EP2560864A2

EP2560864A2 - Boat lift

Info

Publication number: EP2560864A2
Application number: EP11720607A
Authority: EP
Inventors: Tom Willy Grongan
Original assignee: Optimum Engineering AS
Current assignee: Optimum Engineering AS
Priority date: 2010-04-19
Filing date: 2011-04-19
Publication date: 2013-02-27
Also published as: NO336339B1; NO20100561A1; WO2011133047A2; WO2011133047A3

Abstract

A boat lift (10) for use with a boat (40) and an ocean structure (20) is provided, wherein the lift (10) includes one or more mechanisms (100, 120) for raising the boat (40) in respect of the structure (20) and/or for lowering the boat (40) in respect of the structure (20). The one or more mechanisms (100, 120) are mounted to the boat (40), and the one or more mechanisms (100, 120) are adapted to engage onto one or more upright members (130) of the structure (20). Each mechanism (100, 120) includes a configuration of at least two rollers (120A, 120B) for engaging onto the one or more upright members (130), the at least two rollers (120, 120B) being adapted to be forced in operation into engagement onto the one or more upright members (130) by a weight of the boat (40) acting upon the at least two rollers (120A, 120B). The lift (10) further includes lifting actuators (140) operable to rotate one or more of the rollers (120A, 120B). The structure (20) includes one or more of: a portion of an oil rig, a hull of a cargo vessel, a base of a tower of a large offshore wind turbine, a central floating platform of an ocean wave energy park, a passenger ship.

Description

BOAT LIFT

Field of the invention

The present invention relates to boat lifts, for example to boat lifts for use in conjunction with offshore structures for receiving boats. Moreover, the present invention also concerns methods of operating these boat lifts.

Background of the invention

There is an increasing trend for large structures to be deployed offshore, for example oil rigs, oil production platforms, offshore wind turbines, offshore wave energy systems. Such offshore structures are required to operate under various weather conditions, namely both calm sea conditions and rough sea conditions. Rough sea conditions include, for example, storm conditions. Moreover, these structures often need maintenance and servicing, for example for repairing storm damage or for upgrading and/or maintaining equipment.

Contemporary methods of moving personnel and provisions to and from offshore structures include using helicopters and service boats. Helicopter service is generally much more expensive than boat service. Boat service generally suffers from a potentially dangerous situation of a small boat being affected by large wave swell coming in close proximity to a large structure; the boat can be slung at the large structure and be thereby damaged. Moreover, with large movements between a service boat and a large offshore structure, it is very dangerous for personnel to attempt to leave the service boat to climb onto the large structure. A conventional approach to try to address this problem has been to use winches. However, winches are dangerous on account of a risk of impact associated with relative movement between a winch hook at an end of a winch cable of a winch and a boat to be engaged by the hook for winching up.

In a published United States patent no. US 5, 706, 755 (Seascape Systems Ltd., Canada), a system is described which includes a rotating arm for pivotally mounting onto a support structure of an offshore platform. The arm is selectively moveable between an upper position in which an outer end of the arm is adjacent to the platform, and a lower position in which the outer end of the arm is below water and remote from the platform. The system includes a pickup adjacent the outer end of the arm for capturing and suspending a boat. A winch is included for selectively raising and lowering the boat. Moreover, the boat is provided with a suspension for mating with the pickup. Shock absorbers are incorporated on the suspension to reduce shock to the boat when the boat is being captured by the pickup. The system is suitable for relatively small craft and potentially utilizes a considerable amount^' of material for its implementation, thereby rendering it a costly solution. Furthermore, coupling the boat to the end of the arm is potentially difficult in rough ocean conditions.

In a more recently published US patent no. US 6, 786, 170B2, there is described a lifting device for a boat. The lifting device includes a first platform and a plurality of linkage members, the plurality of linkage members configured to form at least four-bar linkage assemblies, each having a first end pivotally attached to the platform and a second end pivotally attached to a boat. The lifting device further includes at least one hydraulic cylinder, the cylinder having a first end and a second end, the first end being pivotally affixed to the structure of a boat and the second end pivotally attached to at least one linkage member, and a fluid device in communication with the hydraulic cylinder. A load sharing member connects the two four-bar linkage assemblies and prevents uneven or tilted motion of the platform. The lifting device is suitable for use in calm waters, for example within harbours, but is quite unsuitable for use offshore in adverse weather conditions when wave swells of several meters are encountered.

