Trefoil submarine power cable bundle

Patent metadata

Field	Value
Publication number	US-12537115-B2
Application number	US-202318463478-A
Country	US
Kind code	B2
Filing date	Sep 8, 2023
Priority date	Sep 13, 2022
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

A submarine power cable bundle including: a first bottom direct current, DC, submarine power cable, a second bottom DC submarine power cable, and a top DC submarine power cable, wherein the first bottom DC submarine power cable and the second bottom DC submarine power cable are bundled together by means of a first elongated bundling element, forming a first bundle, wherein the first bundle is bundled together with the top DC submarine power cable by means of a second elongated bundling element, forming a trefoil configuration, wherein the first elongated bundling element bundles the first bundle tighter than the second elongated bundling element bundles the first bundle and the top DC submarine power cable.

First claim

The invention claimed is:

1 . A submarine power cable bundle comprising:
a first bottom direct current, DC, submarine power cable, a second bottom DC submarine power cable, and a top DC submarine power cable, wherein the first bottom DC submarine power cable and the second bottom DC submarine power cable are bundled together by means of a first elongated bundling element, forming a first bundle, wherein the first bundle is bundled together with the top DC submarine power cable by means of a second elongated bundling element, forming a trefoil configuration, wherein the first elongated bundling element bundles the first bundle tighter than the second elongated bundling element bundles the first bundle and the top DC submarine power cable.

2 . The submarine power cable bundle as claimed in claim 1 , wherein the first bundle is bundled with a tightness that prevents the top DC submarine power cable to fully slide in between and align with the first bottom DC submarine power cable and the second bottom DC submarine power cable, and wherein the second elongated bundling element bundles the first bundle and the top DC submarine power cable with a tightness that enables axial movement of the top DC submarine power cable relative to the first bundle when the submarine power cable bundle is laid on the seabed via a vessel chute.

3 . The submarine power cable bundle as claimed in claim 1 , wherein the first elongated bundling element bundles the first bottom DC submarine power cable and the second bottom DC submarine power cable along a majority of the length of the first bottom DC submarine power cable and the second bottom DC submarine power cable.

4 . The submarine power cable bundle as claimed in claim 1 , wherein the second elongated bundling element bundles the first bundle and the top DC submarine power cable along a majority of the length of the first bottom DC submarine power cable, the second bottom DC submarine power cable, and the top DC submarine power cable.

5 . The submarine power cable bundle as claimed in claim 1 , wherein the trefoil configuration has an outer bundle circumference which is defined by a length of the second elongated bundling element as it extends one turn around the first bundle and the top DC submarine power cable, seen in a cross-sectional view along a longitudinal axis of the submarine power cable bundle, wherein a first lay length of the first elongated bundling element is at most 3 times the outer bundle circumference, such as at most 2.5 times the outer bundle circumference.

6 . The submarine power cable bundle as claimed in claim 5 , wherein a second lay length of the second elongated bundling element is at most 9 times the outer bundle circumference, such as at most 3.75 times the outer bundle circumference.

7 . The submarine power cable bundle as claimed in claim 1 , wherein the first elongated bundling element has a tensile stiffness of at most 15 kN, 12 kN, or 10 kN.

8 . The submarine power cable bundle as claimed in claim 7 , wherein the trefoil configuration has an outer bundle circumference which is defined by a length of the second elongated bundling element as it extends one turn around the first bundle and the top DC submarine power cable, seen in a cross-sectional view along a longitudinal axis of the submarine power cable bundle, wherein a first lay length of the first elongated bundling element is at most 3 times the outer bundle circumference, such as at most 2.5 times the outer bundle circumference,
wherein a ratio between the number N of first elongated bundling elements used times the tensile stiffness of a first elongated bundling element and the first lay length is at least 4 kN/m.

9 . The submarine power cable bundle as claimed in claim 1 , wherein the second elongated bundling element has a tensile stiffness of at most 15 kN, 12 kN, or 10 kN.

10 . The submarine power cable bundle as claimed in claim 9 , wherein a second lay length of the second elongated bundling element is at most 9 times the outer bundle circumference, such as at most 3.75 times the outer bundle circumference,
wherein a ratio between a number M of second elongated bundling elements used times the tensile stiffness of a second elongated bundling element and the second lay length is at least 2 kN/m and at most 10 KN/m.

11 . The submarine power cable bundle as claimed in claim 1 , wherein the first elongated bundling element is arranged in an 8-shaped formation as it bundles the first bottom DC submarine power cable and the second bottom DC submarine power cable.

12 . The submarine power cable bundle as claimed in claim 1 , comprising a submarine fibre optic cable, wherein the submarine fibre optic cable is bundled with the first bundle by means of the second elongated bundling element or forms part of the first bundle.

13 . The submarine power cable bundle as claimed in claim 1 , wherein the first elongated bundling element is a rope or yarn and wherein the second elongated bundling element is a rope or yarn.

14 . The submarine power cable bundle as claimed in claim 1 , wherein the first elongated bundling element is laid with a first lay direction and the second elongated bundling element is laid with a second lay direction, opposite to the first lay direction.

15 . A method of laying DC submarine power cables from a marine vessel, the method comprising:
a) providing a first bottom DC submarine power cable, a second bottom DC submarine power cable, and a top DC submarine power cable, b) bunding the first bottom DC submarine power cable with the second bottom DC submarine power cable by means of a first elongated bundling element, to form a first bundle, c) bundling the first bundle with the top DC submarine power cable by means of a second elongated bundling element, to form a submarine power cable bundle with a trefoil configuration, wherein the bundling in step b) is made tighter than the bundling in step c), and d) laying the submarine power cable bundle on the seabed.

16 . The submarine power cable bundle as claimed in claim 2 , wherein the first elongated bundling element bundles the first bottom DC submarine power cable and the second bottom DC submarine power cable along a majority of the length of the first bottom DC submarine power cable and the second bottom DC submarine power cable.

17 . The submarine power cable bundle as claimed in claim 2 , wherein the second elongated bundling element bundles the first bundle and the top DC submarine power cable along a majority of the length of the first bottom DC submarine power cable, the second bottom DC submarine power cable, and the top DC submarine power cable.

18 . The submarine power cable bundle as claimed in claim 2 , wherein the trefoil configuration has an outer bundle circumference which is defined by a length of the second elongated bundling element as it extends one turn around the first bundle and the top DC submarine power cable, seen in a cross-sectional view along a longitudinal axis of the submarine power cable bundle, wherein a first lay length of the first elongated bundling element is at most 3 times the outer bundle circumference, such as at most 2.5 times the outer bundle circumference.

19 . The submarine power cable bundle as claimed in claim 2 , wherein the first elongated bundling element has a tensile stiffness of at most 15 kN, 12 kN, or 10 kN.

20 . The submarine power cable bundle as claimed in claim 2 , wherein the second elongated bundling element has a tensile stiffness of at

Assignees

• Nkt Hv Cables Ab

Inventors

• Tyrberg Andreas
• Sandell Håkan
• Tjahjanto Denny

Classifications

• H02G9/02

  laid directly in or on the ground, river-bed or sea-bottom; Coverings therefor, e.g. tile · CPC title

• H02G1/10

  in or under water · CPC title

• H01B11/22

  Cables including at least one electrical conductor together with optical fibres · CPC title

• H01B7/14 Primary

  Submarine cables · CPC title