INSTALLATION PALLET

Abstract

An accessory installation pallet for handling an accessory on an offshore vessel includes a pallet frame and multiple pivotable deck sections. The pallet frame provides the pallet with structural rigidity and is provided with fixating devices for securing an accessory, e.g. a PLET, to the pallet. The pallet frame is furthermore provided with one or more coupling devices adapted to couple the pallet with a PLET handler, to allow the PLET handler to pivot the pallet from a horizontal transport position into an upright support position. The pivotable deck sections are pivotable mounted in the pallet frame, such that each deck sections can pivot between a folded position, in which the deck section is located adjacent the pallet frame, and an extended position, in which the deck section extends in a direction away from the pallet frame.

Claims

1.-23. (canceled)

24. An accessory installation pallet for handling an accessory on an off-shore vessel, the installation pallet comprising: a pallet frame, the pallet frame providing the pallet with structural rigidity and being provided with fixating devices for securing an accessory to the pallet, wherein the pallet frame is provided with one or more coupling devices adapted to couple the pallet with a PLET handler, to allow the PLET handler to pivot the pallet from a horizontal transport position into an upright support position, and wherein the pallet frame has a support side, the support side facing the accessory when the accessory is mounted on the pallet, and a transport side, the transport side facing away from the support side, and at the transport side, the pallet frame is configured as a skid frame for transporting, to enable transport of the accessory over the deck of the off-shore vessel; and multiple pivotable deck sections, the pivotable deck sections being pivotably mounted in the pallet frame, such that each deck sections can pivot between a folded position, in which the deck section is located adjacent the pallet frame, and an extended position, in which the deck section at the support side of the pallet frame extends in a direction away from the pallet frame.

25. The accessory installation pallet according to claim 24, wherein one or more of the pivotable deck sections comprise: a deck section support frame, the deck section support frame being pivotably mounted to the pallet frame; and one or more deck panels mounted to the deck section support frame to provide a deck surface.

26. The accessory installation pallet according to claim 24, wherein one or more of the pivotable deck sections are provided with mounts and/or hoisting devices, such that the pivotable deck sections can function as a hoisting beam when in the extended position.

27. The accessory installation pallet according to claim 24, wherein one or more of the pivotable deck sections can be locked in intermediate positions, to provide a horizontal working deck when the pallet is supported in an inclined position.

28. The accessory installation pallet according to claim 24, wherein one or more of the pivotable decks sections are at one end provided with an opening for receiving a tubular supported in a firing line.

29. The accessory installation pallet according to claim 24, wherein one or more of the pivotable decks sections are provided with fixating devices for securing equipment to the deck sections.

30. The accessory installation pallet according to claim 24, wherein the pivotable deck sections, when in the folded position, are flush with each other such that together the pivotable deck sections provide the pallet with a support surface for supporting equipment, and wherein hoisting beams, if provided, when in the folded position are located below said support surface when the pallet is in the horizontal position.

31. The accessory installation pallet according to claim 24, wherein one or more of the pivotable decks sections are provided with mounts for mounting railing to the deck sections when in the extended position.

32. The accessory installation pallet according to claim 24, wherein the pallet frame comprises two longitudinal side beams, and multiple cross beams connecting the longitudinal side beams, the side beams extending along the length of the pallet frame and providing a skid surface at the transport side of the pallet frame.

33. The accessory installation pallet according to claim 24, wherein the longitudinal side beams with one side form the upper most part of the pallet and with an opposite side form the lower most part of the pallet when the pallet is in its transport position and the pivotable decks sections are in the folded position.

34. The accessory installation pallet according to claim 24, wherein the pallet frame comprises one or more hoist beams, the hoist beams being pivotably mounted to the pallet frame such that the hoist beams can be pivoted between a folded position, in which the hoist beam is located adjacent the pallet frame, and an extended position, and in the extended position the hoist beam at the support side of the pallet frame extends in a direction away from the pallet frame, to enable hoisting of equipment when the pallet is held in the support position.

