Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B23/00—Equipment for handling lifeboats or the like
  • B63B23/40—Use of lowering or hoisting gear
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B27/00—Arrangement of ship-based loading or unloading equipment for cargo or passengers
  • B63B27/36—Arrangement of ship-based loading or unloading equipment for floating cargo

Definitions

• the present invention relates to arrangements and methods at devices capable of floating, such as rescue craft or the like, wherein the device is hoisted and/or lowered by means of a flexible primary hoisting member which in operation extends essentially vertically and which is included in a hoisting arrangement comprising hoisting means, e.g., a winch or the like device which is provided at a ship or at a corresponding arrangement.
• hoisting means e.g., a winch or the like device which is provided at a ship or at a corresponding arrangement.
• the present invention relates to a method for attaching to and, respectively, releasing from a flexible primary hoisting member, a device which is capable of floating on a water surface, e.g., a vessel such as a rescue craft or the like, suitably so that an attaching and, respectively, a detaching include coupling operations between the device capable of floating and a secondary hoisting member.
• the invention also relates to a method for connecting, in a releasable manner, a device capable of floating, wherein said device is hoisted and/or lowered by means of a flexible primary hoisting member which in operation extends essentially vertically and which is included in a hoisting arrangement which is provided at a ship or the like.
• the invention further relates to an arrangement for hoisting and, respectively, lowering a floatable arrangement in relation to a water surface, suitably for launching and, respectively, taking aboard rescue craft or the like at ships, the arrangement comprising at least one flexible primary hoisting member, known per se, which is provided at a hoisting arrangement.
• Prior art includes various arrangements for launching, at a ship's side, floatable devices such as rescue craft, rafts and similar small craft. Often the purpose of these arrangements is to secure, in an emergency situation, a safe transfer of passengers and crew between the ship and the small craft.
• One such known arrangement comprises davits, of which an outer end can be positioned out over the ship's side so that a hoisting member running form the davit can be attached to or separately be detached from the small craft when it is located on the water surface at the ship's side.
• Classic lifeboat arrangements at least comprise the feature that a lifeboat located on board the ship can be launched m this manner, the arrangement comprising engaging means which primarily are intended to be released from the lifeboat, which should be possible even m difficult circumstances with wind and heavy sea.
• Norwegian Patent No. 89234 and British patent application No. 2 092 101 may serve as examples.
• such hoisting devices usually are provided with self-tensionmg means m order to facilitate the coupling between a lifeboat and a hoisting cable, the purpose of such arrangements being an automatic compensation of the impact of heavy sea.
• self-tensionmg means m order to facilitate the coupling between a lifeboat and a hoisting cable, the purpose of such arrangements being an automatic compensation of the impact of heavy sea.
• the object of the present invention is to provide a simple way for attaching lifeboats, rescue craft or similar freely floating arrangements to a hoisting member, also in conditions where the connection of the hoisting member to the small craft can be done even by hand.
• a further object of the present invention is to provide an arrangement where at a ship already existing davits, lifeboats and the like to a wide extent can be utilized without difficulty and extensive modifications.
• the method related to attaching floating devices is characterized in rendering a point at said primary hoisting member, by means of separate floating means, into such a position in relation to the floatable device that a connecting secondary hoisting member acting between said device and said point, while a slack is preserved, can be connected for a hoisting action or, respectively, be released from such a connection.
• the method for connecting a device capable of floating is characterized in that said device capable of floating and separately provided floating means are maintained in a mutually generally horizontally centered position in such a way that one or several first connecting points at said device will be located essentially underneath and at a distance from one or more co-operating second connecting points at said floating means, said distance being maintained by means of said separately provided floating means through affecting primary hoisting members in such a manner that secondary hoisting members acting between said first and said second attachment points can be connected to or, respectively, released from said cooperation while maintaining a slack which is suitable for the coupling operation.
• the arrangement according to the present invention is characterized in that the arrangement includes, on one hand, floating means which are floating as such and acting at such a point at the flexible primary hoisting member which point is located at a vertical distance from the floatable device's engaging means, and, on the other hand, includes connecting secondary hoisting members which are flexible in at least one direction and arranged for connection between said point and said floatable device's said engaging means.
