WO2015158367A1

WO2015158367A1 - A method for a subsea power cable installation procedure

Info

Publication number: WO2015158367A1
Application number: PCT/EP2014/057596
Authority: WO
Inventors: Niklas NORDÉ; Anders Hansson
Original assignee: ABB Technology AG
Current assignee: ABB Technology AG
Priority date: 2014-04-15
Filing date: 2014-04-15
Publication date: 2015-10-22
Anticipated expiration: 2016-10-15

Abstract

The present disclosure relates to a method of facilitating an offshore installation procedure of an armoured subsea power cable. The method comprises a) providing a first armoured subsea power cable, which first armoured subsea power cable has a first fixed collar attached to its armour at an end portion of the first armoured subsea power cable, wherein the first fixed collar is adapted to be attached to a first temporary cable attachment device, b) attaching a first temporary cable attachment device to the first fixed collar, which first temporary cable attachment device has connecting means for connecting the first temporary cable attachment device to a first armoured subsea power cable actuation device to enable axial movement control of the first armoured subsea power cable, c) performing a first installation-related operation with the first armoured subsea power cable while the first temporary cable attachment device is attached to the first fixed collar and the armoured subsea power cable actuation device is attached to the first temporary cable attachment device, and d) removing the first temporary cable attachment device from the first fixed collar after the first installation-related operation in step c) has been performed.

Description

A METHOD FOR A SUBSEA POWER CABLE INSTALLATION PROCEDURE

TECHNICAL FIELD

The present disclosure generally relates to armoured subsea power cables. In particular it relates to the offshore installation procedure of armoured subsea power cables.

BACKGROUND

Subsea power cables are often brought from land to offshore installations such as oil platforms and wind turbines, in order to enable power

transmission between land and sea. Such power cables are typically laid from land to the destination of installation by means of special cable laying marine vessels onto which the subsea power cable is loaded, for example onto a large cable carousel. The subsea power cable, which may have a weight of thousands of tons and a length of a number of kilometres, is successively rolled off the carousel and laid down on the ocean floor as the vessel travels towards the destination of installation.

In the process of bringing a subsea power cable offshore it may be necessary to control its axial movement in certain situations. When the cable laying marine vessel has reached the destination of installation, it may for example be desirable to test the subsea power cable e.g. the optical transmission and power transmission capabilities of the subsea power cable, in order to ensure proper functioning prior to finalizing the installation. While performing the test, it is desirable to maintain the subsea power cable in a fixed position, in particular to restrict axial movement of the subsea power cable which may occur due to pulling forces from the weight of the majority of the subsea power cable submerged in the sea.

A second situation which could involve the necessity of controlling the axial movement of a subsea power cable is in the event that two subsea power cables are joined offshore, for example when installing a very long subsea power cable which must be created from at least two joined subsea power cables.

For the situations mentioned above, tensioners arranged on the vessel, applying radial pressure to the subsea power cable may be used to fixate the subsea power cable. When installing a subsea power cable in deep-water i.e. depths of 500-1500 m, or ultra deep-water i.e. depths starting at 1500 m, it may however be necessary to apply very high radial forces to the subsea power cable by means of the tensioners. The high radial forces may result in that the subsea power cable becomes damaged. A third situation which involves control of axial movement of a subsea power cable is when a subsea power cable is pulled from or onto a marine vessel, or when it is pulled onto an offshore platform for attachment to a hang-off. For this purpose, a Chinese finger is typically pulled onto the subsea power cable end, which can be coupled to a winch to enable axial movement of the subsea power cable. Chinese fingers may however not be able to hold the weight of a subsea power cable for installations in deep-water and ultra deep-water. Moreover, the installation of a Chinese finger may be cumbersome, and takes a considerable amount of time, which translates into higher costs and an increased risk of weather changes. SUMMARY

An object of the present disclosure is thus to provide a method for subsea power cable installation-related operations offshore, which solves or at least mitigates the problems of existing solutions.

