GB2500504A

GB2500504A - A Tensioner

Info

Publication number: GB2500504A
Application number: GB1308118.7A
Authority: GB
Inventors: Derek Smith
Original assignee: Maritime Developments Ltd
Current assignee: Maritime Developments Ltd
Priority date: 2013-02-05
Filing date: 2013-05-07
Publication date: 2013-09-25
Anticipated expiration: 2033-05-07
Also published as: GB201308118D0; GB201301983D0; GB2500504B

Abstract

A tensioner (1) comprising a carcass (3) having a longitudinal axis (5). Four tracks (7) are supported by segments (41, 42, 43, 44) of the carcass and define a cross with an opening (11) in the centre for receiving an elongate component (9). At least two segments are movable between a closed position in which the segment is conjoined with the other segments and an open position in which the segment is moved away from the other segments to form an access opening (15, 17) for inserting the elongate component into the opening (11). The access opening (17) formed when two segments are opened is greater than the access opening (15) formed when one segment is opened. The carcass can be mounted on a support structure so that the cross is in "+" or "x" sign orientation with respect to the support structure when viewed along the longitudinal axis.

Description

A TENSIONER

Field of the Invention

The present invention provides a tensioner and a corresponding method for handling elongate components) such as for installing or retrieving tubulars such as flexible risers, pipelines and/or cables in oil and gas industry, but not limited thereto.

Background of the Invention

In oil and gas industry) tensioners are well known. Tensioners are typically used for the installation and recovery of production pipelines, in offshore or onshore environments, but can also be employed in the installation and recovery of other conduits, such as SURF (Subsea tJmbilicals, Risers and Flowlines) products and power cables.

Offshore, tensioners are typically installed on a stern part of a pipe laying vessel or barge. A typical prior art tensioner comprises several endless tracks, normally) caterpillar tracks, mounted on a support frame. The tracks are mounted on the frame so as to define a central opening in which the pipe is received and the tracks support the pipe in a horizontal orientation. Other, separate tensioners are also known in which are the tracks are mounted on the frame so as to define a central opening in which the pipe is received and the tracks support the pipe in a vertical orientation.

Two-, three-or four-track tensioners are known. Four track machines are preferred these days because they have proven to provide a better grip. As well as being movable longitudinally in order to move the pipe, the tracks are also movable transversely in relation to the longitudinal pipe axis, for example, by hydraulic cylinders, to grip or release the pipe or to adjust the diameter of the central opening to match different pipe diameters. The pipe is often fed into the tensioner from a large reel and is then advanced by the tensioner off the vessel into the sea and down to the seabed. As well as gripping and moving the pipe, the tensioner also supports the weight of the pipe length extending between the vessel and the seabed. The weight of the pipe supported by the tensioner can often reach and even exceed 100 tonnes.

Horizonta' tensioners are arranged to hold the pipe horizontally and the pipe needs to be redirected by other devices, e.g. chutes or goosenecks, to point downwardly) whereas vertical tensioners do not require the use of re-directing devices because the pipe is directed downwardly by the tensioner itself Accordingly, vertical tensioners tend to occupy kss of the valuable deck space than horizontal tensioners.

On the other hand horizontal tensioners tend to be safer because they rely on a combination of gravity and friction in supporting the pipe whereas vertical tensioners rely sol&y on friction. Both vertical and horizontal tensioners can in fact be inclined to a certain extent to direct the pipe along the required aying path, but are still referred to as "horizontal" or "vertical". The choice between horizontal and vertical configuration is dictated by individual features of the site. Prior art tensioners to date hitherto can only be used in one of the two orientations and simply couldn't be re-configured to be suitable to be mounted in the other orientation.

One prior art horizontal tensioner developed by the applicant comprises a tensioner carcass horizontally mounted on a horizontal support frame. The carcass comprises a fixed lower part which is mounted on the support frame and a movable upper part, the parts being connected by a hinge having a pivot axis which extends along a side of carcass. Within the carcass, four caterpillar tracks are arranged, two vertical (upper and lower tracks] and two horizontal (right and left tracks], forming a right angle +cross which has a vertical beam and a horizontth beam (referred to as the St. George's cross configuration as in the red on white St. George's cross on the Engllsh national flag] when seen in end-view and defining a pipe opening in the centre of the cross for accommodating a pipe. The upper vertical track is attached to the upper part of the carcass. The hinge allows the upper part of the carcass together with the upper vertical track o be lifted so that the pipe can be placed from above on the lower vertical track between the right and left horizontal tracks. The upper part of the carcass is then closed and the tracks are tightened around the pipe. The tracks are then actuated so that the pipe can be advanced though the carcass by the moving tracks without slippage. This type of arrangement is not suitable to be mounted vertically because the opening provided when the upper part of the carcass is opened is not sufficiently wide for moving a vertically oriented pipe sideways into the space between the three tracks which remain in place.

Other manufacturers provide a vertical tensioner similar to the above-described horizontal tensioner but with a tensioner carcass being vertically mounted to a vertical support frame, also known as a tower. Similar to the horizontal tensioner) the carcass of the vertical tensioner comprises a fixed inner part which is mounted to the tower and a movable outer part and the parts are connected by a hinge. The carcass also comprises four tracks arranged within the carcass to form a cross. The difference from the horizontal tensioner is that in the vertical tensioner there are two inner tracks in the inner part provided at an angle of approximately 900 to each other and two outer tracks in the outer part also provided at an angle of approximately 900 to each other so that the tracks are oriented diagonally in relation to a plane dividing the inner and outer parts when the inner and outer parts are closed, i.e. the tracks form an X-cross, i.e. a cross having diagonal beams (referred to as the St Andrew's cross configuration as in the white on blue St. Andrew's cross on the Scottish national flag) when seen in plan view. In this arrangement, the two outer tracks can be moved away from the two inner tracks by opening the outer part of the carcass so that the pipe can be placed into the centre of the tensioner sideways into the space between the two inner tracks. The outer part of the carcass is then closed and the tracks are tightened around the pipe so that the pipe can be held securely or advanced downwardly through the carcass. This type of arrangement provides a larger opening for inserting the pipe than that of a horizontal tensioner and thereby makes it easier to locate a vertically oriented pipe in the pipe opening. However, the X-cross arrangement is not the preferred confignration to be used with a horizontal tensioner because the two tracks of the fixed part cannot provide adequate support for a horizontally oriented pipe which can be as heavy as half a tonne per metre as there would be a gap defined between the two tracks of the fixed pan with nothing to support a lowermost part of the pipe.

Accordingly, the object of the present invention is to provide a versatile tensioner which can be mounted in both horizontal and vertical orientations but which mitigates or obviates the above mentioned drawbacks.

Summary of the Invention

According to a first aspect of the invention there is provided a tensioner for handling elongate components, the tensioner comprising:-a carcass having a longitudinal axis; at least four tracks mounted within the carcass for gripping and moving an elongate component; the tracks extending longitudinally and being spaced apart circumferentially relative to the longitudinal axis within the carcass to form a central opening for receiving and accommodating the elongate component to be gripped; and the carcass comprising at least three circumferential segments; wherein at least two segments are movably mounted on the carcass to move between:-a closed position in which said movable segment is conjoined with the other segments to form the central opening; and an open position in which said movable segment is moved away from the other segments to form an access opening for inserting the elongate component into the central opening; each movable segment accommodating at least one track; wherein said movable segments are movable between the open and closed positions together or independently from each other; and wherein an access opening formed when two segments are opened is greater than an access opening formed when one segment is opened.