35. The accessory installation pallet according to claim 24, wherein the pallet comprises a passage opening that allows for a person to pass through the pallet from the transport side to the support side, to provide a person access to a deck section when the pallet is held in the support position.

36. The accessory installation pallet according to claim 24, wherein the pallet comprises one or more pivotable deck sections, the pivotable deck sections being pivotably mounted in the pallet frame, such that each deck sections can pivot between a folded position, in which the deck section is located adjacent the pallet frame, and an extended position, in which the deck section at the transport side of the pallet frame extends in a direction away from the pallet frame.

37. The accessory installation pallet according to claim 24, wherein the pallet comprises hydraulic actuators for pivoting the pivotable deck sections between the folded position and the extended position relative to the pallet frame.

38. A PLET handling system comprising: a PLET handler; and the installation pallet according to claim 24, wherein the installation pallet is adapted to couple with the PLET handler such that the PLET handler can pivot the installation pallet between a transport position and a support position thereof.

39. The PLET Handling system according to claim 38, wherein the PLET handler is provided with skid rails which allow the installation pallet to be skidded onto the PLET handler when the PLET handler is in a lowered position.

40. The PLET Handling system according to claim 38, wherein the PLET handler comprises a tiltable lift arm, and a support bed, the support bed being adapted to couple with the installation pallet, being pivotably supported by the lift arm at one end and being connected to the lift arm via hydraulic cylinders at an opposite end, the hydraulic cylinders enabling pivoting of the bed relative to the lift arm to align the bed, and thus the installation pallet coupled with the bed, relative to the firing line.

41. A vessel comprising the PLET handling system according to claim 38.

42. The vessel according to claim 41, further comprising: a pipe-lay tower; and a PLET handler for bringing a PLET into the firing line.

43. A method for providing a working platform adjacent a firing line, the method comprising the steps: providing the accessory installation pallet according to claim 24; pivoting the installation pallet from a transport position, in which the installation pallet has a substantially horizontal orientation, into a support position, in which the installation pallet has a substantially vertical orientation; supporting the accessory installation pallet in the support position adjacent the firing line; and pivoting at least one of the one or more pivotable deck sections into the extended position, such that the at least one pivotable deck section provides a working platform adjacent the firing line.

Description

[0098] Advantageous embodiments of the installation pallet according to the invention, the PLET handling system, the vessel according to the invention and the method according to the invention are disclosed in the sub claims and in the description, in which the invention is further illustrated and elucidated on the basis of a number of exemplary embodiments, of which some are shown in the schematic drawing.

[0099] In the drawings:

[0100] FIG. 1 schematically shows a side view of an installation pallet according to the invention, with an accessory secured thereto, which installation pallet is supported by a PLET handler in a support position adjacent a J-lay tower;

[0101] FIG. 2 shows a perspective view of the installation pallet with a PLET secured thereto, which installation pallet is supported by a PLET handler in a support position;

[0102] FIG. 3 shows a perspective view of the installation pallet with multiple pivotable working decks in an extend position, and a pipeline supported in a firing line;

[0103] FIG. 4 schematically shows a side view of the installation pallet of FIG. 3, with the multiple pivotable working decks in an extend position, being supported by a PLET handler in a first working position adjacent the firing line:

[0104] FIG. 5 schematically shows a side view of the installation pallet of FIG. 3, with the multiple pivotable working decks in an extend position, being supported by a PLET handler in a second working position away from the firing line;

[0105] FIG. 6 shows a perspective view of the installation pallet of FIG. 2 in a support position with one pivotable working deck and two hoisting beams in an extended position;

[0106] FIG. 7 shows a perspective view of the installation pallet of FIG. 2 in a support position with all pivotable working decks in an extended position, and a pipeline supported in a firing line;

[0107] FIG. 8 shows a perspective view of the installation pallet of FIG. 2 in a support position with one pivotable working deck in an extended position, configured for supporting pipe sections;

[0108] FIG. 9 schematically shows a side view and top view of an alternative installation pallet configured for supporting pipe sections;

[0109] FIG. 10 shows a perspective view of an installation pallet according to the invention with two shipping containers secured thereto, which installation pallet is supported in its transport position by a PLET handler;