In a German utility patent no. DE9002191 U (Gebrauchsmuster), there is described a boat lift for raising and lowering a boat along a substantially horizontal track, wherein the lift includes rollers along the track and a roller track for engaging onto a lower central edge of a hull of the boat. Such a lift is suitable for harbours having calm waters, but is completely unsuitable for offshore structures when significant ocean wave amplitude is encountered.

In a Norwegian patent no. NO 164767, there is described a boat winch which is operable to bear a weight of a boat using a winch-type arrangement. The boat winch is potentially difficult to use when significant ocean wave amplitude is encountered due to difficulties trying to attach an end of a winch cable to the boat prior to winching up the boat.

It will be appreciated from the foregoing that a technical problem of reaching and leaving a large offshore structure using a relatively smaller boat has not yet been adequately addressed.

Summary of the invention

The present invention seeks to provide an improved boat lift which is capable of being deployed on boats for enabling the boats to haul themselves up onto offshore structures and/or off such offshore structures. According to a first aspect of the present invention, there is provided a boat lift as defined in appended claim 1 : there is provided a boat lift for use with a boat and an ocean structure, wherein the lift includes one or more mechanisms for raising the boat in respect of the structure and/or lowering the boat in respect of the structure, characterized in that the one or more mechanisms are mounted to the boat, and the one or more mechanisms are adapted to engage onto one or more elongate upright members of the structure; each mechanism includes a configuration of at least two rollers for engaging onto the one or more elongate upright members, the at least two rollers being adapted to be forced in operation into engagement onto the one or more elongate upright members by a weight of the boat acting upon the at least two rollers; and the lift further includes lifting actuators operable to rotate the one or more of the rollers for lifting and/or lowering the boat.

The invention is of advantage in that the at least two rollers are capable of being rapidly engaged onto the one or more elongate upright members and actuated immediately to move the boat promptly above maximum wave height, thereby reducing a risk of the boat being impacted onto the one or more elongate members and damaged as a consequence thereof.

The expression "roller" is to be construed to be any form of rotatable element which is susceptible to being used to engage onto the one or more elongate members for assisting to raise or lower the boat. For example, the "roller" can be implemented as a wheel, a toothed wheel, an axially elongate roller, a frusto-conical wheel, a dual frusto-conical wheel and so forth.

Optionally, the one or more mechanisms are attached to a front-half portion of the boat.

Optionally, the boat lift is implemented so that the one or more mechanisms are operable to follow motions of the boat in response to ocean waves acting thereupon when the boat is coupled to the structure to a top height of ocean waves, and wherein the one or more mechanisms are operable to maintain the boat at this top height prior to raising the boat above the ocean waves in a lifting operation. More optionally, the boat lift is implemented so that the one or more mechanisms each include pivotally-mounted rollers which are operable to be swung into engagement with and/or from disengagement from one or more elongate upright members of the structure. Optionally, the boat lift includes a winch arrangement for engaging onto the offshore structure, the winch arrangement including an actuator arrangement on the boat for assisting in hauling the boat up and/or down relative to the offshore structure.

More optionally, the boat lift is implemented so that the one or more mechanisms are operable to maintain the boat at an inclined angle when engaged to the structure, the inclined angle being such to prevent the boat from slipping out of engagement with the structure when the boat is suspended above ocean waves.

Optionally, the boat lift is adapted to be retrofitted to boats.

