EP1490260A2

EP1490260A2 - Planing landing craft

Info

Publication number: EP1490260A2
Application number: EP03723754A
Authority: EP
Inventors: Ken Maloney; John Richards; Robert A. Stringer; Jr. Charles S. Whipple
Original assignee: Textron Innovations Inc
Current assignee: Textron Innovations Inc
Priority date: 2002-03-14
Filing date: 2003-03-14
Publication date: 2004-12-29
Also published as: WO2003078242A3; WO2003078242A2; NZ535859A; AU2003235431A1

Abstract

An improved landing craft, includes a hull (11) that supports bow (19) and stern ramps (20) 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

PATENT APPLICATION

TITLE OF THE INVENTION

PLANING LANDING CRAFT INVENTORS:

M ALONE Y, Ken, a US citizen, of New Orleans, Louisiana; RICHARDS, John, a US citizen, of Metairie, Louisiana; STRINGER, Robert, A., a US citizen, of Slidell, Louisiana; WHIPPLE, Jr., Charles, S., a U.S. citizen, of Slidell, Louisiana. ASSIGNEE: TEXTRON INC., Providence, Rhode Island. CROSS-REFERENCE TO RELATED APPLICATIONS

Priority of US Provisional Patent Application Serial No. 60/363,968, filed 14 March 2002, is hereby claimed.

US Provisional Patent Application Serial No. 60/363,968, filed 14 March 2002, is hereby incorporated by reference.

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 PATENT 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 SKID WAY

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 waterjet 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:

Figure 1 is perspective view of the preferred embodiment of the apparatus of the present invention;

Figure 2 is a partial sectional elevation view of the preferred embodiment of the apparatus of the present invention illustrating the hull body; Figure 3 is a schematic partial profile view of the hull body;

Figure 4 is a schematic partial plan view of the hull body;

Figure 5 is a fragmentary view of the preferred embodiment of the apparatus of the present invention showing the chine and spray rail configuration; Figure 6 is a fragmentary view of the preferred embodiment of the apparatus of the present invention illustrating the grounding rail portion;

Figure 7 is a fragmentary plan view of the preferred embodiment of the apparatus of the present invention illustrating the hull stem portion;

Figure 8 is a fragmentary elevation view of the preferred embodiment of the apparatus of the present invention illustrating the hull stem portion in profile;

Figure 9 is a stem elevation view of the preferred embodiment of the apparatus of the present invention;

Figure 10 is a partial plan view of the preferred embodiment of the apparatus of the present invention illustrating the bow portion thereof; Figure 1 1 is a fragmentary elevation view of the preferred embodiment of the apparatus of the present invention illustrating the bow portion thereof;

Figure 12 is a front, elevation view of the preferred embodiment of the apparatus of the present invention;

Figure 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;

Figure 14 is an elevation and partial cutaway view of the preferred embodiment of the apparatus of the present invention illustrating the stem portion thereof;

Figure 15 is an elevation and partial cutaway view of the preferred embodiment of the apparatus of the present invention showing the hull stem portion and illustrating the engine and waterjet portions thereof;

Figure 16 is a partial cutaway plan view of the preferred embodiment of the apparatus of the present invention;

Figure 17 is a partial cutaway elevation view of the preferred embodiment of the apparatus of the present invention; Figure 18 is a partial cutaway elevation view of the preferred embodiment of the apparatus of the present invention;

Figure 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;

Figure 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;

Figure 21 is a fragmentary elevation view of the preferred embodiment of the apparatus of the present invention illustrating the stem portion when spaced from the sea bed(showing full load with maximum trim);

Figure 22 is a fragmentary elevation view of the preferred embodiment of the apparatus of the present invention illustrating the stem portion when resting on the sea bed(showing no cargo); Figure 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;

Figure 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; Figure 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;

Figure 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(LHA well);

Figure 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(showing full load with maximum trim by stem);

Figure 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); Figure 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