Hence, according to a first aspect of the present disclosure there is provided a method of facilitating an offshore installation procedure of an armoured subsea power cable, wherein the method comprises: a) providing a first armoured subsea power cable, which first armoured subsea power cable has a first fixed collar attached to its armour at an end portion of the first armoured subsea power cable, wherein the first fixed collar is adapted to be attached to a first temporary cable attachment device, b) attaching a first temporary cable attachment device to the first fixed collar, which first temporary cable attachment device has connecting means for connecting the first temporary cable attachment device to a first armoured subsea power cable actuation device to enable axial movement control of the first armoured subsea power cable, c) performing a first installation-related operation with the first

armoured subsea power cable while the first temporary cable attachment device is attached to the first fixed collar and the armoured subsea power cable actuation device is attached to the first temporary cable attachment device, and d) removing the first temporary cable attachment device from the first fixed collar after the first installation-related operation in step c) has been performed.

The term "installation procedure" is to be construed to include both the offshore cable laying procedure and the procedure of bringing an armoured subsea power cable onto an offshore structure and mechanically connecting it thereto.

By means of the first fixed collar, a multi-purpose device may be provided which enables a plurality of different kinds of installation-related operations involving control of translational motion of the armoured subsea power cable in the axial direction. The first fixed collar, and the thereto temporarily attached first temporary cable attachment device provides control of the axial movement of the armoured subsea power cable without applying radial forces of the same magnitude as tensioners would have to. Moreover, the first fixed collar which is attached to the armour of the armoured subsea power cable provides more robust gripping possibilities of the armoured subsea cable than for example Chinese fingers could. Furthermore, attachment of the first temporary attachment device may be made in a simpler and quicker manner than would be possible by means of Chinese fingers.

According to one embodiment step c) comprises attaching a second temporary cable attachment device to the first fixed collar prior to step d), which second temporary cable attachment device has connecting means for connecting the second temporary cable attachment device to a second armoured subsea power cable actuation device.

According to one embodiment the second temporary cable attachment device is maintained attached to the first fixed collar after step d), wherein the method comprises e) performing a second installation-related operation with the first armoured subsea power cable.

One embodiment comprises f) removing the second temporary cable attachment device from the first fixed collar after step e).

According to one embodiment the first temporary cable attachment device is a temporary lifting clamp.

According to one embodiment the second temporary cable attachment device is a pull-in head.

According to one embodiment the second installation-related operation involves pulling the first armoured subsea power cable by means of the second armoured subsea power cable actuation device.

According to one embodiment the first temporary cable attachment device is a pull-in head.

According to one embodiment the first installation-related operation involves pulling the first armoured subsea power cable by means of the first armoured subsea power cable actuation device.

According to one embodiment the first armoured subsea power cable has a second fixed collar attached to its armour, which second fixed collar is arranged closer to an end of the armoured subsea power cable than the first fixed collar, wherein the method comprises providing a second armoured subsea power cable, the second armoured subsea power cable having a corresponding first fixed collar and a corresponding second fixed collar. One embodiment comprises attaching a first temporary cable attachment device to the first fixed collar of the second armoured subsea power cable, which first temporary cable attachment device has connecting means for connecting the first temporary cable attachment device to a first armoured subsea power cable actuation device to enable axial movement control of the second armoured subsea power cable, wherein step c) comprises joining the first armoured subsea power cable with the second armoured subsea power cable while the first temporary cable attachment device is attached to the second armoured subsea power cable and the first armoured subsea power cable actuation device is attached to the first temporary cable attachment device of the second armoured subsea power cable.

According to one embodiment step c) involves fixating the first armoured subsea power cable and the second armoured subsea power cable by means of their respective first temporary cable attachment device to enable the joining. One embodiment comprises utilising each second fixed collar as an

attachment device for attaching a rigid joint member extending between the two second fixed collars, thereby forming a joint between the first armoured subsea power cable and the second armoured subsea power cable.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the element, apparatus, component, means, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, etc., unless explicitly stated otherwise. Moreover, any steps of the method presented herein need not necessarily be performed in the described order, unless explicitly stated so. BRIEF DESCRIPTION OF THE DRAWINGS

The specific embodiments of the inventive concept will now be described, by way of example, with reference to the accompanying drawings, in which:

Fig. l schematically depicts a side view of an armoured subsea power cable comprising an example of a first fixed collar;

Fig. 2 schematically depicts a side view of the armoured subsea power cable in Fig. l with a first temporary cable attachment device attached to the first fixed collar;

Figs 3a-3b depict side views of the armoured subsea power cable in Fig. ι with a pull-in head attached to the first fixed collar;

Fig. 4 schematically depicts a side view of two armoured subsea power cables jointed together by means of a rigid joint member;

Figs 5a and 5b depicts the armoured subsea cable in Fig. 1 attached to a hang- off of an offshore structure; and Fig. 6 is a flow chart showing a method of facilitating offshore installation- related operations of an armoured subsea power cable.