S

Thus, when only one movable segment is opened, although the access opening formed by one opened segment is narrower than when both segments are opened, at least three tracks remain in place to define the central opening thereby providing more support for the elongate component being received in the central opening than when both movable segments are opened. This mode is particularly suitable for a horizontally arranged tensioner where the elongate support components are inserted into the central opening downwardly from a location above the tensioner, i.e. where locating the elongate component in the central opening is not a major issue, but where, due to gravity acting transversely to the longitudinal axis of the carcass, the elongate component has to be adequately supported from below once the elongate component has been received in the central opening. On the other hand, when two segments are opened, although the at least two tracks remaining in place to define the central opening provide less support for the elongate component, a wider access opening is formed than when only one segment is opened thereby facilitating insertion of an elongate component into the central opening. This mode is particularly suitable for a vertically arranged tensioner where the elongate support components are inserted into the central opening laterally from a location beside the tensioner, i.e. where ease of access into the central opening is important, whereas gravity presents fewer problems because the elongate component is supported vertically solely relying on friction forces acting between the tracks and the elongate component. Thus the present invention provides a versatile tensioner which can be employed as a horizontal tensioner or as a vertical tensioner, as dictated by the circumstances on a particular site.

Advantageously, the carcass comprises a mounting means adapted to mount the carcass on one or more support structures in either a horizontal orientation, or a vertical orientation, as required.

Further advantageously, the mounting means is adapted to mount the carcass in either a horizontal or a vertical orientation in a first mode, such that only one of the movable segments can be opened, or in a second mode, such that each movable segments can be opened. It will be appreciated that the support structure need not be the same structure, and indeed, one type of structure is preferably used for mounting the carcass horizontally, e.g. a substantially horizontal support frame, and another type of structure is used for mounting the carcass vertically, e.g. a tower.

It will be appreciated that for the purposes of the present description, the term "substantially horizontal" in relation to the carcass denotes the orientation in which the longitudinal axis of carcass is substantially parallel to or inclined at an acute angle to a base surface, to which gravity is acting perpendicular. It will also be appreciated that for the purposes of the present description, the term "substantially vertical" in relation to the carcass denotes the orientation in which the longitudinal axis of carcass is substantially normal to the base surface or inclined at an acute angle to a line normal to that surface.

In a preferred configuration, the tracks define a cross, preferably, a substantially right angled cross, when viewed along the longitudinal axis of the carcass, wherein a first pair of tracks define a first crossbeam and the second pair of tracks define the second cross-beam of the cross.

Preferably, the mounting means is adapted to mount the carcass on a first support structure in the horizontal orientation so that one cross-beam defined by one pair of tracks is substantially horizontal, i.e. substantially parallel to or inclined at an acute angle to the base surface to which gravity is perpendicular, and the other cross-beam defined by the second pair of tracks is vertical, i.e. substantially perpendicular to the first cross-beam, as in a "+" symbol or in a St. George's cross, in relation to the base surface when viewed along the longitudinal axis of the carcass. This orientation will be referred to hereinafter as a St. George's cross mode for brevity.

Preferably, in the St George's cross mode, one of the movable segments of the carcass forms an uppermost segment of the carcass, whereas the remaining segments form side and base segments of the carcass. In this configuration, in order for an elongate component to be inserted into the tensioner, the uppermost segment is opened, the elongate component is lifted above the carcass in a horizontal orientation and then lowered through the access opening formed by opening the uppermost segment into the central opening in the carcass defined by three tracks which remain in place. In this manner, necessary and sufficient support is provided for the elongate component during and after insertion, as a lowermost track of the carcass provides support for a bottom portion of the e'ongate component and the other two tracks provide additional support at the sides of the elongate component Preferably, the mounting means is adapted to mount the carcass on a second support structure in the vertica' orientation so that the at least two movaNe segments form a pair of front segments, i.e. ones facing away from the second support structure when the carcass is mounted on the second support structure whereas the remaining one more segments form a rear part of the carcass, i.e. one facing the second support structure when the carcass is mounted on second support structure and wherein the cross-beams formed by the tracks are substantially diagonaL when viewed along the longitudinal axis of the carcass, to an intended direction of lateral insertion of an elongate component into the central opening when the movable segments are opened, i.e. the cross-beams are oriented as in an X-cross or in a St Andrews cross in relation to the direction of movement of the elongate component when being inserted laterally relative to the longitudinal axis of the carcass into the central opening. This orientation will be referred to hereinafter as a St. Andrew's cross mode for brevity. In the St Andrew's cross mode, in order for an elongate component to be inserted into the tensioner, the two movable segments are opened, the elongate component is advanced laterally relative to the longitudinal axis of the carcass through the access opening formed by opening the two movable segments into the central opening in the carcass defined by the at least two tracks remaining in the rear part of the carcass. In this manner, wider access opening is provided in the St. Andrew's cross mode than in St. George's cross mode thereby facilitating the lateral manoeuvring of the elongate component into the central opening.

Preferably, the segments making up the carcass, in closed positions, define the entire circumference of the carcass.

B

Optionally, the mounting means can be adapted to mount the carcass on the first support structure horizontally in the St Andrew's cross mode so that the cross-beams of the cross defined by the tracks are diagonal to the base surface when viewed along the longitudinal axis of the carcass. Further optionally, the mounting means can be adapted to mount the carcass on the second support structure vertically in the St. George's cross mode so that one cross-beam defined by one pair of tracks is substantially parallel to the intended direction of lateral insertion of an elongate component into the central opening when viewed along the longitudinal axis of the carcass, and the other cross-beam defined by the second pair of tracks is substantially perpendicular to the said direction.

Preferably, the mounting means is provided externally on the carcass. Preferably, the mounting means comprises a first fastening arrangement adapted to mount the carcass to a support structure in the St. George's cross mode and a second fastening arrangement adapted to mount the carcass to a support structure (same as or different from the first mentioned support structure) in the St Andrew's cross mode, the first and second fastening arrangements being circumferentially spaced from each other around the carcass. Thus, in order to change the modes of the carcass between St George's and St Andrew's (at least on the same support structure) the carcass needs to be turned about the longitudinal axis through a portion of a revolution until the relevant first or second fastening arrangement is appropriately aligned with the support structure to enable the carcass to be mounted in the other orientation. In order to change the mounting of the carcass between first and second support structures and between the St. George's and St Andrew's cross modes, and vice versa, the carcass needs to be dismounted from one structure, turned either horizontally or vertically, as appropriate, and turned, if required, about the longitudinal axis of the carcass through a portion of a revolution until the relevant first or second fastening arrangement is appropriately aligned with the other support structure to enable the carcass to be mounted thereon in the required orientation.