Figure 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 figures 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 stem 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 stem 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. Stem ramp 20 is moveably attached to hull 11 at the vessel stern 16. Stem 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 figures 13 and 15). The landing craft 10 of the present invention is adapted to carry multiple large military vehicles such as tanks 23 in figures 1, 20 and 23, trucks 50 as shown in figure 19, or personnel carriers 51 (or other large vehicles, automobiles, etc.) as shown in figure 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 figures 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 figure 9). A chine 30 and spray rail 31 are provided both port and starboard as shown in figures 2, 3 and 4. Forecastles (commonly known as F'ocles) 27, 28 can be provided at port and starboard positions as shown in figures 1 and 10. Ballast tanks are provided in both the bow 15 and stem 16 portion of hull 11 for ballasting either the bow 15 or stem 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 (figure 8) 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 figures 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 figure 8 that also displays keel flat 29, planing wedges 55, 56, port and starboard grounding rails 34, 5. Figure 9 shows the aft facing discharge or propulsion part of the waterjets 32. In figure 8, is waterjet guard 43 extends below stem ramp 20. Guard 43 is contacted by stem ramp 20 when ramp 20 reaches a lower, unloading or loading position. The stem 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 stem 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 stem ramp 20. The port and starboard aft ballast tanks 40, 41 are preferably positioned on opposing sides of stem ramp 20 and behind transom 38. The port 40, starboard 41 and central 43 ballast tanks can be seen in figures 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 figures 25 and 26, the landing craft 10 of the present invention has backed into a wet well so that the stem ramp 20 can be lowered (see figure 26) enabling vehicles 23, 50 or 51 or a combination thereof to be loaded via stem ramp 21 to the vessel deck 12. In figure 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. Figure 27 shows a full load, maximum trim by stem. In figure 28, the stem ramp 28 is in a lower position for receiving cargo, vehicles or the like and wherein a full load is shown with maximum trim by bow.

Figure 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 figure 30, the position of the vessel hull 11 has been reversed so that the stem 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 figure 29, the stem gate 20 extends beyond stem gate 54 whereas in figure 30, the bow of ramp 19 extends beyond stem gate 54 of wet well 53 of a well deck ship.

In figure 23, a tank 23 is shown unloading via bow ramp 19 wherein water surface 52 almost covers ramp 19. In figure 24, ramp 19 is only partially covered by water surface 52.

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 stem

17 port side

18 starboard side

19 bow ramp 20 stem 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 waterjet 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 stem 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 offocsle

114 main deck

115 chine & spray rail 116 baseline

117 buttocks

118 keel keel flat & 6" butt

119 knuckle

120 molded hull 121 chine & spray rail trace

130 stem ramp

140 frames

150 stations

151 length between perpendiculars = 120' 0'(36.6m - 0m)

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(3.7m - 0m) 170 AFT control 171 main exhaust P/S

172 gen exhaust 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 & 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(56.7m)

246 fording depth 4.7 feet( 1.43m) 247 forward ballast P/S empty

248 beach 80 feet(24.4m)

249 fording depth 2.0 feet(O.όlm) 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.

Claims

1. A landing craft, comprising: a) a planing hull having bow, stem, port and starboard portions, a hull bottom that includes a generally flat wide keel portion and port and starboard chines, a transom, and an upper deck; b) the hull supporting one or more engines; c) waterjets powered by the engines for planing the hull; d) a bow ramp supported by the hull and positioned at the hull bow portion, the bow ramp being movable relative to the hull between raised and lowered positions; e) a stem ramp supported by the hull and positioned at the hull stem portion, the stern ramp being movable relative to the hull between raised and lowered positions; f) the hull having one or more bow ballast tanks next to the bow; g) the hull having one or more stem ballast tanks next to the stem; and h) grounding rails on the hull that form a tripod arrangement with the keel portion that ensures the craft stability while improving control and maneuverability during high speed turns when the hull is on plane.

2. The landing craft of claim 1 wherein the bow ramp moves forwardly and away from the hull when it is moved from the raised to the lowered position.

3. The landing craft of claim 1 wherein the bow ramp is pivotally attached to the hull.

4. The landing craft of claim 1 wherein the stem ramp moves rearwardly and away from the hull when it is moved from the raised to the lowered position.

5. The landing craft of claim 1 wherein the stem ramp is pivotally attached to the hull.

6. The landing craft of claim 1 wherein the hull has a beam of between about 35 and 50 feet.

7. The landing craft of claim 1 wherein the hull has a length of between about 130 and 150 feet.

8. The landing craft of claim 1 wherein the hull is configured to be scaled to a different length or beam by increasing the length or width of the generally flat keel portion.

