JPS628237Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a caisson installation ship that can transport and install caissons to the installation sea area. This relates to a semi-submersible catamaran for installing caissons, which increases the number of installation work days throughout the year and expands the work area to the open ocean.

Conventionally, when transporting and installing a caisson to the installation area, the caisson is first transported to the installation area by tugboat as shown in Figure 1 a and b or by a push boat as shown in Figure 2 a and b. A work boat is used to position and install the caissons, then a sand filling boat is used to fill the caissons with sand, and a concrete mixer boat is used to pour concrete to suppress the sand.

Therefore, conventional caisson installation work not only requires a large number of ships and workers, but also has to stop work in case of stormy weather, which reduces the number of installation work days throughout the year. At present, there are problems such as the extremely difficult installation of caissons in the open ocean.

The purpose of this invention is to solve the above-mentioned problems, to allow caisson transportation and installation work to be carried out on a single vessel, to eliminate factors that hinder caisson installation work such as wind and waves, and to expand the caisson installation work area to the open ocean. The purpose of the present invention is to provide an excellent semi-submersible catamaran for installing caissons.

That is, the present invention is a semi-submersible catamaran in which submersible bodies are attached parallel to each other at the bottom of both sides of the superstructure in the longitudinal direction via struts. forming a caisson fitting part that is V-shaped in plan view and opening in the direction of movement of the catamaran, and arranging a fixing means for fixing the caisson fitted to the caisson fitting part to the superstructure;
Furthermore, the gist of the present invention is a semi-submerged catamaran for installing a caisson, characterized in that each of the struts has an opening located at a water-shedding portion thereof.

In the present invention, a caisson is a general term for large marine installation structures.

Hereinafter, the present invention will be explained in detail by way of examples with reference to the drawings.

Fig. 3 is an explanatory side view of a semi-submersible catamaran for installing a caisson according to an embodiment of the present invention, Fig. 4 is an explanatory plan view thereof, Fig. 5 is an explanatory front view thereof, and Fig. 6 is an explanatory side view. is a plan view explanatory diagram showing the process of installing a caisson using the semi-submersible catamaran for caisson installation.

In the figure, E is a semi-submersible catamaran for installing a caisson, which is an embodiment of the present invention, and has submersible bodies 3 attached in parallel to the bottom of both sides in the longitudinal direction of the superstructure 1 via struts 2. A caisson fitting part 4 having a V-shape in plan view and opening between the twin hulls on the traveling direction side of the semi-submerged type catamaran F is formed in the upper structure 1 of the type catamaran F, and By arranging a fixing means H for fixing the caisson G in contact with the caisson fitting part 4 to the upper structure 1, and further providing an opening 2a in the strut 2 at a water-sucking part thereof. It is configured.

To further explain this structure, the opening 2a
In this embodiment, as shown in FIG. 3, there are two openings 2a on the left and right located in the stuttering part of each strut 2, and the water line area of the strut 2, that is, the waterline area of the strut 2, is increased by the openings 2a. The cross-sectional area is made as small as possible to alleviate the shaking of the ship's hull due to waves and to facilitate the installation of the caissons.

Here, it will be briefly explained that, as mentioned above, if the opening 2a is provided in the swamping portion of the strut 2, the shaking of the hull due to waves can be further alleviated.

In the first place, the natural period of vertical heave of the ship's hull can be theoretically determined by the following formula.

Here, Tz... Natural period of the hull (s) V... Displacement volume (m ³ ) Aw... Water line area (m ² ) (cross-sectional area of the hull at the swamping part) π... Pi...Gravity Acceleration of (m/s ² ) As is clear from this formula, the natural period of the vertical motion of the hull is related to the size of the water line area of the hull, and if the hull has the same displacement volume, the water line area can be changed. By doing so, it is possible to avoid synchronization with the wave period and reduce the shaking of the ship.

In the case of the present invention, the stuttering part is the strut 2 as mentioned above, so by making the water line area of the strut 2, that is, the cross-sectional area of the stuttering part, as small as possible, it is possible to match the period of the majority of waves. synchronization can be avoided, the hull will be less likely to sway, and stability characteristics can be improved.

In addition, as shown in FIG. 3, the submerged body 3 includes:
Ballast tanks 3 with the required volume in the front, rear, and middle areas
A is arranged so that the water intake can be adjusted by pouring water into the ballast tank 3a. In particular, in the case of the present invention, by taking advantage of the characteristics of the semi-submerged type, a predetermined amount of water can be achieved with a small amount of ballast, so the water filling time can be significantly shortened compared to a general ship.

