NO20170942A1

NO20170942A1 - Connecting arrangement for attaching first and second vessel

Info

Publication number: NO20170942A1
Application number: NO20170942A
Authority: NO
Inventors: Kim Kise; Johan K Moen
Original assignee: Kmg Tech
Priority date: 2017-06-09
Filing date: 2017-06-09
Publication date: 2018-08-06
Also published as: NO342733B1

Description

CONNECTING ARRANGEMENT FOR ATTACHING FIRST AND SECOND VESSEL

TECHNICAL FIELD

The present invention concerns a connecting arrangement for attaching a first vessel to a second vessel, an assembly of a first vessel and a second vessel such as an installation vessel and a barge arranged with the connecting arrangement. Further the invention also concerns a first vessel such as an installation vessel arranged with a connecting arrangement as well as second vessel such as a barge arranged with the connecting arrangement.

The invention also concerns a method for connecting a first vessel to a second vessel. More specifically the invention relates to an arrangement and method for effecting a releasable and optionally two step connection between a first and second vessel such as a pipe laying vessel and a reel carrying fioating structure ( eg a barge).

BACKGROUND

Conventional laying of pipelines such as rigid and flexible pipelines, umbillicals etc include laying the pipelines directly from their storage on reels and to installation position on the seabed. When laying pipelines from reel lay vessels the total installation time include transit time for the reel lay vessel to get to the installation site, reeling time where reels are mobilized and the pipelines are spooled on to the reels as well as the actual pipe laying time. The actual pipe laying time is estimated to constitute only about 1/3 of the total installation time. The actual pipelaying is dependent on acceptable weather in order to initiate the pipelaying process and is only to occur if the wave height is within required limits. As such multiple factors makes conventional pipelaying sensitive to time delay and thus increased costs as a side effect. When the weather conditions are acceptable and the pipe laying is to be started, the capacity of the available reels determines the effectiveness of the ongoing pipelaying process. Emptying of the available reels prompts the need for reel provisions and involves transporting the laying vessel to shore for reel supply.

To remedy the obvious drawbacks as associated with this conventional pipelaying concept various attempts have been proposed to make the actual installation time more effective and reduce the number of installation vessels involved during the installation period.

Some of these approaches are described in prior art documents:

NO 20130875 discloses a semi submersible platform for reel-laying of pipes to the seabed. The semi-submersible platform is provided with a loading zone håving U shaped docking area for receiving a barge which carries pipes stored on reels. The reels are prepared for transfer to the submersible platform in order to carry out the laying of pipes from the submersible platform and empty reels are transferred to the barge for transport to shore. The U shaped docking area in the semi-submersible platform ensures that the position of the barge is maintained during the transfer of reels between the barge and the platform.

GB 2439295 shows a semi submersible pipelaying vessel capable of submerging to a water depth where the barge which carries the pipe reels is to be accommodated on the loading deck for laying pipes from these reels and to the seabed.

The prior art solutions suggest either providing a docking area shaped to surround the barge for keeping the position of the barge during the loading, or accommodating the barge on board the pipe laying vessel to control the position of the barge relative to the vessel during loading and unloading.

Both these suggested solutions demand a pipe laying vessel with a specific outlay and demand the designation of especially appointed areas for carrying out the control of positions between vessel and barge. The specialized areas for docking of the barge requires that pipe laying vessel have access areas available for occupation of the barge.

An object of the present invention is to provide a connection arrangement for controlling the positions between the vessel and the floating structure in a manner that is simple and easy to carry out. A further object is to provide a connection arrangement that is applicable both for vessel and floating structures to be built, but also on existing vessel and floating structures of various sizes independent on the existing constructional outlay of the hull.

SUMMARY

The invention concerns a connecting arrangement for attaching a first vessel to a second vessel. The second vessel may comprise a barge such as one carrying pipelines spooled on reels to be carried to an installation site and the first vessel may comprise an installation vessel for installation of the pipelines that are carried by the barge. However also other loads may be carried by the second vessel for transport to a designated area such as an installation site. These loads may comprise umbilicals, initiation equipment, PLEM, PLET, manifolds, riserbases, covers, templates etc and all sort or subsea installation equipment needed ror the purpose or hydrocarbon recovery operations.

The connecting arrangement may be fitted on to the vessels during the manufacturing of the vessels or the connecting arrangement may be retrofitted to existing vessels.

The connecting arrangement comprises first and second connecting assemblies each provided to be operated separately. The separate operation of the first and second connecting assemblies ensures that a pivot connection may be established between the first and second vessel and should circumstantial conditions require that no relative movement is acceptable between the two vessel,a rigid connection is then established subsequent to the pivot connection between the two vessels. The first and second connecting assemblies are selectively operated for attachment of the vessels in a pivot connection mode and in a rigid connection mode. As such the first connecting assembly is provided for establishing a pivot connection of one end portion of the first vessel to an end portion of the second vessel. In the pivot connection mode the first connecting assembly is adapted for establishing pivot connection of the first and the second vessel allowing relative movements between the two vessels. The relative movement between the two vessels as to occur by the pivot connection may be acceptable within a set weather window and relative movement are then acceptable between the vessels.

The connecting arrangement also comprises the second connecting assembly, but connecting the vessels by first connecting assembly in the pivot connection mode would for most circumstances be sufficiently and thus it is not necessary to connect the vessels by the second connecting assembly to ensure a complete attachment between the two vessels. However should the circumstances such as for instance demanding wind and wave motions or other operational conditions require that relative movements such as pivot movements between the two vessels should be prevented, a subsequent connecting sequence is to executed by the second connecting assembly and rigid connection mode may then be selected. In the rigid connection mode the second connecting assembly is provided for rigid connection of the end portions of the first and second vessels subsequent to establishment of the pivot connection of the first and the second vessel. When the two vessels are connected by the rigid connection, the preceding relative movements between the vessels are prevented and the vessels then move as a single unit. Should the wind and wave motions decline, it is of course possible to release the rigid connection to resume the pivot connection mode where relative movements are allowed between the two vessels due to the now working pivot connection between the vessels.

In principle attaching a first vessel to a second vessel by the connecting arrangement in accordance with the invention may be carried out at all sites and locations with a present need for switching between modes where the vessels are pivotally connected or rigidly connected. An offshore location for instance a pipe installation site is a typical place where the connecting arrangement may be used for selecting the pivot connection mode or rigid connection mode. However, vessels may also be attached at a first site, for instance close to shore, initially by establishing a pivot connection between the vessels and then later at a second site, for instance at an offshore location, the rigid connection is established if needed. A possible scenario is also that the vessels are only connected by the pivot connection and the rigid connection is not established between the vessels. The possibility for establishing a rigid connection is then available, but executed only if needed.

In an embodiment of the invention the pivot connection may be provided to allow for the occurrence of relative movements of the two vessels about a pivot axis of the first connecting assembly. Further the rigid connection may be arranged so that relative movements of the two vessels about the pivot axis of the first connecting assembly is prevented.

The pivot connection functionality of the first connecting assembly may be provided with various arrangements capable of both ensuring a secure connection between first and second vessel and preparing for a pivoting or articulated movement to occur between the first and second vessel. In an embodiment the first connecting assembly comprises

-a coupling shaft arranged for mounting at one end portion of the first vessel,

-at least one coupling locking device arranged for mounting at one end portion of the second vessel, the coupling locking device has an open position for insert of the coupling shaft and a closed position for accommodating the coupling shaft in a pivot connection in the coupling locking device.

By this provision of the first connecting assembly a number of coupling locking devices may be displayed along the end portion of the second vessel, all configured to close around the coupling shaft attached to the first vessel. It may also be possible to arrange the second vessel with a single coupling locking device capable of receiving and accommodating the coupling shaft.

Several mounting assemblies may comprise the coupling locking device which may be arranged to connect to the coupling shaft by gripping around the coupling shaft to make a pivot connection with the coupling shaft. In one embodiment the coupling locking device(s) may (each) comprise at least one assembly of linked arm members operatively arranged for configuration of the open position and the closed position. The linked arm members may be actuated for operation between the configuration for open and closed positions by repositioning of the linked arm members to allow for insert or removal of the coupling shaft into or from the coupling locking device(s) and to allow for the pivoting of the coupling shaft in accommodated position in the coupling locking device(s).

