NL2014953B1

NL2014953B1 - End fitting handling in a marine pipeline installation system.

Info

Publication number: NL2014953B1
Application number: NL2014953A
Authority: NL
Inventors: Roodenburg Joop; Willem August Vehmeijer Terence; Adrianus Joseph Donkers Jeroen
Original assignee: Itrec Bv
Priority date: 2015-06-11
Filing date: 2015-06-11
Publication date: 2017-02-03
Also published as: NL2014953A

Abstract

A marine pipeline installation system for laying an offshore pipeline and/or installing a subsea riser. The system comprises a pipeline guide mounted at an elevated position on the launch tower providing an arctuate guide surface in a vertical plane for guiding said pipeline from the storage reel into the firing line. The system further comprises flexible pipeline end fitting transfer mechanism adapted to transfer an end fitting on a flexible pipeline over the pipeline guide. This mechanism comprises a beam carrier, a beam carrier support device, and an end fitting handling beam. The beam has first and second ends and is longitudinally movable between first and second extension positions. The beam carrier support device and the beam carrier are adapted to establish an arctuate motion path of the beam in a vertical plane laterally offset from the guide surface of the pipeline guide. The first and second ends of the beam are each provided with at least one of: - a sheave for a winch driven cable to be connected to a respective pipeline end fitting, - a winch with a winch driven cable to be connected to a respective pipeline end fitting, - a retainer adapted to engage with a respective pipeline end fitting, an end fitting adapter connected to a respective end fitting, or a cable connected to a respective end fitting.

Description

END FITTING HANDLING IN A MARINE PIPELINE INSTALLATION SYSTEM

The present invention relates to the handling of end fittings on a flexible pipeline in a marine pipeline installation system for laying an offshore pipeline and/or installing a subsea riser.

In the field of subsea pipeline installation flexible pipelines commonly do not require straightening after passage thereof over an arctuate pipeline guide as the deformation of the pipeline is well within the elastic range of the pipeline. In embodiments the flexible pipeline is manufactured by wrapping of intertwining layers of high strength stainless steel and polymers. In contrast rigid pipelines are commonly carbon steel pipe which, after passing the pipeline guide, is subjected to a straightening of the pipeline by a straightener assembly in order to compensate for plastic deformation. WO 2007/108673 discloses a marine pipeline installation system for laying an offshore pipeline and/or installing a subsea riser. This system comprises a storage reel for storage of the pipeline to be installed and a launch tower which is adapted for launching the pipeline in a firing line into the sea. A pipeline guide, shown in the figures embodied as a semi-circular chute, is mounted at an elevated position of the launch tower and provides a semi-circular arctuate guide surface that extends in a vertical plane for guiding the pipeline from the storage reel into the firing line. One or more tensioners are mounted on the launch tower below the pipeline guide and serve to pay out the pipeline into the sea, whilst supporting the weight of the launched pipeline. An abandonment and recovery (A&R) system is provided which comprises an A&R cable and an associated A&R winch as well as a sheave arrangement with A&R sheaves supported by the launch tower above the one or more tensioners.

Whereas steel pipe rigid pipelines are commonly interconnected directly by welding, flexible pipelines for reel-laying are commonly provided during their production with special end fittings, in particular with end connector fittings that allow to connect a flexible pipeline to another flexible pipeline or other subsea equipment. In many embodiments the end connector fitting comprises a part that serves as the actual connector and a bend restrictor that prevents excessive bending near the actual connector part. The actual connector part e.g. includes a flange or a Grayloc connector. An end fitting present at the leading end of the pipeline, which end will enter into the sea first, is commonly identified as a first end fitting. An end fitting present at the trailing end of the pipeline, which enters into the sea last, is commonly identified as a second end fitting. Therefore a flexible pipeline may have a first end connector fitting and a second end connector fitting.

As is known in the field end connector fittings have a larger diameter than the flexible pipeline and have a different bending behaviour. In general end connector fittings are much stiffer than the flexible pipeline.

When unspooling a flexible pipeline provided with a first end connector fitting from a storage reel, the first end connector fitting has to be passed over the pipeline guide in order to then lower the first end connector fitting in the firing line and then engage the pipeline with the one or more tensioners.

It is known in the field to handle the first end connector fitting by means of a relatively small service crane, e.g. a knuckle-boom crane, that is mounted on the launch tower near the pipeline guide. The end fitting is then hooked up to the service crane and a crane operator carefully manoeuvres the end fitting so that it passes in a path over and about the arctuate guide surface of the pipeline guide so as to reach a position aligned with the firing line. An example hereof is shown in WO02/057675.

In WO2014/120004, with reference to figures 9 - 11, a known approach for handling a second end connector fitting on a flexible pipeline is disclosed. The service crane near the pipeline guide is used to pass the second end connector fitting over the pipeline guide into the firing line. Then the second end connector fitting is attached, via the end fitting adapter, to a trolley suspended from the A&R system for further lowering the second end connector along the launch tower with the tensioners in a retracted position thereof so that the trolley can pass the retracted tensioners.

The sole use of a service crane for handling an end fitting on a flexible pipeline places stringent requirements on the skills and experience of the service crane operator and is therefore less desirable, taking into account that the pipeline guide is at a rather great height and therefore sea-motions of the vessel may have a major impact on such an operation.

In GB 2 173 760 the problem of passing end fittings over and about a pipeline guide is addressed. Instead of the use of a service crane a flexible pipeline end fitting transfer mechanism is disclosed that is adapted to transfer an end fitting on a flexible pipeline over the pipeline guide. This known transfer mechanism comprises a transfer arm which is rotatable about a horizontal transfer arm axis so as to rotate relative to the pipeline guide.

This arm has a leading side and a trailing side when seen in direction of rotation over the top of the pipeline guide towards the firing line. The transfer arm is provided, radially outward from the pipeline guide surface, with a retainer for an end fitting adapter. This adapter, in embodiments disclosed in this document, comprises two transverse trunnions on a collar that is secured to the pipeline end fitting. This known transfer mechanism allows to handle the first end connector fitting, the second end connector fitting, as well as an intermediate fitting.

The use of an A-frame or similar structure as a transfer mechanism to pass end fittings on a pipeline and the like over a pipeline guide is also discussed in the introduction of GB2428080. The figure 1 of said document shows an A-frame that is provided with a sheave at a position radially outward of the pipeline guide surface. This sheave guides a cable to be connected to the pipeline end fitting via an end fitting adapter. A similar A-frame is disclosed in W02005/095835 and in EP 2 685 146.

In GB2509597 a flexible pipeline end fitting transfer mechanism is disclosed that is adapted to transfer a first end fitting on a flexible pipeline over and about the pipeline guide. The transfer arm is provided, radially outward from the pipeline guide surface and at the trailing side, with a retainer for an end fitting adapter, which retainer is adapted to retain, at the trailing side of the transfer arm, a first end connector fitting on a flexible pipeline that is provided with an end fitting adapter. The transfer arm is further provided with a sheave at a position radially outward from the retainer. The sheave is adapted and arranged to guide a winch driven cable that is attached via the end fitting adapter to the first end fitting such that, with the transfer arm in a first end fitting pick up position thereof, the first end fitting is lifted and the end fitting adapter reaches the retainer allowing for engagement with the retainer whilst suspended from the cable. This known transfer mechanism is not able to handle second end fittings.

It is an object of the present invention to provide a marine pipeline installation system with a flexible pipeline end fitting transfer mechanism that is able to handle at least a first end fitting as well as a second end fitting on a flexible pipeline in an efficient and controlled manner. It is a further object to provide a transfer mechanism that is relatively compact and has a relatively limited weight whilst showing great versatility and reliability for handling both end fittings on a flexible pipeline.