[0110] FIG. 11 schematically shows a side view of the installation pallet of FIG. 10;

[0111] FIG. 12 shows a side view of an alternative embodiment of a PLET handing system according to the invention, the PLET handling system comprising an installation pallet and a PLET handler;

[0112] FIG. 13 shows a rear view, facing the PLET handler, of the PLET handling system of FIG. 12;

[0113] FIG. 14 again shows rear view, facing the PLET handler, of the PLET handling system of FIG. 12;

[0114] FIG. 15 shows a perspective view of the PLET handling system of FIG. 12:

[0115] FIG. 16 shows the PLET handler system of FIG. 12 in a first position;

[0116] FIG. 17 shows the PLET handler system of FIG. 12 in a second position;

[0117] FIG. 18 shows the PLET handler system of FIG. 12 in combination with a raised deck and a second installation pallet.

[0118] FIG. 1 schematically shows a side view of an installation pallet 1 according to the invention, with an accessory 3 secured thereto. The installation pallet 1 is supported by a PLET handler 2 in a support position adjacent a J-lay tower 4, which J-lay tower is mounted on an off-shore vessel 5, is partially shown and is shown in see through. The PLET handler 2 supports the installation pallet 1 such accessory 3 is located in the firing line 6 of the J-lay tower 4.

[0119] FIG. 2 shows a perspective view of the installation pallet 1 with a PLET 7 secured thereto. The installation pallet 1 is supported by a PLET handler 2 in a support position. In the FIG. 2 the vessel is not depicted, Only part of the J-lay tower 4 is depicted. In the embodiment shown, the J-lay tower 4 comprises an A-frame, and the PLET handler 2 is configured to introduce a PLET, and thus the installation pallet 1, through an access opening defined by the A-frame of the J-lay tower.

[0120] As a comparison. FIG. 10 depicts the installation pallet 1 according to the invention in its support position, in which it is supported horizontally, and is located on the opposite side of the J-lay tower compared to the support position in which the installation pallet 1 is depicted in FIGS. 1 and 2.

[0121] In FIG. 10 two shipping containers 7 are secured to the installation pallet 1. FIG. 11 schematically shows a side view of the installation pallet 1 of FIG. 10.

[0122] FIG. 3 shows a perspective view of the installation pallet 01 with multiple pivotable working decks 8 in an extend position, and a pipeline 9 supported in the firing line 6. Vessel and J-lay tower are not depicted in FIG. 3.

[0123] FIG. 4 and FIG. 5 schematically shows a side view of the installation pallet 1 of FIG. 3. In both figures, the installation pallet 01 is supported by the PLET handler 2 in the support position, with the multiple pivotable working decks 8 in the extend position.

[0124] In FIG. 4, the installation pallet 1 is supported in a first working position adjacent the firing line. In FIG. 5, the installation pallet is supported in a second working position away from the firing line.

[0125] According to the invention, the installation pallet 1 comprises a pallet frame 8. The pallet frame 8 provides the installation pallet 1 with structural rigidity.

[0126] The pallet frame 8 has a support side 11, which support side faces the accessory 3 mounted on the pallet 1, and a transport side 12, which transport side faces away from the support side. When the pallet 1 is in the transport position, e.g. shown in FIG. 10, the support side 11 is the top side of the pallet and the transport side 12 is the bottom side of the pallet. In the upright position, e.g. shown in FIG. 10 the support side faces the firing line, while the transport side faces away from the firing line, typically faces the vessel.

[0127] The pallet frame 8 is provided with fixating devices 9 for securing an accessory 3, e.g. a PLET, to the pallet 1 at the support side thereof.

[0128] The pallet frame 8 is provided with coupling devices 10 adapted to couple the pallet with a PLET handler, to allow the PLET handler to pivot the pallet from a horizontal transport position into an upright support position.