DETAILED DESCRIPTION

The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplifying

embodiments are shown. The inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description.

Fig. 1 depicts an example of a first armoured subsea power cable 1. The armoured subsea power cable 1 comprises 1 one or more power cores adapted to transmit electric power, an electrical insulation system enclosing the power core, one or more layers of armour i.e. armour wires, enclosing the one or more power cores, and an external sheath 3 enclosing the armour. The armoured subsea power cable 1 may further comprise one or more optical cables. The first armoured subsea power cable 1 comprises a first fixed collar 5 which is fixed to the first armoured subsea power cable 1 by means of the armour. The exemplified first fixed collar 5 comprises a central part 5a, a first lateral part sd and a second lateral part 5e. The first lateral part sd and the central part 5a define a first groove 5b, and the second lateral part 5e and the central part 5a define a second groove 5c. Each of the first groove 5b and the second groove 5c may extend around the entire periphery of the first fixed collar 5.

As an alternative to the first fixed collar 5 exemplified in Fig. 1, it could be designed such that it would comprise a respective shoulder instead of each groove, which shoulders would be extending around the periphery of the first fixed collar. Yet another variation would be to provide a plurality of recesses and/or protrusions in the peripheral direction along the external surface of the first fixed collar. In fact, any structure which allows proper attachment of a temporary cable attachment device, such as a clamp, to the first fixed collar and which enables the temporary cable attachment device to engage the first fixed collar to prevent relative axial movement between the first fixed collar and the temporary cable attachment device would be suitable.

It should be noted that the first fixed collar may not necessarily have to be made from three pieces as exemplified above. According to one variation the first fixed collar may for example consist of a single piece, i.e. a part which enables attachment of a temporary cable attachment device. Furthermore, according to some variations there may be fewer than two or more than two grooves/shoulders provided around the periphery of the first fixed collar.

As noted above, the first fixed collar is attached to the first armoured subsea power cable 1 by means of the armour of the first armoured subsea power cable 1. This may be achieved in a plurality of ways, with only a few examples provided in the following. The first armoured subsea power cable 1 has a portion where the external sheath 3 has been peeled off around the entire periphery to expose the armour wires. The armour wires are first cut along the periphery of the first armoured subsea power cable 1 at two locations where the external sheath has been peeled off. A section that is free from armour is thereby created. The cut armour wires may then be bent radially outwards.

According to a first example, the central part 5a may be placed around the section which is without armour, wherein the armour wires are bent radially inwards back towards their original position, towards the external surface of the first fixed collar. The armour wires may then be welded to the external surface of the central part 5a. The first lateral part sd and the second lateral part 5e may afterwards be arranged around the welded armour wires on a respective side of the central part 5a, attaching them to the central part 5a for example by means of corresponding threaded portions.

According to a second example, the central part 5a is placed in the section which is without the armour wires, wherein annular wedge members are placed on the cut armour wire at each end of the central part 5a. The armour wires are then bent backwards over a respective wedge member. The first lateral part sd and the second lateral part se define sleeves which may be placed around a respective wedge member such that an end portion of each of the first lateral part sd and the second lateral part se extend onto the central part 5a. The backwardly bent armour wires on each side of the central part 5a are thus clamped between a wedge member and a lateral part sd, se on each side of the central part 5a. The first lateral part sd and the second lateral part 5e may be attached to the central part 5a by means of corresponding threaded portions. The arrangement is thereby locked when subjected to axial forces.

The first fixed collar 5 may be mounted to the first armoured subsea power cable 1 prior to the first armoured subsea power cable 1 is loaded onto a marine vessel, e.g. onto a cable carousel. Alternatively, the first fixed collar 5 may be mounted to the armoured subsea power cable 1 when it has been loaded onto the marine vessel. The first fixed collar 5 is normally mounted at an end portion of the armoured subsea power cable 1, typically within 1-10 metres from the cable end. The first fixed collar 5 is made of a material which exhibits high mechanical strength such as metal, for example galvanised steel or aluminium. The material which the first fixed collar 5 is made of typically depends on the material used for the armour of the armoured subsea power cable. Normally, the armour and the first fixed collar 5 are made of the same material in order to facilitate the welding procedure.