• the arrangement according to the present invention can be described so that a craft or a similar floatable arrangement is being handled freely hanging in a primary hoisting member via a secondary portion of the same arranged in line with said first portion, or via a correspondingly provided separate secondary hoisting member, while a docking unit is arranged, in order to position said secondary portion or hoisting member in relation to the water surface, to be hanging in another portion of the same hoisting member at a point which is located above said secondary portion.
• both the craft and the docking unit load the hoisting member essentially directly, while the water lifts the craft somewhat in relation to the docking unit and thus creates a slack in said secondary portion.
• said secondary portion has such a slack which renders possible a manual coupling operation between said portion and said craft .
• the lifting force which the water exerts on a floating means which at least in a vertical direction is independent in relation to said craft and which is attached to said primary hoisting member is utilized for vertically positioning a portion of said hoisting members in relation to said craft, suitably so that the buoyancy of said floating means is caused to act on said hoisting member at such a point which is located above said secondary portion or above such an end thereof which is intended to be coupled to said craft.
• one portion of said secondary flexible hoisting then be functionally located suitably at least slightly beneath engaging means arranged at the craft, or beneath an attachment point which is defined in some other way, to which point said portion will be connected, said portion meanwhile being horizontally essentially freely movable in relation to the attachment point.
• the craft can now be attached to or, respectively, released from this portion by means of, for example, a crane hook or a corresponding engaging means.
• both the craft and the floating means will be located freely floating on the water surface.
• said secondary hoisting member in practice, will exhibit a slack which renders possible a performing without any risk of accidents the coupling operations, i.e. a releasing and, respectively, an attaching .
• Figure 1 m cross section discloses an explanatory sketch of an arrangement m accordance with the present invention
• Figure 2 m a view seen towards a ship's side or the like discloses a practical embodiment of the present invention
• Figure 3 discloses the embodiment according to Fig. 2 viewed along the ship's side
• Figure 4 discloses a plane view of the same embodiment
• Figures 5 to 8 disclose, step by step m detail and partially m cross section, how an attachment of the small craft to the hoisting member is performed by means of the arrangement according to Fig 1
• an arrangement m accordance with the present invention comprises a flexible primary hoisting member 1, known per se, for example a hoisting cable or the like, which member at its upper end is attached to a hoisting arrangement including, for example, a winch 2 or some similar means which is shown m more detail m Fig. 2, by means of which means the vertical position of a lower portion la of said primary hoisting member 1 can be adjusted As Figs.
• said hoisting member 1 is suitably guided over a davit 3 or the like means having an arm 4 which defines a horizontal position for an upper portion lb of said hoisting member 1 m relation to a device which is relatively stationary m comparison with the device capable of floating
• said relatively stationary device can comprise a ship's side 5 or the like, or, e.g., an oil rig, a wall of a quay, or some other such major device, while the floatable device can comprise, e.g., a small craft or the like.
• a ship's side 5 is roughly indicated in phantom in Fig. 1 in a schematic manner, and in the same schematic manner is shown a level 6 which, for example, indicates the height of a ship's deck or the like which is located at a considerable distance "a" from a water surface 7.
• This distance can, in practice, be anything from a few meters to tens of meters.
• the distance between said level 6 and the water surface 7 may greatly vary in a relatively short period of time, which is illustrated in Fig. 1 by indications 7' and 7", respectively.
• a small craft 8 or some other floatable device which floats relatively freely on the water surface 7 behaves in the same manner.
• the vertical position of said lower end can be considered as relatively stationary in relation to said level 6.
• a ship in the water is not, in practice, fully stationary either, since also the ship 5 heaves. This heaving also causes the ship's deck to move horizontally, so that not either the horizontal position of the upper end lb of the hoisting member 1 will be in any way fully fixed.
• the ship's movements are of a considerably slower character in comparison to the movements of the smaller craft, one can, in theory, primarily start from the assumption that said one end lb is essentially fixed while the other one is movable at least in vertical direction.
• the impact of the wave motion on the water surface 7 is now transferred to the lower portion la of the hoisting member 1 by allowing the buoyancy of means 9 which float on the water surface 7 to act suitably directly on an attachment point 10 which is connected to said lower portion la of the hoisting member 1.
