BACKGROUND

The invention relates to an assembly of an anchoring wire and a clamping joint that engages the anchoring wire to attach a ramification line thereto.

These clamping joints are applied in anchoring wires for anchoring floating off-shore units. The clamping joints are used to lift the anchoring wires above hinder on the sea bottom for example, such as a pipeline or submarine constructions. Off-shore units are typically anchored by using eight or twelve anchoring wires, having a diameter from about 64 millimeters to 90 millimeters, and the length is typically about 2000 to 2300 meters.

Known clamping joints comprise two wire clamps that are bolted against each other. The wire clamps are internally coated with a thin layer of polyurethane that engages the outer surface of the anchoring wire. When the anchoring wire is decommissioned the wire clamps need to be taken apart again. This causes difficulties as the polyurethane coating has firmly bonded to the anchoring wire. The wire clamps are reused for another anchoring wire after the entire coating is stripped off and a fresh polyurethane coating is applied. Stripping off the polyurethane coating is only possible by applying heat whereby the polyurethane is burned off. For that purpose the wire clamps need to be sent back to the manufacturer. As the clamping joints are usually decommissioned and installed during a single offshore operation, the operator takes one set of clamping joints offshore and brings the used clamping joints back home again, which causes logistic difficulties .

It is an object of the present invention to provide a clamping joint that can be installed directly after its decommissioning.

SUMMARY OF THE INVENTION

According to a first aspect, the invention provides an assembly of an anchoring wire and a clamping joint that engages the anchoring wire to attach a ramification line thereto, wherein the clamping joint comprises two complementary steel wire clamps that together define an inner passage for the anchoring wire, multiple clamping bolts that connect the wire clamps to each other, and an exchangeable first insert that is releasably confined in an inner confinement chamber of the wire clamps, wherein the first insert comprises a plastic contact layer having an imprint that corresponds to the outer shape of the anchoring wire, wherein the contact layer is pressed against the anchoring wire by tightening the clamping bolts.

The clamping joint according to the invention comprises two complimentary steel wire clamps in which the first insert is releasably confined. The first insert forms the actual contact with the anchoring wire. When the wire clamps are taken apart the insert can be is released again. After insertion of a new insert the clamping joint is ready again for installation. The insertion of the insert can be executed offshore during a single offshore operation. The new insert may be different than the earlier insert, whereby the insert can be adapted to the actual anchoring wire by choosing the appropriate insert.

In an embodiment the first insert comprises a metal outer shell in which the contact layer extends, wherein the outer shell is in releasable contact with the wire clamp. The outer shell forms the actual contact between the contact layer and the wire clamps and can prevent that the contact layer bonds to the wire clamps. This facilitates an easy release of the first insert from the wire clamp.

In an embodiment thereof the metal outer shell is a steel outer layer.

In an embodiment the contact layer is a casted body that is bonded to the outer shell.

In an embodiment the first insert comprises two complementary parts that are releasably confined in the respective inner confinement chambers of the wire clamps. Each complementary part forms one unity with one wire clamp only for easy installation to the anchoring wire.

In an embodiment the contact layer comprises or is made of a form stable, plastically deformable plastic. Such plastic conforms to the actual outer shape of the anchoring wire by local deformation.

In an embodiment thereof the contact layer comprises or is made of a casted polymer, preferably polyurethane .

In an embodiment the wire clamps comprise a middle section in which the inner confinement chamber is located, and two wider end sections with flanges through which the clamping bolts extend.

In an embodiment thereof the inner passage widens outwardly inside the end sections.

In an embodiment the inner confinement chamber is bound by an inner surface of the wire clamp that corresponds to the outer shape of the first insert for a form locked confinement of the first insert.

In an embodiment thereof the first insert is kept in the inner confinement chamber by means of retaining bolts .

In an embodiment the clamping joint comprises a shackle that is connected to the wire clamps to attach the ramification line to the clamping joint.

In an embodiment thereof the clamping joint comprises a separate mounting support that engages the wire clamps, wherein the shackle is connected to the mounting support .

In a combined embodiment the mounting support engages the middle section of the wire clamps.

