Abstract
A test rig for a subsea cable product 1 includes a sheave module 22 including a sheave 10 for holding a subsea cable product 1 that is to be tested and a load module 30 for applying tension to the subsea cable product 1 on the sheave 10 in order to perform a tensile bending test. An elongate base 28 is provided for placement between the sheave module 22 and the load module 30, the elongate base 28 providing a horizontal beam that can hold a compressive load generated by tension in the subsea cable product 1 during the tensile bending test. The sheave 10 can be reversibly divided into parts for transportation in one or more container(s) of smaller cross-section than the diameter of the sheave 10. The elongate base 28 can be reversibly divided into parts for transportation in one or more container(s) of smaller length than the whole length of the elongate base 28. In this way the test rig is made portable, for example as a kit of parts, and may be used in methods involving transport to different locations along with assembly/disassembly of the test rig.
Claims
1. A test rig for a subsea cable product, the test rig comprising: a sheave module including a sheave for holding a subsea cable product that is to be tested; a load module for applying tension to the subsea cable product on the sheave in order to perform a tensile bending test; and an elongate base for placement between the sheave module and the load module, the elongate base being configured to act as a horizontal beam that can hold a compressive load generated by tension in the subsea cable product during the tensile bending test; wherein the sheave can be reversibly divided into parts for transportation in one or more container(s) of smaller cross-section than the diameter of the sheave; and wherein the elongate base can be reversibly divided into parts for transportation in one or more container(s) of smaller length than the whole length of the elongate base.
2. The test rig as claimed in claim 1, being configured to fully reversibly disassemble into parts each sized to fit into an intermodal shipping container.
3. The test rig as claimed in claim 1, wherein the divided parts of the sheave and the elongate base each fit into a cross-section defined by a rectangle of 2.3 m by 2.5 m or less.
4. The test rig as claimed in claim 1, wherein the sheave comprises a wheel that can be disassembled into segments and/or sectors in order to fit into the container(s) of smaller cross-section than the diameter of the sheave.
5. The test rig as claimed in claim 1, wherein the sheave comprises an inner sheave wheel of smaller diameter and a sheave wheel extension that can combine with the inner sheave wheel to provide a wheel of larger diameter.
6. The test rig as claimed in claim 5, wherein the inner sheave wheel divides into segments, whilst the sheave wheel extension is formed by multiple wheel extension sectors, each wheel extension sector having a partial circumference of the wheel of larger diameter.
7. The test rig as claimed in claim 1, wherein the elongate base comprises an upper load bearing structure formed by a number of upper base sections and a lower load bearing structure formed by a number of lower base sections.
8. The test rig as claimed in claim 7, wherein fixings between the upper base sections and the lower base sections are the same for each of the sections in order to allow the sections to be joined in any order as well as permitting a different number of sections to be included to vary the overall length of the assembled test rig by changing the length of the elongate base.
9. The test rig as claimed in claim 1, wherein the test rig is arranged so that, when said test rig is in use, the location of the subsea cable product is aligned with a shear centre of the elongate base in order to ensure that the elongate base is loaded in compression without any bending or twisting load.
10. The test rig as claimed in claim 1, wherein the elongate base is structurally symmetrical in cross-section and the test rig is arranged so that, when it is in use, the location of the subsea cable product is aligned with a halfway point on the height of the elongate base.
11. The test rig as claimed in claim 1, comprising a block mounted on the load module for pulling a winch cable attached to the subsea cable product that is being tested, wherein the block comprises two block wheels mounted spaced apart from one another so that the distance between the outer edges of the two block wheels is larger than 2.5 m.
12. The test rig as claimed in claim 1, wherein the test rig as a whole has a maximum assembled length of more than 80 m.
13. The test rig as claimed in claim 1, wherein the compressive load bearing capacity of the elongate base is 100 ton or more.