• this is suitably accomplished by means of a framework 18 which is provided at a pontoon means, a buoy means or the like, which framework is included as a part of a floating arrangement 11 in order to position said attachment point 10.
• a dash-dotted line is used to indicate an alternative position 7' for the water surface 7 and said framework 18.
• this arrangement provides a functional connection or positioning between said lower portion la of said hoisting member 1 and the water surface 7. At the same time this, however, means that a functional positioning of said lower end la is achieved also in relation to all other such means which float on the water surface 7 at essentially the same spot and which have an essentially similar displacement and pattern of motion as said pontoons 9.
• said floatable device can have a displacement of, for instance, 1.6 tons while its docking unit, i.e. the floating arrangement which performs the positioning of the primary hoisting members 1 can have a displacement of 0.6 tons, whereby the whole arrangement can be hoisted, with a good safety margin, in a normal 3 ton davit.
• the coupling portion lc is disclosed, in order to show the principle, as a flexible loose member having cooperating engaging means 12, 12a and 13, 13a, respectively, at each end, but in practice the most favorable arrangement is one where one end is more or less permanently attached, suitably so that the upper end 12a is attached at least in advance to the engaging means 13a of said the floating arrangement 11, if it is not attached thereto in a completely fixed manner.
• engaging means comprising an open hook and a simple ring have been schematically shown, but in practice these means are designed, of course, to match all such safety precautions which are required for hoisting, for example, rescue crafts 8 including crew and people in distress.
• Figures 5 to 8 show in more detail embodiments wherein the actual rescue craft 8 is provided with heavier hook means 13, for instance known remotely releasable means, while the associated engaging means 12 are essentially light weight means, which facilitates their handling and minimizes the risks in heaving sea.
• the co-operating engaging means 12, 13 can be attached with no lifting effect whatsoever during the actual coupling operation, and with this the risk of such injury to people or equipment is eliminated which possibly arises at coupling.
• said means 12 and 13 have been interconnected the craft and the pontoon means 9 can continue to float freely, but, contrary to the earlier stage, the whole arrangement can now also be hoisted as an entity, which situation will be described below in more detail .
• FIGS 2 to 4 generally present a favorable arrangement for putting in practice the present invention.
• This arrangement includes a pulling means 14, for instance a drag wire which extends in a generally slanting horizontal manner in the direction of the ship's side 5.
• this pulling means 14 emerges from a favorably collapsible boom 15 which comprises winching means 16 for controlling the length of the drag wire 14, where said winching means suitably comprise shock absorbing means for counteracting any jerks.
• the general direction is stabilized for the floatable docking unit 11 which is constituted by the generally parallel pontoons 9, which stabilization makes it easy to drive the craft 8 in between the pontoons 9 also in rough weather and heavy sea.
• the entity comprising the craft 8, the pontoons 9 and the framework 18 arranged in connection with the is also stabilized by means of said pulling means 14 when said entity is hoisted and, respectively, lowered.
• the length of the drag wire 14 and the general geometry of the arrangement is preferably adapted to the dimensions of the ship so that the length of the pulling cable during launching will be adapted to the point where the docking unit 11 and the rescue craft 8 meet the water surface .
• the drag wire's 14 elevation angle from the water surface 7 up towards the deck should not exceed about 33°.
• the embodiment disclosed in Figs. 2 to 4 favorably includes the ship's standard cranes or davits 3, which already, according to current requirements, are provided with a self tensioning feature.
• This feature which usually can be switched on and off, normally works for such loads as lifeboats and the like, which loads have a weight exceeding 300 kilograms, and it ensures that the hoisting cable 1 automatically will be tensioned so that slack is prevented when the waves lift the lifeboat, while it gives out more of the hoisting cable as the waves subside.
• this self tensioning device operates based on the dead weight of the docking unit 11 which is constituted by the pontoon arrangement.
• said dead weight suitably is in the order of 600 kilograms.
• Fig. 3 shows that the docking unit 11 which is constituted by said pontoon arrangement 9 and said framework 18 suitably is designed as a catamaran-like device, wherein the pontoons 9 at the same time constitute fender means against the ship's side 5.