Preferably, each fastening arrangement includes at least a pair of fastening positions circumferentially spaced from each other on the carcass. Each fastening position, however, can include one or more fastening points spaced longitudinally along the carcass.

In one configuration, in the first fastening arrangement, at least one fastening position is provided on one of the at least two movable segments and at least one fastening position is provided on one of the remaining segments adjacent the other of the two segments so that when the carcass is fastened to the support structure only one movable segment can be opened to form an access opening whereas the other segments are fixed to the support structure. In this manner, it is ensured that only one segment of the carcass can be opened in the St. George's cross mode and the other segments are not moved unnecessarily so that necessary and sufficient support is provided for the elongate component by the at least three tracks which remain in place during and after insertion. On the other hand, in the second fastening arrangement, both fastening positions are preferably provided on the carcass such the at least two movable segments remain movable so that when the carcass is fastened to the support structure both movable segments can be opened to form an access opening in the St Andrew's cross mode.

It will be appreciated that in some embodiments the fastening positions can be shared between the first and second fastening arrangements.

In a preferred arrangement, the carcass comprises at least four segments, each segment accommodating at least one track and the four segments being connected so that at least three and preferably all the four segments are movable with respect to the other segments between open and closed positions. That is, for example, in the horizontal orientation, in a St George's cross mode, any one of the four segments can form the uppermost segment Likewise, in the vertical orientation in a St. Andrew's cross mode, any two adjacent segments can be fixed to the support structure so that the remaining two segments can be opened. Preferably, each of the four segments occupies and/or forms a quarter of the circumference of the carcass.

In an alternative arrangement, each of the at least two movable segments may occupy and/or form approximately a quarter of the circumference of the carcass and one segment may occupy and/or form approximately half of the circumference of the carcass.

Preferably, each segment making up the carcass is coupled to adjacent segments of the carcass via a respective coupling arrangement Preferably, the coupling arrangements are provided on or adjacent the exterior of the carcass. Preferably) one or more of the coupling arrangements are configured to provide a pivot axis to allow the respective segments connected by the coupling arrangement to pivot relative to each other and/or a locking arrangement to prevent the respective segments connected by the coupling arrangement from moving relative to each othen Further preferably, one or more of the coupling arrangements are configured to allow the respective segments connected by the coupling arrangement to be disconnected. Preferably, one or more of the coupling arrangements of the segments of the carcass are configured to couple pivotally the respective movable segment to at least one adjacent segment. In one arrangement, one or more of the coupling arrangements of the movable segments of the carcass comprise respective hinges having respective pivot axes. The hinge of a coupling arrangement may be of a type having a pivot pin or rod defining the pivot axis. Preferably, the pivot axis of the or each hinge extends substantially parallel to the longitudinal axis of the carcass. The or each hinge is preferably cooperatively arranged with the locking arrangement for locking the respective adjacent segments thereby preventing said segments from pivoting relative to each other. Further preferably, the or each hinge is demountable so that at least the movable segments can be disconnected from adjacent segments to be opened.

In one arrangement, the or each hinge preferably includes a first pin which functions as a pivot pin for pivoting the respective segments relative to each other.

The locking arrangement may comprise a second pin laterally spaced apart from the first pin, the second pin functioning as a locking pin for preventing the relative 1l rotation of the respective segments relative to each other. Preferably, each locking pin is movable between locking and unlocking positions, preferably, by an actuator, such as for example, a hydraulic or pneumatic cylinder. In one arrangement, the or each hinge comprises first and second cooperating leaf parts connected by the first pin, a first leaf part being attached one segment and the second leaf part being attached to the respective adjacent segment. Preferably, the leaf parts in a hinge are arranged to align with each other when the respective segments are closed.

Preferably, the locking means, e.g. a second locking pin, is arranged to lock the two leaf parts of a hinge together thereby preventing the leaf parts from pivoting relative to each other. Preferably, the first pin is removably mounted so that the segments held together by the pin can be disconnected altogether. The first pin is preferably movable between connected and disconnected positions, preferably, by an actuator, such as for example, a hydraulic or pneumatic cylinder.

The tracks are preferably endless tracks, preferably, but not limited thereto caterpillar tracks.

Additionally, the invention provides a marine vessel comprising an apparatus in accordance with the first aspect of the invention.

The elongate components are preferably those installed during pipeline installation offshore and may include pipelines, SURF products, power cables, but it will be appreciated that the invention is not limited thereto.

The segments are preferably movable by actuating means, such as, for example, one or more respective hydraulic or pneumatic cylinders.

According to a second aspect of the invention there is provided a method of handling elongate components, the method comprising the steps of:- (a) providing a tensioner for handling elongate components, the tensioner comprising:-a carcass having a longitudinal axis; at least four tracks mounted within the carcass for gripping and moving an elongate component; the tracks extending longitudinally and being spaced apart circumferentially relative to the longitudinal axis within the carcass to form a central opening for receiving and accommodating the elongate component to be gripped; and the carcass comprising at least three circumferential segments; wherein at least two segments are movably mounted on the carcass to move between:-a closed position in which said movable segment is conjoined with the other segments to form the central opening; and an open position in which said movable segment is moved away from the other segments to form an access opening for inserting the elongate component into the central opening; each movable segment accommodating at least one track; wherein said movable segments are movable between the open and closed positions together or independently from each other; and wherein an access opening formed when two segments are opened is greater than an access opening formed when one segment is opened; b) opening one or more movable segments to form an access opening; cJ placing an elongate component laterally relative to the longitudinal axis of the carcass into the central opening; and dJ closing the or each opened segment The method preferably comprises the step of mounting the carcass on one or more support structures in either a horizontal orientation, or a vertical orientation, as required.

Further preferably, the method comprises the step of mounting the carcass in either a horizontal or a vertical orientation in a first mode, such that only one of the movable segments can be opened, or in a second mode, such that each movable segment can be opened. The method preferably includes using one type of structure for mounting the carcass horizontally, e.g. a substantially horizontal support frame, and using another type of structure for mounting the carcass vertically, e.g. a tower.

Preferably the method comprises arranging the tracks to define a cross, preferably, a substantially right angled cross, when viewed along the longitudinal axis of the carcass, wherein a first pair of tracks define a first crossbeam and the second pair of tracks define the second cross-beam of the cross.

Preferably, the method further comprises mounting the carcass on a first support structure in the horizontal orientation in a St. George's cross mode. Preferably, the step of mounting the carcass in the St. George's cross mode comprising orienting the carcass such that one of the movable segments of the carcass forms an uppermost segment of the carcass whereas the remaining segments form side and base segments of the carcass. Preferably, the method further includes the step of opening the uppermost segment, lifting the elongate component above the carcass in a horizontal orientation and then lowering the elongate component through the access opening formed by opening the uppermost segment into the central opening in the carcass defined by three tracks which remain in place. The method further comprises the step of supporting the elongate component during and after insertion by a lowermost track at a bottom portion the elongate component and by the other two tracks at the sides of the elongate component.

