The present invention will be further understood from the following description with references to the drawings, in which all views are schematic and may not be to scale.
a, in a plan view, illustrates the turning dolphin of the berthing facility of
b, in a plan view, illustrates one of the tandem fenders of the turning dolphin of
a, in a plan cross-sectional view, illustrates the end of a pontoon module of the berthing facility of
b, in elevational cross-sectional view, illustrates the join of two such pontoon modules as shown in
a, in a plan view, illustrates the long-span two-level truss ramp of the berthing facility of
b, in a side elevational view, illustrates the ramp of
c, in an end elevational view, illustrates the ramp of
a, in a cross-sectional view, illustrates the ramp of
b, in a side elevational view, illustrates a ramp lift hydraulic cylinder of
a, in a plan view, illustrates line fender of the berthing facility of
b, in a cross-sectional view, illustrates the line fender of
In the drawings, preferred embodiments of the floating pontoon berthing facility for ferries and ships and related equipment according to the invention are illustrated by way of example. It is to be expressly understood that the description and drawings are only for the purpose of illustration and as an aid to understanding, and are not intended to be a constraint on the limits of the invention.
The embodiment described in what follows and shown schematically in the drawings is suitable for accommodating bow/stern-loading ferries having a length of roughly 550 feet; a gross tonnage of roughly 19,000 tons; and two pairs of bow/stern vehicle access ports, an upper pair and a lower pair. A typical such ferry would have a capacity of roughly 470 automobiles, and roughly 2,100 passengers and crew. In the drawings, the water surface is identified by reference number 206 and the seabed is identified by reference number 208. As shown in
The pontoon 1 comprises five interconnected pontoon modules, an offshore end module 20, a main pier module 22, a first wingwall module 24, a ramp module 26, and a second wingwall module 28, the modules being joined together as discussed below.
The offshore end module 20 is of generally rectangular shape with a rounded distal end comprising the turning dolphin 13. The proximal end of the offshore end module 20 is configured for attachment with the distal end of the generally rectangular main pier module 22. The proximal end of the main pier module 22 is configured for attachment with the distal end of the first wingwall module 24. Although the first wingwall module 24 is of a generally rectangular structure, the proximal inner wall of the first wingwall module 24 is contoured to receive the bow or stern, as the case may be, of a ferry. The offshore end module 20, the main pier module 22 and the first wingwall module 24 are joined together end-to-end to form a projecting finger. The first end of the generally rectangular ramp module 26 is joined to the proximal end of the first wingwall module 24 such that the ramp module 26 projects perpendicularly to the longitudinal axis of the projecting finger comprising the offshore end module 20, the main pier module 22 and the first wingwall module 24. The second end of the ramp module 26 is joined to the proximal end of the generally rectangular second wingwall module 28 such that the second wingwall module 28 lies generally parallel to the projecting finger. The distal end of the first wingwall module 24 is rounded. When assembled, the offshore end module 20, the main pier module 22, the first wingwall module 24, the ramp module 26, and the second wingwall module 28 resemble a J-shaped structure, with the “hook” of the “J” forming a recess dimensioned and configured to receive the bow or stern of a ferry.
The pontoon 1 is secured in its desired location with a combination of a pylon assembly 202 at the shoreward end and an anchor assembly 204 proximate the distal end of the projecting finger.