14. A kit of parts that, that when assembled, provides the test rig of claim 1.
15. A method of providing testing for subsea cable product, the method comprising: employing a test rig as claimed in claim 1 to apply tension to a subsea cable product during a test, wherein the method further comprises either one of or both of: receiving the test rig as a kit of parts transported in intermodal containers, and assembling the test rig before performing the test; and/or after performing the test, disassembling the test rig and loading into intermodal shipping containers.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] In the following description certain embodiments of this invention will be further explained by way of examples shown in the drawings:
[0039] FIG. 1 shows a layered structure of a typical subsea power cable;
[0040] FIG. 2 is a schematic diagram showing the forces applied during a tensile bending test of a subsea cable product;
[0041] FIG. 3 shows a known test rig for carrying out the tensile bending test;
[0042] FIG. 4 is a plan view of a portable test rig;
[0043] FIG. 5 shows the portable test rig of FIG. 4 in a side elevation view;
[0044] FIG. 6 is a plan view of a sheave module of the portable test rig with wheel extensions removed;
[0045] FIG. 7 includes a plan view and a side elevation view of a sheave module in a dissembled configuration;
[0046] FIG. 8 shows disassembled side parts of a centre wheel for the sheave wheel section;
[0047] FIG. 9 includes orthogonal views of a wheel extension part for the sheave wheel section;
[0048] FIG. 10 shows side and plan views for a brace connector;
[0049] FIG. 11 shows a plan view and side elevation view of a lower base section;
[0050] FIG. 12 shows a plan view and side elevation view of an upper base section;
[0051] FIG. 13 shows a variation of a hydraulic cylinder module in a plan view and a side elevation; and
[0052] FIG. 14 shows a plan view and a side elevation view of another hydraulic cylinder module.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
[0053] Often, it is desirable to transmit power via subsea power cables extending over long distances or to allow for transfer of fluids, data and/or power via subsea umbilical cables. Such subsea cable products (i.e. including cables and umbilicals) are subject to significant stresses during installation and whilst in use and therefore they need to be tested in various ways, both as a part of the design process and also to satisfy qualification requirements. This test regime includes a tensile bending test, where the subsea cable product is bent to a required diameter and subject to tensile forces via tension at each end either side of the bend.
[0054] As shown in FIG. 1, a subsea cable product 1 in the form of an electric power cable 1 comprises an elongated electrical conductor 2, typically copper or aluminium, surrounded by a plurality of insulating/protective layers. These layers are positioned successively and coaxially around the conductor 2, and in this example they include: a first semiconducting layer 3 referred to as inner semiconducting layer or ISC, an electrically insulating layer 4 referenced as INS, a second semiconducting layer 5 referred to as outer semiconducting layer or OCS. Single phase cables comprise one conductor 2 as shown. Multiphase cables will have multiple conductors 2 and therefore a more complex shape. Umbilical cables can include conductors 2 as well as flow paths for fluids and/or added conductors for communication of data.
[0055] The insulation layer 4 is located between the semiconducting layers 3, 5. Normally, the conductor 2 has a generally circular cross section. The surrounding insulation 4 and semi-conducting layers 3, 5 usually have a cross-section with a similar shape to the conductor 2, i.e. normally being generally circular. The first semiconducting layer 3, the insulation layer 4 and the second semiconducting layer 5 are often referred to as an insulation system, or an insulation sheath. These power cables 1 are typically produced by triple extrusion placing the insulation sheath 3, 4, 5 directly onto the conductor 2. Added layers may also be present such as layers for adding mechanical strength and for protecting the cable against physical damage as well as chemical damage, e.g. corrosion. In this case there is an earthing and/or protective metal shield 6 and an external protective cladding 7.
[0056] In this document the term cable, or cable product 1, is used to denote any cable to be tested by the test rig. This encompasses power cables as well as umbilical cables and any other form of subsea cable, such as telecommunications cables. The multilayer construction of these cable products 1, including the more complex forms for multiphase power cables or umbilical cables, create challenges in relation to carrying tension in bending. To be sure that the subsea cable product 1 will perform as expected during installation and use then they undergo a tensile bending test as depicted in FIG. 2 and FIG. 3. The tensile bending test demonstrates the cable product's ability to carry tension in combination with deformation in bending over the laying wheel of a cable-laying vessel during installation. The test cable 1 is attached to a winch cable 8 and laid halfway around a large sheave 10, which can be of similar size to the laying wheel (e.g. 6 m or 10 m diameter). A block 12, which may be a part of a winch device, is attached to the cable ends via the winch cable 8 and pulling eyes 14. Via the block 12 and a hydraulic cylinder 16 a tensile force is applied. This may be done while the sample length of the subsea cable product 1 is moved back and forth over the sheave 10, e.g. three times back and forth.