Examples of the utilisation of the first fixed collar 5 will now be provided with reference to Figs 2-6. In particular methods of facilitating an offshore installation procedure of the armoured subsea power cable 1 will be described in more detail. In utilising the first fixed collar 5 for an offshore installation procedure, in a step a) the first armoured subsea power cable 1 having a first fixed collar 5 attached to its armour is provided, typically on a cable laying vessel.

The first temporary cable attachment device 7 is attached to the first fixed collar in a step b), as shown in Fig. 2. In particular, the temporary cable attachment device 7 may be mounted to the central part 5a of the first fixed collar 5.

The first temporary cable attachment device 7 may for example be attached to the first fixed collar 5 by means of human hand. The first temporary cable attachment device 7 may be attached to the first fixed collar 5 in a number of ways, depending on the particular implementation of both the first fixed collar and the first temporary cable attachment device 7. According to one example, the first temporary cable attachment device 7 may comprise two halves each having a central part interaction member arranged to engage the groove or alternatively a shoulder of the central part. The two halves are brought together over the first fixed collar 5 and assembled by means of fasteners such as nuts and bolts. Alternatively or additionally, the first temporary cable attachment device 7 could be provided with a threaded portion at its inner surface and the external surface of the first fixed collar could have a corresponding threaded portion, wherein assembly would include screwing the first temporary cable attachment member 7 onto the first fixed collar 5.

The first temporary cable attachment device 7 has connecting means 7a for connecting the first temporary cable attachment device 7 to a first armoured subsea power cable actuation device to enable axial movement control of the first armoured subsea power cable 1. Such a first armoured subsea power cable actuation device may for example be a winch, a crane or a strong point of the vessel. A strong point is a location on a vessel intended to be used when fixing heavy loads.

In the example in Fig. 2 the first temporary cable attachment device 7 is a temporary lifting clamp.

In the example in Fig. 2 in a step c) a first installation-related operation with the first armoured subsea power cable 1 is performed while the temporary lifting clamp is attached to the first fixed collar 5 and the armoured subsea power cable actuation device is attached to the temporary lifting clamp. In this example, the first installation-related operation may for example be testing of the power transmission capabilities of the power cores, and testing of signal transmission capabilities of the optical cables. Thus, while the armoured subsea power cable actuation device fixates the position of the first armoured subsea power cable 1, tests may be performed in a secure manner without damaging the first armoured subsea power cable 1. Another example of a first installation-related operation could be the joining of the first armoured subsea power cable 1 with a second armoured subsea power cable.

As shown in Fig. 3a, according to one variation which involves a temporary lifting clamp step c) instead comprises attaching a second temporary cable attachment device 9 to the first fixed collar 5 while the temporary lifting clamp is attached to the first fixed collar 5. The second temporary cable attachment device 9 has connecting means 9a for connecting the second temporary cable attachment device 9 to a second armoured subsea power cable actuation device to enable axial movement control of the first armoured subsea power cable 1. According to this example, the second temporary cable attachment device 9 may be a pull-in head.

As mentioned above, the pull-in head is attached to the first fixed collar 5 while the temporary lifting collar is attached to the first fixed collar 5. By restricting movement in the axial and radial directions of the first armoured subsea power cable 1 by means of the first armoured subsea power cable actuation device via the temporary lifting collar the pull-in head may be installed on the first fixed collar 5 in a simple manner.

The pull-in head may be assembled with the first fixed collar 5 in a plurality of ways. The internal surface of the pull-in head may for example have a threaded portion and the external surface of the first fixed collar may have a corresponding threaded portion. Alternatively, or additionally, the pull-in head may have a flange or shoulder which is adapted to engage one of the first groove 5b and the second groove 5c of the first fixed collar 5. To this end, the pull-in head or at least the flange or shoulder of the pull-in head, may comprise two halves that may be mounted together. Furthermore, in variations in which the first fixed collar has a shoulder instead of grooves, the pull-in head could comprise a corresponding groove for engagement with the shoulder.

According to the example depicted in Fig. 3b the first fixed collar 5 is attached to a first temporary cable attachment device 7' which is a pull-in head. The pull-in head may be mounted to the first fixed collar 5 for example in any of the manners described above. In this variation of the method, the pull-in head is attached to the first fixed collar 5 directly, without utilising a temporary lifting collar. In this case, in step c) the first installation-related operation involves pulling the first armoured subsea power cable 1 by means of the first armoured subsea power cable actuation device. The first armoured subsea power cable actuation device may for example be the crane or winch of the vessel when the first installation-related operation involves lowering of the first armoured subsea power cable 1 from the vessel or pulling it onto the vessel, or a pull-in wire of the offshore structure at which the first armoured subsea power cable ι is to be installed.