The present invention provides a marine pipeline installation system according to claim 1.

The system allows for controlled handling of the first end fitting, e.g. end connector, and the second end fitting, e.g. second end connector, with ease and reliability, e.g. in view of avoiding any or undue interference of the end fitting with the pipeline guide and/or undue loads on the end fitting and/or on the pipeline in the handling and transfer process.

In embodiments, as is known in the field, the pipeline guide surface may be circular, e.g. embodied as a rotating circular wheel often called an aligner wheel or diverter wheel.

In other embodiments the pipeline guide surface is semi-circular, e.g. as in a chute. The guide surface may be formed, in embodiments, by a series of rollers in a semi-circular arrangement. In other embodiments the pipeline guide includes a continuous belt or track providing the arctuate guide surface, e.g. a semi-circular guide surface, e.g. in combination with stationary gutter flanks.

In an embodiment the circular or semi-circular pipeline guide surface and the arctuate motion path of the beam carrier have a common centre axis, so that the beam carrier travels through a circular or semi-circular motion path about this common centre axis.

In an embodiment the beam is a rectangular cross-section box-girder type beam, e.g. of suitable grade steel. The beam could also be a latticed beam structure, e.g. with corner posts and diagonal braces.

Preferably the beam is a one piece, fixed length, member, e.g. a hollow steel beam, but one can also envisage an embodiment wherein at one or both ends an additional beam section can be mounted, e.g. bolted, to adapt the operational length of the beam, e.g. in view of handling different length end fittings. In an embodiment one or both end portions of the beam are of a telescopic design to allow for length adjustment, e.g. for reducing length when not in use and/or for adaptation to a specific length of an end fitting to be handled. The beam could also comprises one or more folding end portions, e.g. to reduce length when not in use.

In an embodiment the beam is readily detachable from the beam carrier, e.g. for on deck storage of the beam when not in use.

In an embodiment the beam carrier support device comprises one or more semi-circular rails that support and guide the beam carrier.

For example an outer rail and an inner rail support and guide the beam carrier, which rails have different radii relative to a common centre axis, with the pipeline guide surface extending as a semi-circular guide surface with a radius relative to said common center axis. In an embodiment said one or more semi-circular rails are integrated with a structural frame of the pipeline guide, e.g. mounted on a common base, e.g. on a common base that is adjustable so as to vary the distance relative to the firing line.

In an embodiment the motorized beam carrier drive comprises a motor mounted on the beam carrier that drives a pinion meshing with a semi-circular rack, e.g. said rack being integrated with a structural frame of the pipeline guide.

In an embodiment it is envisaged that when not in use the beam is positioned in a horizontal parking position, e.g. with the beam carrier generally at the top end of the pipeline guide. Preferably in the parking position the beam is arranged so that the beam carrier is in the centre of the beam.

In an embodiment the beam and/or beam carrier is/are provided with one or more operable locking devices that are adapted to lock the beam relative to the beam carrier, e.g. in one or more distinct positions, e.g. including one or more of the first extension position, the second extension position, and/or any more central parking position. For example one or more mobile locking members, e.g. pins, are mounted on the beam carrier, and one or more corresponding apertures for the one or more locking members are provided on the beam, so that in operative position a locking member engages in a respective locking aperture and locks the beam relative to the beam carrier.

In an embodiment the beam carrier and/or the beam carrier support device is/are one or more operable locking devices that are adapted to lock the beam carrier relative to the beam carrier support device, e.g. in one or more distinct positions, e.g. including any parking position, e.g. in a horizontal parking position. For example one or more mobile locking members, e.g. pins, are mounted on the beam carrier, and one or more corresponding apertures for the one or more locking members are provided on the beam carrier support structure, so that in operative position a locking member engages in a respective locking aperture and locks the beam relative to the beam carrier.

In an embodiment a first sheave is mounted at the first end of the beam, the first sheave being adapted to guide a winch driven cable, e.g. an initiation cable from an initiation winch.

In a practical embodiment an initiation cable is made to pass upwards from about deck level along the firing line, over the pipeline guide, and then over the first sheave of the beam in its first end fitting pick up position, and then down in order to connect to a first end fitting and to lift this first end fitting until it reaches a position alongside the beam.

Preferably the first sheave is mobile relative to the beam between an operative position in the vertical plane through the pipeline guide and a retracted position offset from said vertical plane, e.g. allowing to pull the first end fitting further down along the firing line without interfering with the first sheave once it has been brought into said firing line by means of the beam. For example the first sheave is mounted on a pivotal bracket.

In an embodiment a second sheave is mounted at the second end of the beam, the second sheave being adapted to guide a winch driven cable, e.g. a back tension cable from a back tension winch. In a practical embodiment a back tension cable is run from a back tension winch to the second end fitting and is kept under some tension whilst the second end fitting is lifted to reach a height so that it finds itself adjacent the beam in its second end fitting pick up position. This tension e.g. avoids undue swing motion of the commonly rather heavy and bulky second end fitting during this lifting process. Once the beam has been moved into its second end connector release position, with the second end fitting in the process being passed over and about the pipeline guide, the same cable can be employed to lower the second end fitting along the firing line, e.g. until a height wherein the second end fitting can be connected to an A&R cable and/or an A&R cable supported trolley or the like.

Preferably the second sheave is mobile relative to the beam between an operative position in the vertical plane through the pipeline guide and a retracted position offset from said vertical plane. This retractability of the second sheave e.g. allows to provide clearance for the second end fitting in the process of lifting it to the level of the beam. Once the second end fitting has been lifted high enough the second sheave can be moved into operative position and made to engage on the back tension cable or the like.

In an embodiment the beam at its first end is provided with a first retainer and with a first sheave, wherein the first sheave is adapted and arranged to guide a winch driven cable attached via the end fitting adapter to the first end fitting such that, with the beam in its first end fitting pick up position, the first end fitting can be lifted and the end fitting adapter reaches the first retainer allowing for engagement with said first retainer whilst suspended from said cable. Subsequently the beam, with the first end fitting retained in position alongside the beam by said first retainer, is movable or moved into the first end fitting release position thereof so that the first end fitting passes over and about the arctuate guide surface towards the firing line.

In an embodiment the beam is provided with a second retainer and a second sheave, wherein the second retainer is adapted to retain, with the beam in its second end fitting pick up position, the second end fitting, with a winch driven cable passing over the second sheave and connected to the second end fitting, e.g. a back tension cable from a back tension winch. Subsequently the beam is movable or moved into the second end fitting release position, wherein the second end fitting can be suspended from said cable allowing disengagement of from the second retainer and lowering of the second end fitting in the firing line.

In an embodiment the provision of both a first retainer and of a second retainer on the respective first end and second end of the beam, e.g. each retainer being mobile between a retracted position and an operative position by an associated actuator, allows for effective and reliable handling of both the first end fitting and the second end fitting of a pipeline.

In an embodiment a retainer at a respective end of the beam, or each retainer when both beam ends are equipped with a retainer, is embodied to support the weight of the respective pipeline end fitting as well as any additional load resulting from a pipeline section, e.g. the pipeline section between a lifted first end fitting and the deck or the pipeline section between second end fitting held by the beam in the firing line and the tensioner engaging on the pipeline below before securing the second end fitting to an A&R system. Such load bearing capacity of the retainer is e.g. envisaged if no use is made of a winch driven cable to support said load during the transfer process of the end fitting over the pipeline guide into the firing line.

The first and second retainers may be of similar design, but it is also envisaged that each retainer can be adapted for its specific purpose and engagement with a specific adapter, portion of the respective end fitting, or cable end terminal.

