JPH10278873A - Floating body mooring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent excessive tension or impact from being applied to chains or a chain connecting parts even in a water territory of shallow depth of water by fitting the main bodies of elastic mechanisms provided stroke-variably on a floating body rotationally movably in vertical planes containing mooring loci of mooring chains. SOLUTION: When a floating body 1 moored by a plurality of mooring devices is largely moved in the horizontal direction by receiving external force such as wind or wave, mooring chains are pulled, elastic mechanisms 7 fitted to the floating body 1 are expansibly moved, expansible stroke quantities are added to the slackened quantities of the chains 5 so as to absorb the large horizontal moving quantity of the floating body 1, and tension of the chains are lightened. In this case, the elastic mechanism 7 rotationally movably fitted in a recess 8 is properly rotationally moved in the pulled-in direction of the chain 5 around a pin corresponding to the chain tension, namely in the vertical plane containing a chain mooring locus, and the expansible stroke motion of the elastic mechanism 7 is smoothly performed. Hence excessive tension or impact is not applied to the chains 5 and their connecting parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mooring device using a mooring chain for a floating body such as a floating breakwater, a floating pier, and a floating platform, and more particularly to a mooring device suitable for mooring a chain in a shallow deep sea area.

[0002]

2. Description of the Related Art FIG.
As shown in (a), both ends of the floating body 1 are formed in a U-shape,
A dolphin-type mooring device in which each end of the U-shape is fitted via a fender 3 to dolphins 2 and 2 fixedly provided at a fixed position on the sea, or a floating body 1 as shown in FIG. A hose pipe 4 for pulling in the mooring chain is arranged at one end, and one end of the mooring chain 5 is connected to the deck of the floating body 1,
An anchor chain type mooring device having the other end connected to a sinker 6 provided on the seabed through the hose pipe 4 is known.

[0003]

The dolphin-type mooring device shown in FIG. 6 (a) is suitable for a shallow water depth, but the production and construction of the dolphin 2 is expensive, and the overall cost is greatly increased. There is a problem that. For this reason, in general, an anchor chain type mooring device shown in FIG. 6B is often used. However, in this mooring method, when the floating body 1 is moored in a shallow place having a water depth of, for example, 10 m or less, the mooring chain 5 is mainly used. There is a possibility that excessive stress may be generated in the chain 5 and the chain connecting portion of the floating body 1 due to insufficient swing amount due to insufficient loosening of the body.

FIG. 7 shows a comparison between the horizontal displacement of the floating body and the force acting on the chain at the time of large water depth and at the time of shallow water depth in the anchor chain type mooring device. The mooring chain 5 is stretched in a catenary curve under an initial load (chain's own weight), and the slack of the chain 5 is large at a large water depth and small at a shallow water depth. Thus, large horizontal swing amount d ₁ of the floating body 1 up to the point showing the maximum load design from the point indicating the static load chain mooring force in deepwater 7, whereby even when oceanographic condition is poor The floating body 1 can be stably moored.

On the other hand, at shallow water depth, the horizontal swing amount d ₂ of the floating body 1 from when the chain mooring force rises to the design maximum load after the static mooring force is smaller than at the deep water depth.
For this reason, a slight movement of the floating body 1 causes a large tension to be generated in the chain 5, which may eventually lead to an accident such as breakage of the chain.

Accordingly, the present invention improves the mounting structure of a chain to a floating body while adopting an inexpensive anchor chain type mooring system, and applies excessive tension or impact to a chain or a chain connecting portion even in a shallow water area. An object of the present invention is to provide a mooring device for a floating body that does not hang.

[0007]

In order to solve the above-mentioned problem, a floating body mooring device according to the present invention has one end of a mooring chain connected to a seabed anchor and the other end installed on a floating body so that the stroke can be varied. In the mooring device connected to the elastic end of the elastic mechanism, the main body of the elastic mechanism is rotatably mounted on the floating body in a vertical plane including the mooring locus of the mooring chain. .

In the floating body mooring device of the present invention described above, when the floating body subjected to the external force moves largely horizontally and the tension of the chain with little slack stretched at the shallow depth increases, the tension of the chain causes the chain to be lifted. The connected elastic mechanism contracts, and this contraction stroke is added to the slack amount of the chain, thereby increasing the allowable swing amount of the floating body and relaxing the chain tension. The attached elastic mechanism rotates appropriately in the vertical plane including the mooring locus of the chain in accordance with the chain tension, whereby the compression stroke of the elastic mechanism is more smoothly added to the amount of slack in the chain, and The tension gradually increases or decreases.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described with reference to FIG. FIG. 1 schematically shows the state of mooring of a floating body by the mooring device of the present invention. The floating body 1 is provided between an anchor 6 provided on the sea floor and an elastic mechanism 7 inside a recess 8 formed on the floating body 1. It is moored by the mooring chain 5 which is stretched.

The elastic mechanism 7 is extendable and contractable by a predetermined stroke in the direction in which the mooring chain 5 is pulled in, and the mooring chain 5 is connected to the telescopic end of the elastic mechanism 7. Is attached to the floating body 1 so as to be freely rotatable in a vertical plane direction including the following.

FIG. 2 shows a main part of a mooring device according to a first embodiment of the present invention.
The connecting member 9 fixed to the floating body 1 is connected to the connecting member 9 by a pin 10 so as to be rotatable around a center of the pin within a predetermined range, and is installed in a recess 8 formed in the floating body 1. As an auxiliary means for smoothly performing the above-mentioned rotation operation, a restoring means 11 such as a coil spring is provided between the outer wall of the elastic mechanism 7 and the recess 8.
It is inserted between the inner wall. Further, the recess 8 is formed so as to have a space that does not hinder the turning operation of the elastic mechanism 7 and the retracting operation of the mooring chain 5 at that time.

