WO2020090611A1 - Work ship having tower crane and crane operating method therefor - Google Patents

Abstract

According to the present invention, work barges 1A, 1B, 1C, are each provided with, as cranes, tower cranes 10, 10B, 10C in each of which a tower 12 is formed by stacking a plurality of mast blocks 12a, a crane body 13 is placed on the uppermost section of the tower 12, and the height of the tower 12 is adjusted by the number of stacked mast blocks 12a. Accordingly, in this work ship provided with a crane used for oceanic construction in shallow ocean regions, in particular, for the installation of a floor-type oceanic wind power generating device or the maintenance work thereof, the suspension height of the crane is easily changed corresponding to the height of the work target object, and during sailing when crane work is not performed, the height of the crane is lowered, the air draft is lowered, and the overturning moment acting on the base section of the crane is lowered, and thus, the scale of the base structure of the crane may be reduced to be small. Accordingly, an increase in the size of the hull is suppressed.

Description

Work boat equipped with tower crane and method of operating the crane

The present invention relates to a work boat equipped with a crane used for offshore construction in shallow water, particularly for installation of a landing type offshore wind turbine generator and maintenance work thereof, and a method for operating the crane.

For the installation and maintenance of offshore wind turbines in shallow water, work berths equipped with cranes such as jib cranes equipped with a lattice boom with a sheave (pulley) at the tip have generally been used in the past. ing. In order to ensure the stability of crane work during work, the crane is mounted on a jack-up work platform with a deck lift pedestal system that lifts the hull with lift legs (legs, spuds) during crane work. Is being done.

For example, as described in Japanese Patent Application Laid-Open No. 2011-183835, in a jack-up type work berth provided with a plurality of jack-up legs, a traveling rail is provided on a deck and a boom is provided so as to be turnable. A work platform for raising and lowering a deck, which is provided with a movable work carriage for traveling freely, and a jack-up leg, a large and small first crane, and a second crane as described in, for example, Japanese Patent Laid-Open No. 2004-1750. The special work boats provided are proposed.

Further, for example, as described in Japanese Unexamined Patent Application Publication No. 2012-76738, a semi-submerged hull is provided with a deck lifting pedestal system, and along a rail system on the side walls on both sides of the hull. It is equipped with a portal crane and a gantry crane that can be moved by moving the deck crane to the seabed during the work of lowering the offshore structure from between the rear protrusions of the side walls with this portal crane. A vessel for transporting and installing offshore structures in a fixed state has been proposed.

Further, for example, as described in Japanese Unexamined Patent Publication No. 2013-170493, a jack-up ship equipped with a plurality of jack-up legs is equipped with a ship crane such as a jib crane and the space on the deck is effectively used. Therefore, an offshore wind turbine installation vessel has been proposed in which at least one of the jack-up legs that moves up and down is disposed at the center of the swing of the on-board crane.

Further, for example, as described in US Pat. No. 4,652,177, in a jack-up type offshore structure which is supported on the sea by a vertically movable leg (leg) fixed to the seabed, this leg is A technique is disclosed in which a crane is rotatably installed on a guide tower (cylindrical support structure) through which the guide tower is passed and the guide tower is used as a support structure for the crane.

On the other hand, in mountainous areas on land, the size of the wind turbine is limited due to the capacity of the crane device for transportation and installation, but in comparison, in the case of an offshore wind power generator, this wind turbine There are few size restrictions. In the case of offshore wind turbines, the cost of installation work is almost proportional to the number of installations, so it is necessary to reduce the number of installations to reduce costs. Larger capacity is desired. For example, in the current state-of-the-art class, the power generation amount of one wind turbine is 7 MW class, but it is expected to reach 10 MW class within a few years. The suspension height of this 10 MW class wind turbine is considered to reach 200 m.

However, with the cranes proposed in the above patent documents, the installation height cannot be adjusted, and the hanging height of the crane cannot be changed. Therefore, when the required suspension height becomes high as the capacity of the wind turbine increases, the boom length required to secure a high suspension height becomes long even if the suspension load is not so large.

As a result, it is necessary to increase the capacity of the crane despite the large restrictions on the deck area and loading capacity of the work boat. For example, there is an example in which a jib crane of 1000t class or more is used even for a lifting load of 100t or less. Installation of this large capacity jib crane requires a large installation site.

