WO2018160072A1

WO2018160072A1 - Mooring system and an element used in a mooring system

Info

Publication number: WO2018160072A1
Application number: PCT/NO2018/050054
Authority: WO
Inventors: Geir FURBERG
Original assignee: Aqualine As
Priority date: 2017-03-01
Filing date: 2018-03-01
Publication date: 2018-09-07
Also published as: NO343053B1; NO20170303A1

Abstract

The invention relates to an element for attaching three or more lines 4,6 to each other, wherein the lines extend in different directions relative to each other. The element comprises a rope 1 spliced to an endless ring, and three or more cords 2 arranged radially through the rope, between the strands of the rope, in a distance from each other. The at least three lines are attached to the cords. A mantle of several filaments is braided onto the rope 1. The invention also relates to use of such an element for mooring a floating construction.The invention further relates to a mooring system for floating structures, wherein the at least three lines 4, 6 extending in different directions, are attached to a cord 2 of an element according to the invention, and thereby to each other.

Description

MOORING SYSTEM AND AN ELEMENT USED IN A MOORING SYSTEM

The invention relates to an element for attaching three or more lines to each other, use of such an element in a mooring system for aquaculture systems, and a mooring system for floating structures.

Floating constructions to be held at a given location or position, are normally moored with lines from the construction to the sea-bed and/or to the shore if the construction is sufficiently close to the shore. The lines are moored to the sea-bed and/or shore in a convenient way according to prior art. Conditions such as wind, waves and tidal current will affect the constructions, and large forces from different directions will affect the lines holding the construction in place. Thus, it is very important that not only the lines but also the joints are sufficiently strong to resist such forces over time. Damage to the mooring system may result in breakdown of the net cage or plant, which will have environmental consequences in addition to material and financial loss to the owner of the plant.

In the following, the invention will be described with reference to aquaculture systems for fish at sea, but it can also be used in fresh water and/or as mooring for floating rafts, offshore constructions and other floating constructions. An aquaculture system often comprises one or more net cages, an anti-bird net, equipment for holding the anti-bird net, and mooring systems for the net cages. An aquaculture system may also comprise one or more rafts. The expression "aquaculture system" is known to a person skilled of the art, and is thus not further defined here.

A traditional mooring system for an aquaculture system comprises a grid of mooring lines under water, and anchoring lines running from the grid to the mooring in the sea-bed or shore. The grid surrounds several net cages, preferably one net cage in each square of the grid. The mooring system also comprises lines from the grid to floating buoys and lines from the grid to the net cage. The different lines are connected to each other, usually by means of mooring plates being metal plates having thorough holes wherein the lines are fastened by eyelets and shackles. A lot of components of metal, preferably steel, are thus used in traditional mooring systems, and the weight of those components must be compensated by the floating capacity of the system, for instance the floating collar. The connection between the different lines are essential for maintaining the stability of the plant, and must be embodied both to transfer and resist forces from all the lines, downward from the anchoring line(s), horizontally from the grid and the lines running to the fish cage, and upwards from the lines running to the fish cage and to the buoys. It is not unusual that 16 lines running in different directions, are connected in one such joint. Joints in prior art normally comprises a metal plate as said above, which results in wear and tear of the lines over time. The system must be regularly supervised and the worn parts must be replaced. Upon supervision, the mooring system must be raised to the surface, which is heavy and comprehensive work, but it is also dangerous when such heavy elements are raised and lowered.

It is known to use ropes as an alternative to steel in parts of a mooring system, wherein the ropes are tied to each other in knots. In the knots being used, the rope will be bent in steep angles through the knot, and the rupture strength will be reduced. In order to achieve sufficient rupture strength the rope must be oversized.

NO 337394 and NO 339200, both being inventions from Aqualine AS, describe another type of knots for tying the lines of the mooring system to each other. The drawback of these knots is that the whole knot must be untied if one of the lines needs to be loosened or replaced.

