EP3055199A1

EP3055199A1 - Roll on/roll off ferry and multiramp pier

Info

Publication number: EP3055199A1
Application number: EP14786466.4A
Authority: EP
Inventors: Oskar Levander; Esa JOKIOINEN; Mikko Mattila; Mark CALLAWAY; Sauli SIPILÄ
Original assignee: Rolls Royce Marine AS
Current assignee: Kongsberg Maritime AS
Priority date: 2013-10-08
Filing date: 2014-10-03
Publication date: 2016-08-17
Also published as: WO2015052091A1; SE1351188A1; CN105813937A; KR20160067962A; JP2016534921A; SE537544C2

Abstract

Various aspects provide for a ferry having a lower deck (310). An entrance (130) in the hull provides access to the lower deck via an entrance ramp (312). The entrance may be located sufficiently high above the waterline that a sea-tight door to the entrance is not required. One or more upper decks may be accessed via upperdeck access ramps, which may connect an upper deck to an upperdeck entrance. A pier (602) may comprise a plurality of loading platforms, typically at different heights, configured to match up with a corresponding plurality of entrances on a ferry.

Description

ROLL ON/ROLL OFF FERRY AND MULTIRAMP PIER

BACKGROUND

1. Technical Field

[0001] The present invention relates generally to RoRo ferries.

2. Description of Related Art

[0002] A ferry configured to carry wheeled vehicles may provide for "roll-on/roll-off ' access. Vehicles (e.g., cars, trucks, buses, trailers, and the like) may roll onto the ferry and roll off the ferry via one or more entrances; such ferries are described as RoRo ferries.

[0003] Large RoRo ferries often have a beam greater than 15 meters and a draft greater than 4 meters. A freeboard (the vertical distance from the waterline to the lowest point of sheer at which water may enter the hull) may be greater than 3 meters. Large ferries typically have multiple decks, such that vehicles may be loaded onto several decks.

[0004] The incorporation of multiple decks presents challenges. To improve stability, cargo (and thus the decks on which the cargo sits) is generally positioned as low as possible, subject to minimum reserve buoyancy requirements. However, a lower deck positioned below the lowest point of sheer on the hull may be subject to flooding.

[0005] An upper deck may drain into the sea. A deck that does not drain out to the sea (e.g., a lower deck) may be described as a floodable deck. The lowest point on the hull at which water may enter a floodable deck may be described as a downflooding point. A floodable deck and the hull may form an internal "bathtub" within the ship, and a floodable volume between the downflooding point and the floodable deck (bounded by the hull) may describe the volume of the floodable "bathtub." Water that floods into the bathtub may not drain unassisted, presenting a variety of challenges. If such a volume is large, flooding may result in ship instability (e.g., capsizing). To minimize this floodable volume, prior ferries have minimized the vertical distance between the downflooding point and the floodable deck (e.g., to below 1.5 meters), reducing the maximum volume of water that might be held by the "bathtub" and thus destabilize the ferry.

[0006] Because downflooding is often associated with ship failure or weather conditions, regulations (e.g., International Maritime Organization, IMO, regulations) may specify various requirements for resisting downflooding (e.g., a minimum height between the waterline and the downflooding point). Because the downflooding point of an upright ship may be different than that of a listing ship, some tests require a minimum distance between the downflooding point and waterline when the ship is listing (e.g., in an intact stability test). For example, an IMO damage stability regulation may require that a downflooding point not be below the surface of the water when the ship is listing at an angle of 40 degrees and carrying its design load. Simulations are commonly used to test such capabilities.

[0007] Some prior art ferries have a sealable door that seals a doorway into the ferry. At the pier, the door opens to allow vehicles to roll on or off the ferry. The door is closed with a sea-tight seal prior to exiting the pier. The sea-tight seal must provide watertightness under normal conditions and during extreme weather. The seal must provide watertightness during testing (and simulations, including listing), and so sufficient circumference of the doorway must be sealed such that the downflooding point remains above water level (e.g., at 40 degrees listing). Such doors and seals are expensive and cumbersome.

[0008] Some prior art ferries provide access to a lower deck via movable ramps from the upper deck. Such apparatus may be expensive and cumbersome to operate, particularly for large ferries. A damaged movable ramp may not operate, and so may prevent unloading (e.g., after an accident). Moving apparatus may be dangerous, particularly with a large population of people in cars and trucks. A ramp that moves between two decks (i.e., can be positioned to load either an upper deck or a lower deck) may form a "bottleneck" during loading because the decks must be loaded sequentially.

