and 20, 20' are shown in FIG. 5 as the furthermost side extensions of watercraft 1. As will be described below, these wheels guide and provide support for watercraft 1 during docking maneuvers. FIG. 6 illustrates a docking system suitable for use with the watercraft l of the present invention. A pair of receiving rails 60 and 61 are supported by pilings 64 and extend into the water 50. At the receiving end 56, the rails 60 and 61 are separated from one another to a width greater than the width between wheels 18 and 18' (See FIG. 5). The wider receiving end 56 premits the watercraft 1 to be piloted toward the pair of rails 60 and 61 without requiring exact alignment therebetween. Should the watercraft 1 be slightly misaligned, wheels 18' or 18 will contact the respective vertical side 47 (See FIG. 8) of the rail and realign the watercraft l to the centerline between the rails 60 and 61. After contacting both rails 60 and 61, the watercraft 1 will begin to slow down. As the watercraft 1 slows down, the lifting forces generated by the various members of the hull 2 will be reduced. The reduction in lift forces will tend to cause watercraft 1 to settle in the water. As the watercraft 1 settles, wheels and 21 engage the horizontal member 45 of both rails 60 and 61 and thereby provide support for watercraft 1.

While being supported by rails 60 and 61, watercraft 1 may propel itself or be pulled by appropriate means to a docking area shown generally as 73. A movable crane 66 with control tower 67 and appropriate cargo lifting mechanisms will load and unload watercraft 1.

When departing from docking facility 73, the watercraft is accelerated until the various lifting surfaces generate sufficient lift to support the watercraft. Coincident with the generation of supporting lift, the rails 62 and 63 widen in a similar manner as the receiving end 56 to permit the watercraft 1 to depart from the docking facility 73.

FIG. 7 illustrates a docking facility for use in tidal waters to provide compensation for the varying water level 70. A pair of receiving rails 71 slope upwardly from the water surface 70. This permits watercraft 1 to engage the receiving rails 70 at varying points depending upon the relative height of the wheels 18. 18, 20, 20'. The height is of course dependent upon the height of the water surface 70. The watercraft will continue upwardly along the pair of rails 71 to the docking area generally shown as 73. On departing from docking area 73, the watercraft will engage the departing rails 72. The departing rails 72 slope downwardly toward the water surface 70 whereby the watercraft is permitted to accelerate and generate lifting forces until it no longer depends upon the rails for support. The watercraft 1 will be disengaged from rails 72 at varying points therealong depending upon the height of the water surface 70.

Safety of operation requires that all vessels be capable of floating should the propulsion system fail. The

sides

3 and 4 and hull 2 of the watercraft 1 of the present invention provide sufficient buoyancy to satisfy the safety requirements. Thus, the watercraft 1, although preferably requiring a relatively sophisticated docking system, is not limited thereto for safe operation.

It is generally well known that the amount of power required for sustained high speed operation is, with appropriate hull design, sufficient to effect the transition from a displacement vessel to an air supported vessel.

Thus, the power of the propulsion system is sufficient to raise the watercraft 1 from the position at rest within the water to the desired height above the water.

The watercraft l of the present invention is also suit- 5 able for use by the Navy where vessels must have a lingering capability. The pairs of

vanes

15, 16, 17 and 18 (not shown but disposed on either side of the stern of the side 3) may be used as lift generating surfaces rather than as simply control surfaces. Because of the relative higher density of the water within which the vanes l5, 16, 17 and 18 operate the angular deflection required for additional lift is relatively small. In addition, a plurality of vanes (not shown) may be positioned along the

sides

3 and 4 to uniformly distribute the lift. Similarly, the

vanes

15, 16, 17 and 18 may be used as positive lifting members during the transition of the watercraft 1 from a displacement vessel to that of an air supported vessel should the need arise.

The control system for the watercraft of the present invention is necessarily relatively sophisticated in order to integrate the various control surfaces, and lift producing surfaces to obtain a stable operation of the watercraft 1. Such a control system can be accomodated through the knowledge presently available within the aircraft guidance industry.

While the principles of the invention have now been made clear in an illustrative embodiment, there will be immediately obvious to those skilled in the art many modifications of structure, arrangement, proportions, the elements, materials, and components, used in the practice of the invention which are particularly adapted for specific environments and operating requirements without departing from those principles.