For example different load capacity requirements may be attributed to each end fitting adapter for the first and second end fitting respectively. For example a second end fitting adapter that couples with a second retainer at the second end of the beam in the transfer process may be designed to support the weight of the entire seagoing pipeline allowing the second end fitting adapter to be connected to the A&R system. A first end fitting adapter will not have to support such an A&R magnitude load, and can be designed much lighter. Therefore the second end fitting may be designed with a higher load capacity, e.g. with a stem that is thicker than the stem of a first end fitting adapter. The first retainer can then be adapted to engage an end fitting adapter with a stem of a first diameter and the second retainer for a stem with second diameter, the second diameter being greater than the first diameter.

In embodiments the first and second end fittings may differ in other technical features, e.g. be of significantly different design, with each retainer being adapted to the specific design.

In an embodiment an adapter for an end fitting of the pipeline includes two trunnions extending in opposite directions from a central adapter portion, with a retainer being adapted to engage on the two trunnions.

In an embodiment the pipeline guide and the end fitting transfer mechanism are supported by a common base that is movably connected to the launch tower at an elevated position of said launch tower, wherein an adjuster device is arranged between the common base and the launch tower, which adjuster device is adapted to adjust the position of the common base relative to the launch tower and thereby adjust a horizontal distance between the firing line on the one hand and the pipeline guide and end fitting transfer mechanism on the other hand.

In an embodiment the common base is horizontally slidable connected to the launch tower at an elevated position of said launch tower, wherein the adjuster device is arranged between the common base and the launch tower to adjust the horizontal position of the common base and thereby adjust the horizontal distance between the firing line and pipeline guide. For example the common base is skiddable by means of a skid system adjuster device.

In an embodiment the system comprises a control unit linked to the adjuster device and the motorized beam carrier drive, wherein this control unit is programmed to have a second end fitting clearance mode wherein, with the beam in second end fitting release position with the second end fitting suspended and aligned with the firing line, the adjuster device is operated to move the common base and thereby move the pipeline guide away from the firing line whilst simultaneous the beam is moved by the beam carrier drive so as to maintain the second end connector aligned with the firing line, at least until the pipeline guide has been cleared sufficiently from the firing line to allow for the subsequent lowering of the suspended second end fitting without interfering with the pipeline guide.

As is preferred, in the second end fitting release position of the beam, the second end fitting is aligned with the (preferably vertical) firing line.

It is noted that end fitting handling operations are preferably performed with the firing line vertical, e.g. with a tiltable launch tower brought in vertical position.

Preferably a motorized beam carrier drive is provided that is adapted to provide a driving force to move the beam carrier. Preferably this drive is able to provide all required power to perform the motions whilst transferring a pipeline end fitting.

In an embodiment at least one, preferably each, retainer comprises a slotted member having a slot therein and with a mouth at an end of the slot allowing lateral entry of a portion of the end fitting, a portion of an end fitting adapter, or a winch driven cable connected to an end fitting, into the slot. Possibly each slotted retainer further is provided with a mobile locking member and associated locking member drive that allows to move the locking member between a non-operative position and a locking position wherein the locking member is positionable in a locking position wherein it blocks the slot.

In an embodiment a retainer comprises a spherical seat and the end fitting adapter comprises a mating spherical portion and a stem below said spherical portion, wherein the spherical portion can rest on the retainer seat so as to transmit tensile force to the retainer and so as to create a pendulum support for the end fitting adapter allowing for variation of angular orientation of the stem of the end fitting adapter relative to the retainer.

In an embodiment the installation comprises a back tension sheave that is mounted or is to be mounted on a deck of the vessel, generally below the supply side of the pipeline guide remote from the firing line, said back tension sheave, in the transfer of a second end fitting, guiding a winch driven cable and allowing to apply back tension on the second connector, e.g. just during lifting from the deck or even during said transfer over the pipeline guide.

In an embodiment each tensioner comprises a tensioner frame and multiple tracks supported by the tensioner frame, the tracks being adapted for engaging the pipeline and supporting at least part of the weight of the launched pipeline, the tensioner frame being supported via an associated support assembly, the support assembly of one or more tensioner frames being adapted to allow for displacement of the tensioner frame with respect to the tower between an active position, wherein the firing line extends through the tensioner frame and between the tracks, so that the tracks can engage on a pipeline, and a retracted non-operable position.

In an embodiment the launch tower is provided with an auxiliary trolley adapted to support the weight of the launched pipeline and suspended from the A&R cable, which trolley is movable along rails along the firing line when the one or more tensioner frames are in a retracted non-operable position, from a position above the uppermost tensioner to a position below the lowermost tensioner, the rail being supported by the launch tower.

In an embodiment the auxiliary trolley is provided with a retainer, e.g. a clamp, adapted to engage on the end fitting adapter on a second end fitting that is suspended via said winch driven cable in the firing line.

In an embodiment a force sensor is provided that is adapted to measure the force exerted by the second end fitting on the transfer mechanism, e.g. on the second retainer and/or on the beam, at least during motion of the beam from the second end fitting pick up position to the second end fitting release position during which motion the one or more tensioners are operated to advance the pipeline. The system comprises a monitoring and control unit connected to said force sensor and to the one or more tensioners, the monitoring and control unit being adapted to compare the measured force with a predetermined allowable force range and to control the motion of the beam and of the one or more tensioners so as to maintain the force within said predetermined allowable force range.

The system may further comprise an abandonment and recovery (A&R) system comprising at least one A&R cable and associated A&R winch and a sheave arrangement with one or more A&R sheaves supported by the launch tower above said one or more tensioners.

The system may further comprise a trolley mounted on the tower and suspendable from the A&R cable, e.g. as described herein, the trolley being provided with a retainer that is engageable with a pipeline end fitting.

The invention also relates to a flexible pipeline end fitting transfer mechanism as described herein.

The invention also relates to a system comprising a pipeline guide adapted to be mounted at an elevated position of a launch tower and providing an arctuate guide surface in a vertical plane for guiding a flexible pipeline from a storage reel into a firing line, and the system further comprising a flexible pipeline end fitting transfer mechanism as described herein.

The invention also relates to a pipelaying vessel provided with a system of the present invention, e.g. the vessel having a hull and a moonpool and the launch tower, e.g. tiltable or non-tiltable, being arranged on the hull so that the launched pipeline passes through the moonpool into the sea.

The invention also relates to a method for handling of a flexible pipeline with one or two end fittings, wherein use is made of the system as explained herein.

The invention will now be discussed with reference to the drawings. In the drawings:

Fig. 1 illustrates - in side view - a part of pipelaying vessel equipped with an exemplary marine pipeline installation system for laying an offshore pipeline and/or installing a subsea riser,

Fig. 2 illustrates - in front view - the top end of the launch tower of figure 1,

Fig. 3 illustrates - in side view - the upper part of the launch tower with the pipeline guide and the transfer mechanism of figure 1,

Fig. 4 illustrates - in side view - the beam carrier and the end fitting handling beam of the end fitting transfer mechanism of figure 1,

Fig. 5 illustrates - in a view onto the first end of the handling beam, partly in cross-section -the pipeline guide and end fitting transfer mechanism of figure 1,

Fig. 6 illustrates - in side view - the upper part of the launch tower with the end fitting handling beam and beam carrier in a position different than in figure 3,

Fig. 7 illustrates the first end of the end fitting handling beam of the handling end fitting transfer mechanism of figure 1,

Figs. 8-15 illustrate the handling of a first end connector with the end fitting transfer mechanism of figure 1,

Figs. 16 - 20 illustrate the handling of a second end connector with the end fitting transfer mechanism of figure 1,

Fig. 21 illustrates in a view onto the first end of the beam an alternative bracket and first retainer,

Fig. 22 illustrates in a side view the first end of the beam of figure 21.

