Abstract:
An improved landing craft includes a hull that supports bow and stern ramps for enabling vehicles to drive through during loading and unloading. The drive-through arrangement also enables the crew to load and unload the craft much faster and more easily than existing vessels. A ballasting arrangement can be used to trim the hull when it is to be beached or to be extracted and/or during loading/unloading.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Priority of our U.S. Provisional Patent Application Ser. No. 60/363,968, filed Mar. 14, 2002, incorporated herein by reference, is hereby claimed. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     The invention disclosed herein was developed under Navy Contract Nos. N00024-01-C-2234 and N00024-02-C-2231. The government may have rights in this invention. 
    
    
     REFERENCE TO A “MICROFICHE APPENDIX” 
     Not applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to landing craft. More particularly, the present invention relates to an improved landing craft having a planing hull that is particularly suited for military operations that includes the loading, unloading and marine transport of very heavy vehicles such as tanks, trucks and the like. 
     2. General Background of the Invention 
     Landing craft that are currently in use operate in a displacement mode. Such craft usually include a single ramp to allow loading and unloading of tanks and trucks. An example of a prior art landing craft is the U.S. Navy LCU 1640 class craft. Other landing craft are shown in patents listed in the following table as examples. 
     
       
         
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 U.S. Pat. No. 
                 TITLE 
               
               
                   
               
             
             
               
                 4,080,922 
                 FLYABLE HYDROFOIL VESSEL 
               
               
                 4,681,054 
                 MARINE VESSEL LAND METHOD FOR 
               
               
                   
                 TRANSPORTING A VEHICLE 
               
               
                 4,865,275 
                 LAND, WATER AND AIR CRAFT 
               
               
                 5,080,032 
                 MONOHULL FAST SEALIFT OR SEMI-PLANING 
               
               
                   
                 MONOHULL SHIP 
               
               
                 5,129,343 
                 MONOHULL FAST SHIP 
               
               
                 5,231,946 
                 MONOHULL FAST SEALIFT OR SEMI-PLANING 
               
               
                   
                 MONOHULL SHIP 
               
               
                 5,316,409 
                 PORTABLE BOAT SKIDWAY 
               
               
                 5,544,607 
                 MOVEABLE SPONSONS FOR HYDROFOIL 
               
               
                   
                 WATERCRAFT, INCLUDING BOTH LARGE 
               
               
                   
                 EXTENDED-PERFORMANCE HYDROFOIL 
               
               
                   
                 WATERCRAFT AND LEAPING PERSONAL 
               
               
                   
                 HYDROFOIL WATERCRAFT 
               
               
                 5,746,146 
                 SURFACE EFFECT PLANING PONTOON 
               
               
                   
                 SEAPLANE (SEPPS) 
               
               
                 5,832,856 
                 MONOHULL FAST SHIP WITH IMPROVED 
               
               
                   
                 LOADING MECHANISM 
               
               
                 6,000,358 
                 BEACHING BOW FOR LOADING PLATFORMS 
               
               
                   
                 AND WATERCRAFT 
               
               
                 6,095,076 
                 HYDROFOIL BOAT 
               
               
                 6,167,829 
                 LOW-DRAG, HIGH-SPEED SHIP 
               
               
                 6,439,148 
                 LOW-DRAG, HIGH-SPEED SHIP 
               
               
                   
               
             
          
         
       
     