In an embodiment the assembly further comprises a second insert for an alternative anchoring wire having a different outer shape or outer diameter, wherein the second insert comprises a plastic contact layer having an imprint that corresponds to the outer shape of the alternative anchoring wire, wherein the first insert and the second insert are interchangeable in relation to the wire clamps. The first insert and the second insert form two options from which can be chosen on-site during the offshore operation to adapt to the specific anchoring wire. The clamping joint and the first insert and the second insert may together form a kit of parts.

The invention further relates to a clamping joint for use in an assembly according to the invention.

According to a second aspect, the invention provides a method for in situ decommissioning a clamping joint that engages an anchoring wire to attach a ramification line thereto and for re-installation of the clamping joint to an alternative anchoring wire, wherein the clamping joint comprises two complementary steel wire clamps that together define an inner passage for the anchoring wire, multiple clamping bolts that connect the wire clamps to each other, and an exchangeable first insert that is releasably confined in an inner confinement chamber of the wire clamps, wherein the first insert comprises a plastic contact layer having an imprint that corresponds to the outer shape of the anchoring wire, wherein the contact layer is pressed against the anchoring wire by tightening the clamping bolts, wherein the method comprises releasing the clamping bolts and taking the wire clamps apart, wherein the first insert is released from the inner confinement chamber of the wire clamps, inserting a second insert in the confinement chamber, wherein the second insert comprises a plastic contact layer having an imprint that corresponds to the outer side of the alternative anchoring wire, and connecting the wire clamps to each other by means of the multiple clamping bolts, wherein the contact layer of the second insert is pressed against the alternative anchoring wire by tightening the clamping bolts .

The invention further relates to a computer- readable medium having computer-executable instructions adapted to cause a 3D printer to print an assembly or parts thereof according to the invention.

The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, in particular the aspects and features described in the attached dependent claims, can be made subject of divisional patent applications .

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of an exemplary embodiment shown in the attached drawings, in which :

Figure 1 shows a typical anchoring configuration in which an anchoring wire is connected to a ramification line by means of a clamping joint according to the invention;

Figures 2A-2E show the clamping joint of figure 1, wherein in subsequent parts have been taken away to show the details and the exchangeable inner parts thereof. DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a typical offshore anchoring configuration in which an offshore marine platform 1 floating in the sea water 2 is anchored to an anchoring ground 3. The offshore platform 1 is connected to a set of outspread anchoring wires 7 and a set of shorter anchoring wires 6 all having an anchor 8 at the end that is embedded in the anchoring ground 3. The outspread anchoring wires 7 are uphold at the middle by means of an buoy 9 of which only one is shown. The buoy 9 is connected to the anchoring wire 7 by means of a vertically extending ramification line 10. The lower end of the ramification line 10 is connected to the anchoring wire 7 by means of a clamping joint 20 according to the invention. The clamping joint 20 is shown in detail in figures 2A-2E.

As shown in figure 2A, the clamping joint 20 comprises two symmetrically designed steel wire clamps 21, 22 that are the two halves of a cylindrical body with a straight internal passage 23 for the anchoring wire 7. The wire clamps 21, 22 each comprise a middle section 24 and two wider end sections 25 forming one single unity.

As best shown in figure 2B, the clamping joint 20 comprises a steel mounting support 40 having two straight transverse plates 41 and two straight longitudinal plates 45 that are welded to each other. The transverse plates 41 are provided with a circular upper edge 42 to receive the middle section 24 of one or both of the wire clamps 21, 22, and the longitudinal plates 45 are provided with a first mounting hole 43 and a larger second mounting hole 44. The clamping joint 20 comprises a U-formed steel saddle 50 with a handle 54 that is placed over the middle sections 24. The saddle 50 is mounted to the mounting support 40 by means of a first mounting bolt 55 that extends through the first mounting holes 43 and the saddle 50 and that is tightened with a nut 56. The clamping joint 20 comprises a steel shackle 57 for attachment of the ramification line 10. The shackle 57 is pivotably connected to the mounting support 40 by means of a second mounting bolt 52 that extends through the second mounting holes 44. The second bolt 52 is kept in position by means of two counter tightened nuts 53.