WO 2012/154054 describes a joint in a mooring system for an aquaculture system as described above, as the coupling plate and the corresponding shackle and eyelet are replaced by a number of round slings. There are however, problems when parts of the mooring system must be replaced, as the round slings are tied so hard to each other that they must be cut to be released. During rough weather there is also a problem that the lines attached to the round sling, slide along the round sling, and thus that the formation of the mooring may become altered. Object

The object of the present invention is to provide a mooring system without the problems described above. Another object is to provide a mooring system being lighter than traditional systems, and preferably without the need of external parts, especially without the need of metal parts. There is also an object to provide a mooring system having improved operating time, and wherein parts may be replaced in a simple and convenient way without the need for raising and possible replacing the whole system. Yet another object is that the mooring system should be operable even if maintenance and/or replacement of some components are made on the system. Finally, there is an object that the system should be reliable and give low risk for mistakes during installation. The invention

The object is met by an element for attaching three or more lines to each other, use of such an element in a mooring system and a mooring system for floating structures comprising such an element, according to the characterizing part of the independent claims. Further advantageous features are stated in the dependent claims.

The present invention relates to an element for attaching three or more lines to each other, the lines extend in different directions relative to each other. The element comprises a rope wherein the ends are spliced to each other to an endless ring, in the following referred to as a ring-rope. Three or more cords are arranged radially through the ring-rope, between the strands of the ring-rope, in a distance from each other. A mantle of several filaments is braided onto the ring-rope. The lines are attached to the cords.

The wording "line", "cord" or "wire" as used in this application should be regarded as synonyms, and may each and independently be a rope, strap, band, string, thread, cable or the similar having sufficient strength for the intended use, and being suitable for the said purpose. A skilled person would know which type of line, cord or wire is suitable for the purpose in question, and suitable combinations of lines, cords and wires. The lines may be of synthetic or natural fibres, such as hemp, manila, nylon, polypropylene or plastics, and may be woven, twisted or braided of a number of strands.

A "rope" as used in this application is twisted or braided of a number of strands. The strands may be of synthetic or natural fibres, such as hemp, manila, nylon, polypropylene or plastics. A preferred rope is a polyethylene rope, such as a

Dyneema ® Rope, and more preferred it is braided of 8 strands.

The mantle braided onto the ring-rope, should preferably not be braided onto the cords, meaning that the area where the cord is entering and exiting the ring-rope should be covered, but the ends of the cord should be unmantled. However, in an alternative embodiment, another, separate mantle is braided on the cords. The mantle may be any suitable mantle or tubing, for instance a heat-sh nkable tubing or a wire sleeve, such as a wowen wire sleeve. The mantle is according to the invention, braided by a number of filaments onto the ring-rope. The number of filaments may vary in relation to the thickness of the rope and/or the width of each filament. The material of the filament depends on the environment where the element is to be used, which will be obvious to a person skilled of the art. In a preferred embodiment, the mantle is braided of 12 filaments, and the filaments are made of polyester. By braiding the mantle directly onto the ring-rope, each filament of the mantle will be tightened around the rope, and the resulting mantled ring-rope will have an even and durable surface, preventing sand and/or foul from contacting the rope, and without reducing the strength or flexibility of the rope. Further, as the mantle encloses the rope so tight, the risk for foreign substances to unintentionally hook or fasten in the mantle is substantially reduced. Methods for braiding are known for instance from WO2003/054291 or WO2012/1343010.

As said above, the cords are arranged radially through the ring-rope, between the strands of the ring-rope. This means that the cord is arranged perpendicular to the ring-rope, at the attachment. The cords should be distributed evenly on the ring-rope, and when lines are attached to the cords and tensioned, the ring-rope will be triangular if three lines are attached, square if four lines are attached etc. Since the cords are arranged by inserting a cord between the strands of the ring-rope, the cord will not slide along the ring-rope, and the distance between two cords along the ring- rope, will be maintained. The mantle covering the ring-rope will also assist in this, as the hole between the strands, wherein the cord is arranged, may not be widen.