[0009] An improved ferry would provide access to multiple decks without requiring a sea-tight door or cumbersome internal machinery, meet relevant IMO regulations, yet still provide sufficient cargo capacity (and preferably improve docking and/or onloading/offloading speeds). Preferably, an improved ferry would provide increased safety and efficiency at lower capital cost and/or operational cost than existing ferries.

SUMMARY OF THE INVENTION

[0010] Various aspects provide for a ferry having a lower deck, which may be a floodable deck. A ferry may include one or more upper decks above the lower deck. A lowerdeck entrance in the hull provides access to the lower deck via a lowerdeck entrance ramp. The lowerdeck entrance may be located sufficiently high above the waterline that a sea-tight door to the entrance is not required. In some embodiments, no portion of the lowerdeck entrance is below a simulated waterline when the ferry is listing at an angle (e.g., 40 degrees) representative of a damaged situation.

[0011] A ferry may include one or more upper decks, each of which may be connected to an upperdeck entrance via an upperdeck ramp. Some ramps share an entrance; some ramps have their own entrances. Entrance ramps to upper and lower decks are fixed ramps in some embodiments. A plurality of fixed entrance ramps and entrances may provide for rapid simultaneous loading (or unloading) of an upper deck and a lower deck, improving efficiency. In some cases, a plurality of entrances is located at one end of a ferry. A ferry may have entrances at the bow and stern. [0012] In a preferred embodiment, a ferry includes a lower deck and at least two upper decks. Fixed entrance ramps connect entrances to each of the decks, and traffic may simultaneously load onto the lower deck and upper decks. In some embodiments, a ferry includes fore and aft entrance ramp, and one of the fore and aft entrance ramps is used for loading (and the other for unloading). A ferry may include entrance ramps at one end (e.g., the stern or the bow), and may include several ramps accessing a given deck (e.g., a first aft ramp and a second aft ramp). A first aft ramp may be used for onloading while a second aft ramp provides for (e.g., simultaneous) offloading. First and second aft ramps may be used in parallel (e.g., both onloading at the same time). In an embodiment, a ferry comprises fore and aft entrances, each having multiple ramps, each ramp accessing a deck.

[0013] Some embodiments comprise a pier having loading ramps with proximal ends (i.e., that would be close to a ferry docked at the pier) at different vertical levels. The proximal ends may be offset by a vertical distance that is at least 0.5m. Vehicles may simultaneously load onto (or off of) entrances (to a docked ferry) at corresponding heights. In some cases, first, second, and third loading ramps have their respective proximal ends at different vertical levels, and vehicles may simultaneously onload (or offload) between three different levels of entrances on a ferry docked at the pier.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIGS. 1A and IB are schematic illustrations of various aspects of a ferry, according to some embodiments. FIG. 1A is a side elevation; FIG. IB is a plan view.

[0015] FIGS. 2A-D are schematic illustrations of various aspects of a bow and/or stern of a ferry, according to some embodiments. FIGS. 2A and 2B illustrate a prow (or transom) of ferry 202, and show an exemplary lowerdeck entrance 130. FIGS. 2C and 2D illustrate a prow (or transom) of ferry 204.

[0016] FIGS. 3A-C are schematic illustrations of a ferry, according to some embodiments. FIG. 3A illustrates a side elevation; FIG. 3B illustrates a plan view, and FIG. 3C illustrates a rear elevation of the rearmost section of ferry 300.

[0017] FIGS. 4A-C are schematic illustrations of a ferry, according to some embodiments. FIG. 4 A illustrates a side elevation; FIG. 4B illustrates a plan view, and FIG. 4C illustrates a rear elevation of the rearmost section of ferry 400.

[0018] FIG. 5 is a schematic illustration of a ferry, according to some embodiments. FIG. 5 illustrates a perspective view.

[0019] FIGS. 6A-B are schematic illustrations of a pier configured to operate with a ferry, according to some embodiments. FIG. 6A illustrates a side elevation; FIG. 6B illustrates a plan view.

[0020] FIGS. 7A and 7B are schematic illustrations of a ferry, according to some embodiments. FIG. 7A illustrates a side elevation; FIG. 7B illustrates a plan view.