     BRIEF SUMMARY OF THE INVENTION 
     The landing craft of the present invention has been designed as simply as possible. The hull lines consist of developable surfaces, which simplify construction and repairs. 
     The bow and stern ramp systems can employ simple hydraulic winch stations and hinge pin connections, as opposed to articulated or ram actuated designs. 
     A drive-through arrangement enables a crew to load and unload the craft much faster and more easily than the prior known landing craft. 
     The landing craft of the present invention employs control station redundancy. The craft can be operated from either of the two control stations. 
     The craft is powered with one or more power units that can be engine powered waterjet systems installed on the craft to provide a rugged alternative to propellers. The waterjet system has one or more water jet intakes that feature bar gratings that prevent the ingestion of large debris and limit the possibility of impeller damage from underwater obstructions. 
     The hull of the can be manufactured with A588 high strength steel. This steel has a 25% higher yield strength than the A36. This higher strength allows for lighter plating with equivalent strength to be used. In addition, its corrosion resistant characteristics should help reduce maintenance efforts and increase the structural life of the craft. 
     The hull can be constructed of 5086 alloy, and other marine aluminum alloys. The natural corrosion-resistant characteristics of the aluminum help reduce overall maintenance efforts and increase the structural life of the craft. 
     The craft of the present invention has no moving components exposed below the bottom of the hull. All propulsion and maneuvering systems are protected by hull structural components, improving reliability and survivability. 
     Two unique functions of this craft are its ability to load and offload cargo from well deck ships (e.g., classes LSD-41, LSD-49, LHD-1, LPD-17, and LHA) to beaches. To assist the crew in completing these tasks safely and efficiently, the craft has been fitted with two control stations, each affording the operator excellent visibility. These features should allow the craft to back down at speeds approaching seven knots, hold its position in a 30-knot cross wind, or rapidly rotate in position. The increase in maneuverability will allow speed and ease of control during wet well and beaching evolutions. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the attached drawings which are identified as follows: 
     FIG. 1 is perspective view of the preferred embodiment of the apparatus of the present invention; 
     FIG. 2 is a partial sectional elevation view of the preferred embodiment of the apparatus of the present invention illustrating the hull body; 
     FIG. 3 is a schematic partial profile view of the hull body; 
     FIG. 4 is a schematic partial plan view of the hull body; 
     FIG. 5 is a fragmentary view of the preferred embodiment of the apparatus of the present invention showing the chine and spray rail configuration; 
     FIG. 6 is a fragmentary view of the preferred embodiment of the apparatus of the present invention illustrating the grounding rail portion; 
     FIG. 7 is a fragmentary plan view of the preferred embodiment of the apparatus of the present invention illustrating the hull stern portion; 
     FIG. 8 is a fragmentary elevation view of the preferred embodiment of the apparatus of the present invention illustrating the hull stern portion in profile; 
     FIG. 9 is a stern elevation view of the preferred embodiment of the apparatus of the present invention; 
     FIG. 10 is a partial plan view of the preferred embodiment of the apparatus of the present invention illustrating the bow portion thereof; 
     FIG. 11 is a fragmentary elevation view of the preferred embodiment of the apparatus of the present invention illustrating the bow portion thereof; 
     FIG. 12 is a front, elevation view of the preferred embodiment of the apparatus of the present invention; 
     FIG. 13 is a partial cutaway plan view of the preferred embodiment of the apparatus of the present invention illustrating the hold plan, engines, and waterjets; 
     FIG. 14 is an elevation and partial cutaway view of the preferred embodiment of the apparatus of the present invention illustrating the stern portion thereof; 
     FIG. 15 is an elevation and partial cutaway view of the preferred embodiment of the apparatus of the present invention showing the hull stern portion and illustrating the engine and waterjet portions thereof; 
     FIG. 16 is a partial cutaway plan view of the preferred embodiment of the apparatus of the present invention; 
     FIG. 17 is a partial cutaway elevation view of the preferred embodiment of the apparatus of the present invention; 
     FIG. 18 is a partial cutaway elevation view of the preferred embodiment of the apparatus of the present invention; 