The increase in capacity of these cranes results in an increase in the weight of the crane. In these cranes, the load of the crane and the load of the suspended load are received by the offshore structure either directly or via a guide tower, etc. There is a problem that the structure becomes large-scale.

∙ On the other hand, there are tower cranes that have a small installation area and the lifting capacity hardly depends on the height. For example, as described in Japanese Unexamined Patent Publication No. 2009-280367 and Japanese Unexamined Patent Publication No. 5-178566, this tower crane is also called a climbing type jib crane and is used for the construction of a high-rise building or a large building, or It is used for concrete pouring of dams.

In this tower crane, at the construction site, set the base frame, set up the tower assembled with multiple mast blocks (crane mast: post) on it, and set the crane body with the swing frame on it. Can be assembled. This mast block is replenished according to the progress of construction work, and the crane main body is raised accordingly, resulting in a high suspension height. Then, after the construction is completed, the tower and the crane body are dismantled, transferred to another construction site, reassembled, and repeatedly used.

Japanese Patent Laid-Open No. 2011-183835 Japanese Patent Laid-Open No. 2004-1750 Japanese Patent Laid-Open No. 2012-76738 Japanese Unexamined Patent Publication No. 2013-170493 U.S. Pat. No. 4,652,177 Japanese Unexamined Patent Publication No. 2009-280367 Japanese Patent Laid-Open No. 5-178566

In this situation, the inventor obtained the following knowledge. If this tower crane can be used for offshore installation of the latest wind turbine, which is increasing in capacity and increasing in suspension height, this wind turbine can be installed without using a large hoist ship. The cost can be reduced significantly. Further, not only the cost at the time of installation but also the maintenance of the landing type offshore wind turbine already installed on the ocean does not require an expensive hoist ship, so that the economical efficiency of the lifetime of the wind turbine can be greatly improved. Furthermore, even if an offshore wind turbine is assembled at a port and then shipped by a carrier ship with a stern having a fork shape, a tower crane can be easily used as a crane that can be used for this assembly and shipping. it can.

The present invention has been made in view of the above situation, and an object thereof is to provide an offshore construction work in a shallow sea area, particularly a work provided with a crane used for installation of a landing type offshore wind turbine generator and its maintenance work. On the ship, the hanging height of the crane can be easily changed according to the height of the work object, and when navigating without crane work, lower the crane height and lower the air draft. A work boat equipped with a crane and a crane therefor capable of reducing the overturning moment acting on the base of the crane and reducing the size of the base structure of the crane, and suppressing the increase in the size of the hull of the work pontoon. To provide an operation method.

A work platform provided with the crane of the present invention for achieving the above object is a work platform provided with a crane that uses a crane for installation of an offshore structure. To form a tower, the crane main body is placed on the top of the tower, and the tower crane is provided to adjust the height of the tower according to the number of stacked mast blocks. ..

Due to the shape of this tower crane, the load applied to the tower is configured so that the overturning moment is minimized and the load in the vertical direction is the main component. Therefore, it is easier in strength than the supporting structure (base structure) in other types of cranes. As a result, the crane support structure requires less member weight and deck area than prior art work pontoons with other types of cranes. Therefore, it is possible to suppress an increase in the deck area and weight of the work table required for mounting the crane, and it is possible to prevent the work table from increasing in size.

Also, with tower cranes, the mast blocks are stacked to form a tower, and the crane body is installed on top of it. In this tower, the "crane height" can be easily increased by increasing the number of stacked mast blocks when performing crane work. Therefore, it is possible to easily increase the "hanging load height" at which a hanging load having a preset hanging load can be lifted.

Also, when navigating without crane work, the "crane height" can be lowered by reducing the number of stacked mast blocks, so it is possible to increase the height from the water surface to the highest point of the hull structure. It is easy to lower the "air draft", which is the height of ().

Also, when the crane is not in operation, the mast blocks forming the tower are removed and the number of them is reduced to lower the height of the tower, so the removed mast blocks can be arranged in a plane on the work table ship. This mast block can be used as a weight for adjusting the attitude (trim (vertical tilt), heel (horizontal tilt)) of the hull. Therefore, in the work pontoon, it is possible to suppress an increase in the mechanism for adjusting the attitude of the hull (such as the capacity of the ballast tank) required to mount the crane, and it is possible to prevent the work pontoon from increasing in size.

