SE1351188A1 - Roll-on / roll-off ferry as well as berth for such ferry - Google Patents

Abstract

23 ABSTRACT[0045] Various aspects provide for a ferry having a lower deck. An entrance in the hull provides access to the lower deck Via an entrance ramp. The entrance may belocated sufficiently high aboVe the Waterline that a sea-tight door to the entrance is notrequired. One or more upper decks may be accessed Via upperdeck access ramps, Whichmay connect an upper deck to an upperdeck entrance. A pier may comprise a plurality of platforrns configured to mate With a corresponding plurality of entrances on a ferry.

Description

ROLL-ON / ROLL-OFF-FARJA BACKGROUND Technical area

The present invention relates to ro-ro ferries in general.

Description of related technology

A ferry designed so that only wheeled vehicles can allow access according to the "roll-on / roll-off" principle. Vehicles (for example cars, trucks, buses, trailers and the like) can run on and off the ferry via one or more pas sager; sadana farjor benamns roro-farjor.

Large ro-ro ferries often have a stone vessel width of 15 meters and a stone draft of 4 meters. A freeboard (the vertical distance from the waterline to the lowest point on the jump where water can enter the hull) can be more than 3 meters. Large ferries usually have several decks, so that vehicles can be loaded on several

Hosting multiple clacks posed challenges. In order to improve stability, the load (and thus the clack warp load is placed) is generally placed as far as possible, taking into account the minimum requirements for reserve buoyancy. However, a lower clack located below the lowest point on the gap on the hull may be subject to flooding.

An upper clack can be drained into the sea. A clack that is not drained into the sea (for example a lower clack) can be called a floodable clack. The lowest point on the hull at which water can enter a floodable clack can be called the flood point. A floodable clack and hull may form an inner "bathtub" within the vessel, and a floodable volume between the flood point and the floodable deck (defined by the hull) may describe the volume of the floodable "bathtub". Water that flows into the bathtub cannot flow out without impact, which meant a variety of challenges. If such a volume is large, flooding can result in the vessel becoming unstable (and, for example, capsizing). To minimize this floodable volume, previous ferries have minimized the vertical distance between the flood point and the floodable deck (for example to less than 1.5 meters), which reduces the maximum volume of water that could be accommodated in the "bathtub" and thus destabilizes the ferry.

Since flooding is often associated with shipwrecks or weather conditions, regulations (eg frail International Maritime Organization, IMO) may specify different requirements to prevent flooding (eg a minimum height between the waterline and the flood point). Since the tipping point of an upright vessel may be different from that of a tipping vessel, some tests require a minimum distance between the tipping point and the waterline when the vessel has a tipping point (for example in a test of intact stability). For example, an IMO provision on paint stability may require that a flood point must not be below the water surface when the vessel has a list with an angle of 40 degrees and transports its dimensioning load. Simulations are widely used to test this shape.

Some prior art ferries have a closable hatch that penetrates a port into the ferry. At the quay, the hatch is opened to allow the vehicles to drive on or off the ferry. The hatch is closed with a watertight seal before the ship leaves the quay. The waterproof closure must guarantee water tightness under normal conditions and under extreme weather conditions. The closure must provide water tightness during testing (and simulations, including tilt), so a sufficient circumference of the gate must be sealed so that the flood point remains above the water level (for example at a 40 degree tilt). Such doors and closures are expensive and easy to handle.

Some prior art ferries provide access to a lower clack via movable ramps from the deck. Such devices can be expensive and cumbersome to maneuver, especially for large ferries. A damaged movable ramp cannot be used and can therefore prevent unloading (for example after an accident). Movable devices can be dangerous, especially with a large number of people in cars and trucks. A ramp that is moved between two clacks (i.e. can be placed to load either a byre clack or a lower clack) can form a "bottleneck" during loading because the decks must be loaded sequentially.

An improved ferry would provide access to multiple clacks without requiring a waterproof hatch or responsive internal equipment, meet relevant IMO regulations and provide adequate load capacity (and preferably improve mooring and / or loading / unloading speed). Ideally, an improved ferry should provide increased safety and efficiency at lower capital costs and / or operating costs than existing ferries.