DETAILED DESCRIPTION OF THE INVENTION

[0021] A RoRo ferry may comprise one or more ramps providing vehicular access to one or more decks, including a floodable deck. An entrance to the ferry leading to a floodable deck may be located high above the waterline to substantially prevent ingress of water to the lower decks. In some cases, the ferry has an integrated, contiguous hull, without a sealable vehicle door between the entrance and the waterline. A contiguous hull without a sealable door may provide for reduced cost and/or improved safety. [0022] Various features are described herein. Reference numerals describing features are generally consistent among figures. For simplicity, certain numerals have been omitted from various figures to facilitate the explanation of other features. Any feature may be combined with any other feature. Any feature may be omitted from a combination of other features.

[0023] FIGS. 1A and IB are schematic illustrations of various aspects of a ferry, according to some embodiments. FIG. 1A is a side elevation; FIG. IB is a plan view. Following typical nomenclature, ferry 100 (and other ferries described herein) includes a hull 101 having a bow 102 and a stern 104. The bow includes a prow 103 and the stern includes a transom 105. The ferry has a port side 106, a starboard side 107, and a centerline 109 from the bow to stern midway between the port and starboard sides. A beam 108 between the port and starboard sides describes the width of the ferry. Beam 108 may be between 10 and 45 meters, including between 18 and 40 meters. The beam may be greater than 15 meters, greater than 20 meters, and greater than 25 meters.

[0024] The ferry has a baseline 110 and a design waterline 120 (e.g., an expected waterline when empty, carrying a standard load, or carrying a maximum load). A draft 115 describes the vertical distance between baseline 110 and waterline 120. In some embodiments, draft 115 may be greater than 4 meters, including greater than 4.5 meters, greater than 5.8 meters, or even greater than 7 meters. The draft may be less than 10 meters.

[0025] A ferry may include one or more decks, including a lower deck (e.g., a floodable deck, not shown). A lowerdeck entrance 130 in the hull located above the lower deck provides for vehicular access to the lower deck via a lowerdeck entrance ramp (not shown).

Entrances may be annotated herein using the portion of the entrance closest to waterline 120 (e.g., the floor of the entrance), notwithstanding that an entrance comprises an open "area" sufficient for vehicles to pass through the hull. Lowerdeck entrance 130 may reduce the risk of downflooding by being located well above waterline 120, depending upon the size of the ferry (e.g., the height of the lower deck above the baseline and the number of upper decks above the lower deck, if any).

[0026] Lowerdeck entrance 130 may be located at a height 140 above waterline 120 that is at least 50%, preferably at least 60%>, including at least 80%> of draft 115. Height 140 may be greater than draft 115, including 20%> or even 50%> of draft 115 greater than draft 115. Height 140 may be twice as large as draft 115. Lowerdeck entrance 130 may be located at least two meters, preferably at least 3 meters, including at least 4 meters above waterline 120. Lowerdeck entrance 130 may be wide enough (FIG. IB) for vehicles to drive onto the ferry and descend down the lowerdeck entrance ramp to the lower deck. In some embodiments, lowerdeck entrance 130 is wide enough for at least two parallel lanes of truck traffic. Lowerdeck entrance 130 may be at least 6 meters wide, including at least 8 meters wide.

[0027] In some embodiments, a ferry described herein (e.g., ferry 100) does not have a sealable doorway (e.g., a vehicle doorway) below height 140 above waterline 120. As such, hull 101 does not have an entrance below height 140 that would allow water to flow to lower deck 310. Without such an entrance, the ferry does not require a sealable door that opens (providing access to the lower deck) and closes (to keep water out), reducing complexity and cost.

[0028] Lowerdeck entrance 130 may be located in various positions around the hull, including proximate to the bow and/or stern of the ferry (e.g., in the prow or transom). In exemplary ferry 100, lowerdeck entrance 130 is located in transom 104. Lowerdeck entrance 130 may be located in prow 103. Some ferries have only one lowerdeck entrance; some ferries include several lowerdeck entrances. A plurality of lowerdeck entrances may be located in one location (e.g., the stern). In some cases, the stern includes a lowerdeck entrance (e.g., at the transom) and the bow includes another lowerdeck entrance (e.g., at the prow). Different lowerdeck entrances may be at the same height 140 and/or different heights 140. [0029] FIGS. 2A-D are schematic illustrations of various aspects of a bow and/or stern of a ferry, according to some embodiments. FIGS. 2A and 2B illustrate a prow (or transom) of ferry 202, and show an exemplary lowerdeck entrance 130. FIGS. 2C and 2D illustrate a prow (or transom) of ferry 204. For clarity the entrances are annotated by surfaces closest to the waterline.