Preferably, the method comprises the step of mounting the carcass on a second support structure in the vertical orientation a St. Andrew's cross mode. Preferably, the method includes the step of opening two movable segments and advancing the elongate component laterally relative to the longitudinal axis of the carcass through the access opening formed by opening the two movable segments into the central opening in the carcass defined by the at least two tracks remaining in a rear, fixed part of the carcass.

Optionally, the method includes the step of mounting the carcass on the first support structure horizontally in the St Andrew's cross mode so that the cross-beams defined by the tracks are diagonal to the base surface when viewed along the longitudinal axis of the carcass. Further optionally, the method includes the step of mounting the carcass on the second support structure vertically in the St. George's cross mode so that one cross-beam defined by one pair of tracks is substantially parallel to the intended direction of lateral insertion of an elongate component into the central opening when viewed along the longitudinal axis of the carcass, and the other cross-beam defined by the second pair of tracks is substantially perpendicular to the said direction.

Preferably, the method includes the step of providing a mounting means externally on the carcass, the mounting means comprising a first fastening arrangement adapted to mount the carcass to a support structure in the St George's cross mode and a second fastening arrangement adapted to mount the carcass to a support structure (same as or different from the first mentioned support structure) in the St Andrew's cross mode, wherein the method includes spacing the first and second fastening arrangements circumferentially from each other around the carcass.

Preferably, in order to change the modes of the carcass between St George's and St. Andrew's (at least on the on the same support structure) the method includes the steps of turning the carcass about the longitudinal axis through a portion of a revolution until the second fastening arrangement is appropriately aligned with the support structure and then mounting the carcass in the other orientation. The method preferably further comprises the step of reinstalling the carcass between first and second support structures and between the St. George's and St. Andrew's cross modes, and vice versa, wherein the method includes the step of dismounting the carcass from one structure; turning the carcass either horizontally or vertically) as appropriate, and turning the carcass, if required, about the longitudinal axis of the carcass through a portion of a revolution until the relevant first or second fastening arrangement is appropriately aligned with the other support structure; and mounting the carcass on the support structure in the required orientation.

Preferably, the method includes providing each fastening arrangement with least a pair of fastening positions circumferentially spaced from each other on the carcass.

In one variation, the method comprises the step of coupling each segment making up the carcass to adjacent segments of the carcass via a respective coupling arrangement. Preferably, the method comprises providing the coupling arrangements on or adjacent the exterior of the carcass. Preferably) the method comprises allowing the segments to pivot relative to each other; or preventing the respective segments connected by the coupling arrangement from moving relative to each other. Further preferably, the method includes allowing the respective segments connected by the coupling arrangement to be disconnected. In one arrangement, the method comprise the step of coupling the movable segments of the carcass via respective hinges having respective pivot axes.

In one arrangement, the method comprises the step of providing the or each hinge with a first pin which functions as a pivot pin for pivoting the respective segments relative to each other. The method may comprise the step of providing the locking arrangement with a second pin laterally spaced apart from the first pin, the second pin functioning as a locking pin for preventing the relative rotation of the respective segments relative to each other. Preferably, the method comprises the step of moving the or each locking pin between locking and unlocking positions, preferably, by an actuator, such as for example, a hydraulic or pneumatic cylinder. In one arrangement, the method comprises the step of providing the or each hinge with first and second cooperating leaf parts connected by the first pin, and attaching a first leaf part to one segment and the second leaf part to the respective adjacent segment. Preferably, method includes the step of aligning the leaf parts in a hinge with each other when the respective segments are put together and, preferably, locking the two leaf parts of a hinge together thereby preventing the leaf parts from pivoting relative to each other. The method may include the step of removing the first pin and disconnecting the respective segments altogether.

Additionally, the method includes the step of installing the apparatus in accordance with the first aspect of the invention on a marine vessel.

All essential, preferred or optional features of the first aspect of the present invention can be provided in conjunction with the second aspect of the present invention and vice versa where appropriate.

Detailed Description of the Invention

Embodiments of the present invention will now be described, by way of examp'e only, with reference to the accompanying drawings in which: Figures 1 and 2 are respective side and end views of a tensioner in accordance with the invention installed horizontally in a fist mode (St. George's cross mode]) the tensioner being dosed; Figures 3 and 4 show the tensioner of Figures 1 and 2, respectiv&y, in an open state; Figures 5 and 6 are respective front and plan views of a tensioner in accordance with the invention installed vertically in a second mode (St Andrew's cross mode], the tensioner being closed; Figures 7 and S show the tensioner of Figures 5 and 6, respectively, in an open state; Figure 9 is an enlarged view of detail X in Figure 8 showing a hinge arrangement for pivoting segments of a carcass of the tensioner; Figure 10 is an enlarged view of detail Yin Figure 9; Figure 11 is a perspective view of the hinge of Figures 9 and 10; and Figure 12 is a perspective view of a Thckable hinge provided between two pivotable segments of the carcass of the tensioner.

Referring initially to Figures 1 to 8, a tensioner for handling elongate components of the invention is indicated generally by reference numeral 1. The tensioner 1 comprises a carcass 3 having a longitudinal axis 5 and at least four endless caterpillar tracks 7 mounted within the carcass 36 for gripping and moving an elongate component 9 (typically a product installed during offshore pipeline installation, such as pipeline itself or other auxiliary line including SURF products, power cables etc.]. The tracks 7 extend longitudinally (i.e. substantially parallel to the longitudinal axis 5] within the carcass 3 and are spaced apart circumferentially around the longitudinal axis 5 within the carcass 3 to form a central opening 11 for receiving and accommodating the elongate component 9 to be gripped by the tracks 7.

The carcass 3 comprises four circumferential segments 41, 42) 43, 44, each segment 41, 42, 43, 44 accommodating a track 7. The segments 41, 42, 43, 44, when put together) define the entire circumference of the carcass 3 and each of the four segments 41,42)43)44 occupies and/or forms a quarter of the circumference of the carcass 3. The segments 41) 42, 43, 44 are movably mounted on the carcass 3 to move between a dosed position (Figures 1, 2, 5 and 6] in which the segments 41,42) 43,44 are conjoined with the other segments to form the central opening 11 and an open position (Figures 3, 4, 7 and 8) in which one or two segments, are moved away from the other segments to form an access opening 15, 17 for inserting the elongate component 9 into the central opening 11, as will be described in more detail below.

Although in the presently described embodiments all the four segments 41, 42, 43, 44 can move between open and closed positions, the tensioner 1 is arranged that only three segments 41,42 and 43 are opened and closed when the tensioner one is in use, as will be understood from the description below. However, the tensioner 1 can readily be modified so that any one or two adjacent segments of the four segments 41, 42, 43, 44 can be opened or closed. In the presently described embodiment, in one mode of operation of the tensioner 1, (shown in Figures ito 4] one movable segment 41 is movable between the open and closed positions. In another mode of operation (shown in Figures 5 to 8) of the tensioner 1, two movable segments 42, 43 are movable between the open and closed positions. As can be appreciated from Figures 3 and 7, an access opening 17 formed when two segments 42, 43 are opened is greater than an access 15 opening formed when one segment 41 is opened. The segments 41, 42, 43 are preferably movable by one or more respective hydraulic cylinders S3 (Figure 11).