Optionally, the boat lift includes a wind shield at an upper portion of the one or more elongate upright members to protect the boat from wind gusts when elevated by the boat lift above ocean waves. Optionally, the boat lift is adapted for use with the structure, wherein the structure includes one or more of: a portion of an oil rig, a hull of a cargo vessel, a base of a tower of a large offshore wind turbine, a central floating platform of an ocean wave energy park, a passenger ship. According to a second aspect of the invention, there is provided a method of engaging a boat lift attached to a boat: there is provided a method of engaging a boat lift attached to a boat, wherein the method includes:

(a) manoeuvring the boat so that its one or more mechanisms are brought into contact with one or more elongate upright members of a structure;

(b) allowing the one or more mechanisms to move with the boat when engaged to the one or more elongate upright members, so that the boat is retained at a maximum height of ocean waves acting upon the boat; and

(c) actuating the one or more mechanisms together with the boat in an upward direction above the ocean waves. Optionally, the method includes using a water jet propulsion system and/or a propeller propulsion system of the boat for manoeuvring the boat via its one or more mount components onto the structure. Optionally, a winch arrangement is used to assist to raise the boat in step (c) of the method of the second aspect of the invention.

According to a third aspect of the invention, there is provided a method of disengaging a boat lift attached to a boat: there is provided a method of disengaging a boat lift attached to a boat from a structure, the method including:

a) using one or more mechanisms of the lift mounted onto the boat to engage onto one or more elongate upright members of the structure, the one or more mechanisms being attached to side regions a boat, to lower the boat towards ocean waves;

(b) when the boat begins to engage ocean waves, allowing the one or more mechanisms and the boat to move with the ocean waves and starting a propulsion system of the boat; and

(c) using the propulsion system to move the boat away from the structure.

Optionally, the method includes using a configuration of one or more elongate upright members and a roller arrangement cooperating with the one or more elongate upright members for implementing the one or more mechanisms. Optionally, the method involves employing a winch arrangement to assist in step (a) of the method pursuant to the third aspect of the invention. According to a fourth aspect of the invention, there is provided a boat adapted at its side regions for use with a boat lift pursuant to the first aspect of the invention.

It will be appreciated that features of the invention are susceptible to being combined in various combinations within the scope of the invention.

Description of the diagrams

Embodiments of the present invention will now be described, by way of example only, with reference to the following diagrams wherein:

FIG. 1 is a general illustration of a boat lift according to the present invention;

FIG. 2 is an illustration of boat-mounted supporting rollers of the boat lift of FIG. 1 ;

FIG. 3A to FIG. 3D are a series of illustrations of the boat lift of FIG. 1 being used to haul up a boat; FIG. 4A to 4D are a series of illustrations of the boat lift of FIG. 1 being used to iower a boat for releasing it to an ocean environment;

FIG. 5 is another general illustration of a boat lift according to the present invention;

and

FIG. 6 is a plan view illustration of an implementation of a boat lift pursuant to the present invention.

In the accompanying diagrams, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non- underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.