SUMMARY OF THE INVENTION

Various aspects provide a ferry having a lower deck, which may be a floodable clack. A ferry may comprise one or more upper clack above the lower deck. A passage to the lower deck in the hull provides access to the lower clack via a passage ramp to the lower deck. The passage to the lower clack can be placed sufficiently Mgt above the waterline that no watertight hatch is required for the passage. In some embodiments, no portion of the passage to the lower clack is below a simulated waterline when the ferry is tilted at an angle (e.g., 40 degrees) that represents a damage situation.

A ferry may comprise one or more upper decks, each of which may be connected to a passage to the upper clack via a ramp to the upper deck. Some ramps have a common passage; some ramps have separate passages. Passage ramps to the upper and lower clack are fixed ramps in certain embodiments. A number of fixed passenger ramps and passages can offer fast simultaneous loading (or unloading) of an upper clack and a lower one which improves efficiency. In some cases, several passages are in the spirit of a ferry. A faija can have passages in the fore and aft.

In a preferred embodiment, a ferry comprises a lower clack and at least two byre decks. Fixed passenger ramps connect passages to each of the decks, and traffic can be loaded simultaneously on the lower 'Jacket' and the upper decks. In some embodiments, one ferry comprises front and stern ramps, and one of the front and stern ramps is used for loading (and the other for unloading). A ferry may comprise passenger ramps in one spirit (for example the stern or forenoon), and may comprise several ramps for access to a given clack (for example a first front ramp and a second stern ramp). A first stern ramp can be used for loading while a second stern ramp allows (for example simultaneously) unloading. The first and second stern ramps can be used in parallel (for example, swimming for loading). In one embodiment, a ferry includes front and aft pass saws, each with multiple ramps, each ramp giving access to a clack.

BRIEF DESCRIPTION OF FIGURES

FIG. 1A and 1B are schematic illustrations of various aspects of a ferry, according to certain embodiments. Fig. 1A is a side view; Fig. 1B is a plan view.

FIG. 2A-D are schematic illustrations of various aspects of a fore and / or stern of a ferry, according to certain embodiments. Figs. 2A and 2B illustrate a bow (or transom) of the ferry 202, showing an exemplary passage 130 to the lower clack. Figs. 2C and 2D illustrate a bow (or transom) of the ferry 204.

FIG. 3A-C are schematic illustrations of a ferry, according to certain embodiments. Fig. 3A illustrates a side view; Fig. 3B illustrates a plan view, and Fig. 3C illustrates a side view from behind of the portion furthest aft on the ferry 300.

FIG. 4A-C are schematic illustrations of a ferry, according to certain embodiments. Fig. 4A illustrates a side view; Fig. 4B illustrates a plan view, and Fig. 4C illustrates a side view from behind of the portion furthest aft on the ferry 400.

FIG. 5 is a schematic illustration of a ferry, according to certain embodiments. Fig. 5 illustrates a perspective view.

FIG. 6A-B are schematic illustrations of a quay designed to operate a ferry, according to certain embodiments. Fig. 6A illustrates a side view; Fig. 6B illustrates a plan view.

FIG. 7A and 7B are schematic illustrations of a ferry, according to certain embodiments. Fig. 7A illustrates a side view; Fig. 7B illustrates a plan view.

DETAILED DESCRIPTION OF THE INVENTION

A ro-ro ferry may include one or more ramps that provide vehicles access to one or more decks, including a floodable clack. A passage to the ferry leading to a floodable clack may be located Mgt above the waterline to substantially prevent the ingress of water to the lower decks. In some cases, the ferry has an integrated, cohesive hull, without a closable vehicle gate between the passage and the waterline. A cohesive hull without a closable door can mean reduced cost and / or improved safety.

Various features are described. Reference numerals denoting features are generally the same between the figures. For the sake of simplicity, certain reference numerals have been omitted from certain figures to facilitate the explanation of other features. Each special feature can be combined with any other special feature.

