JPS5820813A - Fabrication of landing and elevating type offshore working platform - Google Patents

Abstract

PURPOSE:To reduce the weight to be applied on the bottom of a dock by a method in which a working platform and the lower structure of legs are fabricated while being supported on blocks in the dock and then while supporting the working platform by its buoyance, the upper structure of the legs is fabricated. CONSTITUTION:A working platform 1 with an elevating device 2 is supported on blocks 3 in a dock A, an unit leg 5-1 having a footing on its lower end is loosely fitted into the elevating device 2, and the second unit leg 5-2 is lifted up by a portal crane 6 and connected to the upside of the unit leg 5-1. In the same way, the second and third unit legs are orderly connected upwardly. Then, water is charged into the dock A so as to support part of the weight of the working platform by its buoyance. After the ending of the fabrication of the lower portion of the legs, the unit leg 5-3 is lifted up by a luffing tower crane 7 and connected to the upside of the already fabricated legs.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for assembling an industrial table. More specifically, when assembling the legs (pillars) of a buoyant work platform, the work platform and the lower structure of the legs that support it are assembled, and then water is poured into the dock where the work platform is assembled, and these seven operations are carried out. It provides a method of reducing the weight on the bottom of the dock supporting the platform.

In recent years, due to the depletion of existing oil resources, the development of these resources on the continental shelf has become active, and in this case offshore work platforms are used. Various types of this offshore work platform KFi are used, one of which is a landing type lifting type offshore work platform that has a plurality of legs that land on the ground and the work platform that moves up and down along the legs.

By the way, the length of the support for such a workbench is generally SO.
Since it is a heavy object weighing more than W and weighing as much as 7,000 mm, there are various problems in manufacturing it, one of which is the method of assembling the legs.

That is, in this type of workbench, the workbench with the lifting device and the legs are generally manufactured separately, and then the legs are fitted loosely into the lifting device. Part 4d
Since the length is 80m, it is difficult to fit the legs loosely into the workbench.
A crane with a lifting height of 9 ohm or more is required. However, since constructing such a large crane would require a huge amount of cost, the legs were manufactured as unit legs of about 5 to 20 meters, depending on the capacity of the existing crane. A common method is to assemble the legs by adding legs together.

Another problem is that, as mentioned above, the weight of the workbench is 70.
Since the ship weighs 1,000 tons, it is difficult to support its entire weight at the bottom of the dock. Therefore, when assembling the workbench, it is necessary to install a number of boards or special supports below the footings provided at the lower ends of the legs to prevent local loads from acting on the bottom. Ta. To do this, it was necessary to add boards or change the arrangement depending on the level of completion of the workbench.

The present invention was obtained in order to improve the shortcomings of the above-mentioned conventional method of assembling a landing lift type offshore work platform. Afterwards, water is poured into the dock, and the upper structure of the legs is assembled while the work platform is supported by buoyancy.

Next, embodiments of the present invention will be described with reference to the drawings.

Figure 1 is a diagram showing how the lower structure of a marine work platform is assembled in a dock A. A work platform 1 having a lifting device 2 is supported by a board 3 in a dock A, and a footing 4 is attached to the lower end of the work platform 1.
A unit leg 5-1 having a structure is loosely fitted into the lifting device 2,
The second unit leg 5 is moved by a crane 6 installed on the dock side.
-2 is lifted and added onto the unit leg 5-1. Thereafter, the second and third unit legs are added upward, and when the lifting height of the crane 6 is reached, a considerable weight acts on the bottom of the dock A that supports the board 3 and the granular supports 8. It happens.

Therefore, as shown in Fig. 2, water is poured into the dock A, and the weight of the workbench 1 is supported to some extent by its buoyancy. In addition, when supporting the entire weight of the workbench 1, legs, etc. on the bottom of the dock, it is necessary to sufficiently reinforce the board 3 and the like.

When the lower part of the buttock is assembled as described above, the unit leg 5-3 is lifted by the horizontal retractable tower crane 7 installed on the dock side and placed above the leg that has already been assembled. I will continue to add to it.

Once one leg 5 has been assembled, another leg must be assembled. In that case, as shown in FIG. 3, water is further poured into the dock A to float the workbench 1 and slowly rotate it.

Next, as shown in FIG. 4, the leg 5-m is positioned below the working range of the crane and the unit leg 5-n is connected to it.

Thereafter, the unit leg 5-n is connected to the upper part of the next leg in the same manner.

As described above, the present invention involves assembling the lower structure of the workbench 1 and the legs 5 that support it in the dock A, and then injecting water into the dock A to reduce the weight of the workbench 1 by its buoyancy. The feature is that the upper structure of the leg portion 5 is then assembled.

Therefore, according to the present invention, there is no need for special reinforcement within the dock, and there is no need to change the board p arrangement as the work progresses. Also, when assembling one leg and then assembling the other, all you have to do is pour water into the dock, float the work platform, and rotate it. Can be easily assembled by crane.

Although the present invention can be effectively implemented when assembling a work platform using both a gate type crane and a horizontal retractable base type crane as in the above-mentioned embodiments, the present invention is not limited to this. In short, any assembly method may be used as long as the work platform is floated in the dock to reduce its weight.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 shows a situation in which a work platform and a lower structure of legs are assembled in a dock. Figure 2 shows the situation in which the upper structure of the legs is assembled, Figure 3 shows the situation when the work platform is rotated in the dock, and Figure 4 shows another view of the rotated work platform as described above. This shows how to assemble the legs. 1... Workbench, 2... Lifting device, 3... Board, 4
...Footing, 5...Legs, 5-1.5-2.5
-3... Unit leg body, 6.7... Crane. Agent: Patent Attorney Nobuo Ogawa - Patent Attorney Ken Noguchi Teru Patent Attorney Kazuhiko Saishita) Figure 3 Figure 4

Claims (1)

[Claims] In a state in which the semi-finished product of the lower structure of the work platform and the legs is supported by boards in the dock, water is poured into the dock to reduce the weight of the work platform, and then the upper part of the legs is completed. Features: How to assemble a landing lift type offshore work platform.