In a step d) the first temporary cable attachment device 7, 7' is removed from the first fixed collar 5 after the first installation-related operation in step c) has been performed, typically after the armoured subsea power cable actuation device has been detached from the temporary lifting clamp. In embodiments in which the pull-in head is attached to the first fixed collar 5 in addition to the temporary lifting collar, as shown in Fig. 3a, the pull-in head is maintained attached to the first fixed collar 5 after step d). In this case in a step e) a second installation-related operation with the armoured subsea power cable 1 is performed. The second installation-related operation involves pulling the first armoured subsea power cable 1 by means of the second armoured subsea power cable actuation device. The second armoured subsea power cable actuation device may for example be the crane or winch of the vessel when the second installation-related operation involves lowering of the first armoured subsea power cable 1 from the vessel or pulling it onto the vessel, or a pull-in wire of the offshore structure at which the armoured subsea power cable 1 is to be installed.

In a step f) the second temporary cable attachment device 9, i.e. the pull-in head, is removed from the first fixed collar after step e). Step f) is hence performed after the second installation-related operation, i.e. when the first armoured subsea power cable 1 has been pulled into a desired position.

Fig. 4 depicts a variation of the method which involves joining the first armoured subsea power cable 1 with a second armoured subsea power cable 2 identical to the first armoured subsea power cable 1. The first armoured subsea power cable 1 is joined with the second armoured subsea power cable 1 by means of a rigid joint member 11. Each of the first armoured subsea power cable 1 and the second armoured subsea power cable 2 has a respective first fixed collar 5, 5" and a respective second fixed collar 13, 13" each of which is identical to the first fixed collars 5. The second fixed collars 13 are arranged closer to the cable ends of the respective armoured subsea power cable relative to the corresponding first fixed collars 5, 5".

In this variation of the method, in step b) a respective first temporary cable attachment device 7, 7" is attached to each first fixed collar 5, 5". The first temporary cable attachment devices 7, 7" may be temporary lifting collars for enabling lifting and fixating the position of the first armoured subsea power cable 1 and of the second armoured subsea power cable 2. Each of the first temporary cable attachment devices 7, 7" are coupled to a respective first armoured subsea power cable actuation device, for example a crane or a winch arranged on a vessel. According to this variation the installation-related operation in step c) comprises fixating the first armoured subsea power cable 1 and the second armoured subsea power cable 2 by means of their respective first temporary cable attachment device 7, 7" to enable joining of the two armoured subsea power cables. Furthermore, in step c) the first installation-related operation involves attaching the rigid joint member 11 to each of the second fixed collars 13, 13" so that the rigid joint member 11 extends between the two second fixed collars 13, 13" which hence act as rigid joint member coupling devices enabling attachment of the rigid joint member 11 to the first armoured subsea power cable 1 and to the second armoured subsea power cable 2. The rigid joint member 11 has means for engaging the first groove and the second groove of the second fixed collars 13, 13", or corresponding grooves if for example the grooves of the second fixed collars are replaced with shoulders.

In step d) the first temporary cable attachment devices 7, 7" are removed from the first armoured subsea power cable 1 and the second armoured subsea power cable 2 when the joining has been performed. Figs 5a and 5b illustrate yet another example of use of the first fixed collar 5. According to this example the first installation-related operation in step c) involves securing the load of the first armoured subsea power cable 1 when mounting the first armoured subsea power cable 1 to a hang-off 15 at an offshore structure such as an offshore platform or wind turbine. The first fixed collar 5 is attached to a first temporary cable attachment device 7, in this example a temporary lifting collar, which in turn is attached to a first armoured subsea power cable actuation device, such as a wrench or crane of the offshore structure. The first fixed collar 5 also functions as attachment means for assembly with the hang-off 15. When the first fixed collar 5 has been assembled with the hang-off, thus securing the first armoured subsea power cable 1 to the offshore structure, the first temporary cable attachment device 7 is removed from the first fixed collar 5.