[0030] FIGS. 2A-D illustrate exemplary elevations of a prow or transom as viewed along centerline 109 (looking aftward from ahead of the bow or forward from behind the stern). FIGS. 2A-D illustrate various designs for a lowerdeck entrance as compared to (inter alia) other ingress/egress points of the ferry.

[0031] As explained in more detail with respect to FIGS. 3A-C, an upperdeck entrance 321 may provide access to an upper deck located above the lower deck. An upper deck may be an entrance to a drainable deck from which water can drain into the sea, and water that enters an upperdeck entrance 321 may drain to the sea and not to a lower deck. An upperdeck entrance may 321 , in some simulations, descend below waterline 120 without causing

downflooding because the upperdeck entrance is not in fluid communication with the lower deck.

[0032] A lowerdeck entrance 130 may be centrally located (between port and starboard sides) and/or be laterally symmetrical with respect to centerline 109, so that no portion of the lowerdeck entrance 130 descends below waterline 120 during an expected (simulated) listing condition. FIG. 2A illustrates an embodiment with a lowerdeck entrance 130 located below (in this example) an upperdeck entrance 321, as shown by vertical offset 135. FIG. 2C illustrates an embodiment with a lowerdeck entrance located higher than upperdeck entrance 321 by vertical offset 135. A lowerdeck entrance and an upperdeck entrance may be located at the same height 140. Vertical offset 135 may be between 0.3 and 3 m, including between 0.5 and 2 m, including between 0.75 and 1.5 meters. [0033] A width of lowerdeck entrance 130 may be chosen that optimizes freight loading and safety (e.g., as wide as possible, subject to preventing downflooding during simulated listing). According to various specifications (e.g., International Maritime Organization, IMO), a listing ship (e.g., listing at an angle 40 of 40 degrees) should resist flooding via a variety of measures. Angle 40 may be between 30-50 degrees, including between 35-45 degrees, including 40 degrees. In some ferries, damage tolerance requires a minimum buoyancy when damaged (e.g., when listing). FIGS. 2A and 2B compare ferry 202 in an upright and listing position, respectively. FIGS. 2C and 2D compare ferry 204 in an upright and listing position, respectively. In some embodiments, a ferry described herein does not have a downflooding point (e.g. a portion of entrance 130) located below the waterline when the ferry is listing at angle 40 (e.g., during a simulation as in FIGS. 2B and 2D). As shown in FIGS. 2B and 2D, the lowermost point of lowerdeck entrance 130 is located a distance 210 above the waterline when the ferry is listing at angle 40 (e.g., during a simulation).

[0034] A width (between the lateral boundaries) of a lowerdeck entrance may be chosen to fulfill various listing requirements. Distance 220 between lowerdeck entrance 130 and the side of the ferry may be chosen according to (inter alia) beam 108, height 140 and a desired width of lowerdeck entrance 130, in combination with one or more simulated listing angles.

Distance 220 may at least 15% of beam 108, preferably at least 20% of beam 108, including at least 25%> of beam 108 or at least 30% of beam 108. In some embodiments, (e.g., as in FIG. 2D), a lowerdeck entrance may remain above the waterline even when a portion of an upperdeck entrance is below the waterline, preventing ingress of water to the lower deck.

[0035] FIGS. 3A-C are schematic illustrations of a ferry, according to some embodiments. FIG. 3A illustrates a side elevation; FIG. 3B illustrates a plan view, and FIG. 3C illustrates a rear elevation of the rearmost section of ferry 300. Ferry 300 includes a lower deck 310 connected to lowerdeck entrance 130 by a lowerdeck entrance ramp 312. In certain

implementations, an entrance ramp may be movable (e.g., to different heights). In some embodiments it is preferable to use a fixed entrance ramp. A fixed entrance ramp may provide for lower cost construction, easier operation, reduced maintenance, and/or safer implementation than a movable ramp. A fixed ramp may generally be more resistant to damage than a movable ramp. A movable ramp requiring machinery for use (e.g., to raise and lower the ramp) might be damaged in an accident, and such damage might prevent unloading. A fixed entrance ramp may facilitate unloading, particularly when the ferry is damaged, partially sunken, tilting, listing, and the like.