Referring to
The pylon opening 15 is situated at the joint between the first wingwall module 24 and the ramp module 26. This location permits assembly of the pontoon 1 after the pylon 2 is in place and later disassembly for maintenance or repair. Referring to
In the embodiment shown in
Referring to
As shown in
At rest, that is without appreciable loading on the chains 5 due to force against the pontoon 1, there is some slack in the chains 5, both to allow for vertical movement of the pontoon 1 with changing water levels and to permit some lateral movement of the projecting finger (that is movement of the projecting finger in a direction generally perpendicular to the longitudinal axis of the projecting finger), in response to a force applied against the projecting finger (e.g. due to vessel impact, wind or current loading etc.) When viewed from the side, at rest, the sections of each chain between the chain post 38 and the seabed lies in a curve (referred to as a catenary). The shape of the curve is variable and dependent on several factors including the depth of water, weight of chain etc., but it can be said that when at rest, each chain is curved, and when under load the curve decreases such that at a theoretical maximum load the lie of the chain would approximate a straight line. In the result, the opposed-anchors configuration: tends to maintain the projecting finger in an at-rest position at which the load on the set of chains on one side of the projecting finger balances the load on the set of chains on the other side of the projecting finger, and resiliently resists lateral movement of the projecting finger from this at-rest position. The at-rest lateral position of the projecting finger; the resistance to lateral movement provided by the anchor assembly; and the range of lateral movement of the pontoon 1 permitted by the anchor assembly 204, may be altered by adjusting the lengths of the chains 5 between the lower end of the chain post 38, and the respective gravity anchors 4 and rock sockets 14. Adjustments to the lengths of a chain between the lower end of the chain post 38, and the respective gravity anchor 4 or rock socket 14, may be made by disengaging from the chain keeper 54 the link of the chain 5 engaged with the chain keeper 54 and engaging another link of the chain 5 with the chain keeper 54. As referred to above, such adjustments to a chain 5 typically require the use of a crane (preferably a mobile crane suitable for travel on the pontoon 1), or a jack, to support the chain 5.
The combination of the pylon assembly 202 (which permits pivoting of the pontoon 1 about the pylon 2) and the anchor assembly 204 (which permits restrained lateral movement of the projecting finger) provides a semi-rigid fixity at the shore end of the pontoon 1 giving an essentially positionally stable interface between a ferry in the berthing facility 200 and the ramp 6, while the projecting finger behaves much like a floating lead with flexible restraint. The shoreward mooring pylon 2 forms a pivot point about which the pontoon 1 may pivot within the bounds permitted by the anchor assembly. In the described embodiment, the maximum intended lateral movement of the distal end of the projecting finger is approximately 12 feet each way from an at-rest position, under full expected impact or wind load. Under most tide conditions and vessel docking maneuvers, the lateral movement will be less. Flexibility and capacity for relatively large lateral movement at the distal end of the projecting finger are desirable to dissipate berthing impact forces between a ferry and the pontoon 1.
As discussed above, the chains 5 exit the chain post 38 at a location below the water surface so as to ensure sufficient vertical clearance between the chains 5 and vessels using the berthing facility 200. By contrast, the loci of the forces on the pontoon 1 associated with a vessel (primarily impact and wind loading), will tend to be on the upper side of the pontoon 1 as this is where the line fenders 9, and mooring bollards, cleats and/or winches (i.e. the members and/or devices on the pontoon 1 to which the lines used to secure a vessel to the pontoon 1 are attached, not shown). In the result, there is a vertical displacement between the expected loci of lateral forces expected to be applied to the pontoon 1 and the locus (i.e. the lower end of the chain post 38) at which resistance to lateral movement of the pontoon 1 is effected. This vertical displacement results in a torque being applied to the pontoon 1 essentially along the longitudinal axis of the projecting finger, when a lateral force is applied to the projecting finger. The pontoon 1 must be sufficiently strong to withstand this torque. Further, in terms of resistance to lateral movement, the projecting finger is only supported at each end (i.e. by the pylon assembly at one end and by the anchor assembly 204 at the other end). The pontoon 1 must be sufficiently strong for the unsupported span of the projecting finger to withstand the expected lateral forces along its length.
Each pontoon module is preferably constructed from high-quality reinforced concrete formed over expanded-polystyrene (e.g. styrofoam™) billets 30 (see
The pontoon modules are preferably fabricated off-site; once afloat they may be towed to the location of the berthing facility 200. The modules are joined one to the other once afloat, either at the location of the berthing facility 200 or at some other location as is most convenient for construction.
To attach one module to another, the two modules are winched together while afloat and are aligned using the mating sockets/pins 34 of the two modules. Once the modules are aligned, the steel tubes 32 of one module align with the corresponding steel tubes 32 of the other module. Once the modules have been drawn together sufficiently so that the two gaskets abut one another so as to impede the flow of water into the steel tubes 32 that are below sea level, the removeable plugs are removed and steel threadbars 36 (preferably with plastic sheathing) are inserted into the steel tubes from one or the other of the work chambers 37. Access to each of the work chambers 37 is via a manhole (not shown) at the top of the work chamber 37. An associated manhole cover (also not shown) is used to close the manhole as desired. A nut 33 (and associated washer or washer plate, as required), is threaded on to each end of each threadbar 36.
