JPS61155089A - Single point mooring apparatus - Google Patents

Abstract

PURPOSE:To secure a high mooring stability through a simple structure by connecting an intermediate sinker, by means of a first chain, to a buoy with which a hull to be moored is to be connected through a york and connecting a rigid link, which is connected to the intermediate sinker at one end of the link, to a mooring base through a swivel joint at the other end of the link. CONSTITUTION:A first chain 16 has its upper end connected with a buoy 8 connected to a hull 2 to be moored through a york 4 and has the lower end connected with an intermediate sinker 18. A rigid link 22 has one end connected to the intermediate sinker 18 and has the other end connected to a mooring base 28 locked to the sea-bed through an arm hinge 24 and a swivel joint 26. This simplifies the overall structure and enables a high mooring stability to be secured by an apparatus with a small scale and light weight.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for mooring ships and marine structures at sea.

[Conventional technology]

Conventionally, there are various types of devices for mooring ships and offshore structures at sea, such as multi-point mooring devices, single-point mooring devices, and other devices.
It has the advantage of being able to rotate around the mooring device so that ships and offshore structures that are moored floating bodies are exposed to the least amount of external force due to wind, waves, currents, etc., and that only a small-scale mooring device is required. It has been gradually put into practical use in recent years.

Semi-permanent single-point mooring devices for ships and offshore structures that are currently in practical use are shown in Figure 5 (a), (b),
An example is the one shown in (0).

Figure 5 (#L) shows CALM (Catenary Anc).
One end of a yoke 42 is connected to the tip of the ship 4o via a hinge 41, and the other end of the yoke 42 is connected to a turntable 44 provided with a buoy 4317C. ing. There are multiple chains 4 around the lower part of the buoy 43.
One end of 5 is connected. The chain 45 extends into the sea in the shape of an octopus, and is connected to an anchor 46 at the other end, thereby anchoring it to the seabed 47.

Figure 5(b) shows SALM (Single Ancho
This is a mooring device called a mooring device (JJeg Mooring), and a yoke 4 is attached to the tip of the vessel 4o via a hinge 41.
The other end of the yoke 42 is connected via a similar hinge to a turntable 44 provided at the upper end of the buoy 43'. The buoy 43' is a tower-shaped buoy, and its lower end is connected to a mooring base 49 via a universal joint 48. The mooring base 49 is anchored to the seabed 47 by an anchor/4'ile 50.

Figure 5(c) shows 5ALS (Single Ancho
This is a mooring device called a yoke 4, which is connected to the tip of the ship 40 via a hinge 41.
One end of the yoke 2 is connected to the other end of the yoke 42, and a swivel joint 51 is provided at the other end of the yoke 42. A buoy 43# is connected to the yoke 42, and the buoy 431 is submerged in the sea. The upper end of the rider 53v is connected to the swivel 51 via a universal joint 52, and the lower end of the rider 53v is connected to the mooring base 49 on the seabed 47 via a universal joint 54.

[Problem that the invention seeks to solve]

Generally, CALM is a relatively small-scale mooring device, but it is not suitable for use in sea areas with severe weather and sea conditions because the catenary characteristics of the mooring chain have relatively little buffering effect. Furthermore, in areas where the water is deep, the length of the chain becomes longer and the total weight becomes heavier. On the other hand, SA
Due to their mooring characteristics and device structure, LM and 5ALS are suitable for deep sea areas and sea areas with severe weather and sea conditions, but the scale of the devices themselves is large and installation work is not easy. .

[Means for solving problems]

According to the present invention, in order to solve the problems of the prior art, the upper end of the first mooring line body is connected to a buoy having moored floating body connection means, and the lower end of the first mooring line body is connected to an intermediate sinker, one end of a second mooring line body made of one rigid body is connected to the intermediate sinker, and a hinge and a swivel are connected to the other end of the second mooring line body. A single point mooring device is provided, characterized in that the mooring bases are connected by a joint.

〔Example〕

Embodiments of the one-point mooring device according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 and FIG. 2 are both side views showing a first embodiment of the present invention. FIG. 1 shows the state in calm weather, and FIG. 2 shows the state in stormy weather.

Projecting members 3 are fixed on both sides of the tip of the ship 2, and a yoke 4 made of a rigid body is connected to the projecting members 3 by a hinge 6. A buoy 8 is connected to the yoke 4 via two hinges 10. This allows the vessel 2 and the buoy 8 to move relative to each other in the vertical direction.

A swivel joint 12 is firmly connected to the lower part of the buoy 8, and one end of a chain 16 constituting the first mooring line body is connected to the swivel joint 12 via a universal joint 14. ing. Che y16
An intermediate sinker 18 is connected to the lower end of cl via a universal joint 2°. The intermediate sinker 18 has an arm 2 made of a rigid body that constitutes a second mooring line body.
One end of the arm 22 is connected and fixed, and the other end of the arm 22 is connected to a mooring heir 28 via an arm hinge 24 and a swivel joint 26. The mooring base 28 is /
It is firmly anchored and fixed to the seabed 30 by a coil or the like.