• the rescue craft 8 or the like will at a hoisting operation be directly suspended from the hoisting member 1, the docking unit 11 thus carrying only its own weight.
• the actual docking unit 11 can be made very light.
• the docking unit 11 comprises a generally U-shaped cradle which favorably is open at the stern, which cradle is formed of said suitably pontoonlike buoyant bodies 9.
• Said buoyant bodies 9 are connected by means of said framework 18, which above an open space forms a hoisting yoke by means of which the docking unit 11 can be hoisted.
• said hoisting yoke serves as a hoisting means for the attachment point 10 at the hoisting members 1.
• the open space formed between the pontoons 9 is intended to receive the rescue craft 8, and favorably it is dimensioned accordingly.
• Fig. 3 further shows that the framework 18 favorably also comprises one or more connecting supports 19 which extend below said open space and thus reinforce the structure.
• This support 19 is arranged at such a distance "b" from the bottom of the rescue craft 8 that the weight of the craft to no essential extent will be resting on the support 19 even in a hoisted position.
• the rescue craft 8 and the docking unit 11 will be freely suspended at the primary hoisting member 1 as well as, respectively, at the secondary hoisting member lc attached to it, essentially independent of each other, while a clearance "b'" is maintained, i.e.
• the whole framework 18 can be designed to have very light structures, since they mainly need to support just their own weight.
• the docking unit 11 can be composed of, for example, foam- filled plastic tubes which serve as said buoyant bodies 9, while the framework 18 suitably can be made of aluminium, fibre glass, plastics, steel or the like.
• a craft 8 is suitably parked on the deck 6 at the ship's side 5.
• the craft 8 and the docking unit 11 are lowered into the water.
• the docking unit is preferably connected by means of a drag wire 14 fore to the ship in order to give the docking unit 11, and thus also the craft 8 connected to it, a forward speed.
• the retrieving on board is done in a corresponding manner so that the craft 8 runs in into the docking unit 11, whereafter the crew engages a short length of wire lc to means 13 provided at the craft 8 for this purpose.
• a preventer wire 17 serves as a lock between the craft 8 and the docking unit 11 for preventing such horizontal movements, which otherwise could be possible within the range of the slack in the length of wire lc.
• the distance "b" between the keel of the craft and a bottom rail 19 which preferably is arranged for stabilizing the floating means, i.e. the docking unit 11, is larger than the slack in the short length of wire lc .
• a primary hoisting cable 1 is attached to, for example, a davit 3 which is suitably arranged in a pivotable manner on the deck of the ship (not shown in Figs. 5 to 8) , while a winch arrangement 2 connected to said davit 3 comprises means which, suitably with a self tensioning action, tighten the hoisting cable into a position shown in Fig. 5.
• the ship is moving forward at a speed of suitably 5 to 8 knots, while a drag wire 14 provided at a suitably collapsible hauling boom 15 tows the docking unit 11 as described above.
• a drag wire 14 provided at a suitably collapsible hauling boom 15 tows the docking unit 11 as described above.
• the docking unit 11 is kept at a safe distance "e" from the ship's side 5, the position at the same time being such, that the hoisting cable 1 extends essentially vertically. This position also corresponds to the situation where the docking unit 11 together with the rescue craft 8 is being launched off the deck.
• the craft 8 can move essentially freely at its own power into the space between the pontoons 9 of the docking unit 11 and, respectively, out of this space.
• the coupling portion i.e. the secondary hoisting member lc
• the coupling portion can be constituted by a portion of said hoisting member 1 or, alternatively, be a separate corresponding device provided at the hoisting yoke of the framework 18, for instance the separate length of wire lc described above, which separate length of wire is essentially loosely arranged as a suitably direct extension of the hoisting member 1.
• This portion lc comprises a crane hook 12, a loop or the like means for co- operation with corresponding means 13 arranged at the rescue craft 8, and said portion preferably exhibits a slack of about 100 millimeters.
• a preventer wire 17 is preferably arranged for stabilizing the movements of the length of wire lc and thus for facilitating the engagement operations . Said preventer wire 17 also prevents the rescue craft 8 from sliding out of the docking unit 11 at hoisting.
