JP2001114189A - Floating body type sea platform - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a floating body type platform capable of holding down vertical rocking due to waves and moving more quickly by simple and easy work. SOLUTION: This floating body type platform is provided with a lower floating body having a ballast tank, an upper platform connected and supported on the lower floating body through a column, and a winch mounted on the upper platform, and a bob is fastened to a wire rope wound or unwound on the winch, whereby preliminary buoyancy smaller than the mass of the bob is given to the floating body by supply and discharge of ballast.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a floating offshore platform.

[0002]

2. Description of the Related Art Offshore platforms are used for various purposes such as helipads, offshore work platforms, and quays in stricken areas. Since the platform by the floating body swings up and down due to the waves, it is difficult to work on the platform and the working efficiency is low. In addition, there was an inconvenience that the shaking was not comfortable on the platform.

[0003] For this reason, a tension leg platform has been developed and used as a platform with little vertical swing. The tension leg platform embeds an anchor on the seabed, connects the floating body to a wire rope secured to the anchor, applies a slight preliminary buoyancy to the floating body, and applies initial tension to the wire rope, so that the vertical swing by the wave Is to be suppressed.

According to this method, since the wire rope is tied to the seabed, the installation requires an undersea operation such as burying an anchor and tying the wire rope. For this reason, moving the once-installed platform to the extra space is extremely large and requires time-consuming work, so it was practically impossible to move the platform to the extra space.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a floating platform which can move up and down by a simple and easy operation while suppressing the vertical swing caused by waves.

[0006]

SUMMARY OF THE INVENTION The present invention is a floating offshore platform comprising a lower floating body having a ballast tank, an upper platform connected to and supported by the lower floating body, and a winch on the upper platform. A weight was fastened to the wire rope which was wound up and rewinded by the winch so that a preliminary buoyancy smaller than the weight of the weight could be given to the floating body by supplying and discharging ballast to the floating body.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The figures sequentially show the installation, operation, and movement states and postures of the platform of the present invention. Reference numeral 1 denotes a lower floating body, which has ballast tanks A, B, and C divided into several compartments. Although not shown, each of the ballast tanks A, B, and C has a ballast supply / discharge system. Pumps and pipes are provided to supply and discharge the ballast.

An upper platform 2 is connected and supported on the lower floating body 1 via a plurality of columns 3 and floats on the sea by the buoyancy of the lower floating body 1. The column 3 is also sealed at the top and bottom, and functions as a buoyant body. 4 is the upper platform 2
5 is a wire rope wound and wound on the winch 4, and 6 is a weight fastened to the wire rope 5. In addition, 7 in the figure is the sea floor,
8 shows the sea surface.

When the ballast tanks A, B and C are completely filled with ballast, the lower floating body 1 is given a small buoyancy as preliminary buoyancy. The weight 6 is larger than the preliminary buoyancy given to the lower floating body 1, discharges the ballast from the ballast tanks A, B, and C, and has a smaller mass than the large buoyancy given to the lower floating body 1.

The wire rope 5 is suspended straight by a guide member (not shown) attached to the lower side of the lower floating body 1. Further, as shown in FIG. 5, it is also possible to provide a wire rope guide pipe 9 in the columns 3 at the four corners of the platform 2 and guide the wire rope through the guide pipe 9.

The configuration of the present invention is as described above. Next, the operation and the action and posture of the operation will be described. First, the platform according to the present invention is towed by a tug boat to the installation location while the lower floating body 1 is kept floating. The floating posture of the platform at this time is the posture shown in FIG.

When reaching the installation location, the wire rope 5 is rewound by the winch 4 and the weight 6 is landed on the seabed 7 (FIG. 1). In this state, ballast tanks A, B,
A seawater ballast is stretched on C to leave a preliminary buoyancy in the lower floating body 1 (FIG. 2).

Next, the wire rope 5 is
Take up. In this state, since the lower floating body 1 has only a buoyancy smaller than the mass of the weight 6, if the wire rope 5 is wound up as it is, the lower floating body 1 is drawn into the sea.
The lower floating body 1 is drawn into the sea, and when the draft reaches a predetermined draft, the winding of the wire rope 5 is stopped, and the winch 4
Is fixed with a ratchet or the like. In this state, it is used as a platform (FIG. 3).

Next, when the platform is moved, the winch 4 is unlocked and the wire rope 5
And the lower floating body 1 is floated by the preliminary buoyancy (return to the state of FIG. 2). When the lower floating body 1 floats, the ballasts of the ballast tanks A, B, and C are discharged, and the lower floating body 1
Give the buoyancy a great deal of buoyancy and make it even more prominent. Then, the wire rope 5 is wound up by the winch 4,
The weight 6 is wound up to a moving state (FIG. 4). In this state, the platform can be moved.

When the ballast is discharged, the weight 6 is naturally cut off as the buoyancy of the lower floating body 1 increases.
You will be able to lift it slightly. . Also, as shown in FIG. 6, for example, a compressor 10 is installed on the upper platform 2, and compressed air is supplied to the ballast tanks A, B, and C through a pipe 11, and the pressure in the tank is increased to discharge the ballast. In this case, the ballast can be drained in the state where the lower floating body 1 is submerged, that is, in the state shown in FIG.

At this time, since the wire rope 5 is under tension and the lower floating body 1 is submerged, the weight 6 can be lifted at the same time by the amount of floating, so that the amount of winding by the winch 4 is reduced. In addition, it is possible to take a quicker action in addition to omitting the step of floating by the preliminary buoyancy.

[0017]

The present invention provides preliminary buoyancy to the lower floating body,
Since the weight having a mass greater than the preliminary buoyancy is fastened with a wire rope, the lower floating body can be submerged in the sea and fixed by pulling the weight with the wire rope. I have almost never received it. As a result, work efficiency on the floating offshore platform has been greatly improved, and comfort on the platform has also been improved.

In moving the platform, the ballast can be moved only by offshore work such as drainage of the ballast, winding by a winch, and rewinding. Now you can. In addition, since the work of securing to the seabed has been eliminated, it has become possible to install it anywhere as needed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a state in which a wire rope is rewound and a weight is landed.

FIG. 2 is a diagram showing a state where a ballast is stretched and preliminary buoyancy is applied to a lower floating body.

FIG. 3 is a diagram showing a state in which a wire rope is wound up and a lower floating body is submerged.

FIG. 4 is a view showing a state where a lower floating body is lifted up and a weight is wound up.

FIG. 5 is a view showing another embodiment of a guide for a wire rope.

FIG. 6 is a diagram showing another embodiment of ballast supply / discharge.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower floating body 2 Upper platform 3 Column 4 Winch 5 Wire rope 6 Weight 7 Sea bottom 8 Sea surface 9 Wire rope guide pipe 10 Compressor 11 Piping

Claims (3)

[Claims] 1. A floating offshore platform having a lower floating body provided with a ballast tank and an upper platform connected and supported via a column on the lower floating body, a winch is provided on the upper platform, and the winch is wound around the winch. Fasten the weight to the wire rope to be rewound, supply and discharge the ballast, give the lower floating body a preliminary buoyancy smaller than the weight of the weight, pull the weight with the wire rope, submerge the lower floating body, at the planned draft position, A floating offshore platform characterized in that the rotation of the winch can be fixed. 2. A floating offshore sea according to claim 1, wherein a compressor is provided on the upper platform, compressed air is supplied from the compressor via a pipe, and the pressure in the ballast tank is increased to discharge the ballast. platform. 3. The floating offshore platform according to claim 1, wherein the wire rope is guided from the winch to the lower floating body through the column.