[0057] FIG. 3 shows a real-world example of such a test rig, with the cable length and diameter of the sheave 10 shown to scale. As well as the main parts shown in FIG. 2 the test rig of FIG. 3 also includes wagons 18 that are used to support the cable 1 and the pulling eyes 14 along with winch drums 20 of a winch system that also includes the winch cable 8 and the block 12. The winch system can be used to pre-tension the test rig as well as for aiding movement of the sample cable 1 back and forth around the sheave 10, although this is not essential since the same effect can be achieved via an actuated block 12 or actuated sheave 10, for example via a hydraulic motor that can turn the block 12 or sheave 10.
[0058] The load/tensile force during the tensile bending test can vary depending on the subsea cable product 1 as well as the intended installation location. The cable weight and the water depth at the installation location both have a significant impact on the size of the tension forces that might be experienced during installation.
[0059] It is known for subsea cable production facilities to have a dedicated tensile test rig on site of a similar form to the test rig of FIG. 3. In that case cable products 1 requiring testing are transported only a short distance from the factory to the test rig. However, many production facilities do not have their own test rig and it is not efficient to build a test rig for each production site, especially considering that it may only need to be used from one to three times per year. Therefore, it is commonplace in the prior art to transport sample cables 1 from the production facility to another site with a suitable test rig. This results in significant added cost for transport as well as time delays in completing qualification tests for the cable products 1. In addition, with this type of prior art testing routine there are challenges in transport of test samples due to a need to move a large length of cable (often 80 m) with restrictions on bending radius and a need for careful handling to avoid any risk of damage to the test sample.
[0060] These issues are avoided by the use of a portable test rig, which may for example be as shown in FIGS. 4 to 14. When it is assembled portable test rig can perform similar testing operations to the known fixed test rigs, i.e. tensile bend testing in accordance with the relevant standards such as Cigr Electra 171 for power cables, or similar standards for umbilical cables. The test rig is also able to be disassembled to provide a transportation configuration in which all of the parts can be packed into a set of standardised intermodal shipping containers (ISO container), e.g. containers as defined by International Organization for Standardization (ISO) standard 668:2020. These containers are typically 8 feet (2.44 m) wide, either 20 or 40 feet (6.10 or 12.19 m) long and 8 feet 6 inches (2.59 m) high. The portable test rig can be disassembled into parts that will all fit into a 40-foot intermodal container, with the option for transport of smaller parts in 20-foot containers. With this portable test rig, it can be possible for multiple production facilities to be served by a single test rig, which can increase efficiency and avoid delays, as well as avoiding the challenges of transportation of sample cables.
[0061] As seen in FIGS. 4 and 5 the assembled portable test rig includes a sheave module 22 that comprises an inner sheave wheel 24 encircled by a sheave wheel extension 26. The inner sheave wheel 24, optionally with the sheave wheel extension 26, acts as the sheave 10 of the mechanism shown in FIG. 2. In this example the sheave wheel extension 26 creates a wheel with a diameter of 10 m and the inner sheave wheel 24 has a diameter of 6 m. The sheave module 22 is connected to one end of an elongate base 28 that takes the form of a horizontal beam structure. The other end of the base 28 is connected to a load module 30, which in this case is a hydraulic cylinder module with a hydraulic cylinder 16 for applying tension to the cable 1 being tested. This is done via a block 12 as in the mechanism of FIG. 2.
[0062] Both of FIGS. 4 and 5 omit a centre part of the elongate base 28 to allow the end parts to be enlarged. It will be appreciated that the centre part of the base 28 will have a similar form to the remainder of the base 28. In FIG. 5, which shows the test rig of FIG. 4 in a side elevation, more detail of the base 28 can be seen, in particular the upper base sections 32 and lower base sections 34. The elongate base 28 divides into several pieces lengthwise allowing for transport in a standard length shipping container. Each piece has an upper base section 32, as shown in FIG. 10, and a lower base section 34, which is seen in more detail in FIG. 11. The pieces of the upper base section 32 and lower base section 34 are offset from one another in the longitudinal direction of the base 28, so that the joins between adjacent lower base sections 34 are at different points along the longitudinal direction than the joins between adjacent upper base sections 32.
[0063] In the omitted centre part of FIGS. 4 and 5 there will also be a connection point between the subsea cable product 1 that is being tested and a winch cable 8 that fits around the block 12. These connection points may take any suitable form, e.g. as used in prior art fixed test rigs.