FIG. 1A and 1B are schematic illustrations of various aspects of a ferry, according to certain embodiments. Fig. 1A is a side view; Fig. 1B is a plan view. In accordance with normal terminology, the ferry 100 (and other ferries described as having) comprises a hull 101 with a fore 102 and a stern 104. The bow comprises a bow 103 and the stern comprises a transom 105. The ferry has a port side 106, a starboard side 107 and a center line 109 frail went to the stern midway between the port and starboard sides. A vessel width 108 between the port and starboard sides indicates the width of the vessel. The vessel width 108 can be between 10 and 45 meters, including between 18 and 40 meters. The vessel width can be more than 15 meters, more than 20 meters, and more than 25 meters.

The ferry has a baseline 110 and a construction waterline 1 (for example, a predetermined waterline when empty, has a standard load or has a maximum load). Depth 115 indicates the vertical distance between baseline 110 and waterline 120. In some embodiments, depth 115 may be stone at 4 meters, including stone at 4.5 meters, stone at 5.8 meters or even stone at 7 meters. The depth can be less than 10 meters.

A ferry may comprise one or more clacks, including a lower clack (for example, a floodable clack, not shown). A passage 1 to the lower deck of the hull gives vehicles access to the lower clack via a passage ramp to the lower clack (not shown). Passages can in this representation be indicated by the part of the passage closest to the waterline 120 (for example the passage floor), although a passage includes an open "area" that is sufficient for vehicles to pass through the hull. The passage 130 to the lower clack can reduce the risk of flooding by being placed over the waterline 120, depending on the size of the vessel (for example, the height of the lower deck above the baseline and the number of upper clack above the lower deck, if any).

The passage 130 to the lower clack may be located at a height 140 above the waterline 120 which is at least 50%, preferably at least 60%, including at least 80% of the depth 115. The height 140 may be stone at the depth 115, including 20% or up to 50% of the draft 115 stone at the draft 115. The height 140 can be twice as large as the draft 115. The passage 130 to the lower clack can be located at least two meters, preferably at least 3 meters, including at least 4 meters Above the waterline 120. The passage 130 to the lower clack can be sufficiently wide (Fig. 1B) for vehicles to be able to drive on the ferry and drive down the passenger ramp to the lower clack to the lower deck. In some embodiments, the lower clack pass 130 is sufficiently wide for at least two parallel lanes of truck traffic. The passage 130 to the lower clack can be at least 6 meters wide, including at least 8 meters wide.

In some embodiments, a ferry as described (e.g., ferry 100) does not have a closable port (e.g., a vehicle port) below the hood 140 above the waterline 120. The hull 101 itself does not have a passage below the hood 140 that may allow water to flow to the lower clack 310. Without such a passage, the ferry does not need a closable gate which is opened (to give access to the lower deck) and closed (to shut out water), which reduces the complexity and cost.

The passage 130 to the lower clack may be located at various positions around the hull, including near the front and / or stern of the ferry (for example in the bow or transom). In the exemplary ferry 100, the passage 130 to the lower clack is located in the transom 104. The passage 130 to the lower clack may be located in the bow 103. Some ferries have only one passage to the lower clack; some ferries include several passages to the lower deck. Several passages to the lower clack may be located in one place (for example the stern). In some cases the stern comprises a passage to the lower clack (for example in the transom) and the forehead comprises another passage to the lower clack (for example in the bow). Different passages to the lower clack may be at the same height 140 and / or different heights 140.

FIG. 2A-D are schematic illustrations of various aspects of a liner and / or stern of a ferry, according to certain embodiments. Figs. 2A and 2B illustrate a bow (or transom) of the ferry 202, showing an exemplary passage 130 to the lower clack. Figs. 2C and 2D illustrate a bow (or transom) of the ferry 204. For the sake of clarity, the passages are indicated by surfaces closest to the waterline.

FIG. 2A — D illustrate exemplary side views of a bow or transom seen along the centerline 109 (viewed aft from a position in front of the bow or forward from a position behind the stern). Fig. 2A — D illustrates different embodiments of a passage to the lower clack compared with (among other things) other points for getting on board or ashore from the ferry.