The element comprises three or more cords for attaching three or more lines to the ring-rope. However, more lines than cords may be attached to the element, either by attaching more than one line to each cord, or by attaching lines directly to the ring- rope, on the outside of the mantle, between the cords. The cords will ensure that lines attached directly to the ring-rope stays in the intended area between the cords.

In a preferred embodiment, the cord is a rope and the ends of each cord are spliced to each other, and constitute thus an endless ring running through the rope of the ring-rope. The lines may then be fastened to the cords in any convenient way. When the cord is arranged between the strands of the ring-rope, as described above, the strength of the lines, cords and/or ropes will not be reduced. Thus, one achieves a safe and sufficiently strong attachment without needing to over dimensioning the lines, cords and ropes, and without external elements or materials which may cause tear and wear and possible rupture of a mooring system. A mooring system wherein the mooring lines are connected to each other by an element according to the present invention is thus considerably lighter than traditional solutions comprising a mooring plate, but still equally safe and reliable. The rope of the ring-rope of the invention is made of strands, preferably braided strands. In a preferred embodiment, the cord is also a rope made of strands, preferably braided strands. When the ends of a rope are spliced, the splicing is preferably secured by a seizing. The invention also relates to a mooring system comprising at least three lines extending in different directions, wherein each of the lines are attached or connected to each other by means of an element as described above. The lines are preferably attached to the cords arranged radially through the ring-rope of the element. The invention further relates to a mooring system for floating constructions such as aquaculture systems. A well known mooring system for aquaculture plants with several net cages, comprises a grid of mooring lines, the lines are running in at least two directions and create a grid with several squares. The grid is preferably submerged. Net cages are arranged within the grid, and preferably the grid is designed in such a way that each net cage is arranged in a different square, surrounded by the lines of the grid. The size of each square of the grid depends thus on the preferred size of the net cage. The number of squares, and thus the number of joints and mooring lines depends on the number of net cages. The mooring lines which constitute the grid are connected to each other in the joints by means of an element as described above, preferably in that each line is attached to a cord arranged radially through the ring-rope.

The mooring system further comprises anchoring lines from the grid to the sea-bed or shore, lines from the grid to floating elements, such as buoys, and cage-lines from the grid to the net cages. These lines are also attached to the element, either to a cord or directly to the ring-rope. In a preferred embodiment, further wires are attached to the ring-rope, and protrude to a common suspension point centred above the ring-rope, where the wires are attached to each other. A line to a floating element on the surface of the water may preferably be fastened to this suspension point.

A mooring system according to the present invention does not use a traditional mooring plate of steel, and is thus substantially lighter. The work related to mounting and inspection of the mooring system will be easier and less dangerous. Upon mounting of a mooring system according to the present invention one may use only manpower, while mounting of traditional systems comprising a mooring plate, requires use of a crane due to the weight of the mooring plate. During inspections of the mooring system, a junction between the lines will often be lifted to the surface, and thus work related to inspections is also related to the weight of the system. The lines to be used according to the present invention may be any line suitable for mooring an aquaculture system, which will be obvious to a person skilled of the art. It is however, preferred to use ropes, more preferred braided rope, and most preferred tubular or round braided rope. Further, a mooring line may be assembled of many lines connected to each other, and the different lines may not necessarily be of the same type.

In the following the invention will be described by reference to mooring of an aquaculture system, but it may of course also be used in other areas, which will be obvious to a person skilled in the art. As said above the element may be used to connect three or more lines.

Example

The invention will now be described with the help of the enclosed figures, showing an element and a mooring system according to the present invention. The different parts of the figure are not necessarily in scale to each other, as the figures are merely for illustrating the invention.

The following description of an exemplary embodiment refers to the figures, and the following detailed description is not meant or intended to limit the invention. Instead, the scope of the invention is defined by the appended claims. Reference throughout the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases "in one embodiment" or "in an embodiment" in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more

embodiments. The invention will in the following be described with reference to the enclosed figures, where

Figure 1 shows an element according to the invention,

Figure 2 shows a part of the element shown in Figure 1 , in detail,

Figure 3 shows a part of an element according to the present invention, before a mantle is braided, and

Figure 4 shows a mooring system of an aquaculture system, according to the invention.