9. The landing craft of claim 1 wherein the rear ballast tanks include port and starboard ballast tanks the are aft the transom and on opposing sides of the stem ramp.

10. The landing craft of claim 1 further comprising a jet guard on the hull stem portion that defines a wedge that helps to damp aft pitching motions initiated by waves.

11. The landing craft of claim 1 wherein the transom has a deadrise angle of less than 10 degrees.

12. The landing craft of claim 1 wherein the transom has a deadrise angle of about 5 degrees.

13. The landing craft of claim 1 wherein the hull is configured to be beached wherein the flat keel portion contacts the seabed.

14. The landing craft of claim 1 wherein the waterjets are mounted just forward of the transom.

15. The landing craft of figure 1 wherein the hull is of a aluminum material.

16. The landing craft of figure 1 wherein the hull is of an steel material.

17. A landing craft, comprising: a) a planing hull having bow, stem, port and starboard portions, a hull bottom that includes a generally flat wide keel portion and port and starboard chines, a transom, and an upper deck; b) the hull supporting one or more power units for planing the hull; c) a bow ramp supported by the hull and positioned at the hull bow portion, the bow ramp being movable relative to the hull between raised and lowered positions; d) a stem ramp supported by the hull and positioned at the hull stern portion, the stem ramp being movable relative to the hull between raised and lowered positions; e) the hull having one or more bow ballast tanks next to the bow; f) the hull having one or more stem ballast tanks next to the stem; and g) a waterjet guard extending from the transom that engages the ramp when the ramp is lowered.

18. The landing craft of claim 17 wherein the bow ramp moves forwardly and away from the hull when it is moved from the raised to the lowered position.

19. The landing craft of claim 17 wherein the bow ramp is pivotally attached to the hull.

20. The landing craft of claim 17 wherein each ramp has a pivot and the pivots are generally parallel.

21. The landing craft of claim 17 wherein the ramps are so positioned that a wheeled vehicle can drive through the deck area by entering the deck area via one of the ramps and leaving the deck area via the other of the ramps.

22. The landing craft of claim 17 wherein the ramps are so positioned that a truck can drive through the deck area by entering the deck area via one of the ramps and leaving the deck area via the other of the ramps.

23. The landing craft of claim 17 wherein the ramps are so positioned that a tank can drive through the deck area by entering the deck area via one of the ramps and leaving the deck area via the other of the ramps.

24. The landing craft of claim 17 wherein the ramps are so positioned that an automobile can drive through the deck area by entering the deck area via one of the ramps and leaving the deck area via the other of the ramps.

25. The landing craft of claim 17 wherein the stem ramp moves rearwardly and away from the hull when it is moved from the raised to the lowered position.

26. The landing craft of claim 17 wherein the stem ramp is pivotally attached to the hull.

27. The landing craft of claim 17 wherein the hull has a beam of between about 35 and 50 feet.

28. The landing craft of claim 17 wherein the hull has a length of between about

130 and 150 feet.

29. The landing craft of claim 17 wherein the hull can be scaled to different length and beam by increasing the length or width of the generally flat keel portion.

30. The landing craft of claim 17 wherein the rear ballast tanks include port and starboard ballast tanks the are aft the transom and on opposing sides of the stem ramp.

31. The landing craft of claim 17 wherein the jet guard defines a wedge that helps to damp aft pitching motions initiated by waves.

32. The landing craft of claim 17 wherein the transom has a deadrise angle of less than 10 degrees.

33. The landing craft of claim 17 wherein the transom has a deadrise angle of about 5 degrees.

34. The landing craft of claim 17 wherein the hull is configured to be beached wherein the flat keel portion contacts the seabed.

35. The landing craft of claim 17 further comprising grounding rails on the hull that are spaced away from the generally flat wide keep portion forming a tripod arrangement that ensures craft stability when beached or when resting in the wet well of a well deck ship.

36. A landing craft, comprising: a) a planing hull having bow, stem, port and starboard portions, a hull bottom that includes a generally flat wide keel portion and port and starboard chines, a transom, and an upper deck; b) the hull supporting one or more power units; c) a bow ramp supported by the hull and positioned at the hull bow portion, the bow ramp being movable relative to the hull between raised and lowered positions wherein the bow ramp inclines forwardly in front of the hull when lowered; d) a stem ramp supported by the hull and positioned at the hull stem portion, the bow ramp being movable relative to the hull between raised and lowered positions, the stern ramp forming an obtuse angle with the generally flat keel portion; e) the hull having one or more bow ballast tanks next to the bow; f) the hull having a pair of stem ballast tanks that are positioned next to the stem portion of the hull and on opposing sides of the stem ramp.

37. The landing craft of claim 36 wherein the bow ramp moves forwardly away from the hull when it is moved from the raised to the lowered position.

38. The landing craft of claim 36 wherein the bow ramp is pivotally attached to the hull.

39. The landing craft of claim 36 wherein the stem ramp moves rearwardly away from the hull when it is moved from the raised to the lowered position.

40. The landing craft of claim 36 wherein the stem ramp is pivotally attached to the hull.

41. The landing craft of claim 36 wherein the hull has a beam of between about 35 and 50 feet.

42. The landing craft of claim 36 wherein the hul 1 has a length of between about

130 and 150 feet.

43. The landing craft of claim 36 wherein the hull can be scaled to different length and beam by increasing the length or width of the generally flat keel portion.

44. The landing craft of claim 36 wherein the rear ballast tanks include port and starboard ballast tanks the are aft the transom.

45. The landing craft of claim 36 further comprising a jet guard on the hull stem portion that defines a wedge that helps to damp aft pitching motions initiated by waves.

46. The landing craft of claim 36 wherein the transom has a deadrise angle of less than 10 degrees.

47. The landing craft of claim 36 wherein the transom has a deadrise angle of about 5 degrees.

48. The landing craft of claim 36 wherein the hull is configured to be beached wherein the flat keel portion contacts the seabed.

49. The landing craft of claim 36 wherein the waterjets are mounted just forward of the transom.

50. The landing craft of figure 36 wherein the hull is of an aluminum material.

51. The landing craft of figure 36 wherein the hull is of a steel material.

52. A landing craft, comprising: a) a planing hull having bow, stem, port and starboard portions, a hull bottom that includes a generally flat wide keel portion and port and starboard chines, a transom, and an upper deck; b) the hull supporting one or more power units; c) a bow ramp supported by the hull and positioned at the hull bow portion, the bow ramp being movable relative to the hull between raised and lowered positions; d) a bow facing control station for controlling the craft and bow ramp from a forward position; e) a stem ramp supported by the hull and positioned at the hull stem portion, the bow ramp being movable relative to the hull between raised and lowered positions, the stem ramp forming an obtuse angle with the generally flat keel portion; f) an aft facing control station for controlling the craft and stem ramp from an aft position; g) the hull having one or more bow ballast tanks next to the bow; and h) the hull having stem ballast tanks that are positioned next to the stem portion of the hull and on opposing sides of the stem ramp.

53. The landing craft of claim 52 wherein the bow ramp moves forwardly away from the hull when it is moved from the raised to the lowered position.

54. The landing craft of claim 52 wherein the bow ramp is pivotally attached to the hull.

55. The landing craft of claim 52 wherein the stem ramp moves rearwardly away from the hull when it is moved from the raised to the lowered position.

56. The landing craft of claim 52 wherein the stem ramp is pivotally attached to the hull.

57. The landing craft of claim 52 wherein the hull has a beam of between about 35 and 50 feet.

58. The landing craft of claim 52 wherein the hull has a length of between about 130 and 150 feet.

59. The landing craft of claim 52 wherein the hull can be scaled to different length and beam by increasing the length or width of the generally flat keel portion.

60. The landing craft of claim 52 wherein the rear ballast tanks include port and starboard ballast tanks the are aft the transom.

61. The landing craft of claim 52 further comprising a jet guard on the hull stem portion that defines a wedge that helps to damp aft pitching motions initiated by waves.

62. The landing craft of claim 52 wherein the transom has a deadrise angle of less than 10 degrees.

63. The landing craft of claim 52 wherein the transom has a deadrise angle of about 5 degrees.

64. The landing craft of claim 52 wherein the hull is configured to be beached wherein the flat keel portion contacts the seabed.

65. The landing craft of claim 52 wherein the waterjets are mounted just forward of the transom.

66. The landing craft of figure 52 wherein the hull is of an aluminum material.

67. The landing craft of figure 52 wherein the hull is of a steel material.