Description of embodiments of the invention

In overview, the present invention is concerned with a boat lift 10 for lifting boats onto offshore structures 20 and also off these offshore structures 20. Moreover, an example of the offshore structures 20 is optionally a portion of an oil rig, a hull of a cargo vessel, a base of a tower of a large offshore wind turbine, a central floating platform of an ocean wave energy park or a passenger ship. An example of a boat lift pursuant to the present invention is illustrated in FIG. 1 and FIG. 2, wherein the boat lift is indicated generally by 10. The boat lift 10 is attached to a side portion of a boat 40, and enables the boat 40 to haul itself onto an offshore structure 20 and also Iower itself from the offshore structure 20. As illustrated, the boat lift 10 is installed substantially in a front-half portion of the boat 40. The offshore structure 20 is considerably larger than a boat 40 to be manipulated by the boat lift 10. Beneficially, the boat 40 is a high-power sea vessel equipped with a water jet propulsion system providing the boat 40 with a high degree of manoeuvrability; however, the present invention is also relevant for use with boats employing propeller propulsion systems. Moreover, as aforementioned, the offshore structure 20 is optionally a portion of an oil rig, a hull of a cargo vessel, a base of a tower of a large offshore wind turbine, a central floating platform of an ocean wave energy park. The boat 40 includes a lift mount 100 disposed at side regions of the boat 40, more preferably towards a front portion of boat 40 as illustrated. The lift mount 100 includes two rollers 120A, 120B for engaging onto corresponding one or more elongate upright members 130 of the structure 20. The rollers 120A, 120B are optionally provided with one or more drive motors 140A, 140B and/or are coupled to a propulsion engine of the boat 40 via a suitable clutch and gear arrangement. In FIG. 2, the lift mount 100 is shown in greater detail with its two rollers 120A, 120B; the rollers 120A, 120B are optionally implemented as a configuration of wheels, and the rollers 120A, 120B are beneficially contoured to provide a larger contact surface area onto their associated upright member 130. A first roller 120A is highest on the boat lift 10 and abuts onto a side of the upright member 130 remote from the lift mount 100. A second roller 120B is lower on the boat lift 10 than the first roller 120A and abuts onto a side of the upright member 130 facing towards the lift mount 100. Optionally, a third roller 120C is included in the boat lift 10 lower than the second roller 120B and loosely abuts onto a side of the one or more upright members 130 remote from the lift mount 100; optionally, the third roller 120C, optionally with its associated drive motor 140C, is actuated selectively to bind the boat 40 even more rigidly and securely onto the one or more upright members 130. Optionally, the rollers 120A, 120B are provided with projecting surface features which engage into corresponding projecting surface features formed onto sides of their one or more upright members 130; for example, the rollers 120A, 120B and their corresponding upright members 130 are optionally provided with mutually cooperating teeth-like projecting surface features for enhancing their mutual grip when brought into mutual engagement. Optionally, the one or more upright members 130 are hollow tubular components, for example fabricated from steel and welded or otherwise affixed to the structure 20. The boat 40 is illustrated in plan view at a lower portion of FIG. 2, wherein an operating disposition of the rollers 120A, 120B in respect of the upright members 130 is shown in an upper portion of FIG. 2 in side view.

A method of docking the boat 40 using the boat lift 10 will now be described with reference to FIG. 3A to FIG. 3D. In FIG. 3A, the lift mount 100 on the boat 40 is moving up and down in synchronism with ocean waves 210. The boat 40 employs its jet thrusters and/or propeller system to move rapidly into a direction of the one or more upright members 130 for engaging side regions of the boat 40 via its rollers 120A, 120B onto the one or more elongate members 130 as illustrated in FIG. 3B. With the weight of the boat 40, the mount 100 experiences a turning moment which causes the rollers 120A, 120B to couple strongly to the one or more upright members 130. The rollers 120A, 120B are provided with a uni- directional ratchet such that the waves 210 haul the boat 40 to a height corresponding to a peak of the waves 210 as illustrated in FIG. 3C. When this occurs, the drive motors 140 and/or the propulsion unit of the boat 40 draw the boat 40 up as rapidly as possible to a height well over the waves 210 as illustrated in FIG. 3D; optionally, the boat 40 includes a winch arrangement which assists to draw the boat 40 up from a position corresponding to the peak of the waves 210. Personnel within the boat 40 do not need to leave the boat 40 until it is raised to a safe height above the waves 210. Optionally, a gangway 250 is offered to the boat 40 for enabling personnel to leave the boat 40 to alight onto the offshore structure 20. Optionally, a roller 120C is included which is actuated by a hydraulic actuator so that, when the boat 40 reaches a maximum wave height as illustrated in FIG. 3C, the roller 120C is forced by the hydraulic actuator into robust positive engagement with the one or more upright members 130 to further reduce any risk of the mount 100 slipping back into the ocean environment 200. Moreover, the winch arrangement mounted on the boat 40 also beneficially reduces a risk of the boat 40 slipping unintentionally back into the ocean environment 200.