[0129] At the transport side 12 the pallet frame 8 of the installation pallet 1 is configured as a skid frame for transporting, i.e. skidding. Thus, the installation frame 8 enables transport of the accessory 3 over the deck of the off-shore vessel 5. Typically, the deck of off shore vessels is provided with skid rails to enable transport of heavy tools and equipment over the deck. In a preferred embodiment, the installation frame is adapted to cooperate with those skid rails.

[0130] According to the invention, the installation pallet 1 comprises multiple pivotable deck sections 13. The pivotable deck sections 13 are pivotable mounted in the pallet frame 8. Each pivotable deck section 13 can pivot between a folded position, in which the pivotable deck section 13 is located adjacent the pallet frame 8, and an extended position, in which the pivotable deck section 13 at the support side of the pallet frame 1 extends in a direction away from the pallet frame. In the installation pallet 1 shown in FIGS. 2, 4 and 6 is provided with four pivotable deck sections 13. In FIG. 2, the pivotable deck sections 13 are all in the folded position. In FIG. 3 the pivotable deck sections are all in the extended position. In FIG. 6 the lower pivotable deck section is in the extended position and the three other pivotable deck sections are in the folded position.

[0131] In the embodiment of an installation pallet according to the invention shown in FIG. 3, the installation pallet 1, in particular the pivotable deck sections 13, are at the end that faces the tubular 15 supported in the firing line 6, provided with an tubular receiving opening 16 for receiving the tubular, e.g. a pipe, tubing or cable, supported in a firing line.

[0132] In the preferred embodiment shown, the tubular receiving opening 16 is substantially U-shaped, thus, the deck portions provides access along 180 degrees of the pipe, i.e. at three sides. Furthermore, the deck section 13 are each provided with a door section 17 that can be used to close an entry port of the receiving opening 16, and thus secure tubular 15 within the receiving opening 16, and stabilizing the position of the tubular 15 relative to the deck section 13.

[0133] In FIG. 3, the pivotable deck sections 13 are thus in combination used to center the tubular relative to the deck section in particular to the installation pallet, and thus the PLET handler. In a further preferred embodiment, rollers are provided on the deck sections adjacent the receiving opening to guide the tubular relative to the deck sections.

[0134] In the preferred embodiment shown, the installation pallet 1 has a pallet frame 8 comprising two longitudinal side beams 27, and multiple cross beams 28 connecting the longitudinal side beams. The side beams 27 extend along the length of the installation pallet, in particular along the pallet frame, and provide a skid surface at the transport side of the pallet frame.

[0135] In the preferred embodiment shown, the longitudinal beams 28 furthermore provide a mounting surface at the support side of the pallet, which mounting surface is furthermore provided with mounts for securing equipment.

[0136] In the embodiment shown, the longitudinal side beams 27 with one side, in the embodiment shown the support surface at the top side, form the upper most part of the pallet and with an opposite side form the lower most part, in the embodiment shown being the skid surface, of the pallet when the pallet is in its transport position and the pivotable decks sections are in the folded positions.

[0137] In the preferred embodiment shown, the pivotable deck sections, when in the folded position, are flush with each other such that together they provide the pallet with a support surface for supporting equipment, which support surface is flush with a top side of the pallet frame, and wherein the hoisting beams, if provided, when in the folded position are located below said support surface when the pallet is in the horizontal position, see for example FIG. 2.

[0138] In the preferred embodiment shown, the pivotable deck sections, when in the folded position are located adjacent each other, such that together they form a support deck, for example as shown in FIG. 2

[0139] In the preferred embodiment shown, the pivotable deck sections, when in the folded position, are located within the pallet frame, i.e. the pivotable deck sections when in the folded position are at most flush with the top of the pallet frame of the installation pallet, or are recessed in the frame such that they are located below the top of the frame. When the deck sections are flush with the top of the pallet frame, the support deck defined by the folded deck sections is also flush with the top of the pallet frame, such that the pallet frame, or at least the top thereof, is also part of the support deck.