Furthermore, in this embodiment, the caisson fitting part 4 is opened on one side between the twin hulls of the superstructure 1, that is, on the traveling direction side of the semi-submerged catamaran F, as shown in FIG. It is formed into a V-shape in plan view, and its internal angle α is 90°, so that the two sides including the even corner of the caisson G, which is formed into a square or rectangle in plan view, can tightly abut. It's summery. Therefore, in the present invention, the wave force that the caisson G receives during transportation of the caisson can be received by the two sides 4b and 4c including the inner corner 4a of the caisson fitting part 4, which is different from the case of conventional flat pushing. In comparison, the behavior of the caisson G can be reduced, the caisson fixing means described later can be simplified, and the non-contact side of the caisson G includes an even corner part of the caisson G as shown in FIG. Since a wave cut portion is formed by two sides, navigational resistance can be greatly reduced.

Note that the internal angle α of the caisson fitting portion was set to 90° as described above in this embodiment;
Of course, it is not limited to ゜.

As described above, the fixing means H for fixing the caisson G in contact with the caisson fitting part 4 to the upper structure 1 is a double-hulled one as shown in FIGS. 4 and 6 in this embodiment. When mooring Vessel F in a caisson installation area or when installing a caisson, this catamaran F
A winch 5 is used for towing. That is, the winch 5 is positioned at each even corner of the upper structure 1 as shown in the figure.
One set of stands is arranged, and the caisson G is fixed to the upper structure 1 by pulling the wire 6 holding the caisson G through pulleys 7 and 8 using a winch of one of the sets.

Note that 9 in the figure is a support column, which is used for assistance and installation when fixing the caisson G to the superstructure 1.
It can be used together with each of the winches 5 mentioned above. Reference numeral 10 denotes a cushion material, which is attached to the caisson fitting portion 4 which is V-shaped in plan view, as shown in FIG.

As described above, the present invention provides a semi-submersible catamaran in which submersible bodies are attached parallel to each other at the bottom of both sides in the longitudinal direction of the superstructure through struts, and the submersible bodies are installed between the twin bodies of the superstructure. A caisson fitting part is formed that is V-shaped in plan view and opens in the direction of travel of the submersible catamaran, and a fixing means is provided for fixing the caisson in contact with the caisson fitting part to the upper structure. Furthermore, since each strut is provided with an opening located in its water-shedding portion, the following effects can be achieved. In other words, (a) each strut connecting the superstructure and the submerged body has an opening located in the swamping part, so that the water line area of the strut, that is, the cross-sectional area of the swamping part, is reduced by this opening. can be made as small as possible, and the shaking of the ship due to waves can be significantly alleviated.

Therefore, the working limit value of wave height can be increased compared to a conventional caisson installation ship, and the number of installation work days throughout the year can be greatly increased. On the other hand, since the ship's hull is less shaken by waves, it is possible to work on the ship. This also improves the performance and makes the caisson installation work easier.

(b) In addition, the caisson fitting part provided in the superstructure is formed in a V-shape in plan view, and is opened between the twin hulls of the semi-submersible catamaran in the direction of movement. Therefore, when the caisson is attached to this caisson fitting part, a wave cut part can be formed by the two non-contact sides of the caisson,
Navigation resistance can be significantly reduced. Therefore, in combination with the above-mentioned effect of preventing the hull from shaking due to the provision of the opening in the water-shedding portion of the strut, the work area can be expanded to the open ocean.

[Brief explanation of the drawing]

Figure 1 a, b and Figure 2 a, b are explanatory diagrams showing the conventional caisson transportation situation, respectively, and Figures 3 to 6
The figures show an embodiment of the present invention; Fig. 3 is an explanatory side view of a semi-submersible catamaran for installing a caisson, which is an embodiment of the invention; Fig. 4 is an explanatory plan view of the same; This figure is an explanatory front view of the same, and FIG. 6 is an explanatory plan view showing the process of installing a caisson using the semi-submersible catamaran for installing the caisson. 1... superstructure, 2... strut, 3...
Submerged body, 4... Caisson fitting part, F... Semi-submersible catamaran, G... Caisson, H... Fixing means.

Claims (1)

[Scope of utility model registration request] A semi-submersible catamaran has submerged bodies attached parallel to each other at the bottom of both sides in the longitudinal direction of the superstructure through struts. A caisson fitting part having a V-shape in plan view opened in the direction is formed, and a fixing means for fixing the caisson in contact with the caisson fitting part to the upper structure is disposed, and each of the struts is a semi-submersible catamaran for installing a caisson, which is characterized by having an opening located in the stagnant part.