As explained in more detail with reference to Figs. 3A-C, a passage 321 to the upper clack may provide access to an upper clack located above the lower deck. An upper clack can be a passage to a drainable clack from which water can flow into the sea, and water that enters a passage 321 to the upper clack can flow out into the sea - not to a lower clack. A passage 321 to the upper clack may in some simulations go below the waterline 120 without causing flooding because the passage to the upper clack is not in fluid communication with the lower deck.

A passage 130 to the lower clack may be centrally located (between the port and starboard sides) and / or be laterally symmetrical with respect to the center line 109, so that no section of the passage to the lower clack 130 passes below the waterline 120 at a related ( simulated) tilt. Fig. 2A illustrates an embodiment with a passage 130 to the lower clack located below (in this example) a passage 321 to the upper deck, as shown by the vertical offset 135. Fig. 2C illustrates an embodiment with a passage to the lower clack located the vertical the displacement 135 higher than the passage 321 to the upper A passage to the lower clack and a passage to the upper clack can be placed at the same height 11 140. The vertical displacement 135 can be between 0.3 and 3 m, including between 0.5 and 2 m , including between 0.75 and 1.5 meters.

The width of the passage 130 to the lower deck can be chosen so that it optimizes cargo loading and safety (for example, as wide as possible, with the consideration taken to prevent flooding in the case of simulated bias). According to various specifications (for example, the International Maritime Organization, IMO), a ship with a list (for example, if the angle of the list 40 is 40 degrees) must resist flooding through a variety of atgards. The angle 40 can be 30-50 degrees, including 35-45 degrees, including 40 degrees. In some ferries, the damage tolerance requires a minimum buoyancy in the event of damage (for example at a list). Figs. 2A and 2B compare the ferry 202 in an upright position and with a list, respectively. Fig. 2C and 2D compare ferry 204 in upright position and with list, respectively. In some embodiments, a ferry described has no flood point (e.g., a portion of passage 130) located below the waterline when the ferry is tilted at an angle of 40 (e.g. during a simulation as in Figs. 2B and 2D). As shown in Figs. 2B and 2D, the lowest point of the passage 130 to the lower deck is at a distance 210 above the waterline when the ferry is inclined at an angle of 40 (for example during a simulation).

The width (between the side boundaries) of a passage to the lower deck can be chosen so that it meets different bias requirements. The distance 220 between the passage 130 to the lower deck and the side of the ferry can be selected in accordance with (among other things) the ship width 108, the height 140 and a desired width of the passage 130 to the lower deck, in combination with one or more simulated list angles. The distance 220 may be at least 15% of the vessel width 108, preferably at least 20% of the vessel width 108, including at least 25% of the vessel width 108 or at least 30% of the vessel width 108. In some embodiments (e.g. as in Fig. 2D) a passage to The lower clack remains above the waterline even when a portion of a passage to the upper clack is below the waterline, which prevents water from entering the lower deck.

FIG. 3A-C are schematic illustrations of a ferry, according to certain embodiments. Fig. 3A illustrates a side view; Fig. 3B illustrates a plan view, and Fig. 3C illustrates a side view from behind of the portion furthest aft of the ferry 300. The ferry 300 comprises a lower clack 310 connected to the passage 130 to the lower clack via a passenger ramp 312 to the lower clack. In some implementations, a passenger ramp can be movable (for example to different heights). In some embodiments, it is preferable to use a fixed passenger ramp. A fixed passenger saw ramp can lead to lower construction costs, easier handling, reduced maintenance and / or safer implementation than a mobile ramp. A fixed ramp can generally be more resistant to damage than a movable ramp. A movable ramp that requires equipment for use (for example to raise and lower the ramp) could be damaged in an accident, and such damage could prevent unloading. A fixed passenger ramp can facilitate unloading, especially when the ferry is damaged, is partially sunk, tilts, has a list and the like.