A method of undocking the boat 40 using the boat lift 10 will now be described with reference to FIG. 4A to FIG. 4D. In FIG. 4A, the boat 40 is at a top of the one or more upright members 130 and personnel enter into the boat 40. The uni-way ratchets of the rollers 120A, 120A are disabled and the drive motors 140 and/or a propulsion unit of the boat 40 is then operated to lower the boat 40 to a height of the waves 210 as illustrated in FIG. 4B; optionally, a winch arrangement mounted on the boat 40 is also employed to assist to lower the boat 40. The boat 40 then starts its water jet propulsion system and/or propeller propulsion systems simultaneously whilst the mount 100 is freely allowed to follow wave movement of the waves 210 together with the boat 40 as illustrated in FIG. 4C. The boat 40 then moves away from the one or more elongate members 130 as rapidly as possible to achieve a separation as illustrated in FIG. 4D. Rapid movement of the boat 40 to and from the elongate members 130 is desirable during operation of the boat lift 10 to avoid the boat 40 being thrust against the one or more upright members 130 and/or the offshore structure 20.

Many robust boats 40 built to withstand adverse weather conditions can be adapted to function with the boat lift 10 with little or no modification. When boats 40 need to be adapted to be compatible with the boat lift 10, additional runners 300 can be added to the boat 40 to assist the lift mount 100 to bear of weight of the boat 40 when suspended upon the one or more elongate members 130, for example as illustrated in plan view at a bottom region in FIG. 2. In the foregoing, it will be appreciated that the lift mount 100 is designed so that boat 40 subtends an angle p relative to a vertical 330 to ensure that the boat 40 does not slide when being hauled up along the one or more upright members 130. Optionally, the lift mount 100 is provided with a safety latching mechanism to ensure the boat 40 is locked into position onto the one or more elongate members 130 to prevent the boat 40 from being dislodged, for example due to severe gusts of wind in storm conditions. As aforementioned, the boat lift 10 can itself be designed into the boat 40 at initial construction, or can be added to the boat 40 later by way of a retrofit. Optionally, the upright members 130 are not precisely vertical, but subtend in an angle p of -30° to +30° relative to vertical 330. Optionally, an upper portion of the one or more upright members 130 is provided with a wind shield to provide a more comfortable environment when personnel are leaving the boat 40 or to re-entering the boat 40. Optionally, the one or more upright members 130 are extended down into the ocean environment 200 so that the boat lift 10 is also capable of raising and lowering mini-submarines; when at wave height, the lift mount 100 is able to move with the waves 210 to lift the mini-submarine up to a maximum height of the waves 210; when the mini-submarine is to be returned to the ocean environment 200, the uni-direction ratchets of one or more of the rollers 120A, 120B are beneficially modified to operate in an opposite sense so that the mini-submarine is able to freely attain a lowest trough height of the waves 210 as rapidly as possible so as to avoid wave damage in adverse weather conditions.

The present invention is also susceptible to being used along coast lines, in harbours, along jetties and so forth. Optionally, as illustrated in FIG.6, the rollers 120A, 120B are mounted to corresponding pivotally-mounted components 350 for enabling the boat 40 to engage rapidly onto the one or more elongate members 130 and then be secured by pivotally introducing the rollers 120A, 120B into contact with the one or more elongate members 130. The drive motors 140 are beneficially implemented as one or more of: electric motors, hydraulic motors, clutch systems engaging onto a main engine of the boat 40.

Modifications to embodiments of the invention described in the foregoing are possible without departing from the scope of the invention as defined by the accompanying claims. Expressions such as "including", "comprising", "incorporating", "consisting of, "have", "is" used to describe and claim the present invention are intended to be construed in a nonexclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural. Numerals included within parentheses in the accompanying claims are intended to assist understanding of the claims and should not be construed in any way to limit subject matter claimed by these claims.

Claims

1. A boat lift (10) for use with a boat (40) and an ocean structure (20), wherein the lift (10) includes one or more mechanisms (100, 120) for raising the boat (40) in respect of the structure (20) and/or lowering the boat (40) in respect of the structure (20), characterized in that said one or more mechanisms (100, 120) are mounted to the boat (40), and the one or more mechanisms (100, 120) are adapted to engage onto one or more elongate upright members (130) of the structure (20); each mechanism (100, 120) includes a configuration of at least two rollers (120A, 120B) for engaging onto the one or more elongate upright members (130), the at least two rollers (120A, 120B) being adapted to be forced in operation into engagement onto the one or more elongate upright members (130) by a weight of the boat (40) acting upon the at least two rollers (120A, 120B); and said lift (10) further includes lifting actuators (140) operable to rotate one or more of the rollers (120A, 120B) for raising and/or lowering the boat (40).