[0036] Preferably, lowerdeck entrance ramp 312 has a slope that does not exceed 18 degrees from horizontal, preferably 11 degrees, preferably 7 degrees. Lower deck 310 may be positioned close to waterline 120. In some cases, a lower deck is below waterline 120. Some ferries have a minimum reserve buoyancy requirement, that may be at least partially fulfilled by locating lower deck 310 above the waterline and creating a sealable compartment below lower deck 310. Lower deck 310 may be located a distance 316 that is 2 to 5 meters, including 2.5 to 3.5 meters, above waterline 120. A slope and length of lowerdeck entrance ramp 312 may be chosen according to the size of the ferry, height 140, distance 316, and a desired (e.g., maximum slope) limitation associated with the type of vehicles that will use the ramp. In some embodiments, lowerdeck entrance 130 may be located a height 140 above waterline 120 chosen in concert with the distance 316 of the lower deck above the waterline (e.g., height 140 may be greater than the distance between the lower deck and waterline 120, including more than twice the distance, including more than three times the distance). A vertical distance from lower deck 310 to lowerdeck entrance 130 (height 140 - distance 316) may be greater than 1.5 meters, greater than 2.5 meters, greater than 3.5 meters, or even greater than 4.5 meters. In some embodiments, the vertical distance from lower deck 310 to lowerdeck entrance 130 is greater than 25%, including greater than 50%, including greater than 75%, including greater than 100%, including greater than 125%, of the vertical distance from lower deck 310 to baseline 110 (distance 316 plus draft 115). In a preferred embodiment, draft 115 may be at 4 to 11 meters, distance 316 may be 2 to 4 meters, and the lowerdeck entrance 130 is at least 2 meters, preferably at least 3 meters, above the lower deck.

[0037] A ferry may include one or more upper decks located above a lower deck. An upper deck may be a deck that is not floodable, and may be a drainable deck from which water may exit to the sea via gravity. Exemplary ferry 300 includes a first upper deck 320 and a second upper deck 330. Upper deck 320 is connected to an upperdeck entrance 321 (located, in this example, at the stern) by upperdeck ramp 322. Upper deck 330 is connected to (in this example) upperdeck entrance 321 by upperdeck ramp 332. An upperdeck entrance ramp need not slope (e.g., with an upperdeck entrance at substantially the same level as its respective upper deck). An upperdeck entrance ramp may slope downward from its respective upper deck to its respective upperdeck entrance. In some embodiments, a first and second upper deck may use the same upperdeck entrance. In some cases, different upper decks use different entrances. An upperdeck entrance ramp may be movable. Preferably, an entrance ramp is a fixed ramp.

[0038] Distances 326 and 336 between decks may be chosen according to expected vehicle heights. In an exemplary embodiment, distances 326 and 336 may each be large enough for trucks and trailers, and so may provide for at least 4.4 meters of free height between the floor of one deck and the ceiling above. In some cases, a free height above a deck (e.g., an upperdeck) may be sized to receive light duty vehicles (e.g., not exceeding 3 meters). Decks may be connected by one or more optional access ramps 314. An access ramp may be sized (e.g., width, length, location, slope) to allow traffic on a deck below to ascend to a deck above, and may be located in various positions to facilitate smooth traffic flow within the ferry. As shown in FIG. 3B, an access ramp 314 may be located at a side of a ferry. [0039] A ferry may include a plurality of entrances and entrance ramps, which may all be located at one end (e.g., the bow or stern). As shown in FIG. 3B, in ferry 300, upper deck 320 may be accessed via two upperdeck entrance ramps 322, each of which is connected to a separate upperdeck entrance 321. Similarly, upper deck 330 may be accessed via two upperdeck entrance ramps 332, each of which is connected to a separate upperdeck entrance 321. An entrance (e.g., a port entrance or starboard entrance) may provide for access to two or more upper decks. In an arrangement, lowerdeck entrance 130 is centrally located, with upperdeck entrances 321 disposed to either side, and each upperdeck entrance 321 provides access to an upperdeck ramp 322 and an upperdeck ramp 332. In some cases, a port entrance provides access to one upper deck and a starboard entrance provides access to another upper deck. An upperdeck entrance may be at the same height as a lowerdeck entrance. An upperdeck entrance may be at a different height than that of a lowerdeck entrance, as illustrated by vertical offset 135. A watertight barrier 142 may prevent water from flowing onto lower deck 310 (e.g., from upperdeck ramp 322).