In the work platform provided with the crane, the tower crane raises the crane main body while sequentially adding the mast block to the tower, and while sequentially removing the mast block from the tower, the crane. When the mast climbing device of the self-elevating type for lowering the main body is provided, the tower crane can be quickly assembled to a predetermined height without using an auxiliary crane or the like.

In the work pontoons equipped with the above-mentioned cranes, the work pontoons are drainage type work pontoons, half SEPs in which the hull is floating on the water surface during crane work, and the hull is on the water surface during crane work. The following effects can be obtained with any one of the work pontoons of the full SEP in the upper position.

When the work pontoon is a drainage type work pontoon, it is necessary to hold the position of the own ship by a mooring system such as mooring lines or an automatic position keeping (DPS) system during crane work, but SEP (self There is no need for the structure of lifting legs (legs, spuds) that can be lifted up and down by jacking up like a lifting work boat.

When the work pontoon is a half SEP, when the crane work is performed, the support force of the lifting legs and the buoyancy of the hull are used together to raise the work pontoons, but the lifting legs have been jacked up. However, instead of raising the entire hull above the surface of the water, the hull is kept floating above the surface of the water.

When the work pontoon is full SEP, when performing crane work, raise the whole work pontoon to a height above the water surface where the waves cannot reach, so that the influence of the waves on the water surface and the influence of the tidal current may occur. It should not reach the hull of the work pontoon.

In addition, in these half SEP work pontoons and full SEP work pontoons, when the tower crane operation is stopped and the ship is to be navigated, the lifting legs are moved away from the bottom of the water so that the lowest part of the lifting legs is on the water surface. Raise the lift legs until they are close to each other, and keep the lift legs fixed to the deck of the work platform.

In a work platform equipped with the above-mentioned crane, if the base platform that supports the tower is fixedly supported by the work platform during crane work, the tower crane can be fixedly supported with a relatively simple structure. The phrase "when performing a crane operation" may mean moving, disassembling and assembling before and after that. For example, even when the base pedestal is movably provided on the rail laid on the deck of the work pontoon ship, the base pedestal may be fixed so as not to move on the rail when performing the crane work.

In the work pontoon ship including the above crane, the tower crane is configured to include a leg portion formed by assembling a leg block at a lower portion of the tower formed by assembling the mast block, and The following effects can be achieved by being configured with a tower lifting system that lowers the legs into the water.

According to this configuration, when the crane operation is performed, the tower lifting system causes the legs to bottom on the bottom of the water, and part or all of the load of the tower crane and the load of suspension is transferred via the mast block and the legs. It can be transmitted to the bottom and supported on the bottom. Therefore, the hull side of the work pontoon may bear part of the load of the tower crane and the load of the suspended load, or may not bear the load at all, so that the support structure for supporting the tower crane becomes strong in strength.

In other words, by using a tower crane for offshore installation of a wind turbine, when using a crane other than this tower crane, a strong hull structure is required as a support structure for the tower crane on the deck of the work platform ship. Since the structure for distributing the load is provided, the problem of occupying a large deck area can be solved.

In a work platform equipped with the above-mentioned crane, when performing a crane work, it is provided with a support structure for supporting the relative displacement of the tower crane with respect to the hull of the work platform, Almost all of the load of the tower crane and the load applied to the tower crane can be borne on the bottom of the water, the load received by the work pontoon can be significantly reduced, and the movement of the work pontoon (platform) side is transmitted to the tower crane. It is possible to solve the problem of interference that affects the crane work.

In other words, if the crane is fixed to the work platform and part or all of the load of the tower crane and the load of suspension is carried by the work platform, the load of the crane changes and the boom position changes. Due to changes and the like, the hull attitude (trim, heel) of the work pontoon that holds the crane changes. Therefore, it is necessary to carry out planned or periodical draft adjustment by ballast operation and jack-up operation according to the progress of crane work. Since changes in the ship's posture and draft due to this draft adjustment affect the crane work of the tower crane, there is a problem that the crane work is interrupted and the work efficiency of the crane is significantly reduced. The problem of this interference is that in the half SEP type (semi SEP type) work pontoons, the buoyancy changes during crane work due to the tidal range and the weight of the suspended load, and the work pontoons due to waves and wind. Will be upset, which will be a more important issue.