The rigid connection functionality of second connecting assembly may be provided with various arrangements capable of ensuring a secure fixed or rigid connection between first and second vessel. In an embodiment the second connecting assembly comprises -at least one locking element arranged for mounting in a protruding position from one end portion of the first vessel, -locking receptor prepared for arrangement at one end portion of the second vessel and provided for accommodating the locking element(s) in a locked position to provide the rigid connection between the first and second vessel.

The locking elements may be provided so that each locking element is accommodated in locked position in the corresponding locking receptor. The number of locking elements and corresponding locking receptor may vary, but may in one embodiment amount to two.

The locking receptor may be disposed in between the coupling locking device. To ensure the locked position of the locking element accommodated in the locking receptor various arrangements may be provided. The locking element may be arranged as a protruding bar or pipe element to be received in a corresponding socket to establish a tight fitting rigid connection. Removably arranged locking devices such as retractable locking bars may be positioned in the locking receptor to secure the locking element in the locking position in the locking receptor. The locking element may have a configuration for interaction with the locking devices to ensure a fixed retaining of the locking element in the locking receptor.

The parts making up the first and second connecting assemblies may be installed on the first and second vessel separately or may be integrated in a common structure such as for instance a frame structure prepared for mounting to one of the vessels.

In one embodiment the coupling shaft is included as a part of a frame structure prepared for attachment to the end portion of the first vessel. Further the locking elements may also be arranged as part of the frame structure and optionally the frame structure comprises a support structure prepared for engagement with contact areas arranged at the second vessel. The support structure in engagement with contact areas arranged at the second vessel ensures the correct position for accommodating the locking element in the locking receptor. With the coupling shaft and the locking elements as well as the support structure arranged as part of the same frame structure, this makes for an easy installment where only one mounting operation is necessary to position all functional parts in the designated installation locations on the end portion of the first vessel (for instance the installation vessel).

The invention also concerns the assembly of a first vessel such as an installation vessel and a second vessel such as a barge arranged with a connecting arrangement as described. Further the invention also concerns a first vessel such as an installation vessel arranged with a connecting arrangement as previously described as well as second vessel such as a barge arranged with a connecting arrangement as previously described.

The invention also concerns a method for connecting a first vessel to a second vessel comprising the following steps

-establishing a pivotal connection between the two vessels to allow for relative movement between the two vessels, -considering the operational conditions (wind and wave motion) affecting the two vessels and if the operation conditions are within a set weather window, -establishing a fixed connection between the two vessels to allow for the two vessels to move as a single unit.

These and other characteristics of the invention will be clear from the following description of an exemplary embodiment, given as a non-restrictive example, with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig 1-2 is a perspective view of the transport of a barge from dock area to installation site. Fig 3 show a detail of the connection arrangement between a first and second vessel. Fig 4-8 show the stepwise pivot connection of the first and second vessel by the first connection assembly. Fig 9-12 show the rigid connection of the first and second vessel by the second connection assembly

DETAILED DESCRIPTION

Fig. 1 shows a second vessel, here shown as a barge 1. The barge 1 is loaded with pipelines 2 spooled onto reels 3 to be transported to the installation site. The reels 3 are skidded from a docking area 4 directly onto the barge 1. Tracks 5 as provided in the docking area 4 and continued onto the barge 1 facilitates the transfer of reels 3 onboard the barge.

A tug boat 6 transports the barge 1 to the pipe installation site as shown in fig 2 and upon arrival the barge is to be connected to first vessel such as an installation vessel 7 to ensure an uninterrupted laying of pipelines. After the connection between the barge 1 and the installation vessel 7 is completed, the pipeline 2 is supplied directly from the reels 3 to the pipe laying structure 8 arranged on the installation vessel 7.

To ensure that the pipelaying is not interrupted another barge loaded with reels 3 carrying pipelines 2 may be prepared for arrival at the installation site for continuing the pipelaying at the time when the reels 3 located on the barge at the installation site are emptied. Fig 3 shows a connecting arrangement 8 for attaching the barge 1 to the installation vessel 7. The connecting arrangement 8 is provided to connect an end portion 9 of the barge 1 to an end portion 10 of the installation vessel 7 in a tandem manner. In the figs the stern of the barge 1 is connected to the installation vessel 7. Fig 4-6 show a first connecting assembly 12 of the connecting arrangement. The first connecting assembly 12 is arranged for pivotally connecting the end portions 9,10 of the barge 1 and the installation vessel 7 in a pivot connection mode.