[0040] A ferry may include a propulsion system 342, which may comprise a reciprocating engine, a turbine, and the like configured to generate a thrust on the ferry (e.g., 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 pod-based propeller 344) may be configured to provide for lateral thrust. A ferry may comprise coaxial propellers (e.g., counterrotating). A significant lateral thrust (e.g., at the stern) may provide for a reduced turning radius for the ferry, enabling the ferry to quickly "turn around" and (e.g.,) back into a pier. A ferry having onload/offload ramps at one end (e.g., the stern) and a propulsion system providing for fast turnaround may be able to steam to a destination and quickly turn around, backing into the pier for offloading. In some applications, such a configuration may reduce the need for fore and aft loading entrances, simplifying construction, yet still provide sufficiently rapid turnaround times in the harbor. In some embodiments, a ferry includes a large centrally located axially driven propeller and a pod-based propeller on each side.

[0041] A ramp and its associated entrance may be used for onloading and/or offloading. In some cases, a ramp and its associated entrance is used for both onloading and offloading. Some ferries include a turnaround zone 334 to allow vehicles to turn around (e.g., without reversing), which may provide for using the same entrance for ingress and egress.

Turnaround zone 334 may be larger than 12 m in diameter, including larger than 14 m in diameter.

[0042] FIGS. 4A-C are schematic illustrations of a ferry, according to some embodiments. FIG. 4 A illustrates a side elevation; FIG. 4B illustrates a plan view, and FIG. 4C illustrates a rear elevation of the rearmost section of ferry 400. Ferry 400 includes a propulsion system 342 powered by natural gas (e.g., methane, ethane, and the like). The natural gas may preferably be delivered and stored as liquefied natural gas (LNG). Ferry 400 includes an LNG engine 410 configured to power one or more propellers and/or water jets. An LNG fueling station 420 may be connected by a fueling ramp 324 to a deck (in this case, an upper deck 320) to receive an LNG tank delivered on a trailer (e.g., by a truck). LNG fueling station 420 may include a detachable LNG fueling connection 430, which may detachably couple to the LNG trailer and convey LNG from the trailer to engine 410. An LNG vent mast 450 may provide for the venting of excess LNG (e.g., during storage).

[0043] LNG fueling ramp may ascend from the deck in a direction moving toward the LNG fueling station. In a preferred embodiment, a truck and LNG trailer drives onto ferry 400 via an entrance ramp, then reverses up LNG fueling ramp 440 to LNG fueling station 420. The LNG trailer may be detached from the truck, and the truck may exit the ferry. Such a configuration may provide for an efficient "swapping" of empty LNG trailers with full trailers, and may eliminate the need for an onboard (e.g., internal) LNG storage tank. Fueling station 420 may comprise a plurality of walls 422. Walls 422 may be configured (e.g., with straps or chains) to stabilize an LNG trailer, particularly with respect to listing and/or sudden stops. Walls 422 may be explosion- proof and/or fireproof (e.g., directing gases away from ferry 400 in the event of a fire or explosion), which may improve safety as compared to an internal LNG tank contained within a vessel.

[0044] A method for swapping LNG fuel tanks may comprise delivering a full LNG tank on a trailer, using the fuel in the tank, reattaching a truck to the empty LNG tank to remove the empty LNG tank, and replacing the empty LNG tank with a full LNG tank.

[0045] FIG. 5 is a schematic illustration of a ferry, according to some embodiments. FIG. 5 illustrates a perspective view. Ferry 500 includes a lower deck 310 (not shown), and upper deck 320 and a second upper deck 330. The upper decks are accessed via port and starboard upperdeck entrance ramps 322 and 332, which access port and starboard upperdeck entrances 321. Lower deck 310 is accessed via lowerdeck entrance ramp 312 from lowerdeck entrance 130.

Upperdeck entrances 321 are located a vertical offset 135 from lowerdeck entrance 130. An LNG fueling station 420 (not shown) includes an LNG fueling ramp 440 and vent mast 450.

[0046] FIGS. 6A-B are schematic illustrations of a pier configured to operate with a ferry, according to some embodiments. FIG. 6A illustrates a side elevation; FIG. 6B illustrates a plan view. To facilitate loading and unloading, a pier may be designed to integrate with various ferries described herein and/or other ferries. A pier 602 may include loading ramps configurable to mate with corresponding entrances on a ferry (e.g., ferry 600). Pier 602 may include a first loading ramp 610 configured to convey vehicles to a lowerdeck entrance and a second loading ramp 620 configured to convey vehicles to an upperdeck entrance. Loading ramps 610 and 620 may be configurable to adjust to the respective vertical offset 135 (FIG. 3) between entrances. Loading ramps 610 and 620 may have distal ends (with respect to a ferry) at the same level (e.g., street level of pier 602) and/or at different levels. An exemplary pier may have one or more loading ramps 610 and one or more loading ramps 620. The proximal ends (with respect to the ferry) of the loading ramps may be at different levels (e.g., vertically displaced with respect to each other by vertical offset 135 (FIG. 3). In an embodiment, the loading ramps are fixed ramps, having distal ends at street level, and proximal ends (close to the ferry) offset by vertical offset 135; in some cases the ramps can adjust to different levels. In some implementations, pier 602 includes two loading ramps going to one deck entrance and one loading ramp going to another deck entrance.

