NO339200B1

NO339200B1 - Mooring system

Info

Publication number: NO339200B1
Application number: NO20150859A
Authority: NO
Inventors: Geir Furberg
Original assignee: Aqualine As
Priority date: 2015-07-02
Filing date: 2015-07-02
Publication date: 2016-11-14
Also published as: NO20150859A1

Description

Mooring system

The invention relates to a joint between four or more lines, a method for joining the lines, and use of such a joint in a mooring system, preferably in a mooring system for aquaculture systems.

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 and plant, which will have environmentally 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 comprises often one or more net cages, an anti-bird net, equipment for holding the anti-bird net, and mooring systems for the net cages. Further, 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 underwater, 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 bodies and lines from the grid to the net cage. The different lines are connected to each other, and often it is used mooring plates being metal plates håving thorough holes wherein the lines are fastened by eyelets and shackles. As described, it is used a lot of components of metal, preferably steel, in traditional mooring systems, and the weight of those components must be compensated by the floating capacity of the system, for instance the floating coilar.

By the wording "line" it is in this application meant any rope or strap, håving sufficient strength for the intended use, both twisted and 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 joint between the different lines are essential for maintaining the stability of the plant, and must be embodied to transfer and resist forces from all the lines, both 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 floating elements. It is not unusual that 16 lines running in different directions, are connected in such a joint. Joints in prior art normally comprises as said, a metal plate 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 supervisjon, the mooring system must be raised to the surface, which is a heavy and comprehensive work, but it is also dangerous when such 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.

In US 3583749 it is described a joint of two lines, wherein each line has a loop in the end, and one loop is running through the other loop. In Norwegian patent application 20120444 it is described a junction 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 is however, a problem when parts of the mooring system must be replaced, as the round slings are tied so hard that they must be cut. Upon use of a knife or the similar tool, it is a risk that underlying rope also will be damaged or cut.

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. Further there is an object to provide a mooring system håving 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.

The invention

The object is met by a joint of four or more lines, a method for and use of such a joint in a mooring system, according to the characterizing part of the independent claims. Further advantageous features are stated in the dependent claims.

According to the present invention it is not used any external element for connecting the different lines in a joint, as the lines are connected directly to each other.

The present invention relates to a joint of four lines wherein each line has a loop in one end, and the loops of three lines run through the loops of each other, wherein the loop of the fourth line runs through only one loop, that is the loop of the line running in opposite direction. When the joint is made in this way, the joint is allowing some displacement in that direction, while the other lines are held tight. The displacement is limited by the size of the loop of line 1. This may for instance be an advantage if more lines are to be added to a joint already made.

Described herein is a joint connecting three or more lines, each line has a loop in one end and the joint comprises at least three lines whereby a loop of each of the lines runs through the loops of both the other two lines. This means that when the

joint connects three lines, each loop runs through the two other loops. When the joint connects more lines, the fourth and further lines may also be connected in the same way, each loop running through every other loop, but the fourth and further lines may also be part of the joint even if the loop is not running through every other loop.

In a joint, according to the invention, the forces will be equally distributed through the joint, and the strength of the lines will not be reduced. Thus, one achieves a safe and sufficiently strong joint without over dimensioning the lines, and without external elements or materials which may cause tear and wear and possible rupture of a mooring system. A mooring system wherein the lines are connected to each other by a joint according to the present invention is thus considerably lighter than corresponding solutions of prior art.

In a preferred embodiment of the invention, the lines are rope, preferably braided rope. Further it is an advantage that the loop is made by splicing. A spliced braided rope offers more resistance when the rope is stretched, and thus the distance the rope needs to be spliced may be reduced.

The present invention also comprises a method for joining three or more lines in a joint. The method comprises the following steps

a) Making a loop at the end of the first line.

b) Threading the second line through the loop of the first line, and then bending the line back towards itself, and fasten the end to the line in such a way that a loop is made on the second line. The loop of the second line is running through the loop of the first line. c) Threading the third line through the loops of the first and second line, and then bending the line back towards it seif, and fasten the end to the line in such a way that a loop is made on the third line. The loop of the third line is running through the loops of the first and second line. d) Threading a new line through one loop, that is the loop of the line which is not adjacent to the new line, but is running in opposite direction to the new line. Then one should bend the new line back towards itself, and fasten the end to the line in such a way that a loop is made on the new line. In this embodiment, the loop of the new line will only run through one loop.

In a preferred embodiment of the method according to the invention, the lines are rope, preferably braided rope, and the fastening of the end of each rope to itself, is performed by splicing the end of the rope into the rope itself. In a further preferred embodiment, the splicing is secured by a seizing.

The invention further relates to a mooring system for floating constructions such as aquaculture systems. A mooring system according to the present invention comprises a grid of a number of 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. In a mooring system according to the invention, the grid lines are connected in joints according to the invention.

The size of each square of the grid depends on the size of the net cage. The number of squares, and thus the number of joints and lines depends on the number of net cages.

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 connected to the grid, and according to prior art they are connected to the metal mooring plate being arranged in each joint. According to the present invention however, these lines may be connected to the grid at the joint between the lines, either by being a part of the joint, or by placing a round sling, a rope shackle or the similar around the joint, and then connecting the line thereto.

By "rope shackle" it is, in the present patent application, meant a rope håving a loop in one end and a knot in the other, for instance a "Dyneema shackle". The knot is led into the loop, and will lock the shackle when it is in use. This will be obvious to a person skilled of the art, and is thus not described any further here.

The lines not being a part of the grid, should preferably have a length measured from the joint to the free end, at least corresponding to the depth of the submerged joint. This means that if the joint is 10 meters below water, the length of the lines should at the least be 10 meters. At the free end of the line, a further line running to the destination should be connected. With such an embodiment, a damaged line, for instance a line running to a net cage, may be replaced be elevating the connection between the line running to the grid, and the line running to the net cage, without the need to elevate or replace the joint.