Thus, when only one movable segment 41 is opened, as shown in Figures 3 and 4, although the access opening 15 formed by one opened segment 41 is narrower than when two segments 42, 43 are opened, at least three tracks 7 remain in place to define the central opening 11 thereby providing more support for the elongate component 9 being received in the central opening 11 than when two movable segments 42, 43 are opened. This mode is particularly advantageous in a horizontally arranged tensioner 1 as shown in Figures 1 to 4 where the elongate components 9 are inserted into the central opening 11 downwardly, as indicated by arrow B in Figure 3, from a location above the tensioner 1, i.e. where locating the elongate component 9 in the central opening 11 is not a major issue) but where) due to gravity acting transversely to the longitudinal axis 5 of the carcass 3, the elongate component 9 has to be adequately supported from below once the elongate component 9 has been received in the central opening 11. On the other hand, when two segments 42) 43 are opened, as shown in Figures 6 and 7, although the at least two tracks 7 remaining in place to define the central opening 11 provide less support for the elongate component 9, a wider access opening 17 is formed than the access opening 15 formed when only one segment 41 is opened thereby facilitating insertion of an elongate component 9 into the central opening 11. This mode is particularly advantageous in a vertically arranged tensioner 1 as shown in Figures 5 to 8 where the elongate components 9 are inserted into the central opening 11 laterally, as indicated by arrow D in Figure 7 from a location beside the tensioner 1) i.e. where ease of access into the central opening 11 is important, whereas gravity presents fewer problems because the elongate component 9 is supported vertically in the tensioner 1 solely relying on friction forces acting between the tracks 7 and the elongate component 9. Thus, the present invention provides a versatile tensioner 1 which can be employed as a horizontal tensioner or as a vertical tensioner) as dictated by particular circumstances.

The carcass 3 comprises a mounting means provided externally on the carcass 3 and adapted to mount the carcass 3 on one or more support structures in either a horizontal orientation, or a vertical orientation, as required, as will be described below.

As shown in Figures 1 and 5, the tracks 7 define a substantially right angled cross (not indicated by a reference numeral) when viewed along the longitudinal axis 5 of the carcass 3, as indicated by arrows A and C in Figures 2 and 6, respectively, wherein a first pair of tracks 7 define a first crossbeam 19 and the second pair of tracks 7 define the second cross-beam 21 of the cross.

As shown in Figures 1 to 4, the mounting means includes a first fastening arrangement to mount the carcass 3 on a horizontal support frame 25 in the horizontal orientation so that one cross-beam 21 defined by one pair of tracks 7 is substantially horizontal and the other cross-beam 19 defined by the second pair of tracks 7 is vertical, i.e. the cross looks like a "+" symbol or a St. George's cross in Figure 1, when viewed along the longitudinal axis 5 of the carcass 3. This orientation will be referred to hereinafter as a St. George's cross mode for brevity.

The first fastening arrangement provides a pair of diametrically opposite fastening positions 23 on segments 42 and 44 of the carcass 3. Each fastening position 23 includes at least a pair of fastening points 23a spaced longitudinally along the carcass 3, as shown in Figure 2. The segments 42 and 44 are fastened to the horizontal support frame 25 at the fastening points 23a. In the St. George's cross mode, the segment 41 of the carcass 3 forms an uppermost segment of the carcass 3, whereas the remaining segments 42, 43, 44 form side and base segments of the carcass 3. In this configuration, in order for an elongate component 9 to be inserted into the tensioner 1, the uppermost segment 41 is opened as shown in Figure 3, the elongate component 9 is lifted above the carcass 3 in a horizontal orientation and then lowered through the access opening 15 formed by opening the uppermost segment 41 into the central opening 11 in the carcass 3 defined by three tracks 7 which remain in place. In this manner, necessary and sufficient support is provided for the elongate component 9 during and after insertion, as a lowermost track 7 of the carcass 3 provides support for a bottom portion 27 of the elongate component 9 and the other two tracks 7 provide additional support at the sides of the elongate component 9. In the first fastening arrangement, it is ensured that only one segment 41 of the carcass 3 can be opened in the St George's cross mode and the other segments 42, 43, 44 are not moved unnecessarily so that necessary and sufficient support is provided for the elongate component 9 by the three tracks 7 remaining in place. It will be appreciated however, that the tensioner 1 can be readily adapted so that any one of the four segments 41,42,43,44 can form the uppermost segment As shown in Figures 5 to 8, the mounting means includes a second fastening arrangement to mount the carcass 3 on a vertica' tower 29 in the vertical orientation so that the movable segments 42, 43 form a pair of front segments, i.e. ones facing away from the tower 29 when the carcass 3 is mounted on the tower 29 whereas the remaining segments 41 and 44 form a rear part of the carcass 3, i.e. one facing the tower 29 when the carcass is mounted on the tower 29. As shown in Figure 5, the cross-beams 19, 21 formed by the tracks 7 are substantially diagonal, when viewed a'ong the longitudinth axis 5 of the carcass 3 (a'ong arrow C in Figure 6), to an intended direction of lateral insertion of an &ongate component 9 into the central opening 11 when the movaNe segments 42, 43 are opened (as indicated by arrow D in Figure 7). In other words, the cross-beams 19, 21 are oriented as in an X-cross or in a St Andrews cross in relation to the direction of movement of the elongate component 9 when being inserted laterally relative to the longitudinal axis S of the carcass 3 into the central opening 11, i.e. along the arrow D. This orientation will be referred to hereinafter as a St. Andrew's cross mode for brevity.

The second fastening arrangement includes a pair of diametrically opposite fastening positions 33 on segments 41 and 44 of the carcass 3. Each fastening position 33 includes at least two fastening points 33a spaced longitudinally along the carcass 3 as shown in Figures 6 and 8. The fastening positions 33 are provided on the carcass 3 such the two adjacent segments 42, 43 remain movable so that when the carcass 3 is fastened to the tower 29 both movable segments 42, 43 can be opened to form the access opening 17 in the St. Andrew's cross mode while the other two segments 41, 44 are fastened to the tower 29. In the St. Andrew's cross mode, in order for an elongate component 9 to be inserted into the tensioner 1, the two movaNe segments 42, 43 are opened as shown in Figure 7, the elongate component 9 is advanced laterally relative to the longitudinal axis S of the carcass 3, i.e. along the arrow Din Figure 7, through the access opening 17 formed by opening the two movable segments 42, 43 into the central opening 11 in the carcass 3, the central opening 11 being defined by the at least two tracks 7 remaining in the rear part of the carcass 7. In this manner, wider access opening 17 is provided in the St. Andrew's cross mode than the access opening 15 provided in St. George's cross mode thereby facilitating the latera' manoeuvring of the elongate component 9 into the central opening 11 in a vertically oriented tensioner 1. It wifi be appreciated however that the tensioner 1 can be readily adapted so that any two adjacent segments of the four segments 41,42, 43, 44 can be fixed to the tower 29 so that the remaining two segments can be opened.