I claim:

1. A watercraft generating lift through forward motion of said watercraft, said watercraft comprising:

A. a hull having a deck and a lower surface, said hull interacting with the air stream at a variable angle of attack to produce a lifting force;

B. A pair of sides, each said side depending from a longitudinal side of said hull and extending below the surface of the water said pair of sides being the only appendages adjacent either said deck or said lower surface;

C. A propulsion unit for propelling said watercraft along the surface of the water; and

D. a plurality of positionable vanes extending outwardly from each of said sides, said vanes being disposed beneath the surface of the water, whereby said vanes are positioned to vary the angle of attack of said hull to adjust the lifting force.

2. A watercraft generating lift through forward motion of said watercraft, said watercraft comprising:

A. a hull having a deck and a lower surface, said lower surface having two planar surfaces set at an angle with respect to one another, each of said two planar surfaces being at a different angle with respect to said deck, said hull interacting with the air stream at a variable angle of attack to produce a lifting force;

B. a pair of sides, each said side depending from a longitudinal side of said hull and extending below the surface of the water;

D. a plurality of positionable vanes extending upwardly from each of said sides, said vanes being disposed beneath the surface of the water, whereby said vanes are positioned to vary the angle of attack of said bull to adjust the lifting force.

3. The watercraft as set forth in claim 1 further including an airfoil disposed between said sides above said deck for generating lift while said watercraft is in motion.

4. The watercraft as set forth in claim 3 wherein said airfoil encloses a control room for said watercraft.

5. The watercraft as set forth in claim 1 further including a positionable horizontal stabilizer located above said deck at the stern of said watercraft for providing control of said watercraft in the pitch axis.

6. The watercraft as set forth in claim 1 further including a plurality of airfoil surfaces extending outwardly from said watercraft, one of said surfaces being disposed in proximity to the bow and stern of each of said sides.

7. The watercraft as set forth in claim 6 further including a pair of vertical stabilizers, one of said stabilizers extending upwardly from each of said airfoil surfaces disposed at the stern of said watercraft.

8. The watercraft as set forth in claim 7 further including a controllable stabilizer connected between said pair of vertical stabilizers for providing control of said watercraft in the pitch axis.

9. The watercraft as set forth in claim 1 wherein said deck includes at least one curved surface for generating a lift force.

10. A watercraft generating lift through forward motion of said watercraft, said watercraft comprising:

A. a hull having a deck and lower surface, said deck and said lower surface being at an angle with respect to one another, the apex of said angle being in proximity to the bow of said watercraft, said hull interacting with the air stream at a variable angle of attack to produce a lifting force;

11. The watercraft as set forth in claim 10 wherein the width of said lower surface is greater at the bow of said watercraft than at the stern thereof.

12. The watercraft as set forth in claim 11 including an airfoil disposed between said sides above said deck for generating lift while said watercraft is in motion.

13. The watercraft as set forth in claim 12 further inclusing a plurality of airfoil surfaces extending away from said watercraft, one of said surfaces being disposed in proximity to the bow and stem of each of said sides.

14. The watercraft as set forth in claim 13 including a pair of vertical stabilizers, one of said stabilizers extending upwardly from each of said surfaces disposed at the stern of said watercraft.

15. The watercraft as set forth in claim 14 including a controllable horizontal stabilizer connected between said pair of vertical stabilizers for providing control of said watercraft in the pitch axis.

16. The watercraft as set forth in claim 15 further including a plurality of nozzles, said nozzles being disposed along the inside bow of each of said sides, whereby a water mist is injected into the airstream passing between said sides.

17. The watercraft as set forth in claim 16 also including a plurality of pivotally mounted jet engines disposed along the outward surface of each of said sides.

18. A watercraft and docking system wherein:

I. said watercraft comprises:

c. a plurality of positionable vanes extending outwardly from each of said sides, said vanes being disposed beneath the surface of the water and in teracting with the water to position said hull at an angle of attack with respect to the air stream;

d. a plurality of airfoil surfaces extending away from said hull, one of said surfaces being disposed in proximity to the bow and stem of each of said sides;

e. a plurality of horizontally and vertically oriented wheels disposed at the extremity of each of said surfaces;

ll. said docking system comprises:

a. an extended pair of rails, including a receiving rail section, a docking rail section and a departing rail section, said pair of rails having a horizontal surface and a vertical surface;

b. said receiving rail section having said rails horizontally displaced from another at a distance greater than the distance between said wheels located at opposed ones of said surfaces, the distance between said rails diminishing to the approximate distance between said wheels located at opposed ones of said surfaces at the junction of said receiving rail section and said docking rail section;

0. said departing rail section having said rails horizontally displaced from one another at a distance approximately equal to the distance between said wheels located at opposed ones of said surfaces at the junction of said docking rail section and said departing rail section, the distance between said rails increasing toward the extremity of said departing rail section; whereby said wheels of said watercraft initially engage said rails of said receiving rail section for guiding said watercraft into said docking rail section and supporting said watercraft on said rails at said docking section, said departing rail section supporting and guiding said watercraft on departing from said docking rail section until said watercraft becomes self supporting.