2. A boat lift (10) as claimed in claim 1 , characterized in that the one or more mechanisms (100, 120) are attached to the boat (40) at a front portion of the boat (40).

3. A boat lift (10) as claimed in claim 1 or 2, characterized in that the one or more mechanisms (120, 140) are operable to follow motions of the boat (40) in response to ocean waves (210) acting thereupon when the boat (40) is coupled to the structure (20) to a top height of ocean waves (210), and wherein the one or more mechanisms (120, 140) are operable to maintain the boat (40) at this height prior to raising the boat (40) above the ocean waves (210) in a lifting operation.

4. A boat lift (10) as claimed in claim 1 , characterized in that said one or more mechanisms (120, 140) include said at least two pivotally-mounted rollers (120A, 120B) so that they are operable to be swung into engagement with and/or from disengagement from the one or more elongate upright members (130) of the structure (20).

5. A boat lift (10) as claimed in claim 1 , 2, 3 or 4, characterized in that the boat lift (10) includes a winch arrangement for engaging onto the structure (20), the winch arrangement including an actuator arrangement on the boat (40) for assisting in hauling the boat (40) up and/or down relative to the structure (20).

6. A boat lift (10) as claimed in any one of the preceding claims, characterized in that the one or more mechanisms (100, 120) are operable to maintain the boat (40) at an inclined angle when engaged to the structure (20), the inclined angle being such to prevent the boat (40) from slipping out of engagement with the structure (20) when the boat (40) is suspended above ocean waves (210).

7. A boat lift (10) as claimed in any one of the preceding claims, characterized in that the lift (10) is adapted to be retrofitted to boats (40).

8. A boat lift (10) as claimed in any one of the preceding claims, wherein the lift (10) includes a wind shield at an upper portion of the one or more elongate members (130) to protect the boat (40) from wind gusts when elevated by the lift (10) above ocean waves (210).

9. A boat lift (10) as claimed in any one of the preceding claims adapted for use with the structure (20) including one or more of: a portion of an oil rig, a hull of a cargo vessel, a base of a tower of a large offshore wind turbine, a central floating platform of an ocean wave energy park, a passenger ship.

10. A method of engaging a boat lift (10) attached to a boat (40), characterized in that said method includes:

(a) manoeuvring said boat (40) so that its one or more mechanisms (100, 120) are brought into contact with one or more elongate upright members (130) of a structure (20);

(b) allowing said one or more mechanisms (100, 120) to move with said boat (40) when engaged to the one or more elongate upright members (130), so that said boat (40) is retained at a maximum height of ocean waves (210) acting upon the boat (40); and

(c) actuating said one or more mechanisms (100, 120) together with said boat (40) in an upward direction above said ocean waves (210).

1 1. A method as claimed in claim 10, including using a water jet propulsion system and/or propeller propulsion system of the boat (40) for manoeuvring said boat (40) via its one or more mechanisms (100, 120) onto the structure (20).

12. A method of disengaging a boat lift (20) attached to a boat (40) from a structure (20), characterized in that said method includes:

(a) using one or more mechanisms (100, 120) of the lift (10) mounted onto the boat (40) to engage onto one or more elongate upright members (130) of the structure (20), the one or more mechanisms (100, 120) being attached to side regions a boat (40), to lower the boat (40) towards ocean waves (210);

(b) when the boat (40) begins to engage ocean waves (210), allowing said one or more mechanisms (100, 120) and said boat (40) to move with the ocean waves (210) and starting a propulsion system of the boat (40); and

(c) using the propulsion system (40) to move the boat (40) away from the structure (20).

13. A method as claimed in claim 12, characterized in that said method includes using a configuration of one or more elongate upright members (130) and a roller arrangement ( 00, 120) cooperating with said one or more elongate upright members (130) for implementing said one or more mechanisms (130, 140).

14. A boat (40) adapted at its side portions for use with a boat lift (10) as claimed in any one of claims 1 to 9.