FIGS. 3A and 3B show a main part of a mooring device according to a second embodiment of the present invention. In this embodiment, the elastic mechanism 7 is used.
A pair of connecting members 13 are attached to the upper part of the outer wall of the floating body 1 and connected to the inner wall of the recess 8 formed on the floating body 1 by the pins 12 so as to be rotatable within a predetermined range around the center of the pin. Similarly, the restoring means 11 is inserted between the outer wall of the elastic mechanism 7 and the inner wall of the recess 8.

FIGS. 4A and 4B show examples of the structure of the elastic mechanism 7 in the first and second embodiments. FIG. 4A shows an example in which a coil spring is used as the expansion and contraction means. The ends of the coil spring 15 housed in the case 14 are
A fixed plate 17 fixed to the case 14 and a movable plate 16 movable along the inner wall of the case 14, the mooring chain 5 is passed through the coil spring 15, and an end thereof is connected to the movable plate 16. It is. FIG. 4B shows an example using a cell type fender. Both ends of a fender 19 stored in a case 18 can be moved along a fixed plate 21 fixed to the case 18 and an inner wall of the case 18. The chain 5 is sandwiched by the moving plate 20, the chain 5 is passed through the fender 19, and the end thereof is connected to the moving plate 20.

Hereinafter, the operation of the mooring device according to the first and second embodiments will be described. The floating body 1 is usually moored by a plurality of mooring devices (see FIGS. 1 to 6).
When the floating body 1 is largely moved in the horizontal direction by receiving an external force such as wind or waves, the mooring chain 5 is pulled. By adding the contraction stroke amount to the slack amount of the floating body 1, the large horizontal movement amount of the floating body 1 is absorbed, and the chain tension is reduced. At this time, the elastic mechanism 7 rotatably mounted in the recess 8 moves around the pin 10 in the first embodiment of FIG. In the second embodiment, the pin 12 is appropriately rotated in the pull-in direction of the chain 5, that is, in the vertical plane including the chain mooring locus, whereby the compression stroke of the elastic mechanism 7 is smoothly performed. Chain tension increases or decreases slowly,
Excessive tension or impact is not applied to the chain 5 or the chain connection portion.

Further, the rotation of the elastic mechanism 7 is smoothly performed by the restoring action of the restoring means 11 attached to both side walls of the elastic mechanism 7, and the chain 5 comes into contact with the outlet of the recess 8 to be damaged or worn. Accidents such as dripping are prevented.

FIG. 5 shows the mooring characteristics of the mooring device according to the present invention. The horizontal displacement of the floating body 1, that is, the allowable swing amount, while the chain mooring force increases from the static load (steady load) to the design maximum load. It can be seen that d is greatly increased by the addition of the contraction stroke of the elastic mechanism 7. In the characteristic curves in FIG. 5, the dotted line indicates the case where the elastic mechanism 7 is not provided with a rotation function, and the solid line indicates the case where the same mechanism is provided with a rotation function. It can be seen that the chain tension changes gradually due to this.

[0017]

As described above in detail, in the floating body mooring device of the present invention, the mooring chain is connected to the floating body via the elastic mechanism, and the elastic mechanism is moved in the vertical plane including the mooring locus of the mooring chain. By being rotatable, when the floating body moves largely horizontally and the chain tension increases, the elastic mechanism is contracted, and the contraction stroke is added to the slack amount of the chain, thereby the floating body The allowable swing amount increases and the chain tension is reduced. that time,
Since the elastic mechanism rotates appropriately in response to the chain tension, the contraction stroke operation of the elastic mechanism is performed more smoothly, and the chain tension gradually increases and decreases. This has the effect of preventing damage to the essential parts of the device.

[Brief description of the drawings]

FIG. 1 is an elevational view schematically showing a use state of a floating body mooring device according to the present invention.

FIG. 2 is a longitudinal sectional view showing a main part of the floating body mooring device as the first embodiment of the present invention.

FIGS. 3A and 3B show a main part of a floating body mooring device as a second embodiment of the present invention, wherein FIG. 3A is an elevation view thereof, and FIG.
It is an AA arrow line view of the figure.

4A and 4B show an elastic mechanism used in the floating body mooring device according to the first and second embodiments of the present invention. FIG. 4A is an explanatory view showing the inside of the elastic mechanism as an example, and FIG. FIG. 9 is an explanatory view showing the inside of an elastic mechanism as another example.

FIG. 5 is a graph showing mooring characteristics of each floating body mooring device according to the first and second embodiments of the present invention.

FIG. 6 is a view showing a usage state of a conventional floating body mooring device,
(a) is a perspective view showing one example, and (b) is a perspective view showing another example.

FIG. 7 is a graph showing mooring characteristics of a conventional anchor chain type floating body mooring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Floating body 5 Mooring chain 6 Anchor 7 Elastic mechanism 8 Recess 9 Connecting material 10 Pin 11 Restoring means 12 Pin 13 Connecting material 14 Case 15 Coil spring 16 Moving plate 17 Fixed plate 18 Case 20 Moving plate 21 Fixed plate

Claims (1)

[Claims] 1. A mooring device in which one end of a mooring chain is connected to an anchor on the seabed and the other end is connected to a telescopic end of an elastic mechanism installed on a floating body so as to be capable of changing a stroke. A floating body mooring device, which is attached to the floating body so as to be rotatable in a vertical plane including a mooring locus of the mooring chain.