Claims

1. A watercraft generating lift through forward motion of said watercraft, said watercraft comprising: A. a hull having a deck and a lower surface, said hull interacting with the air stream at a variable angle of attack to produce a lifting force; B. A pair of sides, each said side depending from a longitudinal side of said hull and extending below the surface of the water said pair of sides being the only appendages adjacent either said deck or said lower surface; C. A propulsion unit for propelling said watercraft along the surface of the water; and D. a plurality of positionable vanes extending outwardly from each of said sides, said vanes being disposed beneath the surface of the water, whereby said vanes are positioned to vary the angle of attack of said hull to adjust the lifting force.

2. A watercraft generating lift through forward motion of said watercraft, said watercraft comprisIng: A. a hull having a deck and a lower surface, said lower surface having two planar surfaces set at an angle with respect to one another, each of said two planar surfaces being at a different angle with respect to said deck, said hull interacting with the air stream at a variable angle of attack to produce a lifting force; B. a pair of sides, each said side depending from a longitudinal side of said hull and extending below the surface of the water; C. A propulsion unit for propelling said watercraft along the surface of the water; and D. a plurality of positionable vanes extending upwardly from each of said sides, said vanes being disposed beneath the surface of the water, whereby said vanes are positioned to vary the angle of attack of said hull to adjust the lifting force.

8. The watercraft as set forth in claim 7 further including a controllable horizontal stabilizer connected between said pair of vertical stabilizers for providing control of said watercraft in the pitch axis.

10. A watercraft generating lift through forward motion of said watercraft, said watercraft comprising: A. a hull having a deck and lower surface, said deck and said lower surface being at an angle with respect to one another, the apex of said angle being in proximity to the bow of said watercraft, said hull interacting with the air stream at a variable angle of attack to produce a lifting force; B. a pair of sides, each said side depending from a longitudinal side of said hull and extending below the surface of the water; C. a propulsion unit for propelling said watercraft along the surface of the water; and D. a plurality of positionable vanes extending upwardly from each of said sides, said vanes being disposed beneath the surface of the water, whereby said vanes are positioned to vary the angle of attack of said hull to adjust the lifting force.

13. The watercraft as set forth in claim 12 further including a plurality of airfoil surfaces extending away from said watercraft, one of said surfaces being disposed in proximity to the bow and stern of each of said sides.

18. A watercraft and docking system wherein: I. said watercraft comprises: a. a hull having a deck and a lower surface, said hull interacting with the air stream at a variable angle of attack to produce a lifting force; b. a pair of sides, each said side depending from a longitudinal side of said hull and extending below the surface of the water; c. a plurality of positionable vanes extending outwardly from each of said sides, said vanes being disposed beneath the surface of the water and interacting with the water to position said hull at an angle of attack with respect to the air stream; d. a plurality of airfoil surfaces extending away from said hull, one of said surfaces being disposed in proximity to the bow and stern of each of said sides; e. a plurality of horizontally and vertically oriented wheels disposed at the extremity of each of said surfaces; II. said docking system comprises: a. an extended pair of rails, including a receiving rail section, a docking rail section and a departing rail section, said pair of rails having a horizontal surface and a vertical surface; b. said receiving rail section having said rails horizontally displaced from another at a distance greater than the distance between said wheels located at opposed ones of said surfaces, the distance between said rails diminishing to the approximate distance between said wheels located at opposed ones of said surfaces at the junction of said receiving rail section and said docking rail section; c. said departing rail section having said rails horizontally displaced from one another at a distance approximately equal to the distance between said wheels located at opposed ones of said surfaces at the junction of said docking rail section and said departing rail section, the distance between said rails increasing toward the extremity of said departing rail section; whereby said wheels of said watercraft initially engage said rails of said receiving rail section for guiding said watercraft into said docking rail section and supporting said watercraft on said rails at said docking section, said departing rail section supporting and guiding said watercraft on departing from said docking rail section until said watercraft becomes self supporting.