[0047] A pier for conveying vehicles on and off a ferry docked at the pier may comprise first and second (and optionally additional) loading ramps. A first loading ramp may have a proximal end (611) configured to substantially match an entrance to a ferry (i.e., within a tolerance such that vehicles may travel between the ferry and loading ramp). The proximal end of the first loading ramp may be at a first height (e.g., at least three meters above the water beneath the pier), preferably at least four meters, preferably at least six meters. A second loading ramp may have a proximal end (621), which may, in some embodiments, be substantially adjacent to/laterally displaced with respect to the proximal end (61 1) of the first loading ramp. Typically, vehicles may use the first and second loading ramps simultaneously. The proximal ends of the first and second loading ramps may be offset from each other, in a vertical direction, by a vertical offset (135) (FIGS. 2a-d) that is at least 0.5 meters, preferably at least 1 meter, preferably at least 1.5 meters, preferably at least 2 meters, preferably at least 3 meters. The pier may comprise a third loading ramp (or even more loading ramps). The third loading ramp may have its own proximal end configured to convey vehicles onto a ferry, which may be offset a vertical direction from at least one of the proximal ends of the first and second loading ramps by a vertical offset (135) that is at least 0.5 m, preferably at least lm, preferably at least 1.5m, preferably wherein the proximal end of the third loading ramp is adjacent to at least one of the proximal ends of the first and second loading ramps. The proximal ends of the first and second loading ramps may be offset by a first vertical offset (135) and the proximal ends of the second and third loading ramps are offset by a second vertical offset (135). The values of the first and second vertical offsets may be within 5% of each other. The values of the first and second vertical offsets may differ from each other by more than 0.5 meters, preferably more than 1 meter, preferably more than 2 meters.

[0048] As shown in FIG. 6B, vehicular traffic may access various decks

simultaneously. In exemplary pier 602, the deck accessed by each traffic lane is annotated to the left of each loading ramp. In a configuration, traffic may access three different decks

simultaneously. In some cases, inbound traffic boards the ferry via a first entrance (e.g., the top loading ramp 620 and its associated upperdeck entrance 321) while outbound traffic offloads via a second entrance (e.g., the bottom loading ramp 620, via the other upperdeck entrance 321). A turnaround zone may allow for onloading and offloading without reversing, and may allow one side of a ramp (e.g., lowerdeck entrance ramp 312) to be used for onloading while the other side is used for offloading. Ferry 600 illustrates another location for an access ramp 314 (in this case, close to the midpoint of ferry 600).

[0049] FIGS. 7A and 7B are schematic illustrations of a ferry, according to some embodiments. FIG. 7A illustrates a side elevation; FIG. 7B illustrates a plan view. Exemplary ferry 700 includes a lowerdeck 310 and an upperdeck 330. The decks may be accessed via bow and stern entrances. An aft lowerdeck ramp 312 connects an aft lowerdeck entrance 130 to lower deck 310, and a forward lowerdeck ramp 312 connects a forward lowerdeck entrance 130 to lower deck 310. An aft upperdeck ramp 332 connects an aft upperdeck entrance 321 to upper deck 330, and a forward upperdeck ramp 332 connects a forward upperdeck entrance 321 to upper deck 330.

[0050] Fore and aft entrances may provide for substantially unidirectional traffic flow, as illustrated schematically by the dark arrows in FIG. 7B. Traffic may enter via one entrance and exit via the other entrance. [0051] In some embodiments, a forward entrance is higher than a corresponding aft entrance, which may improve seaworthiness with respect to oncoming waves during passage. In exemplary ferry 700, forward lowerdeck entrance 130 is higher above the waterline than aft lowerdeck entrance 130. The prow may be shaped to deflect oncoming waves away from forward lowerdeck entrance 130. In exemplary ferry 700, lowerdeck entrance 130 is below the upperdeck entrances 321 at the stern, and lowerdeck entrance 130 is above the upperdeck entrances 321 at the bow.

[0052] The above description is illustrative and not restrictive. Many variations of the invention will become apparent to those of skill in the art upon review of this disclosure. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.