[0140] In an alternative embodiment, the pivotable deck sections, when in the folded position, are located at least partially above the pallet frame, such that the top of the pallet frame is located below the support deck defined by the folded pivotable deck sections. In such an embodiment, the accessory, e.g. the PLET, when supported on the support deck, may extend beyond the pallet frame. In contrast, when the pivotable deck sections are recessed in the pallet frame, and the accessory is mounted on the support deck, the accessory may not extend beyond the parts of the pallet frame that is located above the support deck. For example, when the pallet frame comprise two longitudinal beams extending on opposite sides of the pallet, for example as shown in FIG. 2, and the pivotable deck sections, when in the folded position are located within the pallet frame, an accessory mounted on the support deck may collide with the beams when it is wider than the pivotable deck sections.

[0141] In an embodiment, the pivotable working deck sections, when in the folded position are located within the pallet frame, and the pallet frame provides a support surface for mounting the accessories. For example, when the pallet frame comprise two longitudinal beams extending on opposite sides of the pallet, for example as shown in FIG. 2, and the pivotable deck sections, when in the folded position are located within the pallet frame, an can be mounted on the top sides surface of those support beams. This is beneficial since it allows for mounting accessories on the installation pallet which are wider than the installation pallet.

[0142] The pivotable deck sections are pivoted about a pivot axis that extend perpendicular to a longitudinal axis of the installation pallet.

[0143] It is noted that in the embodiments shown, the pivotable deck sections are pivoted downward when pivoted into the extended position. Preferably, the pallet frame is provided with stops that interact with the pivotable deck sections such that they define the outermost positions of the pivotable deck sections, i.e. the folded position and the extended position. Thus, when the deck sections are in the extended position, they cannot pivot in a downward direction.

[0144] In an alternative embodiment, the pivotable deck sections are pivoted upward when pivoted into the extended position.

[0145] Preferably, the pallet frame and/or the pivotable deck sections, are provided with locking devices for securing the pivotable deck sections in their folded position and extended position, and preferably in intermediate positions as well.

[0146] In an embodiment the of shore vessel 5 provided with a PLET handling system comprising the PLET handler 2 and the installation pallet 1 according to the invention, the PLET handler 2 is provided with skid rails which allow the installation pallet to be skidded onto the PLET handler 2 when the PLET handler is in a lowered position, show in FIG. 10. The rails on he PLET handler preferably are aligned with rails on the deck of a vessel when the PLET handler is in the lowered position, such that the pallet frame can skid from the deck onto the PLET handler and vice versa.

[0147] In the preferred embodiments shown, the pivotable deck sections 13 comprise a deck section support frame 14, which deck section support frame is pivotably mounted to the pallet frame 8, and a deck panel 15 mounted to the deck section support frame to provide a deck surface.

[0148] In the embodiment shown, the deck panel 15 is a combination of beams and metal sheets, the latter defining the actual deck surface.

[0149] FIG. 4 shows a schematic side view of an installation pallet according to the invention, the installation pallet comprising six pivotable deck sections, which are all in the extended position in FIG. 4. In the preferred embodiment shown, the deck section support frame of the pivotable deck section, is provided with mounts and hoisting devices, such that the pivotable deck sections, when in the extended position, can be used as a hoisting beam.

[0150] FIG. 4 in combination with FIG. 5 shows that the PLET handler can be used to position the installation pallet in different working position relative to the firing line. In FIG. 4 the installation pallet, in particular the deck sections of the installation pallet, are provided adjacent the firing line, while in FIG. 5 the deck sections are located at some distance away from the firing line. The position of the installation pallet can be adapted to fit the requirement of a particular job, and/or for example to make space for lowering a wide section of pipeline, for example a pipe line just provided with an accessory, without the requiring the deck sections to be pivoted into their folded position.

[0151] In the particular embodiment shown, the vessel 5 comprises a PLET handling system comprising the PLET handler 2 and the installation pallet 1. In the particular embodiment shown, the vessel is furthermore provided with a J-lay tower 4 comprises an A-frame, see for example FIG. 2 and FIG. 10, which show the bottom end of the J-lay tower. The PLET handler 2 is configured to introduce a PLET into the firing line through an access opening 18 defined by the A-frame of the J-lay tower.