In addition, in a full SEP type work berth in which the hull is completely lifted above the surface of the water by jacking up the lifting legs, a full SEP type work pontoon vessel may be swayed by the influence of wind, etc. Vibration and the like propagate to the tower crane and are amplified, so that there is a problem that the work efficiency of the crane work is reduced. Since this full SEP type work pontoon generally operates under severer sea and weather conditions than the half SEP, it is important to solve this problem.

Regarding the problem of this interference, when performing crane work, by removing the structural connection between the tower crane and the work pontoon or changing to a flexible connection, the movement on the side of these work pontoons can be improved. , Can be suppressed from being transmitted to the tower crane side. As a result, the work efficiency and safety of the crane work can be improved during the crane work, particularly during the lifting work.

When navigating without crane work, the legs of the tower crane are lifted from the bottom of the water and the legs are disassembled or lifted until the lowest part of the legs is near the water surface, similar to the lifting legs. .. After that, by fixing either one or both of the tower and the legs of the tower crane to the deck of the work pontoon, the tower crane is fixed to the work pontoon for navigation.

In a work platform equipped with a tower crane that bottoms the legs, even when performing crane work, if the tower crane is configured so that it can be firmly fixed to the hull without allowing relative movement of the tower crane, Since the part can be used as a substitute for the lifting leg, one of the lifting legs can be omitted accordingly, the deck area can be saved, and the cost for one lifting leg can be reduced. Further, it is possible to reduce the working time for raising and lowering the hull and the working time for lowering the legs of the tower crane in the on-site sea area. However, this configuration requires a solid support structure for fixing the tower crane to the hull.

Further, in a work table equipped with a tower crane that bottoms the legs, when the crane is operated, by providing a flexible support capable of relative movement and a solid support that does not cause relative movement, Since it is possible to reinforce by supporting the legs, it is possible to reinforce with the support of the legs, against the condition of the water bottom where the work platform cannot be safely supported by only supporting the lifting legs. Will be able to.

In the work platform equipped with the above crane, if the outer shape of the cross section of the mast block and the outer shape of the cross section of the leg block are the same, the underwater portion and the aerial portion are shared. Therefore, the operation of the crane can be simplified. Further, even if the working water depth changes, it is not necessary to replace the mast block and the leg block.

In the work platform equipped with the above-mentioned crane, if the outer shape of the cross section of the mast block and the outer shape of the cross section of the elevating leg are the same shape, the member of the elevating leg with the mast block should be shared. The operation of the work pontoon can be simplified. Also, if necessary, replace the location where the tower crane is installed with the location of the lifting legs, and install the tower crane on the bow side or stern side, making it easier to install the tower crane. The position can be changed.

In the work pontoon ship equipped with the above crane, the work pontoon lifts and lowers the hull of the work pontoon to raise and lower the hull and an elevating and lowering system for elevating and lowering the lift leg. A half SEP or a full SEP equipped with the tower lifting system for lowering the legs of the tower crane into the water is configured to be compatible with the lifting platform lifting system as follows. It is possible to achieve various effects.

According to this configuration, the installation location of the tower crane can be easily replaced with the installation location of the lifting legs, so the installation location of the tower crane can be changed as necessary to move it to the bow, It becomes easy to move to the stern and install it. In addition, by using a common jack system for the lifting system for both the legs and the lifting legs of the tower crane, it is possible to simplify not only the equipment but also the operation in parts procurement, maintenance and inspection.

In the work pontoon ship equipped with the above crane, the work pontoon lifts and lowers the hull of the work pontoon to raise and lower the hull and an elevating and lowering system for elevating and lowering the lift leg. If the tower crane is a half SEP or a full SEP provided and is mounted on one of the elevating legs during crane work, the following effects can be obtained.