As shown in FIG. 1, when the weather and sea conditions are calm, the arm 22 extends almost horizontally, and the intermediate sinker 18
is located at a certain height from the seabed, and the chain 16 extends approximately vertically. The buoy 8 is floating on the sea surface at a position where it balances its own weight, the weight of the Yoek 4, the weight of the chain 16, the weight of the intermediate sinker 18f2), and the weight of the arm 22 to create buoyancy. When the ship 2 is subjected to forces such as wind, waves, or currents, the ship 2 turns in the direction in which the external force due to these forces is minimized. Since the arm 22 is rotatable about a vertical axis with respect to the mooring base 28 by the swivel joint 26, the direction of the arm 22 and the yoke 4 are
Buoy 8, chain 16,
The intermediate sinker 18 and arm 22 move. Furthermore, vertical movement of the vessel 2 due to external force is absorbed by the rotation of the hinges 6 and 10 at both ends of the yoke 4, and no excessive external force is applied to the buoy 8.

As shown in Figure 2, during rough weather, the ship 2 is affected by wind, waves,
The buoy 8 is pulled laterally when subjected to a large external force due to tidal currents or the like. Therefore, the tension in the chain 16 increases, and the intermediate sinker 18, together with the arm 22, rotates around the horizontal axis at the hinge 24 and is lifted upward. As shown in the figure, in this state, the chain 16 and the arm 22 form a dogleg shape, and the mooring restoring force gradually increases.

FIG. 3 is a partial side view showing a second embodiment of the device of the present invention.

In this embodiment, one end of the yoke 4 is connected to a ship (not shown), and the other end of the buoy 8 is connected to the other end of the buoy 8 via a hinge lo and a swivel soyoint 11. This allows the ship to rotate freely relative to the buoy 8. Further, the upper end of a first mooring line body is connected to the lower part of the buoy 8 via a 22''-salge joint 12. The first mooring line body consists of a plurality of hinged rods 4o. An intermediate sinker 22 is connected to the lower end of the lowest rod via a universal joint 20.
One end of a plurality of chains 24 constituting a second mooring line body is connected to the outer circumference of the intermediate sinker 22.

Next, the mooring characteristics of the device of the present invention as described above will be explained.

FIG. 4 is a graph showing the mooring characteristics of the mooring device of the first embodiment. In this figure, the above CALM is used for reference.
The mooring characteristics are also shown. In the figure, the horizontal axis X indicates the amount of movement of the ship from the reference position, and the vertical axis indicates the tension applied to the first mooring line body K connected to the buoy 8. F
indicates the steady outward value, and ΔX indicates the amount of movement of the ship due to waves and other factors. I and II are the cases of the first embodiment of the present invention and the conventional example (CALM), respectively.

In the case of the conventional example, the increase in tension with respect to the amount of ship movement ΔX is extremely large, and therefore a mooring chain that has extremely high strength is required.

On the other hand, in the case of the first embodiment of the present invention, the tension increases very gradually over the entire area, and the increase in tension corresponding to ΔXK is extremely small. Therefore, it is possible to use a mooring line body having relatively low strength, and fatigue of the mooring line and other members can be minimized.

In the above embodiments, a ship was used as an example of a floating body, but
The floating body in the present invention may be any other marine structure.

Furthermore, in the above embodiments, one chain or rod was illustrated as the first mooring line, but the first mooring line in the present invention is not particularly limited to one, and may be one or two. It may also be constructed using the above-mentioned chains, wire ropes, synthetic fiber ropes, linked rods, or the like.

〔Effect of the invention〕

As described above in detail and concretely, according to the present invention, a floating body such as a ship or a marine structure can be moored with a small-scale and light-weight device regardless of water depth and even in waters with severe weather and sea conditions. In addition, compared to conventional single-point mooring devices, the force applied to the mooring base is smaller, making it smaller and lighter.
Also, the seabed installation work will be simplified.

Thus, the device of the present invention can be used as a semi-permanent mooring device for ships or marine structures at sea, and also as an offshore terminal base for tankers.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are both side views showing a first embodiment of the one-point mooring device according to the present invention. FIG. 3 is a partial side view showing a second embodiment of the device of the present invention. FIG. 4 is a mooring spring characteristic diagram. FIGS. 5(a), 5(b), and 5(e) are side views of a conventional single-point mooring device. 2...Ship, 4...Yoke, 8...Buoy, 16.
...Chain, 18...Intermediate sinker, 22...Arm, 28...Mooring base. Figure 1, /L+6 /゛Figure 3゛Figure 4-1-x

Claims (1)

[Claims] (1) In a device for mooring a floating body at one point on water, the upper end of a first mooring line body is connected to a buoy having means for connecting a moored floating body, and the lower end of the first mooring line body is connected to a buoy having a moored floating body connecting means. An intermediate sinker is connected to the intermediate sinker, one end of a second mooring line body made of one rigid body is connected to the intermediate sinker, and the other end of the second mooring line body is connected to the intermediate sinker by a hinge and a swivel joint. A single point mooring device, characterized in that a mooring base is connected.