• Fig. 6 shows that the helmsman at the rescue craft 8 preferably keeps the bow against the docking unit 11 by maintaining a certain forward thrust in order to, at the same time, in this manner clearly position the engaging means 13 provided at the craft in relation to the docking unit 11 and thus also to the engaging means 12 of the secondary hoisting wire lc .
• the docking unit is preferably designed so that it, as such, guides the positioning.
• the rescue craft 8 as such is not in engaging contact with the docking unit's rail 19 located underneath nor with any other submerged portion of the docking unit 11, but on the contrary so that there is a certain vertical clearance "b" between boat and dock.
• the docking unit 11 follows the motions of the rescue craft 8 in the water in such a way that entering and, respectively, exiting as well as the engagement operation between craft and unit can proceed without difficulty.
• both the craft 8 and the docking unit 11 will have essentially the same pattern of motion in the water a distance "d" between said point 10 and said engaging means 13 will remain essentially constant regardless of the heave of the sea. Due to the slack in the lower portion lc of the secondary hoisting members, a coupling maneuver between the engaging portion 12 of the hoisting member and the engaging means 13 of the rescue craft can be performed at this stage, for example, manually without risk of accidents or injuries, while the self tensioning of the davit arrangement as such reacts to the weight of the docking unit 11 and keeps the hoisting cable 1 stretched.
• the engaging means 12, 13 as such are suitably known per se, favorably so that they are manually releasable co-operating means, one 12 of which is provided at the free extension of the hoisting member 1, and a second one at the rescue craft so that at hoisting the connection 12-13 as such can carry the full load constituted by the craft.
• the self tensioning feature of the hoisting winch is deactivated.
• the docking unit 11 gets lifted first, since it is directly attached to the hoisting cable 1 via the attachment point 10 and the hoisting yoke 18. Meanwhile, the slack in the functionally lowest portion lc of the hoisting cable 1 is stretched, after which the hoisting cable acts directly also on the rescue craft 8, the bottom of which still remaining clear of the bottom rail 19 by said clearance "b'" and thus the bottom will be to no essential extent supported by the docking unit.
• any one of the co-operating engaging means can be included as part of the craft, while another part can constitute a structural part of the coupling portion of the hoisting members. It is also irrelevant for the function how, for example, hook means and loop means, respectively, in practice are designed or located. Above a favorable embodiment has also been described mainly as an example, wherein a coupling portion having a slack, for instance a length of wire, is attached more or less permanently at the floating means, i.e. at the docking unit 11.
• the same function can be achieved also at a reverse arrangement wherein the coupling portion primarily is attached to the craft 8, while the docking unit 11 comprises engaging means, to which the coupling portion will be attached. It is also obvious that instead of a length of wire or some similar coupling portion which is flexible in all directions, also means having a more rigid nature, for example restrictedly telescopic and favorably laterally movable means can be used. According to one embodiment the secondary hoisting member lc comprises longitudinally elastic means in order, for example, to facilitate the engagement.

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• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Ocean & Marine Engineering (AREA)
• Chemical & Material Sciences (AREA)
• External Artificial Organs (AREA)
• Jib Cranes (AREA)
• Magnetic Resonance Imaging Apparatus (AREA)
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• Chair Legs, Seat Parts, And Backrests (AREA)
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• 2000
  • 2000-04-05 FI FI20000805A patent/FI109463B/sv not_active IP Right Cessation
• 2001
  • 2001-04-02 AU AU2001252292A patent/AU2001252292A1/en not_active Abandoned
  • 2001-04-02 AT AT01925592T patent/ATE284808T1/de not_active IP Right Cessation
  • 2001-04-02 DE DE60107823T patent/DE60107823D1/de not_active Expired - Lifetime
  • 2001-04-02 WO PCT/FI2001/000317 patent/WO2001074655A1/en active IP Right Grant
  • 2001-04-02 EP EP01925592A patent/EP1268267B1/de not_active Expired - Lifetime
• 2002
  • 2002-10-04 NO NO20024820A patent/NO20024820D0/no not_active Application Discontinuation

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