In figure 1 a portion of a hull 1 of a pipelaying vessel is shown, here equipped with a moonpool 2 via which pipelaying is performed. A storage reel 3 for flexible pipeline 5, e.g. for hydrocarbon transport, is supported by the vessel. The installation of the pipeline may comprise the laying of the pipeline on the seabed but the pipeline may e.g. also serve as a marine riser or part thereof.

In this example a vertical axis reel 3, or basket, is arranged below deck 7 of the vessel but such a basket can also be arranged above deck when desired. In another embodiment the storage reel 3 is a horizontal axis reel, e.g. permanently fitted on the vessel or an exchangeable reel, e.g. arranged on a skid cart that is skiddable on deck of the vessel.

For example the flexible pipeline 5 has a diameter between 0.10 and 0.63 meter. A launch tower 10 is arranged on the hull 1, here adjacent the moonpool 2. The tower 10 is adapted for launching the pipeline 5 in a firing line 6 into the sea. For example the tower 10 is tiltable by means of telescopic adjuster to allow for variation of the angle of the firing line 6 within a tilt range including a vertical orientation of the firing line 6 which is the preferred orientation for performing end fitting handling procedures. In another embodiment the tower 10 is non-tiltable, e.g. with a permanently vertical firing line.

The tower 10 may, as here, have two vertical main tower legs 10a, b which are spaced apart and are interconnected by transverse horizontal tower frame members 10c, d, e.

In the embodiment shown here, the tower 10 is provided with two tensioners 15, 16. Here, as example, the one or more tensioners are retractable tensioners 15, 16 that are movable between a retracted position (e.g. to vacate an envelope around the firing line to allow passage and/or handling of larger objects in the firing line) and an operative position aligned with the firing line 6.

As is known in the art the tensioners 15, 16 allow to support the weight of the launched pipeline. As explained in detail in for example W02007/108673 and W02014/120004, the tensioners 15, 16 here comprise a tensioner frame and multiple tracks supported by the tensioner frame. These tracks are adapted for engaging the pipeline 5 and supporting the launched pipeline. Each tensioner frame is supported via an associated support assembly onto the structural frame of the tower 10. The support assembly of each tensioner frame is adapted to allow for displacement of the tensioner frame with respect to the tower between an active position, wherein the firing line 6 extends through the tensioner frame and between the tracks, so that the tracks can engage on a pipeline, and a retracted non-operable position.

In other embodiments the vessel will not have a moonpool 2 through which pipelaying is performed, e.g. with the tower 10 being arranged along a side, the bow, or the stern of the vessel.

On the top of the launch tower 10, here on the top tower frame member 10c, a pipeline guide 20 is mounted.

On one side of the pipeline guide 20 an auxiliary crane 90 is mounted on the tower 10, here on frame member 10c, here on a pedestal 91. The crane 90 includes a winch with a winch driven cable 100’. The crane 90 may have a telescopic boom that is revolving about a vertical axis. The crane 90 may be used to provide hoisting capacity, e.g. to assist handling procedures for the pipeline and/or an end fitting. In an embodiment the crane 90 may have an operational reach that includes the first end of the beam 60 in its first end fitting pick up position, with the lifting capability of the crane 90 then being sufficient to lift a first end fitting 5a up till the first end of the beam 60 by means of cable 100’.

On the other side of the pipeline guide 20 an A&R sheaves device 120 is arranged with one or more A&R sheaves 121, 122. As is known in the art the one or more sheaves 121, 122 of the device 120 serve to guide an A&R cable 123 from an A&R winch (not shown) into the firing line 6, the cable 123 being provided with an A&R connector 124.

As will be appreciated, and as preferred, the sheaves 121, 122 are mounted on a sheave beam 85 which is displaceable between a retracted position, where the sheave 122 is remote from the firing line 6, e.g. to allow the safe passage of an end fitting on a flexible pipeline, and an A&R position and/or other operative position, e.g. aligned with the firing line or in a double fall arrangement. For example in an embodiment as explained in detail in WO2014/120004, in particular with reference to figures 9-11 thereof, which is incorporated herein by reference, the launch tower 10 is provided with an auxiliary trolley that is adapted to support the weight of the launched pipeline 5 and is suspended from the A&R cable. Such a trolley is preferably movable along rails fitted to the structural frame of the tower 10 so as to move along the firing line 6, e.g. between an upper position above the uppermost tensioner and a lower position below the lowermost tensioner. This motion is possible when the one or more tensioner frames are in their retracted non-operable position.

Here the pipeline guide 20 is embodied as what is known in the art as a chute.

The pipeline guide 20 here has a frame with a base 21 and fixed spokes 22 that support at their ends a semi-circular track 23 over which an endless belt 24 runs. The belt 24 here is made of interconnected belt elements 24a, like a chain, with each belt element having one or more rollers 25 that run over the track 23. This allows the belt 24 to support the pipeline 5 and move along with the pipeline 5 during pipelaying as is known in the art. A motorized drive and/or brake device for the belt 24 may be provided.

In an alternative embodiment the belt 24 is absent. For example a series of rollers is mounted in a semi-circular arrangement for form the pipeline guide surface.

The guide 20, here primarily the belt 24, provides for a semi-circular guide surface 24 for the pipeline 5, which guide surface extends in an imaginary vertical plane. The guide surface 24 serves to guide the pipeline 5 from the storage reel 3 into the firing line 6.

The pipeline guide frame here further has stationary gutter flanks 26, 27 on the opposed sides of the guide surface, here the belt, which gutter flanks bound with the belt 22 or other guide surface a sort of semi-circular gutter for the pipeline 5. In the flanks 26, 27 rotatable rollers 28 are optionally arranged to reduce or avoid frictional contact with the pipeline 5.

The pipeline guide base 21 is displaceable relative to the firing line 6 between an operative pipelaying position so that the take-off point of the guide 20 can be aligned with the firing line 6 if pipelaying takes place and a retracted position away from the firing line 6, e.g. to allow for passage of an end connector 5b on the pipeline as will be explained herein.

In the example the pipeline guide base 21 is horizontally displaceable over one or more rails 29 that are secured to the tower 10.

Displacement of the pipeline guide base 21 relative to the firing line 6 is done by means of an adjuster device, here one or more hydraulic cylinders 30. The adjuster device 30 allows to adjust the horizontal distance between the firing line 6 and pipeline guide 20.

The tower 10 here is provided with two tensioners 15, 16 which are mounted on the launch tower 10 below the pipeline guide 20. As is common the tensioners 15, 16 each include motor driven endless tracks with friction members engaging on the pipeline 5 in the firing line 6 during the pipelaying process.

If desired above the upper tensioner 15 a retractable upper centralizer is arranged on the tower allowing to maintain the pipeline 5 in the firing line, e.g. when not engaged by the tensioners. A retractable lower centralizer may be arranged between the tensioners.

As is known in the field the pipeline 5 to be laid may be equipped with an end fitting, e.g. a first end connector 5a at the leading end of the pipeline 5 to be laid and/or a second end connector 5b at the trailing end of the pipeline to be laid. The end fittings are depicted here including a connector part and a bending restrictor part. The dimensions schematically represent a large version envisaged in practice for the exemplary end fitting transfer mechanism.

In order to transfer an end fitting 5a, 5b on a flexible pipeline over the pipeline guide 20 the system comprises a flexible pipeline end fitting transfer mechanism which will be discussed in more detail below.

In general terms the transfer mechanism comprises: - a beam carrier 40, - a beam carrier support device 50 which supports the beam carrier 40, - an end fitting handling beam 60.