When two modules are aligned for attachment, the rectangular concavity 31 of one module is aligned with the rectangular concavity 31 of the other module, such that the two rectangular concavities 31 define a rectangular cavity at the interface between the two modules. Once the modules have been drawn together sufficiently so that the two gaskets prevent flow of water from the surrounding water into the interface cavity (if necessary to perfect the seal provided by the gaskets, the threadbar 36/nut 33 combinations may be used to compress the gaskets), the water that was trapped in the interface cavity when the modules were brought together is removed, preferably by being drawn from the interface cavity with a suitable pump. After the interface cavity has been de-watered, cement grout is poured into the interface cavity. When the grout reaches sufficient strength, the nuts 33 are tightened to put the threadbars 36 under tension, to provide a compression force across the interface and thus provide joint rigidity. The threadbar 36/nut 33 combinations resist tension across the joint between the modules, and the grout forms a cast-in-place spline or joint key 35 that impedes relative shearing and rotational movement as between the modules.
Each of the line fenders 9, tandem fenders 16 and wing walls 10 includes one or more hydraulic dampers 62 for absorbing vessel impacts. All of the hydraulic dampers 62 are configured and function in a similar manner. An exemplary hydraulic damper, as used in a line fender 9, is shown in
The hydraulic dampers 62 have several desirable characteristics for impact energy absorption. The stroke of the ram piston within the ram cylinder can be designed to control the reaction force for a desired force limit. Rebound force is provided by the nitrogen charge in the accumulator 212 and thus, the ram 210/accumulator 212 combination allows for accurate control of the rebound force after impact, such that the rebound force may relatively easily be made to be considerably less than for conventional rubber bumpers. The size of the container and the preset nitrogen charge pressure determine the rebound force. Reducing the rebound force is desirable as it reduces the tendency for the bow of a ferry to bounce off a wingwall when approaching the docking position, or for the side of a ferry to bounce off a line of fender when the ship is attempting to lay alongside the projecting finger.
As shown in
Referring to
As mentioned above, three tandem fenders 68 are located at the turning dolphin 13 and one tandem fender 68 is located at the distal end of the second wingwall module 28. In what follows, only the tandem fenders 68 located at the turning dolphin 13 are described, but the function and configuration of the tandem fender 68 located at the second wingwall module 28 is in all essential respects the same. The turning dolphin 13 has a curved periphery so that ships can come to rest against the turning dolphin 13 at an angle to the berth center line and pivot about the turning dolphin 13, for example so as to come into alignment with the berthing facility. Referring to
As shown in
Referring to
Referring to
To achieve ramp offshore end lift that behaves as if it is a single point of lift, the outer cylinder of the ramp lift hydraulic cylinders 98 on one side of the ramp 6 is piped in common through hydraulic lines 105 with the outer cylinder of the ramp lift hydraulic cylinders 98 on the other side of the ramp 6. Similarly, the inner cylinder of the ramp lift hydraulic cylinders 98 on one side of the ramp 6 is piped in common through hydraulic lines 104 with the inner cylinder of the ramp lift hydraulic cylinders 98 on the other side of the ramp 6. In the event that there is transverse rolling of the pontoon in response to waves or differential loading, hydraulic fluid is passively pumped from the cylinders on one side of the ramp 6 to the corresponding cylinders on the other side of the ramp 6, thereby maintaining a relatively stable vertical distance of the ramp 6 off the deck of the pontoon at the longitudinal centerline.
Referring to
An adjustable upper level secondary apron 7 is pivotally connected by hinges to the distal end of the upper level 84 of the truss ramp 6 such that the upper level secondary apron 7 may be pivoted about a horizontal transverse axis, to provide driving surface continuity between the deck plate 88 of the upper level 84 of the truss ramp 6 and the corresponding upper loading surface of the ferry. The height of the upper level secondary apron 7 can be adjusted vertically with the use of a pair of upper level secondary apron lift hydraulic cylinders 108, one end of one of said upper level secondary apron lift cylinders 108 being attached to one of the pair of ramp lift brackets 100 and the other end of said upper level secondary apron lift cylinders 108 being attached to the distal end of the upper level secondary apron 7.