[0152] In the particular embodiment shown, the PLET handler 2 comprises a tiltable lift arm 19, and a support bed 20, which support bed is adapted to couple with the installation pallet 1, and which support bed is pivotably supported by the lift arm at one end and is connected to the lift arm via hydraulic cylinders 21 at an opposite end, which hydraulic cylinders enable pivoting of the bed relative to the lift arm to align the bed, and thus the installation pallet coupled with the bed, relative to the firing line.

[0153] In addition to, or instead of, using the PLET handler to position the installation pallet relative to the firing line, the PLET alignment device, if present, can be used to position the installation pallet relative to the firing line. It should be noted that the range of movement that is available with a PLET alignment device is in general less than the range of movement that can be obtained by a PLET handler as shown in FIG. 4 and FIG. 5.

[0154] FIG. 7 shows a perspective view of the installation pallet of FIG. 2 in a support position with one pivotable working deck and two hoisting beams in an extended position. furthermore, in the embodiment shown, the installation pallet has been used to introduce buoyancy cans 22 adjacent the firing line. The buoyancy cans have been be mounted to the different deck sections 13 of the installation pallet 1 such that a vertical row of items is provided by the installation pallet in its upright position adjacent the firing line. Thus, for example, the items 22 can be attached to the tubular 15 one by one starting with the lowest item. Once an items has been attached to the tubular, the empty deck section can be folded from its extended position into its folded position in the installation pallet so that the tubular with the item attached to it can be lowered without the item colliding with the deck section. Once a predetermined section of tubular has been lowered, the next item is attached to the tubular, the deck section is pivoted into its folded position, etc.

[0155] It is noted that appurtenances to be mounted on the pipeline such as buoyancy cans and VIV strakes can be large and heavy and difficult to transport to and install on the pipeline. Such items can be lashed onto these deck sections when the pallet is on deck outside of the work area. The installation pallet with the appurtenances is than skidded towards the PLET handler and is positioned adjacent the firing line using the PLET handler. Once the installation pallet is in place, the items can be attached to a pipe line supported in the firing line.

[0156] FIG. 6 shows a perspective view of the installation pallet of FIG. 2 in a support position with one pivotable working deck and two hoisting beams in an extended position, furthermore, the embodiment of the installation pallet 1 shown comprises two hoist beams 23. The hoist beams 23 are pivotably mounted to the pallet frame 8 such that they can be pivoted between a folded position, in which the hoist beam is located adjacent the pallet frame, in the embodiment shown within the pallet frame (see for example FIG. 3), and an extended position, in which extended position the hoist beam at the support side of the pallet frame extends in a direction away from the pallet frame, to enable hoisting of equipment when the pallet is held in the support position.

[0157] In an embodiment, two hoisting davits are installed at one end of the installation pallet, preferably the end being the top end when the installation pallet is in its upright support position. The davits for example consist of an I-shaped beam that can hinge to position it in the horizontal plane (assuming that the pallet is in supported in its upright position). The beams are stored flat on the pallet when not in use. The beam is equipped with a trolley hoist that travels along the beam.

[0158] In a preferred embodiment, the hoist beam has a length such that when in its unfolded position it extends, in a direction away from the pallet frame, beyond the pivotable deck sections in their extended position, to thus enable to lift and lower objects along the pivotable deck sections, in particular along the side of the deck sections facing the firing line when the installation pallet is supported adjacent the firing line.

[0159] FIG. 8 shows a perspective view of the installation pallet of FIG. 2 in a support position with one pivotable working deck in an extended position, configured for supporting pipe sections.

[0160] In the particular embodiment shown, the installation pallet 1 is used to mount equipment in the form of an installations. For example, during straightening trials or pipe diameter changes in the pipeline significant lengths of pipe have to be scrapped and removed from the firing line. The cut pipe sections are conventionally removed one by one using a crane.

[0161] This operation can be performed more time efficient by equipping the installation pallet 1 as a scrap pipe collecting container by providing a tubular support platform 24 at the bottom end of the installation pallet and a tubular retainer platform 25 at the top end of the installation pallet.