The support device 50 here is comprises two arctuate, here semi-circular, rails 51, 52 that are fitted to one side of the structural frame of the chute 20. The outer rail 51 has a greater radius than the inner rail 52. As can be seen the rails 51, 52 here are integrated with the frame of the guide 20 but in another embodiment the rails could have their own further support, e.g. also fixed to the base 21.

The beam carrier 40 resembles a cart that is displaceable over and carried by the rails 51, 52. A motorized beam carrier drive, here with motors 41,42,43, is provided and is adapted to drive the beam carrier along the arctuate rails 51, 52. In this example each motor 41 drives a corresponding pinion 44 that meshes with a semi-circular rack 45 that is fixed to the frame of the chute 20, here between the rails 51, 52.

The beam 60 is elongated and has a first end 61 and a second end 62. The beam 60 is supported by the beam carrier 40 and is along its longitudinal extension movable relative to the beam carrier 40 so that in a first extension position of the beam the first end 61 is remote from the beam carrier 40 and the second end 62 close to the beam carrier and in a second extension position of the beam the first end 61 is close to the beam carrier 40 and the second end 62 is remote from the beam carrier 40. A motorized beam drive, here with motor 46 on the carrier 40, is provided and is adapted to move the beam in longitudinal direction relative to the beam carrier 40 between the first and second extension positions of the beam 60. In this example a rectilinear rack 63 is mounted along the beam 60 and the motor 46 drives a pinion 47 meshing with the rack 63.

As can be seen the beam carrier support device 50, 51, 52 and the beam carrier 40 are adapted to establish an arctuate motion path of the beam 60 in a vertical plane that is laterally offset from the imaginary vertical plane through the guide surface 21 of the pipeline guide 20, so in other words to one side of the plane where the pipeline passes. The drives allow to establish controlled motion of the beam 60 in this offset plane and allow to establish a motion of the beam 60 along an arctuate motion path in that plane.

The beam 60 has crane like load bearing capacity as will be appreciated by the skilled person. Here the beam is a rectangular cross-section box-girder type beam, but other beam designs are also possible.

In this example the beam 60 is at opposed sides provided with rectilinear guide rails 65, 66, with the beam carrier 40 being provided with mating bearings 48, 49 that allow for rectilinear motion of the beam relative to the carrier 40.

As illustrated, at both the first end 61 and the second end 62, the beam 60 is provided with an arrangement including a mobile bracket 70, 71 holding at least a sheave 72, 73. Here each bracket also holds a retainer 74, 75. As is envisaged these arrangement may be embodied with the same basic structure and therefore only the arrangement at the first end 61 will be described in more detail.

As can be seen e.g. in figures 5 and 7 at the first end 61 of the beam 60 there is a pivotal bracket 70 that is at end thereof pivotally secured to the beam end 61 about an axis 76 which is parallel to the beam 60. An actuator 77, here hydraulic cylinder 77, is provided between the beam 60 and the bracket 70 to cause the pivoting motion of the bracket 70 between an operative position (see figures 4 and 7) and a retracted position (when the cylinder 77 is retracted). A latch device, here with latch pin 78 and latch pin actuator 79 is provided in order to latch the pivotal bracket 70 in its operative position.

The bracket 70 carries the first sheave 72 and, in operative position of the bracket 70, the sheave 72 is in the imaginary vertical plane through the pipeline guide surface.

The bracket 70, as preferred, also carries a first retainer 74 that is here embodied to cooperate with a cable end terminal 100a fitted on a winch driven cable 100, here initiation winch cable 100 to an initiation winch. The cable is to be attached via an end fitting adapter 185 to the first end connector to be transferred. In the depicted embodiment the retainer 74 primarily serves to retain a specific position of the respective end of the first end connector relative to the beam 60 during the transfer process.

In the depicted embodiment the retainer 74 is mounted on a swivelling retainer arm 80 that is pivotal relative to the bracket 70 about an axis parallel to or, as here, coinciding with, the axis of the sheave 72. This retainer 74 has a slot, see figure 5, adapted to allow for lateral entry of cable 100 that passes over the sheave 72 into the retainer body 74 when the retainer arm 80 is pivoted appropriately. A retainer arm actuator 81, here hydraulic cylinder, is provided between the bracket 70 and the arm 80 to cause controlled pivoting of the arm 80. A cable catch member 74a facilitates the catching of the cable 100 and entry into the slot of the retainer 74.

In the depicted embodiment the retainer 74 has a conical bore portion, widening away from the sheave 72, and the cable end terminal 100a has a mating conical portion so that one can pull the cable end terminal into the retainer and thereby obtain a suitable retention of the position of the first end fitting connected to the cable 100.

As will be appreciated the depicted retainer 74 is not adapted to support the entire load when the first end fitting has been lifted from the deck and becomes suspended from the first end of the beam. The cable that is used, here cable 100, carries the majority of the load in this process. In another embodiment one may design the retainer to be so strong that all loads, or the majority of the load, can be carried by the retainer 74, e.g. allowing the cable to be slackened and relieved from said load once the first end connector becomes suspended from the first retainer.

As will be appreciated the mobile bracket 70, 71 at the respective end 61, 62 of the beam 60, with associated sheave 72, 73 and/or with a retainer 74, 75, is adapted to hold the respective end fitting 5a, b in a position generally alongside a lateral side of the beam 60 in the transfer process. This lateral side of the beam faces the pipeline guide 20.

In general, as will be discussed in more detail below, - for handling of a first end fitting 5a on a flexible pipeline end - the beam 60 is positionable in a first end fitting pick up position (figure 11) thereof wherein the beam has been extended into its first extension position and is arranged generally upward at a supply side of the pipeline guide 20 where the pipeline is received from the storage reel. By means of a winch driven cable 100 passing over sheave 71 at the first end 61 of the beam 60, it is possible to lift the first end fitting 5a to a position of the first end fitting alongside the beam in its first end fitting pick up position (figure 11).,

By subsequent displacement of the beam in its first extension position along the mentioned arctuate motion path by means of the motorized beam carrier drive with motors 41,42,43 the beam 60, with the first end fitting 5a held alongside the beam 60, is moved into a first end fitting release position thereof (figure 14) wherein the beam 60 extends generally downward with the first end fitting 5a being located in the firing line 6.

In general, as will be discussed in more detail below, - for handling of a second end fitting 5b on a flexible pipeline end - the beam 60 is positionable in a second end fitting pick up position thereof (figure 16) wherein the beam has been extended into its second extension position and extends generally downward at the supply side of the pipeline guide so that the second end 62 is adjacent a lower end of the second end fitting 5b of the pipeline curving over the pipeline guide 20. The sheave 72 allows a winch driven cable 110, e.g. from a back tension winch mounted on deck of the vessel, to be secured to the rear end of the end fitting 5b with the cable 110 passing over the sheave 72.

By subsequent displacement of the beam carrier 40 with the beam 60 in its second extension position along the mentioned arctuate motion path by means of the motorized beam carrier drive with motors 41,42,43 the beam 60, with the second end fitting 5b held alongside the beam 60, is moved into a second end fitting release position thereof (figure 20) wherein the beam extends generally upward with the second end fitting being located in the firing line 6. The winch driven cable 110 that was secured to the second end fitting 5b is then used to lower the second end fitting in the firing line 6.

With reference to the series of illustrations figures 8-15 the transfer of a first end connector 5a on the end of pipeline 5 will be discussed.

Figure 8 illustrates the beam 60 being in vertical orientation in its second extension position. The sheave 72 is aligned with the firing line 6 by bringing the arm 80 in its operative position. The tensioners 15, 16 (only 15 visible) are retracted. This initiation cable pick-up position of the beam 60 is envisaged to allow the easy raising of an initiation cable 100 from an initiation winch (e.g. on the deck of the vessel or below deck) to the second end of the beam 60 where it is temporarily fastened. The cable 100 then passes over the sheave 72. The auxiliary crane 90 may assist in this procedure.

