JPS5942136B2 - How to assemble a landing lift type offshore work platform - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of assembling a landing lift type workbench by sequentially adding legs and foot cans.

A landing lift type offshore working platform (hereinafter referred to as a working platform) roughly consists of a platform 1, legs 2, foot cans 3, and a lifting device 4, as shown in FIG.

Briefly explaining how this workbench is used, as shown in Fig. 2, the legs 2 are raised by the lifting device 4, the platform 1 floats on the sea, and after being moved on the sea to the desired location by a tugboat, etc. Lower the leg 2 using the lifting device 4 until the foot can 3 reaches the seabed, and then raise the platform 1 several meters above the sea surface to make it stable so that it is not easily affected by wind, waves, and currents (Figure 3). It also provides a work area on the platform 1.

The total assembly of this workbench is carried out in a conventional boat platform, dock, etc., but the height from the bottom of the foot can 3 to the top of the legs 2 is 90mm.
Many of them exceed 50 m in height, which is significantly higher than the 50-odd meter height of general merchant ships. Therefore, the cranes attached to conventional new ship docks and docks built primarily for the purpose of building general merchant ships lack lifts (80 m). (rarely), and it is difficult to complete it with only the crane attached to the above-mentioned general assembly position.

For this reason, conventionally, the cranes attached to the above-mentioned general assembly area were used to lift the cranes up to the maximum height allowed, and the parts of the legs 20 that were higher than that were lifted using the following method.

1. At the newly built slipway or dock, after launching, landing on the quay or on the sea after leaving the dock, and then loading it with the marine crane 5 (No. 4
figure).

2. At the above location, remove the slipway door and dock group, tow the marine crane into the slipway and into the dock, and place it on the tower.

3. At the newly built slipway and dock, load the cargo onto a marine crane from outside the slipway or outside the dock.

The conventional method for assembling the workbench, which is the previous step, is as follows.

1. First, a mounting board with a height of 1 m to 2 m is placed in the general assembly position so that its upper surface coincides with the lower surface of the stand 1.

At the same time, an installation board is similarly placed under the foot can 3.

2. Next, the parts of the stand 1 divided into appropriate sizes are sequentially placed on the installation board and connected and welded together to complete the stand 1.

At the same time, Hootcan 3 will also be developed and completed.

3. When the above 2.0 construction is almost completed, the legs 20 and the lifting device 4 are attached to the foot can 3 and the platform 1, respectively.

Add the remaining part of leg 2 upwards.

4. For sacrificial work, please refer to 2. above. , 3. Do this in parallel.

5. After the joining of the legs 2 is completed and the sacrificial work is also completed, a lifting test of the platform 1 using the lifting device 4 is carried out over the entire length of the legs 2 to complete the work.

In the construction of a landing lift type offshore work platform, the present invention allows the entire assembly of the legs to be carried out in a dry dock or a floating dock, instead of the above-mentioned general assembly of the legs being carried out at sea, often using a marine crane. This eliminates the need to move the workbench back and forth from the construction site to a sea area away from the construction site, investigate the pressure resistance of the seabed, use a marine crane, etc., as described above, and greatly contribute to reducing the number of construction days and costs. It is something.

Conventionally, as described above, the legs 2 have been added by sequentially adding the upper part from the lower part onto the foot can 3 which has been previously installed at a predetermined position.

In this method, as mentioned above, there are cases where the crane attached to the conventional general assembly station cannot accommodate the entire height of the legs 2.

In such a case, the present invention attempts to solve the above-mentioned conventional problems by utilizing a dock and an attached crane. The method is to divide the unit legs into 21°, 22, . . . and sequentially attach them as follows.

The platform 1 is completed to the point where the lifting device 4 of the legs 2 can be operated, and the first unit leg is assembled therein, and the platform is placed on the board 6 in the ditch as shown in FIG. 5 as described below. Asukaru with the left method (
1st step).

The upper end of the second unit leg 21 carried by the transport device 7 is joined to the lower end of the first unit leg (second step).

The assembly of the first and second unit legs made in this way is raised by the height of the unit leg 21 as shown in Figure 6 (third step)
.