[0162] FIG. 9 schematically shows a side view and top view of an alternative installation pallet configured for supporting pipe sections;

[0163] The installation pallet according to the invention is dimensioned such that it can support a PLET, more in particular can act as an intermediate between the PLET and PLET handling systems. The installation pallet is preferably dimensioned such that it allows for two shipping containers to be mounted thereon, preferably two shipping containers.

[0164] FIG. 10 shows a perspective view of an installation pallet according to the invention with two shipping containers secured thereto, which installation pallet is supported in its transport position by a PLET handler; and FIG. 11 schematically shows a side view of the installation pallet of FIG. 10.

[0165] In the embodiment shown in FIG. 10 and FIG. 11 the installation pallet 1 is equipped with standard container twist locks to support two standard 20 ft or 30 ft shipping containers 26. The containers can for example be provided with consumables and/or be configured as a work station. The containers can be lowered on and mounted to the installation pallet away from the work area and be transported to the firing line using the PLET handling system.

[0166] FIG. 12 shows a side view of an alternative embodiment of a PLET handing system 30 according to the invention, the PLET handling system comprising an installation pallet 31 and a PLET handler 32. The PLET handling system is also depicted in FIGS. 13-18, be it that in FIGS. 13-15 only the support bed 34 is depicted, and not the installation pallet 31 and the tiltable lift arm 33.

[0167] In the embodiment shown, the PLET handling system according to the invention comprises a tiltable lift arm 33 and a support bed 34, and the support bed comprises an alignment system 35. In the particular embodiment shown, the support bed 34 comprise a base frame 36, which base frame is pivotably supported by the tiltable lift arm 33, and a top frame 37 adapted to couple with the installation pallet 31. Between the base frame 36 and the top frame 37 is provided the alignment system 35.

[0168] FIGS. 12 to 15 show how the PLET handler is able to position a installation pallet, and thus anything mounted on the installation pallet, relative to the firing line. It is submitted that in all figures, the tiltable lift arm is in a raised position, in which the installation pallet is supported in an upright position adjacent the firing line.

[0169] The support bed can be positioned relative to the firing line by pivoting of the tiltable support arm. The tiltable support arm is pivoted by two main actuators, in the embodiment shown two parallel hydraulic cylinders. It is noted that the PLET handler 32 shown in FIGS. 12-18 differs from the PLET handler shown in FIG. 11 in that the actuator is mounted with one and to the deck and not to the pipe-lay tower. Both PET handlers tilt about a tilt axis that coincides with a tilt axis of the pipe-lay tower.

[0170] With the PLET handler shown in FIGS. 12-18, two actuators, in the embodiment shown hydraulic cylinders 39, are provided between the tiltable liftarm and the support bed, for positioning the bed, which is pivotably supported by the tiltable lift arm, relative to the lift arm. Thus, the tiltable lift arm can be used for positioning the bed relative to the firing line, i.e. closer to and farther away from the firing line. The cylinders between the tiltable lift arm and the support bed can be used to adjust the angle, or tilt, of the bed. Thus, for example, the support bed can be supported parallel to a tilted firing line.

[0171] To enable further adjustment relative to the firing line, the support bed is provided with an alignment system. The top frame of the support bed is moveably connected to the base frame. The top frame can be moved to the left and right using left-right actuators in the form of hydraulic cylinders 40, which possible movement is depicted with arrows in FIG. 13. In the embodiment shown, the actuators 40 can also be used for rotating the top frame relative to the base frame, which possible movement is also indicated with an arrow in FIG. 13. The top frame can be moved to the up and down using up-down actuators in the form of hydraulic cylinders 41, which possible movement is depicted with arrows in FIG. 14. Furthermore, the top frame can be moved towards and away from the base frame using towards-away actuators in the form of screw jacks 42, which possible movement is depicted with arrows in FIG. 15. These towards-away actuators improve on the accuracy of positioning of the support bed by the tiltable lift arm.