Preferably, the lower ramp passenger ramp 312 has a slope not exceeding 18 degrees from the horizontal plane, preferably 11 degrees, preferably 7 degrees. Lower clack 310 can be placed near the waterline 120. In some cases a lower clack is below the waterline 120. Some ferries have a minimum requirement for reserve buoyancy, which can be at least partially met by placing the lower clack 310 above the waterline and creating a closable space below the lower deck. 310. The lower deck 310 may be located at a distance 316 which is 2 to 5 meters, including 2.5 to 3.5 meters, above the waterline 120. The slope and length of the passenger ramp 312 to the lower deck may be selected according to the size of the vessel. the height 140, the distance 316, and a desired limitation (for example for maximum inclination) associated with the type of vehicle to use the ramp. In some embodiments, the passage 130 to the lower deck may be located on a WO 140 Above the waterline 120 selected in accordance with the distance of the lower deck 316 above the waterline (for example, the height 140 may be stone at the distance between the lower deck and the waterline 120, including more than two times the distance, including more than three times the distance). A vertical al / stand from lower clack 310 to passage 130 to lower clack (height 140 - distance 316) can be stone at 1.5 meters, stone at 2.5 meters, stone at 3.5 meters, or even stone at 4.5 meters. In some embodiments, the vertical distance from the lower deck 310 to the passage 130 to the lower deck is greater than 25%, including stone at 50%, including stone at 75%, including stone at 100%, including stone at 125%, of the vertical distance from lower deck 310 to baseline 110 (distance 316 plus draft 115). In a preferred embodiment, the draft 115 may be 4 to 11 meters, the distance 316 may be 2 to 4 meters, and the passage to the lower deck 130 is at least 2 meters, preferably at least 3 meters, above the lower deck.

A ferry may comprise one or more byre clack placed over a lower one. An upper clack may be a clack which is not floodable, and may be a drainable clack from which water can flow into the sea by gravity. The exemplary ferry 300 comprises a first upper clack 320 and a second upper clack 330. The upper deck 320 dr 14 connected to a passage 321 to the upper clack (in this example located in the stern) via a ramp 322 to the upper deck. The upper deck 330 is (in this example) connected to the passage 321 to the upper clack via a ramp 332 to the upper clack. A passage ramp to the upper clack does not have to be inclined (for example with a passage to the upper clack at essentially the same level as its respective upper clack). A passage ramp to the upper clack can slope downwards from its respective upper clack to its respective passage to the upper clack. In some embodiments, a first and a second upper clack may use the same passage to the upper clack. In some cases, different upper clack uses different passages. A passenger ramp to the upper clack can be movable. Preferably, a passenger ramp is a fixed ramp.

The distances 326 and 336 between the tires can be selected according to the expected vehicle heights. In an exemplary embodiment, each of the distances 326 and 336 may be sufficiently large for trucks and trailers, and may thus offer at least 4.4 meters of clear height between a clacks floor and the roof above. In some cases, a free height Over a clack (for example an upper clack) can be dimensioned to receive 1510. vehicles (which for example do not exceed 3 meters). The decks may be connected via one or more non-mandatory loading ramps 314. A loading ramp may be dimensioned (for example width, length, location, slope) to allow traffic on an underlying clack to reach a deck above, and may be located in different layers to facilitate smooth traffic flow inside the ferry. As shown in Fig. 3B, a loading ramp 314 may be located on one side of a ferry.

A ferry may comprise a plurality of passages and passage ramps, all of which may be located in a spirit (for example, the bow or stern). As shown in Fig. 3B, in the ferry 300, the upper deck 320 can be reached via two passage ramps 322 to the upper deck, each of which is connected to a separate passage 321 to the upper deck. Similarly, the upper deck 330 can be accessed via two passage ramps 332 to the upper deck, each of which is connected to a separate passage 321 to the upper deck. A passage (for example a port passage or starboard passage) can offer access to two or more upper decks. In one arrangement, the passage 130 to the lower deck is centrally located, with passages 321 to the upper clack aligned on each side, and each passage 321 to the upper clack giving access to a ramp 322 to the upper clack and a ramp 332 to the upper clack. In some cases, a port passage gives sage access to an upper clack and a starboard passage gives access to another upper clack. A passage to the upper clack may be at the same height as a passage to the lower clack. A passage to the upper deck may be at a different height from a passage to the lower deck, as illustrated by the vertical displacement 135. A waterproof barrier 142 may prevent water from flowing into the lower deck 310 (e.g. from the ramp 322 to the upper deck ).