Although not shown in the drawings, the second fastening arrangement may be configured to be suitable to mount the carcass 3 on the horizontal support frame 27 horizontally in the St. Andrew's cross mode so that the cross-beams 19, 21 of the cross defined by the tracks 7 are diagonal to a base surface 31 when viewed along the longitudinth axis 5 of the carcass in Figure 1. Similarly, the first fastening arrangement may be adapted to mount the carcass 3 on the tower 29 vertically in the St. George's cross mode so that one cross-beam 19 or 21 defined by one pair of tracks 7 is substantially parallel to the intended direction (indicated by the arrow D in Figure 7) of lateral insertion of an elongate component 9 into the central opening 11 when viewed along the longitudinal axis S of the carcass 3, and the other cross-beam 19 or 21 defined by the second pair of tracks 7 is substantially perpendicular to the said direction.

As is evident from the drawings, fastening positions 23 of the first fastening arrangement are circumferentially spaced from corresponding fastening positions 33 of the second fastening arrangement around the carcass 3 by an angle a (approximately 45° in the presently described embodiment). Thus, in order to change the modes of the carcass 3 between St. George's and St. Andrew's cross modes (whether on the same support structure, e.g. on one of the horizontal support frame 25 and the tower 29 or between different structures, such as between the horizontal support frame 25 and the tower 29), the carcass 3 needs to be turned about the longitudinal axis 5 through a portion of a revolution (approximately 45° in the presently described embodiment] until the relevant first or second fastening arrangement, i.e. the fastening positions 23 or 33 are appropriately aligned with horizontal support frame 25 or the tower 29 to enable the carcass 3 to be mounted in the other orientation. In order to change the mounting of the carcass 3 both between the horizontal support frame 25 and the tower 29 and between the St George's and St Andrew's cross modes, and vice versa, the carcass 3 needs to be dismounted from one structure, turned either horizontally or vertically, as appropriate, and turned, if required, about the longitudinal axis 5 of the carcass 3 through a portion of a revolution (approximately 450 in the presently described embodiment) until the fastening positions 23 or 33 are appropriately aligned with the other support structure to enable the carcass 3 to be mounted thereon in the required orientation.

Referring now to Figures 1, 3, 5, 7 and 9 to 12, each segment 41, 42, 43, 44 making up the carcass 3 is coupled to the adjacent segments via respective hinge arrangements provided on or adjacent the exterior of the carcass 3 and indicated generally by reference numeral 35 in the drawings. The hinge arrangements 35 include respective pivot pins 37 which provide pivot axes to allow at least the segments 41,42 and 43 to pivot between opened and dosed positions. Each hinge arrangement 35 comprises first and second cooperating leaf parts 39, 45 connected by the pivot pin 37, a first leaf part 39 being attached to one segment 41, 42, 43, 44 and the second leaf part 45 being attached to an adjacent segment. The leaf parts 39, 45 are arranged to align with each other when the respective segments 41, 42, 43, 44 are closed. Each hinge arrangement 35 includes a locking arrangement to prevent the respective segments 41, 42, 43, 44 connected by the hinge arrangement 35 from pivoting relative to each other. The locking arrangement comprises a second pin 47 laterally inwardly spaced apart from the pivot pin 37. The second pin 47 functions as a locking pin to lock the two leaf parts 39, 45 to preventing the leaf parts 39, 45 from pivoting relative to each other thereby preventing rotation of the segments 41, 42, 43, 44 relative to each other. The locking pin 47 is movable between locking and unlocking positions by a hydraulic cylinder 49 (Figure 12). At least between segments 41 and 42; and 42 and 43 the pivot pin 37 is removably mounted so that the respective segments 41, 42, 43 can be disconnected altogether so that the segments 41, 42, 43 can be opened. The pivot pin 37 is movable between connected and disconnected positions by a hydraulic cylinder 51 [Figure 12).

Whilst specific embodiments of the present invention have been described above) it will be appreciated that modifications are possibk within the scope of the present invention.

Claims

CLAIMS: 1. A tensioner for handling elongate components, the tensioner comprising:-a carcass having a longitudinal axis; at least four tracks mounted within the carcass for gripping and moving an elongate component; the tracks extending longitudinally and being spaced apart circumferentially relative to the longitudinal axis within the carcass to form a central opening for receiving and accommodating the elongate component to be gripped; and the carcass comprising at least three circumferential segments; wherein at least two segments are movably mounted on the carcass to move between:-a closed position in which said movable segment is conjoined with the other segments to form the central opening; and an open position in which said movable segment is moved away from the other segments to form an access opening for inserting the elongate component into the central opening; each movable segment accommodating at least one track; wherein said movable segments are movable between the open and closed positions together or independently from each other; and wherein an access opening formed when two segments are opened is greater than an access opening formed when one segment is opened.
2. A tensioner as claimed in claim 1, wherein the carcass comprises a mounting means adapted to mount the carcass on one or more support structures in either a horizontal orientation, or a vertical orientation, as required.
3. A tensioner as claimed in claim 2, wherein the mounting means is adapted to mount the carcass in either a horizontal or a vertical orientation in a first mode) such that only one of the movable segments can be opened, or in a second mode, such that each movable segments can be opened.
4. A tensioner as claimed in claim 3, wherein the tracks define a cross, wherein a first pair of tracks define a first crossbeam and the second pair of tracks define the second cross-beam of the cross.
5. A tensioner as claimed in claim 4, wherein the mounting means is adapted to mount the carcass on a first support structure in the horizontal orientation so that one cross-beam defined by one pair of tracks is substantially horizontal, i.e. substantially parallel to or inclined at an acute angle to the base surface to which gravity is perpendicular, and the other cross-beam defined by the second pair of tracks is vertical, i.e. substantially perpendicular to the first cross-beam, as in a symbol or in a St. George's cross, in relation to the base surface when viewed along the longitudinal axis of the carcass, this orientation being also termed a "St George's cross mode", wherein in the St George's cross mode, one of the movable segments of the carcass forms an uppermost segment of the carcass, whereas the remaining segments form side and base segments of the carcass.
6. A tensioner as claimed in claim 4 or claim 5, wherein the mounting means is adapted to mount the carcass on a second support structure in the vertical orientation so that the at least two movable segments form a pair of front segments, i.e. ones facing away from the second support structure when the carcass is mounted on the second support structure whereas the remaining one more segments form a rear part of the carcass, i.e. one facing the second support structure when the carcass is mounted on second support structure and wherein the cross-beams formed by the tracks are substantially diagonal, when viewed along the longitudinal axis of the carcass, to an intended direction of lateral insertion of an elongate component into the central opening when the movable segments are opened, i.e. the cross-beams are oriented as in an X-cross or in a St. Andrews cross in relation to the direction of movement of the elongate component when being inserted laterally relative to the longitudinal axis of the carcass into the central opening, this orientation being also termed as a "St. Andrew's cross mode".
7. A tensioner as claimed in claim S or claim 6, wherein the mounting means is adapted to mount the carcass on the first support structure horizontally in a St. Andrew's cross mode so that the cross-beams of the cross defined by the tracks are diagonal to the base surface when viewed a'ong the ongitudinal axis of the carcass.
8. A tensioner as daimed in any one of claims S to 7, wherein the mounting means is adapted to mount the carcass on the second support structure vertically in a St. George's cross mode so that one cross-beam defined by one pair of tracks is substantially parallel to the intended direction of kteral insertion of an elongate component into the central opening when viewed a'ong the longitudinal axis of the carcass, and the other cross-beam defined by the second pair of tracks is substantially perpendicular to the said direction.
9. A tensioner as daimed in any one of claims S to 8, wherein the mounting means comprises a first fastening arrangement adapted to mount the carcass to a support structure in a St George's cross mode and a second fastening arrangement adapted to mount the carcass to a support structure, same as or different from the first mentioned support structure, in a St. Andrew's cross mode, the first and second fastening arrangements being circumferentially spaced from each other around the carcass.
10. A tensioner as claimed in claim 9, wherein each fastening arrangement indudes at least a pair of fastening positions circumferentially spaced from each other on the carcass.
11. A tensioner as chimed in claim 10, wherein each fastening position includes one or more fastening points spaced longitudinally along the carcass.
12. A tensioner as claimed in claim 10 or claim 11, wherein in the first fastening arrangement, at least one fastening position is provided on one of the at least two movable segments and at least one fastening position is provided on one of the remaining segments adjacent the other of the two segments so that when the carcass is fastened to the support structure only one movable segment can be opened to form an access opening whereas the other segments are fixed to the support structure.
13. A tensioner as claimed in any one of claims 10 to 12) wherein in the second fastening arrangement) both fastening positions are provided on the carcass such the at least two movable segments remain movable so that when the carcass is fastened to the support structure both movalMe segments can be opened to form an access opening in a St Andrew's cross mode.
14. A tensioner as claimed in claim 12 and claim 13, wherein the fastening positions are shared between the first and second fastening arrangements.
15. A tensioner as claimed in any one of claims 5 to 14, wherein the carcass comprises at least four segments, each segment accommodating at least one track and the four segments being connected so that at least three or all the four segments are movable with respect to the other segments between open and closed positions, so that, in the horizontal orientation, in a St. Georges cross mode, any one of the four segments can form the uppermost segment, and, in the vertical orientation in a St Andrew's cross mode, any two adjacent segments can be fixed to the support structure so that the remaining two segments can be opened.
16. A tensioner as claimed in claim 15, wherein each of the four segments occupies and/or forms a quarter of the circumference of the carcass.
17. A tensioner as claimed in any one of chims S to 14, wherein each of the at least two movalMe segments occupies and/or forms approximately a quarter of the circumference of the carcass and one further segment occupies and/or forms approximately half of the circumference of the carcass.
18. A tensioner as claimed in any one of claims S to 17, wherein each segment making up the carcass is coupled to adjacent segments of the carcass via a respective coupling arrangement
19. A tensioner as claimed in claim 18, wherein the coupling arrangements are provided on or adjacent the exterior of the carcass.
20. A tensioner as claimed in claims 18 or claim 19, wherein one or more of the coupling arrangements are configured to allow the respective segments connected by the coupling arrangement to be disconnected.
21. A tensioner as daimed in any one of claims 18 to 20, wherein one or more of the coupling arrangements of the segments of the carcass are configured to coup'e pivotally the respective movaNe segment to at least one adjacent segment
22. A tensioner as claimed in any one of claims 18 to 21, wherein one or more of the coupling arrangements are configured to provide a pivot axis to allow the respective segments connected by the coupling arrangement to pivot relative to each other and/or a locking arrangement to prevent the respective segments connected by the coupling arrangement from moving relative to each other.
23. A tensioner as claimed in any one of claims 18 to 22, wherein one or more of the coupling arrangements of the movable segments of the carcass comprise respective hinges having respective pivot axes.
24. A tensioner as claimed in claim 23, wherein the hinge of a coupling arrangement is of a type having a pivot pin or rod defining the pivot axis.
25. A tensioner as claimed in claim 23 or claim 24, wherein the pivot axis of the or each hinge extends substantially parallel to the longitudinal axis of the carcass.
26. A tensioner as claimed in any one of claims 23 to 25, wherein the or each hinge is demountable so that at least the movable segments can be disconnected from adjacent segments to be opened.
27. A tensioner as claimed in claim 22 and in any one of claims 23 to 26, wherein the or each hinge is cooperatively arranged with the locking arrangement for locking the respective adjacent segments thereby preventing said segments from pivoting relative to each other.
28. A tensioner as claimed in claim 27, wherein the or each hinge includes a first pin which functions as a pivot pin for pivoting the respective segments relative to each other, and the locking arrangement comprises a second pin laterally spaced apart from the first pin, the second pin functioning as a locking pin for preventing the relative rotation of the respective segments relative to each other wherein each locking pin is movable between locking and unlocking positions.
29. A tensioner as claimed in claim 28, wherein each locking pin is movable between locking and unlocking positions by an actuator.
30. A tensioner as claimed in claim 29, wherein the actuator comprises a hydraulic or a pneumatic cylinder.
31. A tensioner as claimed in any one of claims 28 to 30, wherein the or each hinge comprises first and second cooperating leaf parts connected by the first pin, a first leaf part being attached one segment and the second leaf part being attached to the respective adjacent segment, wherein the leaf parts in a hinge are arranged to align with each other when the respective segments are closed, wherein the locking means is arranged to lock the two leaf parts of a hinge together thereby preventing the leaf parts from pivoting relative to each other.
32. A tensioner as claimed in any one of claims 28 to 31, wherein the first pin is removably mounted so that the segments held together by the pin can be disconnected altogether.
33. A tensioner as claimed in claim 32, wherein the first pin is movable between connected and disconnected positions by an actuator.
34. A tensioner as claimed in claim 33, wherein the actuator comprises a hydraulic or a pneumatic cylinder.
35. A tensioner as claimed in any preceding claim, wherein the tracks are endless tracks.
36. A tensioner as claimed in claim 36, wherein the endless tracks comprise caterpillar tracks.
37. A tensioner as claimed in any preceding claim, wherein the elongate components comprise those installed during pipeline installation offshore and include pipelines, SURF products and power cables.
38. A tensioner as claimed in any preceding claim, wherein the segments are movable by actuating means.
39. A tensioner as claimed in claim 38, wherein the actuating means comprises one or more respective hydraulic or pneumatic cylinders.
40. A tensioner as claimed in any preceding claim, wherein the segments making up the carcass, in closed positions, define the entire circumference of the carcass.
41. A tensioner as claimed in claim 2 in combination with any other preceding claim, wherein the mounting means is provided externally on the carcass.
42. A tensioner as claimed in claim 4 in combination with any other preceding claim, wherein the cross is a substantially right angled cross, when viewed along the longitudinal axis of the carcass.
43. A marine vessel comprising an apparatus in accordance with any one of claims 1 to 42.
44. A method of handling elongate components) the method comprising the steps of:- (a) providing a tensioner for handling elongate components, the tensioner comprising:-a carcass having a longitudinal axis; at least four tracks mounted within the carcass for gripping and moving an elongate component; the tracks extending longitudinally and being spaced apart circumferentially relative to the longitudinal axis within the carcass to form a central opening for receiving and accommodating the elongate component to be gripped; and the carcass comprising at least three circumferential segments; wherein at least two segments are movably mounted on the carcass to move between:-a closed position in which said movable segment is conjoined with the other segments to form the central opening; and an open position in which said movable segment is moved away from the other segments to form an access opening for inserting the elongate component into the central opening; each movable segment accommodating at least one track; wherein said movable segments are movable between the open and closed positions together or independently from each other; and wherein an access opening formed when two segments are opened is greater than an access opening formed when one segment is opened; b) opening one or more movable segments to form an access opening; C] placing an elongate component laterally relative to the longitudinal axis of the carcass into the central opening; and d] closing the or each opened segment
45. A method as claimed in claim 44, wherein the method comprises the step of mounting the carcass on one or more support structures in either a horizontal orientation, or a vertical orientation, as required.
46. A method as claimed in claim 45, wherein the method comprises the step of mounting the carcass in either a horizontal or a vertical orientation in a first mode) such that only one of the movable segments can be opened, or in a second mode) such that each movable segment can be opened.
47. A method as claimed in claim 46, wherein the method includes using one type of structure for mounting the carcass horizontally) e.g. a substantially horizontal support frame, and using another type of structure for mounting the carcass vertically, e.g. a tower.
48. A method as claimed in claim 47, wherein the first structure comprises a substantially horizontal support frame and the second structure comprises a tower.
49. A method as claimed in claim 47 or claim 48) wherein the method comprises arranging the tracks to define a cross) wherein a first pair of tracks define a first crossbeam and the second pair of tracks define the second cross-beam of the cross.
50. A method as claimed in claim 49, wherein the method comprises mounting the carcass on a first support structure in the horizontal orientation in a St. George's cross mode comprising orienting the carcass such that one of the movable segments of the carcass forms an uppermost segment of the carcass whereas the remaining segments form side and base segments of the carcass.
51. A method as claimed in claim SO, wherein the method includes the seep of opening the uppermost segment, lifting the elongate component above the carcass in a horizontal orientation and then lowering the elongate component through the access opening formed by opening the uppermost segment into the central opening in the carcass defined by three tracks which remain in place.
52. A method as claimed in claim 51, wherein the method further comprises the step of supporting the e'ongate component during and after insertion by a lowermost track at a bottom portion the e'ongate component and by the other two tracks at the sides of the elongate component
53. A method as claimed in any one of claims 49 to 52, wherein the method comprises the step of mounting the carcass on a second support structure in the vertical orientation in a St. Andrew's cross mode.
54. A method as claimed in claim 53, wherein the method includes the step of opening two movable segments and advancing the elongate component laterally relative to the Thngitudinal axis of the carcass through the access opening formed by opening the two movable segments into the central opening in the carcass defined by the at least two tracks remaining in a rear, fixed part of the carcass.
55. A method as claimed in any one of claims 49 to 54, wherein the method includes the step of mounting the carcass on the first support structure horizontally in the St Andrew's cross mode so that the cross-beams defined by the tracks are diagonal to the base surface when viewed a'ong the longitudinal axis of the carcass.
56. A method as claimed in any one of claims 49 to 55, wherein the method includes the step of mounting the carcass on the second support structure vertically in the St George's cross mode so that one cross-beam defined by one pair of tracks is substantiafly paraflel to the intended direction of lateral insertion of an ethngate component into the centra' opening when viewed along the longitudinal axis of the carcass, and the other cross-beam defined by the second pair of tracks is substantially perpendicular to the said direction.
57. A method as claimed in any one of claims 49 to 56, wherein the method includes providing a first fastening arrangement adapted to mount the carcass to a support structure in the St. George's cross mode and a second fastening arrangement adapted to mount the carcass to a support structure) same as or different from the first mentioned support structure, in the St. Andrew's cross mode) wherein the method includes spacing the first and second fastening arrangements circumferentially from each other around the carcass.
58. A method as claimed in claim 57, wherein in order to change the modes of the carcass between St. George's and St. Andrew's [at least on the same support structure) the method includes the steps of turning the carcass about the longitudinal axis through a portion of a revolution until the second fastening arrangement is appropriately aligned with the support structure and then mounting the carcass in the other orientation.
59. A method as claimed in claim 58, wherein the method comprises the step of reinstalling the carcass between first and second support structures and between the St George's and St Andrew's cross modes, and vice versa, wherein the method includes the step of dismounting the carcass from one structure; turning the carcass either horizontally or vertically, as appropriate, and turning the carcass) if required) about the longitudinal axis of the carcass through a portion of a revolution until the relevant first or second fastening arrangement is appropriately aligned with the other support structure; and mounting the carcass on the support structure in the required orientation.
60. A method as claimed in any one of claims 57 to 59, wherein the method includes providing each fastening arrangement with least a pair of fastening positions circumferentially spaced from each other on the carcass.
61. A method as claimed in any one of claims 50 to 60, wherein the method comprises the step of coupling each segment making up the carcass to adjacent segments of the carcass via a respective coupling arrangement
62. A method as claimed in claim 61, wherein the method comprises providing the coupling arrangements on or adjacent the exterior of the carcass.
63. A method as claimed in claim 61 or claim 62, wherein the method comprises allowing the segments to pivot rektive to each other; or preventing the respective segments connected by the coupllng arrangement from moving relative to each other.
64. A method as claimed in any one of claims 61 to 63, wherein the method indudes allowing the respective segments connected by the coupling arrangement to be disconnected.
65. A method as claimed in any one of claims 61 to 64, wherein the method indudes providing a pivot axis to allow the respective segments connected by the coupling arrangement to pivot relative to each other and/or a locking arrangement to prevent the respective segments connected by the coupling arrangement from moving relative to each other.
66. A method as claimed in any one of claims 61 to 65, wherein the method comprise the step of coupling the movable segments of the carcass via respective hinges having respective pivot axes.
67. A method as claimed in claim 66, wherein the method comprises the step of providing the or each hinge with a first pin which functions as a pivot pin for pivoting the respective segments relative to each other, and the step of providing the locking arrangement with a second pin laterally spaced apart from the first pin, the second pin functioning as a locking pin for preventing the relative rotation of the respective segments relative to each other.
68. A method as claimed in claim 67, wherein the method comprises the step of moving the or each locking pin between locking and unlocking positions.
69. A method as claimed in daim 67 or claim 68) wherein the method comprises the step of providing the or each hinge with first and second cooperating leaf parts connected by the first pin) and attaching a first eaf part to one segment and the second leaf part to the respective adjacent segment.
70. A method as claimed in claim 69) wherein the method includes the step of allgning the leaf parts in a hinge with each other when the respective segments are put together and locking the two eaf parts of a hinge together thereby preventing the leaf parts from pivoting relative to each other.
71. A method as claimed in any one of claims 67 to 70, wherein the method includes the step of removing the first pin and disconnecting the respective segments altogether.
72. A method as claimed in any one of claims 44 to 71, wherein the method includes the step of installing the apparatus in accordance with the first aspect of the invention on a marine vessel.
73. A method as claimed in any one of claims 44 to 72, wherein the method indudes the step of providing a mounting means externally on the carcass.