In this way one achieves a safe mooring system being lighter and more sustainable than the known systems. Further, when a line not being part of the grid must be replaced, one only cuts the round sling or similar, and it is not necessary to be in contact with the actual joint. In this way one achieves a mooring system being lighter and stranger than traditional mooring systems, without the need for thicker and more expensive lines.

When the mooring system is lighter, the load carry capacity of the floating coilar and other floating elements such as buoys, may be reduced or used to carry other parts of the cage. Further, the transportation and mounting 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 requires use of a crane.

If the joint is at the outer line of the grid, fewer lines of the grid will be part of the joint, and normally three lines of the grid are part of the joints at the external lines of the grid. Other lines constituting for instance completely or partly the anchoring lines, may be connected to the grid by being part of the joint.

A line constituting a part of the grid of a mooring system, may be made of several lines connected to each other. For instance, a line running from one joint to another may preferably be three parts connected to each other, one part running to the first joint, another part running between joints and a third part running to the second joint. In this way it is more convenient to replace parts of the grid, if parts of the grid are more worn than other parts, or if parts are damaged. In such an embodiment, a line being part of a joint, should preferably have a length measured from the joint to the free end, at the least corresponding to the depth of the submerged grid. This means that if the grid is 10 meters below water, the length of the lines being part of a joint should at the least be 10 meters. Then the connection between the first and second part of a line may be elevated above the surface, and the damaged part may be replaced, without the need to elevate or replace the whole grid or even the joint. If a joint needs so be replaced, one may unfasten the joint without raising it to the surface. In this way one may replace parts of a mooring system without håving to raise the grid to the surface, and more important, without the risk of breakdown during replacement.

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. A line may be many parts connected to each other, and the different parts may not necessarily be of the same type. This means that the line being part of a joint may be a rope, but the second part of a line being part of a grid in a mooring system, may for instance be a strap.

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

Example

The invention will in the following be described with reference to the enclosed figures, where four lines are connected in a joint. The lines and the joint are parts of a mooring system for an aquaculture plant.

Figure 1 shows four lines connected in a joint according to the invention,

Figure 2 shows a part of the mooring of an aquaculture system, including the lines and joints shown in Figure 1, and Figure 3 shows a joint of the mooring system including lines to the net cage being connected.

In Figure 1 it is shown four lines (1, 2, 3, 4) being connected in a joint according to the invention. All lines have a loop at the end the loops of two lines running in opposite directions, being line 1 and 3 in Figure 1, are threaded into each others loop and into the loop of line 2. The loop of line 2 is threaded into the loop of line 1, 3 and 4, and the loop of line 4 is only threaded into the loop of line 1. In this way, once the lines are tighten, lines 2 and 4 may still move a distance in their direction.

The joint shown in Figure 1 may be part of a mooring system of an aquaculture system, as shown in Figure 2. The shown mooring system comprises a grid 5 defining a number of squares, a fish cage 6 arranged in each square, anchoring lines 9 from the grid 5 to the sea-bed or shore, and lines from the grid to floating elements (not shown). The lines of the grid are connected in joints according to the invention, such as the joints shown in Figure 1. The lines 7 running from the grid 5 to the fish cage 6, are connected to the grid, and preferably to the joint. The lines are preferably connected to the grid by means of a round sling 8 arranged around the joint. The fastening of the lines to the fish cage is shown in Figure 3. For clarity issues, only fastening of three lines is shown.

The example above where the invention is described with reference to a mooring system of an aquaculture system, is given to illustrate the invention and should not be used to interpret the invention limiting, as the scope of the invention is stated in the enclosed claims.

Claims

1. Joint for connection of four lines, wherein each line has a loop in one end, and the loops of three lines run through the loops of each other,characterized in thatthe loop of the fourth line (4) only runs through one loop, that is the loop of the line (2) opposite the fourth line.

2. Joint according to claim 1,characterized in thatthe lines are rope, preferably braided rope.

3. Joint according to claim 2,characterized in thatthe loops are made by splicing.

4. Method forjoining four or more lines in a joint according to any one of claims 1-3, the method ischaracterized bycomprising the following steps a) making a loop at the end of the first line (1), b) threading the second line (2) through the loop of the first line (1), and then bending the line back towards itself, and fasten the end to the line in such a way that a loop is made on the second line, c) threading the third line (3) through the loop of the first (1) and second (2) line, and then bending the line back towards itself, and fasten the end to the line in such a way that a loop is made on the third line, and d) threading a new line through the loop of a line not being adjacent to the new line, and then bending the new line back towards itself, and fasten the end to the line in such a way that a loop is made on the new line.

5. Method forjoining four or more lines according to claim 4, wherein the lines are rope, preferably braided rope,characterized in thatthe fastening of the end of each rope to itself, is performed by splicing the end of the rope into the rope itself.

6. Mooring system for floating constructions such as aquaculture systems, comprising a number of lines,characterized in thatthe lines are connected with a joint according to claim 1.

7. Mooring system according to claim 6, wherein the lines are connected to a grid (5) of squares under water,characterized in thatthe lines of the grid (5) are connected to each other with a joint according to claim 1.

8. Mooring system according to claim 6 or 7,characterized in thatthe mooring system further comprises anchoring lines (9) from the grid (5) to the sea-bed or shore, lines from the grid to floating elements, and lines (7) from the grid to net cages (6) arranged in the squares, and in that these lines are connected to a joint of the grid, with a rope shackle, round sling (8) or the similar, being placed around the joint.

9. Use of a joint according to the claims 1-3, for mooring a floating construction.

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