A ferry may comprise a propulsion system 342, which may comprise a piston engine, a turbine and the like, which are arranged to generate a traction force on the ferry (for example with a propeller, a water jet and the like). In some embodiments, a propulsion system (e.g., a water jet, or, as shown in Fig. 3A, a rudder propeller 344) may be provided to provide lateral traction. A significant lateral traction (for example in the stern) can allow a reduced walking radius for the ferry, which makes it possible for the ferry to quickly "turn around" and (for example) back towards a quay. A ferry with loading / unloading ramps in one spirit (for example the stern) and a propulsion system that allows fast watering can sail forward to a destination 16 to quickly turn around and back towards the quay for unloading. Within certain areas of use, such a design can reduce the need for passages for front and aft loading, which simplifies the design work and allows sufficiently short handling times in port. In some embodiments, a ferry comprises a large centrally located shaft-driven propeller and a rudder propeller on each side.

A ramp and its associated passage can be used for loading and / or unloading. In some cases a ramp and its associated passage are used for both loading and unloading. Some ferries include a water zone 334 to allow vehicles to turn around (for example, without reversing), which may allow the use of the same passage for paoch and corn. The water zone 334 can be stone up to 12 m in diameter, including stone up to 14 m in diameter.

FIG. 4A-C are schematic illustrations of a ferry, according to certain embodiments. Fig. 4A illustrates a side view; Fig. 4B illustrates a plan view, and Fig. 4C illustrates a side view from behind of the portion furthest aft of the ferry 400. The ferry 400 comprises a propulsion system 342 which is powered by natural gas (for example, methane, ethane and the like). The natural gas can preferably be delivered and stored as liquefied natural gas (LNG). The ferry 400 comprises an LNG engine 410 configured to drive one or more propellers and / or water jets. An LNG filling station 420 can be connected via a refueling ramp 324 to a clack (in this case an upper clack 320) to receive an LNG tank delivered on a slack (for example by a truck). The LNG refueling station 420 may include a detachable LNG refueling connection 430, which detachably can be connected to the LNG slab and transfer LNG from the slap to the engine 410. An LNG vent pipe 450 may provide ventilation of excess LNG (e.g. during storage).

The LNG refueling ramp can lead up from the deck in a direction towards the LNG refueling station. In a preferred embodiment, a truck with LNG trailer runs on ferry 400 via a passenger ramp, and then backs up LNG refueling ramp 440 to LNG refueling station 420, the LNG trailer can be unloaded from the truck, and the truck can leave the ferry. Such a design can provide an efficient replacement of empty LNG slaps to full slaps, and can eliminate the need for an on-board LNG storage tank (eg built-in). The filling station 420 may comprise a plurality of cradles 422. The cradles 422 may be designed (for example with straps or chains) to stabilize an LNG slack, especially with respect to tilt and / or sudden stops. The rocks 422 may be explosion-proof and / or fireproof (for example, by directing gases away from the ferry 400 in the event of a fire or explosion), which may improve safety compared to an internal LNG tank enclosed in a ship.

A method of replacing LNG fuel tanks may include delivering a full LNG tank at a glance, using the fuel in the tank, coupling a truck to the empty LNG tank to remove the empty LNG tank, and replace the empty LNG tank with a full LNG tank.

FIG. 5 is a schematic illustration of a ferry, according to certain embodiments. Fig. 5 illustrates a perspective view. The ferry 500 comprises a lower clack 310 (not shown), as well as an upper clack 320 and a second upper clack 330. The upper decks are accessed via port and starboard passenger ramps 322 and 332 to the upper deck, which gives access to 18 port and starboard passages 321 to upper deck. Lower deck 310 is accessed via the passenger ramp 312 to the lower deck from the passage 130 to the lower deck. The passages 321 to the upper deck have a vertical offset 135 from the passage 130 to the lower deck. An LNG refueling station 420 (not shown) includes an LNG refueling ramp 440 and a vent pipe 450.