Next, the third unit leg 22 is joined to the lower end of the leg assembly, and the second and third steps are repeated to complete the entire length of the leg.

The following method can be used to place the platform 1 on a sufficiently high board 6 as shown in FIG. 5 during the above operations.

1. A method in which the platform 1 is floated and moved onto a pre-installed board 6 using the water depth at high tide, the dock door is closed, and the water inside the dock is drained.

2. If you want to obtain an even higher installation position, there is the following method, which involves filling the bottom of the beam with sand 10 so that it can withstand the weight of the workbench.

As shown in Fig. 8, the assembled legs are floated and docked with the legs fully raised, and the legs are lowered onto the sand 10 that has been piled up on the bottom of the beam and landed on the temporarily attached foot can 3. As shown in the figure, the platform 1 is raised to the required height, the dock door is closed, and the water inside the dock is drained.

After that, a board is inserted between the bottom of the beam and platform 1, platform 1 is lowered, and the weight of the entire workbench is supported by the board.
After this, separate the leg 2 and foot can 3, and
゜Proceed as shown in Figure 7.

3. Float with your legs fully raised as shown in Figure 10.
The method is to enter the dock, lower the legs onto the sand that has been piled up on the bottom of the beam, and land on it (Figure 11), and then install it using the same procedure as in the previous section (Figure 12). There is no need to temporarily attach and separate the foot can and the foot can.

In this case, it is sufficient for the height of the sand mound to be several meters.

4. Foot can 3 temporarily attached to the lower end of leg 2 in item 2 above
Alternatively, a temporary steel structure may be used instead.

The 20 legs and foot can can be moved in the dock in the following ways.

The unit legs shown in the perspective view in Figure 13 are stable and self-supporting, and the weight is not that heavy at 18T to 28T, so the bottom of the beam is fixed with a steel plate, etc., and an adapter with rollers or rollers is installed under each leg cord 20. It can be easily moved horizontally by attaching something like this and pulling it with a winch.

Although the foot can 3 has a weight of 160 to 200 T, it cannot stand on its own, so it is convenient to provide a temporary support 31 shown in FIG. 14.

Lateral movement is almost the same as for the legs, but since the weight is large, it is necessary to balance the weight, and the inconvenience of assembling the board to accommodate the sloping footcan bottom plate as shown in Figure 14 can be avoided. I can't.

Since the footcan itself is a tank, the above disadvantage can be avoided by using its buoyancy to move horizontally.

In other words, the inside of the culvert is semi-filled with water, and the foot can is moved using a winch installed on the floating beam walls.

This situation is shown in FIG. 41 is the winch on the beam side, 4
2 is a rope.

As described above, according to the present invention, the assembly work of the landing lift type work platform can be completed entirely using the equipment within the shipyard without requiring offshore cranes, tugboats, offshore work, etc., thereby reducing the construction cost and schedule. The savings are significant.

[Brief explanation of the drawing]

The following are side views except for FIG. 13. Fig. 1 is a schematic diagram of the structure of the workbench, Fig. 2.3.4 shows the conventional workbench assembly method, Fig. 5.6.7 shows the assembling method of the present invention, Fig. 8.9, 10, Figures 11 and 12 show the assembly method using sand piled up all over the prefecture.
The figure is an explanatory diagram of an assembly method using a foot can. 1... stand, 2... leg, 3... foot can, 4...
... Lifting device, 5 ... Maritime crane, 6 ... Board, 7
...Movement device, 10...Sand, 20...Code, 2
1,22.23...Unit leg, 31...Temporary support, 41
...Winch, 42...rope. ]4

Claims (1)

[Claims] 1. A first step of supporting a workbench having a lifting device with a first unit leg assembled in the dock with boards, and joining the upper end of the second unit leg to the lower end of the first unit leg. The second step comprises a second step of configuring a membrane assembly, and a third step of raising the membrane assembly by only the length of the second unit leg composing the membrane assembly, and the second step A method for assembling a landing elevating type offshore work platform, characterized in that the entire length of the legs is assembled by sequentially repeating the steps 1 and 3.