Figure 9 then illustrates that the beam 60 is moved into horizontal position, at the top of the guide 20 as it where, and then in figure 10 it is illustrated that the beam is moved into its first extension position. As preferred the beam 60 is locked in place relative to the beam carrier 40 by one or more operable locking devices 150. The cable 100 is slacked in this step to allow this motion. A further auxiliary wire may be secured to the end of the cable 100 near the second end 62 of the beam 60, which auxiliary wire is dropped to the deck 7 of the vessel.

Subsequently the beam carrier 40 is moved in order to bring the beam 60 in the position of figure 11, with the beam 60 remaining in its first extension position. The auxiliary wire may now be used to pull down the cable 100 down to deck level in order to secure the cable 100 via an end fitting adapter 85a to a first end connector 5a on the first end of a flexible pipeline 5.

Then the cable 100, that passes over the sheave 72 at the first end and is also guided by the guide 20 as can be seen in figure 11, is used to lift the first end connector 5a.

During this initial lifting the angular orientation of the beam 60 is chosen such that the end connector 5a, which is commonly of larger diameter than the pipeline 5 itself, stays clear of the guide 20.

Once the lifting has been nearly completed, the arm 80 can be appropriately swung to make sure that the cable 100 passes through the retainer body 74 so that once the terminal 100a reaches the retainer 74 these parts mate. At the same time the beam 60 can be reoriented such that the root of the end connector 5a or the nearby portion of the pipeline, comes into contact with the supply side of the pipeline guide (see figure 12).

It will be appreciated that in figure 12 the end connector 5a is effectively suspended from cable 100 which is passed over the sheave 72.

As illustrated the beam carrier 40 is now made to move over the rails 51, 52 via a horizontal position in figure 13 into the position of figure 14 with the cable 100 being kept under tension.

The first end connector 5a is now in the firing line 6 with the pipeline 5 curving over the pipeline guide 20. Now the retainer 74 can be disengaged from the terminal 100a and the bracket 70 moved into non-operative or retracted position. The beam 60 can now be raised vertically so as to be out of the way for the uppermost tensioner 15.

The first end connector 5a can now be pulled further down along the firing line 6 by means of the still tensioned cable 100 and the one or more tensioners 15, 16 can be made to engage on the pipeline in appropriate manner depending e.g. on the particular design of the tensioners.

During continued pipelaying the beam 60 can for example be parked in horizontal parking position.

As will be appreciated the first end connector 5a has now been passed over the guide in a controlled manner.

With reference to the series of illustrations figures 16-20 the transfer of a second end connector 5b on the end of pipeline 5 will be discussed.

In figure 16 the pipelaying has been interrupted, with the tensioners 15, 16 still engaged on the pipeline 5 to support the weight of the launched pipeline, in order to the process of transfer of second end connector 5b to be started.

The beam 60 has been brought into its second extension position, preferably locked in said position by one or more locking devices relative to the beam carrier 40. The beam 60 points generally downwards alongside the second end connector 5b of which the root has reached, or nearly reached, the pipeline guide 20. A winch driven cable 110, also referred to as back tension cable, was already secured to the rear of the connector 5b via an adapter. For example this cable 110 is run to a separate back tension winch 140, or alternatively via a non-depicted back tension sheave on deck level to another winch, e.g., the initiation winch. In the process of lifting the connector 5b the cable 110 may be used to provide some back tension to control e.g. sway of the connector 5b.

Figure 17 depicts that the beam 60 has been brought in such position, as well as the sheave 73, that the cable 110 passes over the sheave 73. Preferably the associated retainer is matched with a corresponding portion of a terminal on cable 110 or of an end fitting adapter.

Then, as depicted in figure 18, the beam 60 is moved and passes a horizontal position with the cable 110 maintaining some tension in this example in order to keep the second end connector in position relative to the beam 60. During this motion obviously the tensioners 15, 16 are also operated to lower the pipeline somewhat further into the sea.

This motion is continued until the position of figure 19 is reached wherein the second end connector is aligned with the firing line 6 and, in this embodiment, effectively suspended from cable 110 which now also passes over the guide 20. The root of the connector 5b or the near portion of the pipeline still rests against the belt 22 of the guide 20.

In order to further lower the end connector 5b, e.g. to a height where the load can be taken over by the A&R system of the vessel, it is envisaged to retract the pipeline guide 20 from the firing line, whilst at the same time moving the beam carrier so that the end connector 5b is kept in the firing line. Once sufficient clearance is obtained the cable 110 is used to lower the connector 5b so that is passes the guide 20. At an appropriate moment the pipeline connector 5b is the secured to the A&R system, e.g. by engaging it with a clamp on a trolley as mentioned in the introduction or securing of an A&R connector to the connector 5b. Once suspended from an A&R system the second end connector 5b can be lowered, e.g. down to the level of the deck. For example a hang-off clamp supports the end connector at said level in order to allow the first end connector of a new pipeline to be forwarded as described herein and connected to the second end connector 5b.

In order to perform the motion described with reference to figure 20, preferably in some automated manner, the system may comprise a control unit linked to the adjuster device 30 and to the one or more beam carrier drive motors 41,42, 43. This control unit may be programmed to have a second end fitting clearance mode wherein, with the beam in second end fitting release position with the second end fitting suspended from the cable 110 and aligned with the firing line, the adjuster device 30 is operated to move the pipeline guide away from the firing line whilst simultaneous the beam carrier is moved by the beam carrier drive motors so as to maintain the second end connector aligned with the firing line 6, at least until the pipeline guide 20 has been cleared sufficiently from the firing line to allow for the subsequent lowering of the suspended second end fitting without interfering with the pipeline guide.

The beam 60 and/or the beam carrier 40, and/or the beam carrier drive may be provided with a force sensor that is adapted to measure the force exerted by the second end fitting 5b on the beam, at least during motion of the transfer beam 60 from the second end fitting pick up position to the second end fitting release position.

The system may comprises a monitoring and control unit connected to the force sensor and to the one or more tensioners, in particular to the control of the speed of the track drive motors of the tensioners. The monitoring and control unit may be adapted, e.g. programmed in a computerized monitoring and control unit, to compare the measured force with a predetermined allowable force range and to control the motion of the transfer beam 60 by means of drive and to control the speed of the one or more tensioners so as to maintain the force within the predetermined allowable force range. This avoids any undue load on the pipeline 5 and fitting 5b.

It is envisaged that one or more cameras are present on the ends of the beam 60 allow to view the actual operation from a remote operator position, e.g. in order to monitor the engagement of the cable with a retainer.

With reference to figures 21 and 22 an alternative mobile bracket and retainer will be discussed, here arranged at the first end of the beam 60 but the same or similar may also be done at the second end 62 of the beam.

The mobile bracket 170 is pivotally mounted at the first beam end 61 and pivotal about axis 170a between an operative position (shown in figures 21,22) and retracted position. The pivotal motion could also be replaced by a sliding motion or the like. An actuator 177 causes this motion.

The bracket 170 carries a first retainer 174 that is adapted to carry the full weight of the first pipeline end connector 5a and the section of pipeline 5 extending to the deck 7 when held in lifted position at the supply side of the pipeline guide 20 with the beam 60 in pick-up position.

The retainer 174 comprises a slotted member having a slot 175 therein and with a mouth 176 at an end of the slot allowing lateral entry of a portion of an end fitting adapter 185.