FIG. 6A — B are schematic illustrations of a quay configured to operate a ferry, according to certain embodiments. Fig. 6A illustrates a side view; Fig. 6B illustrates a plan view. To facilitate loading and unloading, a quay can be designed to be integrated with various ferries described. A berth 602 may comprise loading ramps that can be configured to fit in with corresponding passages on a ferry (for example, ferry 600). The berth 602 may comprise a first loading ramp 610 configured to transfer vehicles to a lower deck passage and a second loading ramp 620 configured to transfer vehicles to a passing deck. The loading ramps 610 and 620 may be configurable to adjust the respective vertical displacement 135 (Fig. 3) between the passages.

As shown in Fig. 6B, vehicle traffic can have access to different roofs simultaneously. In the exemplary quay 602, the deck is indicated via each traffic lane to the left of each loading ramp. In one design, traffic can reach three different decks simultaneously. In some cases, incoming traffic on board the ferry passes through a first passage (e.g. the upper loading ramp 620 and its associated passage 321 to the upper deck) while outgoing traffic is unloaded via a second passage (e.g. the lower loading ramp 620, via the second passage 321 to the upper deck). clack). A water zone can allow loading and unloading without reversing, and can allow the use of one side of a ramp (for example, the passenger ramp 312 to the lower clack) for loading while the other side is used for unloading. The ferry 600 illustrates another location for a loading ramp 314 (in this case near the center of the ferry 600).

FIG. 7A and 7B are schematic illustrations of a ferry, according to certain embodiments. Fig. 7A illustrates a side view; Fig. 7B illustrates a plan view. The exemplary ferry 700 comprises a lower clack 310 and an upper clack 330. The decks can be reached via front and aft passages. A stern ramp 312 to the lower clack connects a stern passage 130 to the lower clack to the lower deck 310, and a lowered ramp 312 to the lower clack connects a stern passage 130 to the lower clack to the lower deck 310 A stern ramp 332 to the upper clack connects a stern passage 321 to the upper clack to the upper deck 330, and a shank 332 to the upper clack connects a sheathed passage 321 to the upper clack to the upper deck. 330.

The forward and aft passages may allow substantially unidirectional traffic flow, as schematically illustrated by the dark arrows in Fig. 7B. Traffic can enter via one passage and exit via the other passage.

In some embodiments, a front passage is higher than a corresponding stern passage, which can improve seaworthiness with respect to incoming waves during the crossing. In the exemplary ferry 700, the front passage 130 to the lower clack is higher above the waterline than the stern passage 130 to the lower bow may be shaped to direct incoming waves from the front passage 130 to the lower deck. In the exemplary ferry 700, the passage 130 to the lower clack below the passages 321 to the upper clack in the stern, and the passage 130 to the lower clack is above the passages 321 to the upper clack in the liner.

The above description is illustrative and not restrictive. Many variants of the invention will become apparent to those skilled in the art upon review of this disclosure. The scope of the invention should therefore not be determined with reference to the description above, but should instead be determined with reference to the appended claims together with all their equivalent embodiments.

Claims (20)

19 CLAl1\/IS

1. A ferry (100, 202, 204, 300, 400, 500, 600, 700) comprising: a hull (101) having a bow (102) including a prow (103) and a stern (104) including atransom (105), the hull having a port side (106), a starboard side (107), a beam (108)between the port and starboard sides, a baseline (110), a design waterline (120), and adraft (115) between the baseline and the design waterline, the draft greater than 4.5meters, preferably greater than 5.8 meters; a lower deck (310) within the hull; a lowerdeck entrance (130) in the hull, the lowerdeck entrance located at height (140)above the design waterline that is at least 3 meters, preferably at least 4 meters,preferably at least 6 meters, and greater than 50%, preferably greater than 80%, of thedraft; and a lowerdeck entrance ramp (312), preferably a fixed ramp, having a slope that does notexceed 18 degrees, preferably 11 degrees, preferably 7 degrees from horizontal, the lowerdeck entrance ramp connecting the lowerdeck entrance to the lower deck.

2. The ferry of claim 1, wherein the hull does not have a sealable doorway for vehicle access located between the lowerdeck entrance and the design waterline.