[0172] FIG. 16 shows the PLET handler system of FIG. 12 adjacent a pipe-lay tower 43. In the embodiment shown the pipe-lay tower is a pivotable tower, which is pivotable about a pivot axis that coincides with the pivot axis of the PLET handler. The firing line, or at least a section thereof, of the pipe lay tower is indicated with line 45. In the embodiment shown, the pipe-lay tower is slightly tilted, such that the firing line is at an angle with the vertical,

[0173] FIG. 16 shows the PLET handler system 30 in a first position, in which a PLET mounted on the pallet projects through an opening in the tower. FIG. 17 shows the PLET handler in a second position, in which it supports the installation pallet in an upright support position, in this position, the actuators provided between the tiltable lift arm and the support bed can be used to enable the PLET handler to support the installation pallet parallel to the tilted firing line.

[0174] It is noted that in the preferred embodiment shown, the PLET handler is configured to not only support the installation pallet in its horizontal transport position and its upright support position. In the first position, shown in FIG. 16, the PLET handler is pivoted such that the end of the installation pallet further away from the pipe-lay tower is lowered, to thus support the pallet with its support surface substantially perpendicular to the tilted firing line. This may be beneficial when the pallet is to be used to position equipment adjacent the firing line without being tilted into the upright support position.

[0175] FIG. 18 shows the PLET handler system of FIG. 12 in combination with a raised deck and a second installation pallet. A first installation pallet is shown on the PLET handler. The first installation pallet is not provided with equipment, and should be removed from the PLET handler to allow the second installation pallet to be moved onto the PLET handler.

[0176] In the embodiment shown, the PLET handler, more in particular the top frame of the support bed of the PLET handler, is provided with skid rails and a raised deck 46 is provided with skid rails. The rails of the PLET handler are aligned with rails on the deck of when the PLET handler is in the lowered position, shown in FIG. 18, such that the pallet frame can skid from the deck onto the PLET handler and vice versa. It is noted that in the embodiment shown, the pivotable pipe-lay tower is mounted on the deck and the PLET handler is provided with a pivot axis that coincides with the pivot axis of the pipe-lay tower. thus, the top of the support bed of the PLET handler is located above the main deck 47 of the vessel and a raised deck is provided to enable the pallet to be skidded onto an off the PLET handler.

[0177] In an alternative embodiment, for example the pivot axis of the pipe-lay tower may be located below the main deck, or the PLET handler may be recessed in the main deck, such that the top of the support bed is level with the main deck of the vessel. In yet another embodiment, a lift may be used to bring the installation pallet level with the top of the PLET handler, or the PLET pallet may be craned onto the PLET handler. Further alternative embodiments are also possible.

REFERENCE SIGNS

[0178] 01 installation pallet [0179] 02 PLET handler [0180] 03 accessory [0181] 04 J-lay tower [0182] 05 vessel [0183] 06 firing line [0184] 07 shipping containers [0185] 08 pallet frame [0186] 09 fixating devices [0187] 10 coupling devices [0188] 11 support side [0189] 12 transport side [0190] 13 pivotable deck sections [0191] 14 deck section support frame [0192] 15 tubular [0193] 16 tubular receiving opening [0194] 17 door section [0195] 18 access opening A-frame [0196] 19 lift arm PLET [0197] 20 support bed PLET [0198] 21 hydraulic cylinders lift bed [0199] 22 buoyancy cans [0200] 23 hoist beams [0201] 24 tubular support platform [0202] 25 tubular retainer platform [0203] 26 shipping containers [0204] 27 longitudinal side beams [0205] 28 cross beams [0206] 30 PLET handling system [0207] 31 installation pallet [0208] 32 PLET handler [0209] 33 tiltable lift arm [0210] 34 support bed [0211] 35 alignment system [0212] 36 base frame [0213] 37 top frame [0214] 38 hydraulic cylinders tiltable lift arm [0215] 39 cylinders between tiltable lift arm and support bed [0216] 40 left-right actuators [0217] 41 up-down actuator [0218] 42 towards-away actuator [0219] 43 pipe-lay tower [0220] 44 tilt axis PLET handler [0221] 45 firing line pipe-lay tower [0222] 46 raised deck [0223] 47 main deck