In Figure 1 and 2 an element according to the invention is shown. The element comprises a rope 1 which is braided of a number of strands, and spliced to an endless ring, in the following referred to as a ring-rope. Four cords, in the shown embodiment the cords are ropes 2, are arranged radially through the ring-rope, between the strands of the ring-rope, as shown in Figure 3. In the shown

embodiment, the ends of each rope 2 running through the ring-rope 1 , are also spliced to endless rings. Further, the element 1 is enclosed by a mantle which is braided of a number of filaments directly onto the ring-rope. The mantle is braided after the ropes 2 are arranged through the ring-rope, but the mantle does not cover the ropes 2, as shown in Figure 1 and 2. The element shown in Figure 1 is further provided with four wires 3 running from the ring-rope 1 to a point above the centre of the ring-rope. These four wires 3 are connected both to each other and a floating element, such as a buoy. In this way, the position of the element will be marked in the system, and some buoyancy will be given to the element.

The element shown in Figures 1 , 2 and 3 may be part of a mooring system of an aquaculture system, as shown in Figure 4. The shown mooring system comprises a grid of mooring lines 4 defining a number of squares, one fish cage 5 arranged in each square, anchoring lines 6 from the grid to the sea-bed or shore, cage-lines 7 running from the grid to the net cages 5, and lines from the grid to floating elements (not shown).

The mooring lines 4 of the grid are attached to each other by means of an element according to the invention, such as the element shown in Figure 1 and 2. In the embodiment shown in Figure 4, ends of mooring lines 4 of the grid and possibly anchoring lines 6, all at the same joint, are attached to the same element, and so are the cage lines 7 running from the grid to the fish cage 5. The lines are either attached to the ropes 2 running through the ring-rope 1 , or directly to the ring-rope between the ropes 2, for instance by means of a knot or a round sling. In a preferred embodiment, the mooring lines 4 are attached to the ropes 2, and the other lines are attached directly to the ring-rope 1 .

The example above is given to illustrate the invention and should not be used to interpret the following claims limiting. The scope of the invention is not limited by the example give above, but the following claims.

Claims

Patent claims

1 . Element for attaching three or more lines (4, 6) to each other, wherein the lines extend in different directions relative to each other, characterized in that the element comprises a rope (1 ) spliced to an endless ring, three or more cords (2) arranged radially through the rope, between the strands of the rope, in a distance from each other, and a mantle of several filaments braided onto the rope (1 ), wherein the lines are attached to the cords.

2. Element according to claim 1 , characterized in that the cord (2) is a rope.

3. Element according to claim 2, characterized in that the ends of each rope (2) are spliced in such a way that they create an endless ring.

4. Element according to any one of claims 1 - 3, characterized in that further lines may be attached directly to the rope, between the cords.

5. A mooring system for floating structures, wherein at the least three lines (4, 6) extending in different directions, are attached to each other, characterized in that each of the lines are attached to a cord (2) of an element according to any one of claims 1 -4.

6. A mooring system according to claim 5, characterized in that more lines (7) are attached directly to the rope (1 ) spliced to an endless ring, between the cords (2).

7. Mooring system according to claims 5 or 6, characterized in that mooring lines (4) are arranged as a grid under water, and that the lines (4) of the grid are attached to a an element according to any one of claims 1 -4, preferably to a cord (2).

8. Mooring system according to any one of claims 7, characterized in that the mooring system further comprises anchoring lines (6) from the grid to the sea-bed or shore, lines from the grid to floating elements, and lines (7) from the grid to net cages (5) arranged in the squares, and in that these lines are attached to an element according to any one of claims 1 -4.

9. Use of an element according to claim 1 , for mooring a floating construction.

10. Use according to claim 9, wherein the floating constructions is an aquaculture system.