It should be noted that the above-describe load securing by means of the first fixed collar 5 and the assembly of the first fixed collar 5 with the hang-off 15, may be performed after the first fixed collar 5 has been used for allowing joining, testing and/or pulling of the first armoured subsea power cable 1, as previously described. The first fixed collar 5 hence functions as a multipurpose tool adapted to be utilised in a plurality of different situations involved in offshore cable installation at an offshore structure, for example for lifting, joining, pulling, securing and fastening of an armoured subsea power cable.

The inventive concept has mainly been described above with reference to a few examples. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended claims.

Claims

1. A method of facilitating an offshore installation procedure of an armoured subsea power cable, wherein the method comprises: a) providing a first armoured subsea power cable (1), which first

armoured subsea power cable (1) has a first fixed collar (5) attached to its armour at an end portion of the first armoured subsea power cable (1), wherein the first fixed collar (5) is adapted to be attached to a first temporary cable attachment device (7; 7'), b) attaching a first temporary cable attachment device (7; 7') to the first fixed collar, which first temporary cable attachment device (7; 7') has connecting means (7a) for connecting the first temporary cable attachment device (7; 7') to a first armoured subsea power cable actuation device to enable axial movement control of the first armoured subsea power cable (1), c) performing a first installation-related operation with the first

armoured subsea power cable (1) while the first temporary cable attachment device (7; 7') is attached to the first fixed collar (5) and the armoured subsea power cable actuation device is attached to the first temporary cable attachment device (7; 7'), and d) removing the first temporary cable attachment device (7, 7') from the first fixed collar (5) after the first installation-related operation in step c) has been performed.

2. The method as claimed in claim 1, wherein step c) comprises attaching a second temporary cable attachment device (9) to the first fixed collar (5) prior to step d), which second temporary cable attachment device (9) has connecting means (9a) for connecting the second temporary cable

attachment device (9) to a second armoured subsea power cable actuation device.

3. The method as claimed in claim 2, wherein the second temporary cable attachment device (9) is maintained attached to the first fixed collar (5) after step d), wherein the method comprises e) performing a second installation- related operation with the first armoured subsea power cable (1).

4. The method as claimed in claim 3, comprising f) removing the second temporary cable attachment device (9) from the first fixed collar (5) after step e).

5. The method as claimed in any of the preceding claims, wherein the first temporary cable attachment device (7) is a temporary lifting clamp.

6. The method as claimed in any of claims 2-5, wherein the second temporary cable attachment device (9) is a pull-in head.

7. The method as claimed in claim 6, wherein the second installation-related operation involves pulling the first armoured subsea power cable (1) by means of the second armoured subsea power cable actuation device.

8. The method as claimed in claim 1, wherein the first temporary cable attachment device (7') is a pull-in head.

9. The method as claimed in claim 8, wherein the first installation-related operation involves pulling the first armoured subsea power cable (1) by means of the first armoured subsea power cable actuation device.

10. The method as claimed 1, wherein the first armoured subsea power cable (1) has a second fixed collar (13) attached to its armour, which second fixed collar (13) is arranged closer to an end of the armoured subsea power cable than the first fixed collar (5), wherein the method comprises providing a second armoured subsea power cable (2), the second armoured subsea power cable (2) having a corresponding first fixed collar (5") and a corresponding second fixed collar (13").

11. The method as claimed in claim 10, comprising attaching a first temporary cable attachment device (7") to the first fixed collar (5") of the second armoured subsea power cable (2), which first temporary cable attachment device (7") has connecting means for connecting the first temporary cable attachment device (7") to a first armoured subsea power cable actuation device to enable axial movement control of the second armoured subsea power cable (2), wherein step c) comprises joining the first armoured subsea power cable (1) with the second armoured subsea power cable (2) while the first temporary cable attachment device (7") is attached to the second armoured subsea power cable (2) and the first armoured subsea power cable actuation device is attached to the first temporary cable attachment device (7") of the second armoured subsea power cable (2).

12. The method as claimed in claim 11, wherein step c) involves fixating the first armoured subsea power cable (1) and the second armoured subsea power cable (2) by means of their respective first temporary cable attachment device (7, 7") to enable the joining.

13. The method as claimed in claim 12, comprising utilising each second fixed collar (13) as an attachment device for attaching a rigid joint member (11) extending between the two second fixed collars (13, 13"), thereby forming a joint between the first armoured subsea power cable (1) and the second armoured subsea power cable (2).