As best shown in figure 2E, the end sections 25 of the wire clamps 21, 22 each comprise two flanges 26 on the opposite sides of the internal passage 23. The flanges 26 are each provided with a clamping hole 27. The wire clamps 21, 22 comprise webs 28 with a hoisting hole 29 between the flanges 26. As shown in figure 2A, the wire clamps 21, 22 are clamped towards each other by means of four clamping bolts 82 that extend through a stack of disk springs 83 and through the clamping holes 27. The disk springs 83 are biased by means of two counter tightened clamping bolts 82. As shown in figure 2E, the wire clamps 21, 22 each comprise at the middle section 24 a semi cylindrical inner surface 31 that at the ends merges into a circumferentially extending slot 32. This slot 32 is halfway extended by a shorter axially extending slot 33. The circumferentially extending slot 32 merges into trumped shaped inner surfaces 30 in the end sections 25.

As shown in figures 2C-2E, the clamping joint 20 comprises two first inserts 62 that are releasably inserted in direction B in each of the wire clamps 21, 22. The first inserts 62 each comprise a semi cylindrical steel outer shell 63 and a plastic contact layer 70. For illustrative purposes only, the upper one of the two mating first inserts 62 is shown in figure 2C without the upper wire clamp 21 in which it is inserted. For illustrative purposes only, the plastic contact layer 70 is shown in figure 2E separately from the outer shell 63 to which it is bonded.

As best shown in figure 2C, the outer shells 63 each comprise a semi cylindrical outer surface 64 that at the ends merges into a radially outwards projecting rim 65. The rims 65 are halfway interrupted by a axially extending slot 68. The outer surface 64 tightly engages the inner surface 31 of the wire clamps 21, 22, wherein the rims 65 fit inside the circumferentially extending slots 32. In the facing axially extending slots 33, 68 of the wire clamps 21, 22 and the outer shells 63 a steel key 69 is inserted to prevent mutual axial rotation. The outer shells 63 are temporarily fixated inside the wire clamps 21, 22 by means of retaining bolts 34 that engage onto the rims 65. As best shown in figure 2E, the outer shells 63 comprise a semi cylindrical inner surface 66 that at the ends merges into trumpet-shaped inner end surfaces 67.

In this example the anchoring wire 7 comprises seven twisted bundles 8 of twisted steel wire strands 9. In this example the anchoring wire 7 has an outer wire diameter Dl of 74 millimeters, which is the largest wire diameter that can be clamped by the wire clamps 21, 22 and the first inserts 62. This largest diameter Dl is limited by the smallest inner diameter of their trumpet-shaped inner surfaces 30.

The contact layer 70 is bonded to the inner surfaces 66, 68 of the outer shell 63. The contact layer 70 comprises a central footprint or imprint 71 of the actual anchoring wire 7, and two trumpet-shaped inner end surfaces 72 at the ends. The imprint 71 or impression 71 is unique for the applied anchoring wire 7 and forms the negative of the specific outer shape thereof. The contact layer 70 is a casted body of polyurethane . The contact layer 70 is form stable or rigid, having a hardness corresponding to A-95 of the standards given. The contact layer 70 is casted into the outer shells 63. In figure 2C this is only schematically indicated by direction A The contact layer is bonded to the outer shell 63 by the curing or hardening of the polyurethane.

As best shown in figure 2D, the first inserts 62 are interchangeable with second inserts 162 having the same reference numbers for the same features . The second inserts 162 have a central imprint 171 of another type of anchoring wire, in this example with a smaller outer diameter D2, and trumpet-shaped widening inner end surfaces 72 at the ends that are adapted to the smaller outer diameter D2.

The clamping joint 20 according to the invention is clamped onto the anchoring wire 7 after insertion and fixation of the first inserts 62 that are adapted for this anchoring wire 7. The first inserts 62 are inserted in the respective wire clamps 21, 22 in direction B and fixated therein by means of the retaining bolts 34. The wire clamps 21, 22 are then brought together against the anchoring wire 7. By tightening the clamping bolts 84 the contact layer 70 is pressed against the anchor wire 7 and locally plastically deformed. The clamping joint 20 can then not be displaced with respect to the anchor wire 7. The anchor wire 7 with the clamping joint 20 is ready for use.

When after a service term of several months or years the anchoring wire 7 is decommissioned for re ^¬ installation, the clamping bolts 84 are released and the wire clamps 21, 22 with their first inserts 62 are taken apart from each other. The wire clamps 21, 22 can immediately be reused again on site by just installing new inserts 62, 162 that are adapted for the next anchoring wire to be clamped.

It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention.