Flat-bottomed landing craft

Abstract

This landing craft is capable of transporting heavy tracked and/or wheeled vehicles and troops from amphibious assault ships to beachheads or piers. A flat bottom has an unique design using Bernoulli's principle. The benefits are good speed, efficiency, durableness, and relatively economical and low noise.

Description

BACKGROUND OF THE INVENTION

Amphibious operations have played a major role in many wars by many nations in the past millenniums. Amphibious operations are usually considered the most complex form of warfare.

This landing craft would be fast, durable and efficient. If properly designed, it will have a cargo capacity for 3MIAI Abrams tanks or 10 LAVs or 400 plus marines or soldiers.

It will have the looks of a World War 2 landing craft but much faster and with good efficiency. It will be relatively economical when compared to high-tech ones; it will be easy to maintain. The unique design of this landing craft's flat bottom is what gives it its speed and efficiency.

There are several small shipyards in the U.S.A. that could design and build versions of this landing craft. The Navy and the Marine Corps as of 2014, have expressed an interest in the replacement of the present Landing Craft Utility (LCU). The study phase should begin soon.

BRIEF SUMMARY OF THE INVENTION

This landing craft will be designed to fit inside the well deck of current amphibious ships (LHAs, LHDs, LPDs, and LSDs). It is not a replacement for the present Landing Craft Air Cushion (LCAC) or the future Ship-to-Shore Connector (SSC).

It will carry a very heavy load. The utility type of landing craft (LCU) can have a stern gate to permit drive-through capability, and be able to link with other utility type of landing craft (LCU) to form a causeway.

The flat bottom of this landing craft operates on Bernoulli's principle. It would be less noisy than the air cushion landing crafts. Sometimes a vehicle can be wanted to do so much that it can't do anything well! This landing craft will just be a good connector from a ship to the beach, as a fast heavy lifter with a low noise advantage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a landing craft.

FIG. 2 is a side view of the craft.

FIG. 3 is a longitudinal section view of the craft.

FIG. 4 is an enlarged cross section view of the craft.

FIG. 5 is a partial bottom view.

FIG. 6 is an enlarged partial detail view.

FIG. 7 is a front view of a rectangular shape channel.

FIG. 8 is a front view of a triangular shape channel surface.

FIG. 9 is a front view of a partial elliptical shape channel surface.

FIG. 10 is a front view of a partial octagonal shape channel surface.

FIG. 11 is a side view of a moving barge.

DETAIL DESCRIPTION

This landing craft 10 has a ramp 12U in its up position, and a hinge 13 connects it to a cargo bay 16 adjacent a control station 14; see FIG. 1.

Refer to FIG. 2. The ramp about its hinge 13 is shown in its up position 12U and its down position 12D. A side view of the control station 14, propeller 18, and rudder 20 is shown. It doesn't matter if it looks like a World War 2 landing craft, if it gets the job done.

Refer to FIG. 3. The ramp 12U and its hinge 13 are shown. A channel surface CS is seen under the cargo bay 16. Two sets of propeller 18 and rudder 20 combinations can be used at the rear, one on each side of the craft; or just one set in the middle.

Refer to FIG. 4. The control station 14 is shown in the cargo bay 16. The water level WL shown is when the landing craft is under maximum load. The surfing layer SL is associated with the actions and effect of the narrow edges NE and channel surfaces CS, when the craft is in motion. Each channel surface CS has the geometrical shape of a half circle. There will also be some water resistance along the two sides of the craft.

Refer to FIG. 5. The craft in its direction D will generate a water flow WF through each channel surface CS. The water flow WF overall speed will vary directly with the speed of the craft in its direction D. Each narrow edge NE will cut through the water with negligible resistance. The propeller 18 and rudder 20 have been omitted for clarity.

Real fluid has a certain amount of internal friction called viscosity. Viscosity is essentially a frictional force between adjacent layers of fluid as the layers move past one another.

Water directly in contact with a channel surface CS is held to the surface by the adhesive force between the water molecules and those of the channel surface CS. Viscosity in water is very low, even in sea water; it can be neglected for this application.

Where the speed of substantially horizontal (level) water is high the pressure is low, and where the speed is low the pressure is high; this is BERNOULLI'S PRINCIPLE.

FIG. 6 has the ever changing water level WL “around” and the ever changing surfing layer SL “under” the craft 10 and its cargo bay 16. The craft direction D and the velocity gradient VG in the water are in opposite directions. The “speed near” SN the channel surface CS is slightly lesser than the “speed in the middle” SM of the channel.

The substantially horizontal channels create a relatively higher speed in the water within the channels of the craft 10 and produces a LOWER PRESSURE. The craft 10 can surf over the relatively HIGHER PRESSURE of the water under its flat bottom, see FIG. 6. Water is incompressible in its liquid state, thereby forming substantially layers for surfing.

The following is a few of the optional geometrical shapes that can be applied to the channel surfaces CS of the channels. FIG. 7 is a rectangular shape channel surface RCS or a square shape. FIG. 8 is a triangular shape channel surface TCS. FIG. 9 is a partial elliptical shape channel surface ECS. FIG. 10 is a partial octagonal shape channel surface OSC. A barge 10A being moved through the water W with a cargo is shown in FIG. 11.

The basic design comprise a plurality of substantially horizontal channels and their adjacent very, narrow shaped edges NE under the flat bottom of the landing craft 10, running from stem to stern; this is very important. The channels obey BERNOULLI'S PRINCIPLE when the craft 10 is in a fast forward motion in a water environment, and the narrow edges NE cut through the water with negligible resistance.

In FIG. 11, the above applies also to the barge 10A for faster and easier moving through the water W environment. A properly designed barge 10A could carry the marines' “water slow” assault amphibious vehicles (AAV7s) close to the shore and discharge them. The vehicles would travel the remainder short distance in the water. The barge 10A has channels.

The concept can be applied to any type of flat bottom powered craft or unpowered or powered barge. The vessels can be used for transporting freight or passengers and for military or commercial usage. No high-tech plan, manufacture or evaluation is needed for the craft 10 or the barge 10A.

Claims

1) A craft with a bottom for water and having an upper cargo bay and comprising: a) many channels are constructed into said bottom throughout its length;b) many edges are adjacent to said channels and can cut through the water with no resistance, andc) whereby the said channels and edges obey Bernoulli's principle under said craft's bottom.

2) A craft with a flat bottom for a water environment and having an upper cargo bay as claimed in claim 1, said channels further comprising surfaces of various geometrical shapes; whereby said channels obey Bernoulli's principle when water is passing through said channels.