3. The ferry of any of the preceding claims, wherein the height above the design waterlineis greater than 100%, preferably greater than 150%, preferably greater than 200%, of thedraft.

4. The ferry of any of the preceding claims, wherein:the beam is greater than 15 meters, preferably 18 m, and less than 45 meters,preferably 40 meters; andthe lowerdeck entrance is located at or above a simulated waterline determined during a simulation in which the ferry is loaded with its design load and is rolled at an angle (40) of list that is between 30 and 50 degrees, preferably between 35 and 45degrees, preferably 40 degrees.

5. The ferry of any of the preceding claims, wherein no portion of the lowerdeck entrance iswithin a distance (220) that is 15% of the beam, preferably 20%, of the beam, preferably25% of the beam, preferably 30% of the beam, from the port and starboard sides.

6. The ferry of any of the preceding claims, wherein the lowerdeck entrance is disposed in at least one of the prow and transom.

7. The ferry of any of the preceding claims, fiJrther comprising:at least one first upper deck (320), preferably a drainable deck, located at least 4.4meters above the lower deck;a first upperdeck entrance (32l) in the hull, anda first upperdeck entrance ramp (322), preferably a fixed ramp, connecting the first upperdeck entrance to the upper deck.

8. The ferry of claim 7, wherein at least one entrance is disposed in the prow and at least another entrance is disposed in the transom.

9. The ferry of claim 8, wherein the prow entrance is disposed higher aboVe the waterline than is the transom entrance.

10. l0. The ferry of any of claims 7-9, fiJrther comprising:a second upperdeck entrance (32 l) in the hull; anda second upperdeck entrance ramp (322) connecting the second upperdeck entrance to the first upper deck. 21

11. The ferry of claim 10, Wherein the first upperdeck entrance is located on the port sideof the 1oWerdeck entrance, and the second upperdeck entrance is located on the starboard side of the 1oWerdeck entrance.

12. The ferry of any of claims 7-11, Wherein the 1oWerdeck entrance is separated from atleast one upperdeck entrance by a Vertical offset (135) that is at least 0.5m, preferably lm,preferably 1.5 m.

13. The ferry of claim 12, Wherein the 1oWerdeck entrance is lower than the upperdeck entrance.

14. The ferry of any of claims 7-13, further comprising:a second upper deck (330), preferably a drainable deck, located at least 4.4 metersabove the first upper deck; anda second upperdeck entrance ramp (332), preferably a fixed ramp, connecting the second upper deck to the first upperdeck entrance in the hull.

15. The ferry of any of claims 7-14, further comprising an access ramp (314), preferably a fixed ramp, connecting the lower deck to at least one upper deck.

16. The ferry of any of the preceding claims, further comprising a tumaround zone (334)greater than 12 m diameter, preferably greater than 14 m diameter, on at least one deck, thetumaround zone shaped to allow Vehicles to use an entrance for ingress and egress, preferably Without reVersing.

17. The ferry of any of the preceding claims, further comprising:an engine (410) powered by natural gas;a fiaeling station (420) configured to receive a liquefied natural gas (LNG) fiael tank on a trailer and conVey LNG from the fuel tank to the engine; 22 a detachable LNG fueling connection (430) configured to connect the fuel tank tothe fueling station; anda fiJeling ramp (440) connecting the fueling station to at least one deck.

18. The ferry of claim 17, Wherein the fiaeling ramp ascends from the deck toward the fueling station as moving toward the entrance to the deck.

19. A pier (602) comprising: a first loading ramp (610) configured to conVey vehicles to the loWerdeck entranceof a ferry according to any of claims 7-18; and a second loading ramp (620) configured to conVey Vehicles to the first upperdeckentrance of a ferry according to any of claims 7-18, preferably With the second loading ramp disposed adjacent to the first loading ramp.

20. The pier of claim 19, fiirther comprising a third loading ramp (620) configured toconVey Vehicles to the second upperdeck entrance ramp of a ferry according to any ofclaims 10-17, preferably With the third loading ramp disposed adjacent to the first loadingramp, preferably With the second and third loading ramps disposed on either side of the first loading ramp.