According to this configuration, on the hull side of the work pontoon, the elevating leg for mounting the tower crane is reinforced, and the strength of the elevating leg elevating system of the elevating leg is strengthened to newly add a tower crane tower. Without providing the lifting system, part or all of the load of the tower crane and the load of the suspended load can be transmitted to the bottom of the water through the lifting legs and supported on the bottom of the water. In addition, since the tower crane is arranged at the portion of the lifting legs, the deck space for installing the tower crane can be saved, and the workbench can be prevented from increasing in size.

In addition, compared with a work platform equipped with a tower crane equipped with a tower lifting system that is provided separately from the lifting legs, the legs of the tower crane are also used as the lifting legs, so the tower block of the tower crane and the tower Since the lifting system is not necessary, the cost can be reduced, and the work of landing on the legs of the tower crane on the work pontoon in the offshore area can be omitted, thereby reducing the work time.

And, a crane operating method of a work pontoon equipped with a crane for achieving the above-mentioned object is a crane operating method of a work pontoon equipped with the above crane, when performing a crane operation, the tower in the tower crane. Adjusting the suspension height by the number of stacked mast blocks forming the, when sailing while stopping the crane work, the number of stacked mast blocks is reduced from the number when working with the tower crane, This is a method characterized by lowering the height of the tower.

According to this operation method, when the crane work is performed, simply by increasing the number of stacked mast blocks, the installation height and the suspended load height can be easily increased in response to the height of the super-large wind turbine. Can be adjusted to. Further, at the time of navigation, the height of the tower can be easily lowered only by reducing the number of stacked mast blocks, so that the air draft of the work pontoon at the time of navigation can be lowered.

According to a work pontoon equipped with a crane and a method of operating the crane of the present invention, a work boat equipped with a crane used for offshore work in shallow water, particularly for installation of a landing type offshore wind turbine generator and maintenance work therefor. In (3), it is possible to easily change the lifting height of the crane according to the height of the work object, and when navigating without crane work, lower the crane height and lower the air draft. Moreover, since the overturning moment acting on the base of the crane is small, the scale of the base structure of the crane can be small, and the hull of the work pontoon can be prevented from increasing in size.

FIG. 1 is a plan view schematically showing the structure of a work platform (discharging type) equipped with a crane according to a first embodiment of the present invention. FIG. 2 is a side view schematically showing the configuration of a work pontoon (displacement type) equipped with the crane of FIG. 1, and is a diagram showing a configuration when a deck-installed tower crane is lowered to navigate. .. FIG. 3 is a side view schematically showing the configuration of a work pontoon (displacement type) equipped with the crane of FIG. 1, and is a diagram showing a configuration when a deck-installed tower crane is raised to perform crane work. Is. FIG. 4 is a plan view schematically showing the configuration of a work pontoon ship (SEP) equipped with the cranes of the second and third embodiments according to the present invention. FIG. 5 is a side view schematically showing the configuration of a work pontoon ship (SEP) equipped with the crane of FIG. 4, and is a diagram showing the configuration when a deck-installed tower crane is lowered to navigate. FIG. 6 is a side view schematically showing the configuration of a work pontoon (half SEP) equipped with a crane according to the second embodiment of the present invention, in which a deck-installed tower crane is raised to perform crane work. It is a figure which shows the structure in the case of performing. FIG. 7: is a side view which shows typically the structure of the working pontoon ship (full SEP) provided with the crane of the 3rd Embodiment which concerns on this invention, raises the tower crane of a deck installation type, and carries out crane work. It is a figure which shows the structure in the case of performing. FIG. 8: is a top view which shows typically the structure of the work pontoon (drainage type) provided with the crane of the 4th Embodiment which concerns on this invention. 9: is a side view which shows typically the structure of the work pontoon (drainage type) provided with the crane of FIG. 8, and is a figure which shows the structure at the time of making a bottom-mounted tower crane low, and sailing. .. FIG. 10 is a side view schematically showing the configuration of a work pontoon (displacement type) equipped with the crane of FIG. 8, which raises the tower by bottoming the legs of the bottom-mounted tower crane to raise the tower. It is a figure which shows the structure at the time of working. FIG. 11: is a top view which shows typically the structure of the work pontoon ship (SEP) provided with the crane of the 5th and 6th embodiment which concerns on this invention. FIG. 12 is a side view schematically showing the configuration of a work pontoon ship (SEP) equipped with the crane shown in FIG. 11, which is used when navigating while raising the legs of the bottom-mounted tower crane and lowering the tower. It is a figure which shows a structure. FIG. 13: is a side view which shows typically the structure of the work pontoon (half SEP) provided with the crane of the 5th Embodiment which concerns on this invention. It is a figure which shows the structure at the time of performing a crane work by raising a tower. FIG. 14: is a side view which shows typically the structure of the working pontoon (full SEP) provided with the crane of the 6th Embodiment which concerns on this invention. It is a figure which shows the structure at the time of performing a crane work by raising a tower. FIG. 15: is a top view which shows typically the structure of the working table ship (SEP) provided with the crane of the 7th and 8th embodiment which concerns on this invention. FIG. 16 is a side view schematically showing the configuration of a work pontoon ship (SEP) equipped with the crane shown in FIG. 15, which is used when navigating by pulling up the legs of a bottom-mounted tower crane and lowering the tower. It is a figure which shows a structure. FIG. 17 is a side view schematically showing the configuration of a work pontoon (half SEP) equipped with a crane according to a seventh embodiment of the present invention, in which the legs of a bottom-mounted tower crane are bottomed. It is a figure which shows the structure at the time of performing a crane work by raising a tower. FIG. 18: is a side view which shows typically the structure of the working pontoon ship (full SEP) provided with the crane of the 8th Embodiment which concerns on this invention. It is a figure which shows the structure at the time of performing a crane work by raising a tower. FIG. 19 is a diagram for explaining the work of reducing the number of assembled mast blocks in the tower crane. FIG. 20 is a side view schematically showing a state in which the crane main body 13 is placed on the deck of the work platform ship. FIG. 21 is a diagram for explaining the work of increasing the number of assembled mast blocks in the tower crane. 22: is a figure which illustrates the bottom plate of the raising / lowering leg of a working pontoon ship (SEP), (a) is a fixed-type bottom plate, (b) is a figure which shows an opening / closing-type bottom plate.