The first section 116 of a two-part, articulating upper primary apron 8 is pivotally connected by hinges to the distal end of the upper level secondary apron 7 such that the first section 116 of the upper primary apron 8 may be pivoted about a horizontal transverse axis. The second section 118 of the articulating upper primary apron 8 is pivotally connected by hinges to the distal end of the first section 116 of the upper primary apron such that the second section 118 may be pivoted about a horizontal transverse axis. The height of the articulating upper primary apron 8 can be adjusted vertically with the use of a pair of upper primary apron lift hydraulic cylinders 112. One end of each of the upper primary apron lift cylinders 112 is attached to the top of the distal end of the upper level secondary apron 7, while the other ends of the upper primary apron lift cylinders 112 are attached to the distal end of the first section 116 of the upper primary apron 8. Motion of the second section 118 of the upper primary apron 8 with respect to the first section of the upper primary apron 8 is controlled by a pair of primary apron hydraulic cylinders or struts 114 mounted between the first section 116 and the second section 118 of the upper primary apron 8.
Referring to
Conveniently, a single operator can operate the ramp 6 and associated aprons. When a ferry is approaching the berthing facility 200, the operator of the truss ramp 6, knowing the height above the water of the deck of the lower access port of the ferry and the distance between the deck of the lower access port and the deck of the upper access port, will: use the ramp lift hydraulic cylinders 98 to set the distal end of the ramp at the desired height; use the lower level apron lift hydraulic cylinders 104 to position the lower level apron 102 so as to provide a safe clearance between it and the deck of the lower access port; use the upper level secondary apron lift hydraulic cylinders 108 to move the upper level secondary apron 7 so as to adjust for the distance between the deck of the lower access port and the deck of the upper access port; and use the upper primary apron lift hydraulic cylinders 112 and the primary apron hydraulic cylinders 114 to position the first section and second sections of the two-part, articulating upper primary apron 116, 118 so as to provide a safe clearance between the articulating upper primary apron 116, 118 and the deck of the upper access port. When the ferry is secured in the loading/unloading position, the operator; lowers the lower level apron 102 onto the deck of the lower access port; and lowers the articulating upper primary apron 116, 118 onto the deck of the upper access port, to permit vehicles to exit and enter the vehicle decks of the ferry.
The berthing facility 200, is provided with a service ramp having an access trestle 12 and a single lane service ramp span 11 attached thereto. The access trestle 12 is positioned next to the truss ramp 6. The service ramp span 11 is positioned to permit vehicular access to the decks of the pontoon modules. The access trestle 12 provides access from the shore for service vehicles to the service ramp span 11 and hence to the deck of the pontoon 1. The distal end of the service ramp span 11 is provided with a fixed, let down ramp (not shown) to allow the transition from the service ramp span 11 to the deck of the pontoon 1, allowing moderate slopes within the space available.
Other variations and modifications of the invention are possible. For example, depending on the seabed conditions, different types of anchoring arrangements may be required. Further, either fewer or more pontoon modules could be fabricated and later interconnected. A ramp having only a single level could be used for loading the ship and a means for adjusting the height of the ramp to allow loading of, say, the lower level of the ferry and then the upper level of the ferry in sequence could be provided. Further pontoon modules, a second ramp module and a third wingwall module, could be added to the shore end of the berth to form a mirror image of the existing ramp module and second wingwall module thus forming a double recess, one recess on each side of the longitudinal deck of the main pontoon modules, each recess dimensioned and configured to receive a ship or ferry and to accommodate the simultaneous berthing of two ships or ferries. In such a configuration, only the single service ramp would be required, however a second truss ramp would need to be positioned to facilitate loading of the second ship. All such modifications or variations and others that will occur to those skilled in the design of such systems are considered to be within the scope of the invention as defined by the claims appended hereto.