A coupling shaft 13 runs along the end portion of the barge, such as in an orientation essentially perpendicular to the axial axis of the installation vessel 7, and is arranged for being inserted into the coupling locking devices 14 arranged at the end portion of the barge 1. As shown in fig 4, the coupling shaft 13 is included as a part of a frame structure 40 which is attached protruding from the end portion of the installation vessel 7. By the arrangement of the frame structure 40, the coupling shaft 13 is arranged distanced from the end portion of the installation vessel 7 in order to make room for carrying out the locking of the coupling locking devices 14 by the fixation or gripping of the coupling locking devices around the coupling shaft 13.

The coupling locking devices 14 are shown distributed in a row oriented essentially perpendicular to the axial axis of the barge. In fig 4 the coupling locking devices 14 are shown in an open position prepared for receiving the coupling shaft 13. As shown in fig 5 the coupling shaft 13 is aligned in position for inserting into the coupling locking devices 14. Fig 6 shows the coupling shaft 13 received in the coupling locking devices 14. Positioning areas 15, 16 are provided at each side of the coupling locking devices 14 for ensuring the correct positioning of the coupling shaft 13 in the coupling locking devices 14 before bringing the coupling locking devices 14 to closed position. The correct positioning of the coupling shaft 13 is ensured by engaging the end portions of the coupling shaft 13 in contact with the positioning areas.

Fig 6 and 7 show the coupling locking devices 14 of first connecting assembly 12 prepared for assuming a closed position for accommodating the coupling shaft 13 in a pivot connection in the coupling locking device 14.

As illustrated in fig 7 each coupling locking devices 14 comprises an assembly of linked arm members here shown with upper arm members 20 lifted in an elevated position and lower arm members 21 in a corresponding lowered position. In these positions the upper arm members 20 and the lower arm members 21 are configured in open position for receiving the coupling shaft 13. In order to bring the coupling locking devices 14 into closed position the upper arm members 20 are actuated into a lowered position and lower arm members 21 are actuated into an elevated position closing the opening between these arm members 20, 21. In the closed position the coupling locking devices 14 grips around the coupling shaft 13 enabling the coupling shaft 13 to pivot accommodated in the coupling locking devices 14.

The barge 1 and the installation vessel 7 are now brought into a pivot connection where separate or independent pivot movement is allowed to occur for the barge 1 and the installation vessel 7 with the coupling shaft 13 defining a pivot axis for this movement (pitch) as illustrated by arrows A in fig 8.

Fig 9 shows the second connecting assembly 30 which is provided for establishing a fixed or rigid connection between the same end portions 13, 14 of the barge and the installation vessel in a rigid connection mode in order to provide for the barge and the installation vessel to function as a single unit when moving due to wave motions. This is illustrated in fig 11 where arrow B illustrates the common heave movement as conducted by the single unit and in fig 11 where the barge and installation vessel roll as a single unit as illustrated by arrow C

For establishing the fixed connection between the barge and the installation vessel locking elements 31 are arranged projecting from the one end portion of the installation vessel 7. As shown in fig 5 and 9 the projecting locking elements 30 are arranged as part of the frame structure 40 protruding from the end portion of the installation vessel 7. Locking receptors are arranged for mounting at one end portion of the barge 1 and provided for accommodating the locking elements 31 in a locked position to provide the rigid connection between the first and second vessel. In the embodiment shown in the figs the locking receptor are provided as locking receiving areas 32 arranged with locking means such as the shown retractable locking bars 35 prepared for securing the locking elements 31 in locking position.