     FIG. 19 is a partial plan view of the preferred embodiment of the apparatus of the present invention illustrating a typical cargo layout for the deck; 
     FIG. 20 is a schematic, partial plan view of the preferred embodiment of the apparatus of the present invention illustrating another typical cargo layout for the deck; 
     FIG. 21 is a fragmentary elevation view of the preferred embodiment of the apparatus of the present invention illustrating the stern portion when spaced from the sea bed (showing full load with maximum trim); 
     FIG. 22 is a fragmentary elevation view of the preferred embodiment of the apparatus of the present invention illustrating the stern portion when resting on the sea bed (showing no cargo); 
     FIG. 23 is schematic elevation view of the preferred embodiment of the apparatus of the present invention illustrating a beach interface and unloading of a vehicle; 
     FIG. 24 is a schematic elevation view of the preferred embodiment of the apparatus of the present invention illustrating a beach interface and ramp position during unloading of equipment; 
     FIG. 25 is a schematic plan view of the preferred embodiment of the apparatus of the present invention illustrating its position within a wet well of a well deck ship; 
     FIG. 26 is an elevation view illustrating the preferred embodiment of the apparatus of the present invention positioned in a wet well of a well deck ship; 
     FIG. 27 is a schematic view illustrating the preferred embodiment of the apparatus of the present invention positioned in a wet well of a well deck ship; 
     FIG. 28 is a schematic view illustrating the preferred embodiment of the apparatus of the present invention positioned in a wet well of a well deck ship (showing full load with maximum trim by bow) (LHA wet well); 
     FIG. 29 is a schematic plan view of the preferred embodiment of the apparatus of the present invention illustrating (its position when in an angled orientation within a wet well of a well deck ship (LHA well); and 
     FIG. 30 is a schematic plan view of the preferred embodiment of the apparatus of the present invention illustrating its position when in an angled orientation within a wet well of a well deck ship (LHA well). 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention provides an improved landing craft apparatus that is designated generally by the numeral  10  in FIGS. 1, and  25 - 30 . Landing craft  10  provides a hull  11  that has a deck or deck area  12  with a starboard forward control station  13  and a port aft control station  14 . Hull  11  includes bow  15  and stern  16  portions. Hull  11  has a port side  17  and starboard side  18  for reference purposes. The forward control station  13  is occupied by an operator or pilot for use when the craft  10  travels forward or when bow ramp  19  is to be raised or lowered. The aft control station  14  can be occupied by a pilot or operator for use when the craft  10  backs down or when stern ramp  20  is to be raised or lowered. 
     Bow ramp  19  is moveably (preferably pivotally) attached to hull  11 . Bow ramp  19  can be pivotally attached to hull  11  at pivot  21 . Stern ramp  20  is moveably attached to hull  11  at the vessel stern  16 . Stern ramp  20  is preferably pivotally attached at pivot  22  to hull  11 . 
     The vessel of the present invention provides an improved landing craft  10  with a hull  11  that is a planing hull. Hull  11  is powered by at least one and preferably a plurality of power units, preferably powerful engines  39  that drive waterjets  32  (see FIGS.  13  and  15 ). The landing craft  10  of the present invention is adapted to carry multiple large military vehicles such as tanks  23  in FIGS. 1,  20  and  23 , trucks  50  as shown in. FIG. 19, or personnel carriers  51  (or other large vehicles, automobiles, etc.) as shown in FIG.  19 . 
     The bow ramp  19  can be operated with a pair of spaced apart winch lines  24 ,  25 . The winch lines  24 ,  25  can be powered using a winch and roller arrangement as shown in FIGS. 17 and 18 that includes winch  46  and rollers  47 ,  48 ,  49 . 
     Hull  11  includes a lower, generally flat keel  29  that communicates with planing wedges  55 ,  56  (see FIG.  9 ). A chine  30  and spray rail  31  are provided both port and starboard as shown in FIGS. 2,  3  and  4 . 
     Forecastles (commonly known as F′ ocles)  27 ,  28  can be provided at port and starboard positions as shown in FIGS. 1 and 10. Ballast tanks are provided in both the bow  15  and stern  16  portion of hull  11  for ballasting either the bow  15  or stern  16  of the vessel during loading and unloading of vehicles  23 ,  50 ,  51 . Ballast tanks can be used to help beach landing craft  10  for unloading as well as for trimming the hull  11  to remove it after it has been beached or after when docking (or leaving) the wet well  53  of a well deck ship. 