The slotted member, in this example, comprises a spherical seat and the end fitting adapter 185 comprises a mating spherical portion 187 and a stem 186 below the spherical portion. The spherical portion can rest on the retainer seat so as to transmit tensile force to the retainer 174 and so as to create a pendulum support for the end fitting adapter allowing for some variation of angular orientation of the stem of the end fitting adapter relative to the retainer.

The slotted retainer further is provided with a mobile locking member, here locking members 190, 191 and associated locking member drive, here cylinders 192, 293, that allow to move the locking members between a non-operative position and a locking position wherein the locking member is positionable in a locking position wherein it blocks the slot 175.

Figure 22 also depicts the winch driven cable 100’ which is attached to the first end connector 5a via adapter 185.

The cable 100’ could be a winch driven cable of the auxiliary crane 90 that is arranged near the pipeline guide 20 at the elevated position on the tower 10. This embodiment requires that the auxiliary crane has suitable lifting capacity to lift the weight of at least the first end connector 5a and a section of pipeline 5a having the length that about equals the height of the tower 10.

In this arrangement wherein the transfer mechanism is employed in combination with the auxiliary crane 90 the handling and transfer of a first end connector 5a could be performed as described below.

The beam 60 is arranged in first end connector pick-up position, e.g. as shown in figure 11. The cable 100’ is lowered to the deck 7 and the connector 5a is attached via an adapter 185 to the cable 100’. Then the connector 5a is lifted until the adapter 185 reaches the height of the first retainer 174 and then the retainer 174 and adapter 185 are engaged. The locking members 191, 192 secure the adapter 185 relative to the retainer 174. As explained the retainer 174 is adapted to carry the full load, so that the cable 10’ may now be detached if desired.

The beam carrier 40 is now moved over the one or more associated semi-circular rails 51, 52 towards the firing line, with first the root of the connector 5a or the adjacent section of pipeline 5 being gently brought against the supply side of the pipeline guide 20 as shown in figure 12. The one or more motors 41,42,43 preferably provide all the driving force required for the motion of the beam carrier 40 along the rails 51, 52.

Further advancing the beam carrier 40 causes the beam 60 to pass the horizontal position depicted in figure 13 and to reach the first end fitting release position of figure 14 wherein the connector 5a is in the firing line 6.

The auxiliary crane 90 may be used to pull the initiation winch cable 100 up to the first end 61 of the beam 60 in its first end fitting release position, so that the initiation winch cable 100 can be connected to the adapter 185. By suitable tensioning the cable 100, the load may be relieved from the retainer 174 and the retainer 174 can be brought into retracted position, here by pivoting the bracket 170 by means of actuator 177.

In case the downward directed beam 60 in its first end fitting release position, e.g. figure 14, interferes with the uppermost tensioner, as here with the uppermost retractable tensioner 15, it is envisaged that the beam 60 is moved up to its second extension position relative to the beam carrier after disengagement of the retainer 174 from the adapter 185.

Now the first end connector 5a can be pulled down to the level of the deck 7, or at least to a level below one or more tensioners 15, 16, and one or more tensioners 15, 16 can be made to engage on the pipeline 5.

The longitudinal motion of the beam 60 relative to the beam carrier 40 may be performed by the motorized beam drive, e.g. with motor 44, but one may also employ the auxiliary crane 90 to perform said longitudinal motion in order to set the beam 60 in desired longitudinal positions relative to the beam carrier 40. As is preferred then one or more locking devices are provided to secure the beam 60 in one or more distinct longitudinal positions relative to the beam carrier 40.

In an embodiment a bracket and/or retainer having one or more technical features discussed with reference to the bracket 170 and/or retainer 174 is fitted at the second end 62 of the beam 60. It will be appreciated that, e.g. when a corresponding adapter 185 is fitted to the rear end of the second end connector 5b, this second beam end retainer may be employed in similar manner to retain the rear end of the second connector 5b.

In an embodiment the auxiliary crane 90 with cable 100’ is employed in the course of transfer of a second end connector 5b in combination with the end fitting transfer mechanism and beam 60 thereof. For example the back tension cable 110 is only used in the course of controlling the lifting of the second end connector 5b from the deck 7 to the height where the root of the connector 5b or a pipeline section close to the root has reached the pipeline guide 20. For example the cable 110 in this process mainly is used to avoid sway of the second end connector. Then the retainer-with the beam 60 in second end fitting pick up position, e.g. as in figure 16 - is engaged, e.g. with an adapter 185 fitted to the rear end of the second connector 5b. For example the second end retainer has one or more technical features as discussed relative to retainer 174 The cable 110 may now de detached and lowered to the deck 7 by means of the auxiliary crane 90.

Moving the beam 60 by means of beam carrier 40 towards the firing line 6causes the beam 60 to reach the second end fitting release position, e.g. as in figure 20. The second end fitting 5b now is still suspended from the retainer at the second beam end 62.

Now the cable 100’of the auxiliary crane 90 is connected to the connector 5b, e.g. via the adapter 185, and the load is relieved from the second retainer and the connector 5b suspended from the auxiliary crane. Then the connector 5b can be lowered until the A&R system can be coupled to the connector 5b, e.g. involving retraction of the uppermost tensioner 15 to allow the rear end of the connector 5b or the adapter 185 fitted thereon to reach the level for engagement with the A&R system.

In another embodiment instead of having a sheave 72, 73 at a beam end 61,62 one can also envisage the provision of a winch on the respective beam end 61,62 with a winch driven cable. For example a first winch at the first end 61 allowing to lift the first end connector 5a as discussed with reference to figure 11, e.g. with a first retainer 74 or 174 at the beam end 61. Of course the beam 60 could also be equipped with a winch at one location of the beam, with a first sheave 71 at the first end 61 guiding the cable driven by said winch on the beam.

It will be appreciated that a similar arrangement of a second winch at the second end 62 is also possible, or said second winch being arranged elsewhere on the beam 60 with the second sheave 72 guiding the cable driven by said second winch.

It will be appreciated that, if needed, the system may also be operated to move an end fitting from the firing line over and about the guide towards the storage reel or deck of the vessel, e.g. in a pipeline or riser retrieval operation.

When handling and transferring an end fitting use may be made of one or more auxiliary end fitting supports that provide support for the end fitting at one or more intermediate locations along the length of the end fitting. This is for example envisaged when handling delicate and/or heavy end fittings. The one or more auxiliary end fitting supports, e.g. embodied as support brackets, may be secured on the beam prior to engagement thereof with the end fitting or may be fitted to the end fitting first, e.g. on deck, and then secured to transfer beam, e.g. after engagement of the respective retainer with the end fitting or end fitting adapter. In another embodiment the beam is provided with one or more mobile auxiliary end fitting supports, e.g. one or more extensible and retractable end fitting support brackets at one or more intermediate positions along the length of the transfer beam.