The locking receiving areas 32 are arranged between the coupling locking devices 14 in the embodiment shown in the figs, see fig 5 and 9, and is configured as cut outs each fitted for accommodation of a locking element 31 each. Frame structure contact areas 50, 51, 52, 53 are positioned at each side of the two locking elements for contact with a support structure of the frame structure 40 when the locking elements 31 are accommodated in the locking receiving areas 32, see fig 9. In the embodiment in the figs the locking elements 31 each is shown provided with a locking stem 34 projecting from the frame structure 40 ensuring the correct positioning of an enlarged locking portion 33 of the locking element 31 within the receiving locking areas 32. When accommodated correctly in the locking receiving areas 32 retractable locking bars 35 are brought into locking position at opposite sides of the locking stem 34. The distance between the locking bars 35 are provided for the cross section of the locking stem to fit correspondingly between the locking bars and the distance between the locking bars 35 is smaller than the dimension of enlarged locking portion 33. By these arrangements the locking element 31 is accommodated in locked position in the receiving locking areas 32 providing the rigid connection between the barge 1 and the installation vessel 7.

The retractable locking bars 35 may of course be arranged by alternative locking means capable of providing a rigid connection in engagement with the locking element 31. Some sort of movable arranged locking members may obviously replace the retractable locking bars 35, and the second connecting assembly 30 may of course also be provided otherwise than shown in the figs ensuring a rigid connection between the barge 1 and the installation vessel 7, for instance by provision of alternative pipe socket interface connection.

As seen from the figs, and especially fig 10, first connecting assembly 8 is positioned at an upper vertical position of the end portions of the barge and installation vessel 6, 7, while the second connecting assembly 30 is positioned at an lower vertical position of the end portions of the barge and installation vessel 6, 7.

Claims

1. Connecting arrangement for attaching a first vessel to a second vessel comprising first and second connecting assemblies each operated separately for selectively attachment of the vessels in a pivot connection mode or in a rigid connection mode wherein - the first connecting assembly is provided for pivot connection of one end portion of the first vessel to an end portion of the second vessel and in the pivot connection mode the first connecting assembly is adapted for establishing pivot connection of the first and the second vessel allowing relative movements between the two vessels and - the second connecting assembly is provided for rigid connection of the end portions of the first and second vessels and in the rigid connection mode the second connecting assembly is adapted for in a connecting sequence subsequent to the established pivot connection establishing a rigid connection of the first and the second vessel for the vessels to move as a single unit.

2. Connecting arrangement for attaching a first vessel to a second vessel in accordance with claim 1, wherein - the pivot connection is provided to allow for the occurrence of relative movements of the two vessels about a pivot axis of the first connecting assembly, - the rigid connection is provided to prevent relative movements of the two vessels about the pivot axis of the first connecting assembly.

3. Connecting arrangement according to claim 1 or 2, wherein the first connecting assembly comprises -a coupling shaft arranged for mounting at one end portion of the first vessel, -at least one coupling locking device arranged for mounting at one end portion of the second vessel, the coupling locking device has an open position for insert of the coupling shaft and a closed position for accommodating the coupling shaft pivotally connected in the coupling locking device.

4. Connecting arrangement according to one of the claims 1-3, wherein the at least one coupling locking device comprises at least one assembly of linked arm members operatively arranged for configuration of the open position and the closed position.

5. Connecting arrangement according to one of the claims 1-4, wherein the second connecting assembly comprises -at least one locking element prepared for mounting in a protruding position from one end portion of the first vessel, -at least one locking receptor prepared for arrangement at one end portion of the second vessel and provided for accommodating the locking element(s) in a locked position to provide the rigid connection between the first and second vessel.

6. Connecting arrangement according to one of the claims 2-5, wherein the coupling shaft is included as a part of a frame structure prepared for attachment to the end portion of the first vessel and /or the locking elements are arranged as part of the frame structure and optionally the frame structure comprises a support structure prepared for engagement with contact areas arranged at the second vessel.

7. Assembly of a first vessel and a second vessel such as an installation vessel and a barge arranged with a connecting arrangement in accordance with one of the claims 1-6.

8. A first vessel such as an installation vessel arranged with a connecting arrangement in accordance with one of the claims 1-6.

9. A second vessel such as a barge arranged with a connecting arrangement in accordance with one of the claims 1-6.

10. Method for connecting a first vessel to a second vessel comprising the following steps -establishing a pivotal connection between the two vessels to allow for relative movement between the two vessels, -considering the operational conditions (such as wind and wave motions) affecting the two vessels and if the operational conditions are within a set weather window, -establishing a fixed connection between the two vessels to allow for the two vessels to move as a single unit.