     One of the features of the present invention is that the engines  39  and waterjets  32  provide no moving parts externally of the hull. Water intake grates  33  (FIG. 9) enable water to be suctioned into the waterjets  32  and discharged for thrust while filtering or barring any large objects. 
     When the vessel  10  is to beached, port and starboard groundings rails  34 ,  35  form a tripod arrangement with the keel flat  29  (see FIGS.  9  and  21 - 22 ). In such a tripod arrangement, the keel flat  29  and the port and starboard grounding rails  34 ,  35  engage the seabed  37  or wet well deck. The transom  38  is shown in FIG. 8 that also displays keel flat  29 , planing wedges  55 ,  56 , port and starboard grounding rails  34 ,  35 . FIG. 9 shows the aft facing discharge or propulsion part of the waterjets  32 . 
     In FIG. 8, is waterjet guard  43  extends below stern ramp  20 . Guard  43  is contacted by stern ramp  20  when ramp  20  reaches a lower, unloading or loading position. The stern ramp  20  can be operated using a winch  57  and roller  58 ,  59  arrangement that includes a winch line  60  for raising and lowering the stern ramp  20 . The jet guard  43  provides a wedge that engages any wave action, thereby stabilizing the craft  10  by helping to dampen aft pitching motions. The guard  43  has large flat surfaces that create considerable resistance forces when the guard  43  rises and falls with the transom  38  in the waves. 
     A bow thruster  36  can be provided for helping maneuver the landing craft  10 . The combination of the bow thruster  36  and ballast tanks  40 ,  41 ,  42 ,  44  and  45  maneuver and help ballast the craft  10  when it is to be beached, when it is to be extracted from a beached position, or when it is to be placed into or removed from a wet well  53  of a well deep ship. 
     The ballast tanks include an aft port ballast tank  40  and an aft starboard ballast tank  41 . A central ballast tank  42  can be provided in hull  11  forward of aft or stern ramp  20 . The port and starboard aft ballast:tanks  40 ,  41  are preferably positioned on opposing sides of stern ramp  20  and behind transom  38 . The port  40 , starboard  41  and central  43  ballast tanks can be seen in FIGS. 13-15. Ballast tanks  44  and  45  provide port and starboard bow mounted ballast tanks for ballasting the bow of the hull  11  during loading and unloading operations. 
     Using the ballast tanks  40 ,  41 ,  42 ,  44 ,  45  and bow thruster  36 , the landing craft  10  of the present invention can be used to load or unload equipment or vehicles while docked in a wet well vessel wet well in different orientations. In FIGS. 25 and 26, the landing craft  10  of the present invention has backed into a wet well so that the stern ramp  20  can be lowered (see FIG. 26) enabling vehicles  23 ,  50  or  51  or a combination thereof to be loaded via stern ramp  21  to the vessel deck  12 . In FIG. 26, the landing craft  10  bow ramp  19  faces inward within a wet well  53  so that vessels can be added to the hull deck  12  via bow ramp  19 . FIG. 27 shows a full load, maximum trim by stern. 
     In FIG. 28, the stern ramp  20  is in a lower position for receiving cargo, vehicles or the like and wherein a full load is shown with maximum trim by bow. 
     FIG. 29 shows a plan view of the landing craft  10  shown in an angled position within wet well  53  of a well deck ship. In FIG. 30, the position of the vessel hull  11  has been reversed so that the stern ramp  20  is in a position in wet well  53  in order to receive vehicles or the like for transport from the well deck ship. In FIG. 29, the stern gate  20  extends beyond stern gate  54  whereas in FIG. 30, the bow of ramp  19  extends beyond stern gate  54  of wet well  53  of a well deck ship. 
     In FIG. 23, a tank  23  is shown unloading via bow ramp  19  wherein water surface  52  almost covers ramp  19 . In FIG. 24, ramp  19  is only partially covered by water surface  52   
     Landing craft  10  can include hull  11  having a beam of between about 35 and 50 feet. Hull  11  can be made of an aluminum or steel material and can have a length of between about 130 and 150 feet. Hull  11  can be configured to be scaled to a different length and/or beam by increasing the length or width of generally flat keel  29  portion. Transom  38  can have a deadrise angle of less than 10 degrees or preferably of about 5 decrees. 
     Ramps  19 ,  20  can be positioned so that a wheeled vehicle such as a tank  23 , truck, or automobile can drive through the deck  12  area by entering the deck  12  area via one of the ramps  19 ,  20  and leaving the deck  12  area via the other of the ramps  20 ,  19 . 
     The following is a list of part numbers, parts descriptions, and materials used in the specification and suitable for use in the present invention: 
     