[0064] The sheave 10 and block 12 are located at a midpoint of the height of the base 28 so that when the test rig is in use the vertical location of the cable 1 is aligned with the vertical location of the shear centre of the cross-section for the base 28. This may for example be halfway up the height of the base 28 if the upper base section 32 and lower base section 34 have the same stiffness in compression. As the elongate base 28 extends along a line between the centre of the sheave 10 and the centre of the block 12 then the two parts of the cable 1 at either side will be symmetrically located. There will be compressive forces in the base 28 that are produced by loading the cable 1 in tension. Having a symmetrical form for the base 28, along with correct vertical placement of the cable 1 at the same height as the shear centre of the base, means that these compressive forces will act in alignment with the shear centre, minimising the risk of twisting, bending or buckling of the base 28 when the test rig is in use.
[0065] The elongate base 28 is joined to the sheave module 22 via a pair of brace connectors 36, as seen in FIG. 5. A lower part of the sheave module 22 has a similar form to the lower base section 34. The upper base section 32 cannot easily extend into the sheave module 22 as it would obstruct the sheave 10 and cable 1, so the brace connectors 36, one at each transverse side of the base 28, provide a transition including transfer of loads from the upper base section 32 to the lower part of the sheave module 22. The brace connectors 36 include an offset between an upper rail part, which joins to the upper base section 32, and a lower mounting part, which mounts to the lower base section 34 and/or to the base of the sheave module 22. This offset, which is along the longitudinal direction of the elongate base 28, is similar to the offset between the upper base section 32 and lower base section 34.
[0066] The portable test rig of FIGS. 4 and 5 is able to be divided into parts for transport and these different parts are now discussed in further detail with reference to FIGS. 6 to 14. The structural parts can be made of steel, for example.
[0067] As noted above the sheave 10 is formed by an inner sheave wheel 24 that can be surrounded by extension parts to form a sheave wheel extension 26, which takes the form of a larger sheave wheel. FIG. 6 shows a sheave module 22 detached from the base 28, with the sheave wheel extension 26 removed so that the sheave 10 is provided only by the inner sheave wheel 24. The length of the sheave module 22 is selected so that it fits into the desired transport container, in this case a 40-foot ISO container. The length may for example be 11.8 m to fit into the internal space of the container with suitable clearance. The inner sheave wheel 24 typically has a 6 m diameter and this is designed for disassembly in order that it fits into the width/height of the transport container, e.g. based on a cross section of no more than 2.2 m by 2.5 m to allow for clearance within a standard ISO container.
[0068] FIG. 7 shows a plan view and a side view of the sheave module 22 after further disassembly, with only a centre segment 38 of the inner sheave wheel 24 left attached, which reduces the width sufficiently that it can be easily placed into the container. FIG. 8 shows a side segment 54 of the inner sheave wheel 24. Two such side segments 54 are included and when fitted to the centre segment 38 the form the complete inner sheave wheel 24. As seen in FIGS. 7 and 8 the segments 38, 54 each include chord plates 40, which are mounting plates spanning a chord along the line where the side segment 54 is joined to and detached from the centre segment 38. The assembled sheave module 22 of FIG. 6 can be obtained by connecting two side segments 54 as in FIG. 8 with one centre segment 38 on a base part as in FIG. 7. There is a chord plate 40 on each of the segments 38, 54 and they can be joined together by abutting the chord plates 40 and joining them with suitable fixings, e.g. bolts.
[0069] Also visible in FIG. 7, in the side view, are adjustable feet 44 along with lift pockets 60. The adjustable feet 44 are provided at various points along the bottom of the test rig, such as at the sheave module 22 and at the load module 30 (as seen in FIG. 13. They can be vertically adjusted, e.g. via a threaded connection, to provide a suitable support on the ground beneath the test rig even if the ground is not totally flat. The lift pockets 60 are located at the centre of the module 22 and they allow for lifting and transportation via a forklift.
[0070] FIG. 9 shows a wheel extension sector 50, which is one of the extension parts used to form the sheave wheel extension 26. In this example the sheave wheel extension 26 is provided by an assembly of nine such wheel extension sectors 50 with the inner sheave wheel 24. The extension sectors 50 include extension spokes 52 and a section of the circumference of the wheel. They may be joined to the inner sheave wheel 24 by fixings at the ends of the extension spokes, e.g. via bolts, and they may join to each other using fixings at the abutting parts of the circumference sections. The wheel extension sectors 50 are sized to fit within the height and length of an ISO container. Thus, in the radial direction of the wheel extension sectors 50 the maximum dimension may be less than the height of the container, e.g. less than 2.5 m. In this example the radial dimension is about 2.3 m. The largest dimension of this part is the length along the tangent to the circumference section, and this can be placed lengthwise in the container, including in a 20-foot container if required. That length may be less than 4 m and in this case it is about 3.6 m.