Claims

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 a transom (105), the hull having a port side (106), a starboard side (107), a beam (108) between the port and starboard sides, a baseline (1 10), a design waterline (120), and a draft (115) between the baseline and the design waterline, the draft greater than 4.5 meters, 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 the draft; and

a lowerdeck entrance ramp (312), preferably a fixed ramp, having a slope that does not exceed 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 either of claims 1 and 2, wherein the height above the design waterline is greater than 100%o, preferably greater than 150%, preferably greater than 200%>, of the draft.

4. The ferry of any of claims 1 -3, wherein:

the beam is greater than 15 meters, preferably 18 m, and preferably less than 45 meters, preferably less than 40 meters; and

the 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 45 degrees, preferably 40 degrees.

5. The ferry of any of claims 1 -4, wherein no portion of the lowerdeck entrance is within a distance (220) that is 15% of the beam, preferably 20%, of the beam, preferably 25%> of the beam, preferably 30%> of the beam, from the port and starboard sides.

6. The ferry of any of claims 1 -5, wherein the lowerdeck entrance is disposed in at least one of the prow and transom.

7. The ferry of any of of claims 1-6, further comprising:

at least one first upper deck (320), preferably a drainable deck, located at least 4.4 meters above the lower deck;

a first upperdeck entrance (321) in the hull, and

a 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. The ferry of any of claims 7-9, further comprising:

a second upperdeck entrance (321) in the hull; and

a second upperdeck entrance ramp (322) connecting the second upperdeck entrance to the first upper deck.

11. The ferry of claim 10, wherein the first upperdeck entrance is located on the port side of the lowerdeck entrance, and the second upperdeck entrance is located on the starboard side of the lowerdeck entrance.

12. The ferry of any of claims 7-11, wherein the lowerdeck entrance is separated from at least 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 lowerdeck 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 meters above the first upper deck; and

a 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 claims 1-15, further comprising a turnaround zone (334) greater than 12 m diameter, preferably greater than 14 m diameter, on at least one deck, the turnaround zone shaped to allow vehicles to use an entrance for ingress and egress, preferably without reversing.

17. The ferry of any of claims 1-16, further comprising:

an engine (410) powered by natural gas;

a fueling station (420) configured to receive a liquefied natural gas (LNG) fuel tank on a trailer and convey LNG from the fuel tank to the engine;

a detachable LNG fueling connection (430) configured to connect the fuel tank to the fueling station; and

a fueling ramp (440) connecting the fueling station to at least one deck.

18. The ferry of claim 17, wherein the fueling 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 entrance of a ferry according to any of claims 7-18; and

a second loading ramp (620) configured to convey vehicles to the first upperdeck entrance 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, further comprising a third loading ramp (620) configured to convey vehicles to the second upperdeck entrance ramp of a ferry according to any of claims 10-17, preferably with the third loading ramp disposed adjacent to the first loading ramp, preferably with the second and third loading ramps disposed on either side of the first loading ramp.

21. A pier (602) for conveying vehicles onto and off of a ferry docked at the pier, the pier

comprising:

a first loading ramp (610) having a proximal end (611), the proximal end of the first loading ramp at a first height at least 3 meters preferably at least 4 meters, preferably at least 6 meters, above a water level below the pier; and

a second loading ramp (620) having a proximal end (621) disposed substantially adjacent to the proximal end (611) of the first loading ramp, such that vehicles may simultaneously use the first and second loading ramps;

the proximal ends of the first and second loading ramps offset from each other, in a vertical direction, by a vertical offset (135) that is at least 0.5 m, preferably at least lm, preferably at least 1.5m, preferably at least 2m.

22. The pier of claim 21, further comprising a third loading ramp (620) having a proximal end that is offset in a vertical direction from at least one of the proximal ends of the first and second loading ramps by a vertical offset (135) that is at least 0.5 m, preferably at least lm, preferably at least 1.5m, preferably wherein the proximal end of the third loading ramp is adjacent to at least one of the proximal ends of the first and second loading ramps.

23. The pier of claim 22, wherein the proximal ends of the first and second loading ramps are offset by the first vertical offset (135) and the proximal ends of the second and third loading ramps are offset by a second vertical offset (135).

24. The pier of claim 23, wherein the values of the first and second vertical offsets are within 5% of each other.

25. The pier of claim 23, wherein the values of the first and second vertical offsets are different from each other by more than 0.5 m, preferably more than 1 m, preferably more than 2 m.