NO343053B1

NO343053B1 - Mooring system

Info

Publication number: NO343053B1
Application number: NO20170303A
Authority: NO
Inventors: Geir Furberg
Original assignee: Aqualine As
Priority date: 2017-03-01
Filing date: 2017-03-01
Publication date: 2018-10-15
Also published as: WO2018160072A1; NO20170303A1

Abstract

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

Description

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 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.

By the word "line" it is in this application meant any rope or strap, having sufficient strength for the intended use, woven, twisted or braided, and independent of the number of strands. The lines may be of synthetic or natural fibres, such as hemp, manila, nylon, polypropylene or plastics.

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, 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 first lines to each other, the lines extend in different directions relative to each other. The element comprises a first rope wherein the ends are spliced to each other, and thus the first rope is an endless ring. Three or more second lines are arranged radially through the first rope, between the strands of the first rope, in a distance from each other, and attached to the lines. A mantle of several filaments is braided onto the first rope.

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.

In a preferred embodiment, the second lines are ropes in order to reduce wear and tear of the ropes. In the following description the rope spliced to a ring will be referred to as a "first rope", and the lines arranged radially through the first rope, will be referred to as "second ropes". This should, however, not be limiting to the scope of the protection as defined by the enclosed claims.

The mantle braided onto the first rope, should preferably not be braided onto the second ropes, meaning that the area where the second rope is entering and exiting the first rope should be covered, but the ends of the second rope should be unmantled. However, in an alternative embodiment, another, separate mantle is braided on the second ropes.

The mantle is braided by a number of filaments. 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.

The mantle is braided onto the rope which is an advantage compared to a separate hose which surrounds the rope. By braiding the mantle directly onto the rope, each filament of the mantle will be tighten around the rope, and the resulting mantled 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 second lines are arranged radially through the first rope, between the strands of the first rope. This means that the second line is arranged perpendicular to the first rope, at the attachment. The second lines should be distributed evenly on the first rope, and when the first lines attached to the second lines are tensioned, the first rope will be triangular if three first lines are attached, square if four first lines are attached etc. Since the second lines are arranged by inserting a second line between the strands of the first rope, the second line will not slide along the first rope, and the distance between two second lines along the first rope, will be maintained. The mantle covering the first rope will also assist in this, as the hole between the strands, wherein the second line is arranged, may not be widen.

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

In a preferred embodiment, the second line is a rope and the ends of each second rope are spliced to each other, and constitutes thus endless rings. The first lines may then be fastened to the rings of second rope in any convenient way.

When the second line or rope is arranged between the strands of the first rope, as described above, the strength of the lines and/or ropes will not be reduced. Thus, one achieves a safe and sufficiently strong attachment without needing to over dimensioning the lines 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, yet equally safe and reliable.

The first rope of the invention is made of strands, preferably braided strands. In a preferred embodiment, the second rope is also made of strands, preferably braided strands. When the ends of a rope are spliced, the splicing is preferably secured by a seizing.

The invention further relates to a mooring system for floating constructions such as aquaculture systems. A well known mooring system for aquaculture plants comprising several net cages, comprises a grid of a number of mooring lines, the lines are running in at the 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 one 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.

In a mooring system according to the invention, the lines of the grid are attached or connected to each other by means of an element as described above, preferably in that the lines of the grid are attached to the second lines or ropes. 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 lines from the grid to the net cages. These lines are also attached to the element, either to a second line or rope or directly to the first rope.

In a preferred embodiment, further lines are attached to the first rope, creating a suspension point centred above the ring of the first rope. A line to a floating element may preferably be fastened to this suspension point.

When the mooring system is lighter, the work related to mounting and inspections 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 also relates to the weight of the system.

The lines to be used according to the present invention may be any line suitable for mooring of 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 by 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 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 an element according to the invention is shown. The element comprises a first rope 1 which is braided of a number of strands, and spliced to an endless ring. In the shown embodiment, four second ropes 2 are arranged radially through the first rope, between the strands of the first rope, as shown in Figure 3. Further, the ring 1 is enclosed by a mantle which is braided of a number of filaments directly onto the rope. The mantle is braided after the second ropes 2 are arranged through the first rope, but the mantle does not cover the second ropes 2, as shown in Figure 2.

The element shown in Figure 1 is further provided with four lines 3 running from the ring 1 to a point above the centre of the ring. These four lines 3 are connected 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 4 defining a number of squares, a fish cage 5 arranged in each square, anchoring lines 6 from the grid to the sea-bed or shore, and lines from the grid to floating elements (not shown).

The lines 4 of the grid and the anchoring lines 6 constitute the first lines, and 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 shown embodiment, the ends of each second rope 2 are spliced to endless rings, as shown both in Figure 1 and Figure 2, and the lines of the grid 4 are attached to the second ropes 2. Further, the lines 7 running from the grid 4 to the fish cage 5 are attached directly to the first rope 1 of the element, for instance by means of a round sling arranged around the first rope, between the second ropes 2.

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

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

3. Element according to claim 2, characterized in that the ends of each second 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 first lines may be attached directly to the first rope, between the second lines.

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 second line (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 first rope (1) spliced to an endless ring, between the second lines (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 second line (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.