       
         
               
             
               
               
             
               
               
             
           
               
                   
               
               
                 PARTS LIST: 
               
             
          
           
               
                 Part 
                   
               
               
                 Number 
                 Description 
               
               
                   
               
             
          
           
               
                 10 
                 landing craft 
               
               
                 11 
                 hull 
               
               
                 12 
                 deck 
               
               
                 13 
                 starboard forward control station 
               
               
                 14 
                 port aft control station 
               
               
                 15 
                 bow 
               
               
                 16 
                 stern 
               
               
                 17 
                 port side 
               
               
                 18 
                 starboard side 
               
               
                 19 
                 bow ramp 
               
               
                 20 
                 stern ramp 
               
               
                 21 
                 pivot 
               
               
                 22 
                 pivot 
               
               
                 23 
                 tank 
               
               
                 24 
                 winch line (port) 
               
               
                 25 
                 winch line (starboard) 
               
               
                 27 
                 forecastle 
               
               
                 28 
                 forecastle 
               
               
                 29 
                 keel flat 
               
               
                 30 
                 chine 
               
               
                 31 
                 spray rail 
               
               
                 32 
                 water jet 
               
               
                 33 
                 water intake grate 
               
               
                 34 
                 port grounding rail 
               
               
                 35 
                 starboard grounding rail 
               
               
                 36 
                 bow thruster 
               
               
                 37 
                 seabed 
               
               
                 38 
                 transom 
               
               
                 39 
                 engine 
               
               
                 40 
                 port ballast tank (aft) 
               
               
                 41 
                 starboard ballast tank (aft) 
               
               
                 42 
                 central ballast tank 
               
               
                 43 
                 waterjet guard 
               
               
                 44 
                 port ballast tank (bow) 
               
               
                 45 
                 starboard ballast tank (bow) 
               
               
                 46 
                 winch 
               
               
                 47 
                 roller 
               
               
                 48 
                 roller 
               
               
                 49 
                 roller 
               
               
                 50 
                 truck 
               
               
                 51 
                 personnel carrier 
               
               
                 52 
                 water surface 
               
               
                 53 
                 wet well 
               
               
                 54 
                 stern gate 
               
               
                 55 
                 planing wedge 
               
               
                 56 
                 planing wedge 
               
               
                 57 
                 winch 
               
               
                 58 
                 roller 
               
               
                 59 
                 roller 
               
               
                 60 
                 winch line 
               
               
                 102 
                 grounding rail upper INBD 
               
               
                 103 
                 baseline 
               
               
                 104 
                 grounding rail lower INBD 
               
               
                 110 
                 main deck 
               
               
                 111 
                 keel flat 
               
               
                 112 
                 foscle deck 
               
               
                 113 
                 end of focsle 
               
               
                 114 
                 main deck 
               
               
                 115 
                 chine &amp; spray rail 
               
               
                 116 
                 baseline 
               
               
                 117 
                 buttocks 
               
               
                 118 
                 keel keel flat &amp; 6′ butt 
               
               
                 119 
                 knuckle 
               
               
                 120 
                 molded hull 
               
               
                 121 
                 chine &amp; spray rail trace 
               
               
                 130 
                 stern ramp 
               
               
                 140 
                 frames 
               
               
                 150 
                 stations 
               
               
                 151 
                 length between perpendiculars = 120′-0′ (36.6 m-0 m) 
               