[0071] The elongate base 28 is made up of the upper base sections 32 and the lower base sections 34. As seen in FIGS. 4 and 5 these join at one end to the sheave module 22 via brace connectors 36. At the other end they join to the load module 30. As noted above the brace connectors 36 include an offset, in this case where the upper base sections 32 are spaced further from the sheave 10 than the lower base sections 34. The load module 30 has a corresponding offset allowing for the upper base section 32 to overlap with the load module 30 whilst the lower base section 34 does not overlap.
[0072] FIGS. 10, 11 and 12 show a brace connector 36, a lower base section 34, and an upper base section 32. In this example there are six lower base sections 34, each of a length selected to fit into the transport container, which is a length of 11.8 m in this case. There are two brace connectors 36 and six pairs of upper base sections 32, i.e. a total of twelve upper base sections 32. The upper base sections 32 have a length of 11.8 m.
[0073] The sheave module 22 and the load module 30 also have a generally similar length (in this case 11.8 m and 10.5 m respectively) and so the total length of the assembled test rig is over 90 m.
[0074] The lower base sections 34, shown in FIG. 11, include two side beams 56 and cross braces 58 connecting the beams 56. The side beams 56 provide the main structural strength of the lower base sections 34, which together with the upper base sections 32 must carry a significant compressive force during the tensile bending test. These side beams 56 may for example be I-beams or box beams. The lower base sections 34 also include lift pockets 60 allowing for transport via a forklift.
[0075] The upper base sections 32, as shown in FIG. 12, are in this case provided in pairs with one on each of the left and right of the base for each piece of the length. The upper base sections 32 comprise a rail 46 supported on posts 48. The rail 46 may take the form of an I-beam or a box beam similar to the two side beams 56 of the lower base sections 34. The posts 48 can be connected at their lower ends to fixing points on the two side beams 56 of the lower base section 34. Thus, for each lower base section 34 there will be a left upper base section 32 and a right upper base section 32, and the base 28 as a whole may include four beams (the two side beams 56 and the two rails 46) that together hold the compressive load that is generated during the tensile bending test. The four beams can be symmetrically arranged thus giving the base 28 a shear centre at the middle of the cross-section. The sheave 10 and block 12 should then be aligned with this shear centre so that the compressive force due to tension in the cable 1 passes through the shear centre.
[0076] The block 12 is fixed to the load module 30. FIGS. 13 and 14 show two different variations for the load module 30. Both of them include a hydraulic cylinder 16 for displacement of the block 12 and for generating a tensile force in the cable 1 via the winch cable 8 that is wrapped around the wheel(s) of the block 12. The block 12 is movable along the longitudinal direction of the test right (i.e. toward and away from the sheave 10) via the hydraulic cylinder 16 and the displacement of the block 12 can be up to 2.5 m. The hydraulic cylinder 16 is configured to produce forces as required by the applicable test specifications, and in the same way as the forces used in fixed test rigs. The required loading during testing can vary depending on the nature of the subsea cable product 1 and on the installation site, e.g. depth of water. In order to be able to perform a full range of testing then the load module 30 can be configured to apply loads of up to 200 ton, giving a cable tension of 100 ton. In each case the hydraulic cylinder 16 is coupled to the block 12 via a block wheel bracket 42.
[0077] In the example of FIG. 13 the block 12 comprises two block wheels 62 and the block wheel bracket 42 has a Y shape. The two block wheels 62 may for example have a diameter of 1.5 m. By using two wheels in this way it is possible to space the winch cable 8 further from the sides of the test rig, giving more space for wagons 18, as shown, whilst avoiding needing a block wheel with a diameter that is too large for it to fit in one piece into the shipping container. The two block wheels 62 should be removed from the load module 30 of FIG. 13 before it can be transported, as the overall width with the block wheels 62 in place will be too large for the size of the ISO shipping container.
[0078] In the alternative arrangement of FIG. 14, which also corresponds to the load module 30 of FIGS. 4 and 5, there is a single block wheel 62 of a larger diameter, which can be set based on the maximum dimension of the cross-section of the shipping container, e.g. a diameter of 2.5 m. This means that this design for the load module 30 can be transported with the block wheel 62 kept in place.