Claims

A marine pipeline installation system for laying an offshore pipeline and / or installing a subsea riser pipeline, the system comprising: a storage reel (3) for storing a flexible pipeline (5) to be installed, a launch tower (10), which is arranged for launching a flexible pipeline in a firing line (6) into the sea, a pipeline guide (20) disposed at an elevated position of the launch tower and an arcuate guide surface (24) in a vertical plane for guiding the flexible pipeline from the storage reel to the firing line, one or more tensioners (15, 16) mounted on the launch tower below the pipeline guide (20), a transfer mechanism for an end fitting for a flexible pipeline, which is arranged around a moving end fitting (5a, 5b) on the flexible pipeline over the pipeline guide, which transfer mechanism comprises: - a beam support (40); - a beam support support device (50, 51, 52) which supports the beam support, - an end fitting handling beam (60), which beam is elongated and has first and second ends (61, 62), the beam being supported by the beam support and in the longitudinal direction is movable relative to the beam carrier such that in a first extendible position of the beam the first end is further away from the beam carrier than the second end and that in a second extendable position of the beam the first end is closer to the beam carrier than the beam carrier second end, wherein the beam carrier support device (50, 51, 52) and the beam carrier (40) are arranged to create an arcuate path of movement of the beam (60) in a vertical plane which is transverse to the guide surface (24) ) is shifted from the pipeline guide, the first end (61) of the beam (60) being provided with at least one of: - a first pulley (72) for e and a winch-driven cable (100) to be connected to a first end fitting (5a) on one end of the flexible pipeline, - a first winch with a winch-driven cable, which is connected to a first end fitting on one end of the flexible pipeline to be connected, - a first retainer (74; 174), which is arranged to be connected to a first end fitting on one end of the flexible pipeline, an end fitting adapter (185), which is connected to a first end fitting on one end of the flexible pipeline, or a cable (100) which is connected to a first end fitting is connected to one end of the flexible pipeline, being engaged, and wherein the second end (62) of the beam (60) is provided with at least one of: - a second pulley (73) for a winch- driven cable (110), which is to be connected to a second end fitting (5b) on one end of the flexible pipeline, - a second winch with a winch-driven cable, which serves with a second end fitting on one end of the flexible pipeline - a second retainer (75) adapted to be connected to a second end fitting on one end of the flexible pipeline, an end fitting adapter, which is connected to a second end fitting on one end of the flexible pipeline, or a cable (110) connected to a second end fitting on one end of the flexible pipeline, wherein - for transfer of a first end fitting (5a) to an end of the flexible pipeline over the pipeline guide - the beam (60 ) can be positioned in a first end-fitting pick-up position thereof, the beam being generally directed upwards on a supply side of the pipeline guide, where the pipeline is received from the storage reel, the first end-fit pick-up position enabling the first end fitting pick-up position lift up end fitting (5a) by means of a winch-driven cable (100; 100 ') to a position of the first end fitting (5a) along a transverse side of the beam (60), and wherein - by subsequent displacement of the beam (60) along the arcuate path of movement - the beam, with the first end fitting (5a) held along the side of the beam, can be moved to a first end fitting release position thereof, in which the beam is generally positioned downward, the first end fitting (5a) being in the firing line (6), and - for transfer from a second end fitting (5b) on one end of the flexible pipeline over the pipeline guide - the beam (60) can be positioned in a second end fitting pick-up position thereof, the beam generally being arranged downward on the supply side of the pipeline guide, so that the second end (62) of the beam borders on a lower region of the second end fitting (5b) of the pipeline, which curves over the pipeline guide (20), and the second end fitting (5b) is located along the side of the beam (60), and wherein - by subsequent displacement of the beam (60) along the arcuate path of movement - the beam, with the second end fitting (5b) being held along the side of the beam, to a second its end fitting release position can be moved, wherein the beam is generally positioned upwardly, the second end fitting (5b) being in the firing line (6), a winch-powered cable (110); 100 "), which is attached to the second end fitting, allows the second end fitting to be lowered into the firing line.

The system of claim 1, wherein the transfer mechanism comprises a motorized beam drive (44) adapted to move the beam (60) longitudinally relative to the beam carrier (40) between the first and second extend positions of the beam.

A system according to claim 1 or 2, wherein the transfer mechanism comprises a motorized beam carrier drive (41, 42, 43, 45) which is adapted to drive the beam carrier (40) and thereby effect movement of the beam along the arcuate path of movement. to bring.

The system of any one of claims 1-3, wherein a first mobile support (70; 170) is attached to the first end (61) of the beam (60), the first mobile support (70; 170) at least one of the first pulley (72), supports the first winch, and the first retainer (74; 174), the first mobile support (70; 170) being mobile relative to the beam between an operative position, wherein the at least one of the first pulley (72), the first winch, and the first retainer (74; 174) are in a vertical plane through the pipeline guide, and a retracted position away from the vertical plane.

The system of any one of claims 1-4, wherein a second mobile support (71) is attached to the second end (62) of the beam (60), the second mobile support (71) at least one of the second pulley (73), the second winch, and the second retainer (75), wherein the second mobile support (71) is mobile relative to the beam between an operative position, in which the at least one of the second pulley (73) , the second winch, and the second retainer (75) are in the vertical plane through the pipeline guide, and a retracted position away from the vertical plane.

The system of any one of claims 1-5, wherein the beam is provided at its first end (61) with the first retainer (74) and with the first pulley (73), the first pulley being arranged and arranged to , e.g. via an end-fitting adapter, guide winch-driven cable (100) to the first end-fitting (5a) such that, with the beam in its first end-fitting pick-up position, the first end-fitting (5a) is raised by the cable (100) is charged.

A system according to any one of claims 1-6, wherein the beam is provided at its second end (62) with the second retainer (75) and with the second pulley (73), the second pulley being adapted to guiding winch-driven cable (110) via an end-fitting adapter to the second end-fitting (5b) such that, with the beam in its second end-fitting release position, the second end-fitting (5a) can be suspended from the cable (110) whereby disconnection of the second retainer (75) and lowering of the second end fitting in the firing line (6) is possible.

A system according to any of claims 1-6, wherein the pipeline guide is a gutter with a semi-circular pipeline guide surface, e.g. formed by an endless band (24).

The system of claim 8, wherein the beam support device (50) comprises one or more semicircular rails (51, 52) disposed adjacent or on a side of the semicircular channel, the one or more rails supporting the beam carrier (40) support and guidance.

The system of any one of claims 1-9, wherein the beam carrier support device (50) comprises a circular or semi-circular rack (45), and wherein one or more drive motors (41, 42, 43) with motor-driven gears (44) ), which are in engagement with the rack, are arranged on the beam support (40).

The system of any one of claims 1-10, wherein the pipeline guide (20) and the end connector transfer mechanism (40, 50, 60) are supported by a common base (21) movably connected to the launch tower in an elevated position of the launch tower, wherein an adjustment device (30) is arranged between the common base (21) and the launch tower, which adjustment device is adapted to adjust the position of the common base (21) relative to the launch tower and thereby a horizontal distance between adapt the firing line (6) on the one hand and the pipeline guide (20) and end connector transfer mechanism (40, 50, 60) on the other.

The system of claim 11, wherein the system comprises a control unit connected to the adjusting device (30) and a motorized beam carrier drive (41, 42, 43), wherein the control unit is programmed to have a second end fitting play mode, wherein, with the beam in the second end fitting release position with the second end fitting (5b) hanging on a cable (110), released by a second holder and aligned with the firing line, the adjusting device (30) is controlled to move the common base (21) and thereby moving the pipeline guide away from the firing line, while at the same time moving the beam through the beam carrier drive to keep the second end connector (5b) aligned with the firing line, at least until the pipeline guide has sufficiently cleared itself from the firing line for the next lowering of enable the suspended second end fitting without interfering with the pipeline guide.

The system of any one of claims 1-12, wherein a counter-tension pulley and / or counter-tension winch (140) is provided, which is to be mounted on a deck of a vessel, generally below the supply side of the remote pipeline guide of the firing line, the counter-tension pulley or winch guiding the winch-driven cable (110) upon transfer of a second end fitting and allowing the application of counter-tension during the transmission.

Vessel for laying an offshore pipeline, which is provided with a system according to one of claims 1-13.

A method for laying an offshore pipeline and / or installing a subsea riser pipeline with at least one of a first end fitting and a second end fitting, wherein a flexible pipeline with at least one of a first end fitting and a second end fitting of the reel (3) is unrolled and use is made of a system according to one of claims 1-13 or a vessel according to claim 14.