               
                 152 
                 36 inch frame spacing (0.91 m) 
               
               
                 153 
                 centerline 
               
               
                 154 
                 deck tangent 
               
               
                 155 
                 ramp side 
               
               
                 156 
                 kuckle extent 
               
               
                 157 
                 planing wedge 
               
               
                 158 
                 focsle deck 
               
               
                 159 
                 knuckle 
               
               
                 160 
                 end of foscle 
               
               
                 161 
                 12′-0′ station spacing (3.7 m-0 m) 
               
               
                 170 
                 AFT control 
               
               
                 171 
                 main exhaust P/S 
               
               
                 172 
                 gen exhuast P/S 
               
               
                 173 
                 secondary intake P/S 
               
               
                 174 
                 folding jump seats (3) 
               
               
                 175 
                 galley mess table 
               
               
                 176 
                 galley 
               
               
                 177 
                 DWN hatch P/S 
               
               
                 178 
                 cargo tie down sockets (TYP) 
               
               
                 179 
                 folding jump seats (2) 
               
               
                 180 
                 DWN 
               
               
                 181 
                 EMER generator 
               
               
                 182 
                 deck LKR 
               
               
                 183 
                 chain (shown ramp up) 
               
               
                 184 
                 chain lock P/S chain (shown ramp down) 
               
               
                 185 
                 deck LKR 
               
               
                 186 
                 2 spare (waterjet) impellers P/S 
               
               
                 187 
                 navigator 
               
               
                 188 
                 thrust control 
               
               
                 189 
                 steering 
               
               
                 190 
                 ballistic steel plating 
               
               
                 191 
                 ballistic steel plating 
               
               
                 192 
                 transparent armor 
               
               
                 193 
                 ceramic armor overlay IB, OB &amp; FWD face of pilot house P/S 
               
               
                 200 
                 ballast 
               
               
                 201 
                 waterjet compt 
               
               
                 202 
                 intake compt 
               
               
                 203 
                 engine room 
               
               
                 204 
                 pumps 
               
               
                 205 
                 generator 
               
               
                 206 
                 potable water 
               
               
                 207 
                 waste 
               
               
                 208 
                 waterject compt 
               
               
                 209 
                 intake compt 
               
               
                 210 
                 engine room 
               
               
                 211 
                 generator 
               
               
                 212 
                 pumps 
               
               
                 213 
                 primary air intakes P/S 
               
               
                 214 
                 auxiliary machine space 
               
               
                 215 
                 stores 
               
               
                 216 
                 senior petty officers quarters 
               
               
                 217 
                 head 
               
               
                 218 
                 craft master 
               
               
                 219 
                 stores 
               
               
                 220 
                 forward stores 
               
               
                 221 
                 forward stores 
               
               
                 222 
                 forward stores 
               
               
                 230 
                 void 
               
               
                 231 
                 folding chart table 
               
               
                 232 
                 C4N bay 
               
               
                 240 
                 aft ballast P/S full (9.8 LT each) 
               
               
                 241 
                 aft ballast CL full (13.5 LT) 
               
               
                 242 
                 aft ballast P/S empty 
               
               
                 243 
                 aft ballast CL empty 
               
               
                 244 
                 forward ballast P/S empty 
               
               
                 245 
                 beach 186 feet (56.7 m) 
               
               
                 246 
                 fording depth 4.7 feet (1.43 m) 
               
               
                 247 
                 forward ballast P/S empty 
               
               
                 248 
                 beach 80 feet (24.4 m) 
               
               
                 249 
                 fording depth 2.0 feet (0.61 m) 
               
               
                 250 
                 forward ballast P/S full (16.6 LT each) 
               
               
                   
               
             
          
         
       
     
     All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. 
     The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.