[0079] In each case the load module 30 may have a length less than the size of a 40-foot shipping container, e.g. a length of 11.8 m as for the other elongate parts, or in this case a shorter length of about 10.5 m can be used. It can be lifted via a forklift inserted in between the top and bottom parts, so there are no added lift pockets although lift pockets could optionally be included.
[0080] The portable test rig is designed to be reversibly assembled/disassembled without the need for complex equipment or heavy lifting beyond the use of a forklift and/or other load handling equipment of the type that is typically used to move ISO shipping containers. The fixings can be attached by hand tools, so that it becomes possible to assemble or disassemble the test rig without complex equipment. With the proposed design this can be done by two people and a forklift, although the assembly time may be reduced if more people are present.
[0081] The disassembled test rig can be stored and transported in a number of ISO shipping containers. It can thus be easily transported between test locations via ship or road, using standard transport devices. When it is desired to assemble the test rig then a suitable test site should be identified and the parts unloaded from the shipping containers, such as by use of a forklift. The load module 30 should be placed at a first end of the test site and, if necessary, the block should be assembled, such as by fitting the block wheel(s) 62. Then, the six lower base sections 34 and the six pairs of upper base sections 32 should be fixed in sequence to the load module 30 and to one another in order to form the elongate base 28. In some cases the test rig can be assembled without using all six of the lower base sections 34 and upper base sections 32, which may be done for smaller cable tests and/or to fit within a constrained space. The six lower base sections 34 and the six pairs of upper base sections 32 can each have the same fittings giving a modular arrangement. This means that they can be joined in any sequence and the length of the elongate base 28 can be varied by using any number of sections from one up to six.
[0082] The base sections 32, 34 can be connected end to end with the upper base sections 32 joined via the posts 48 to the side beams 56 of the lower base sections 34. The sheave module 22 can then be located after the final base sections 32, 34 and at the other end of the test site. The base of the sheave module 22 should be attached to the last lower base section 34 and the last pair of upper base sections 32 via the two brace connectors 36. Then the inner sheave wheel 24 can be assembled by coupling the two side segments 54 to the centre segment 38. At this point the test rig could be used, i.e. for tests requiring the smaller (e.g. 6 m) wheel size. If needed then the sheave wheel extension 26 can be assembled by joining the nine wheel extension sectors 50 around the inner sheave wheel 24, when then provides for tensile bend testing using the larger (e.g. 10 m) wheel size.
[0083] The test rig can perform tensile bending tests of subsea cable products 1 such as power cables or umbilical cables. It can also be used for tension tests where the subsea cable product 1 is mounted in a straight line between the load module 30 and the sheave module 22.
[0084] When the testing is completed then the test rig can be dismantled by reversal of these steps and packing the separated parts back into their shipping containers. It should also be appreciated that the sequence of steps for assembly can be varied, e.g. the base sections 32, 34 could be put together starting from the sheave module 22 rather than starting from the load module 30. Optionally a protective safety enclosure may be provided for encircling the test rig during use. This can provide protection to users and nearby objects/structures in case of a failure of the subsea cable product 1 or the winch cable 8, or any other failure that might cause damage to the surrounding area.
LIST OF REFERENCE NUMBERS
[0085] 1 Subsea cable product/power cable [0086] 2 Electrical conductor [0087] 3 Inner semiconducting layer [0088] 4 Electrical insulating layer [0089] 5 Outer semiconducting layer [0090] 6 Metal shield [0091] 7 Protective cladding [0092] 8 Winch cable [0093] 10 Sheave [0094] 12 Block [0095] 14 Hydraulic cylinder [0096] 16 Pulling eye [0097] 18 Wagon [0098] 20 Winch drums [0099] 22 Sheave module [0100] 24 Inner sheave wheel [0101] 26 Sheave wheel extension [0102] 28 Elongate base [0103] 30 Load module [0104] 32 Upper base section [0105] 34 Lower base section [0106] 36 Brace connector [0107] 38 Centre segment of inner sheave wheel [0108] 40 Chord plate [0109] 42 Block wheel bracket [0110] 44 Adjustable foot [0111] 46 Rail [0112] 48 Post [0113] 50 Wheel extension sector [0114] 52 Extension spoke [0115] 54 Side segment of inner sheave wheel [0116] 56 Side beam of lower base section [0117] 58 Cross brace of lower base section [0118] 60 Lift pockets [0119] 62 Block wheel