Hereinafter, a work boat equipped with a crane according to an embodiment of the present invention and a method of operating the crane will be described with reference to the drawings.

In addition, here, as the "offshore structure" that is the target of crane work, the power generation capacity per unit is, for example, about 7 MW to 10 MW, and the crane is installed in a shallow sea area with a lifting height of about 200 m. An offshore wind turbine generator (offshore wind turbine) is assumed. However, the present invention is not limited to such an offshore wind turbine generator, and may be any other offshore structure that requires crane work on the sea. Since the offshore structure itself which is the target of the crane work does not directly relate to the present invention, the offshore structure is not shown in order to simplify the drawings and the description thereof.

First, a tower crane provided for a work pontoon (hereinafter referred to as a work pontoon) equipped with the crane according to the embodiment of the present invention will be described. As shown in FIGS. 1 to 21, the tower cranes 10A, 10B, and 10C are also called climbing type jib cranes, and in the field of land, they are used for the construction of high-rise buildings and large-scale buildings, or concrete concrete pouring. It is a well-known crane used. The tower cranes 10A, 10B, and 10C are provided on the work pontoons 1A to 1H for use in installing offshore structures and the like.

This tower crane has a flat top type that horizontally moves a trolley that is mounted on a horizontally fixed boom, and a hammer head that supports this horizontally fixed boom from above with a wire. Type, luffing type with undulating jib. The luffing type has the advantages that the height of the tower to be assembled in the field is lower and the space required around the lifting work is smaller. In the following description, a luffing type tower crane is used.

The tower cranes 10A, 10B and 10C used in the work pontoons 1A to 1I of this embodiment are basically the same as the well-known tower cranes already used in the fields such as land construction and civil engineering. is there. With respect to the load applied to the tower, the tower cranes 10A, 10B, and 10C are configured such that the overturning moment acting on the tower 12 is made as small as possible and the vertical load is mainly due to its shape and use. .. That is, as shown in FIG. 3, in the tower cranes 10A, 10B, and 10C, the overturning moment (W × Lh) depending on the hanging load amount W and the horizontal distance Lh between the tower 12 and the hanging load is set on the opposite side. The crane body 13 is configured so as to be balanced by 13c and 13d.

Next, the structure of the tower cranes 10A, 10B, 10C will be described. The tower cranes 10A, 10B, and 10C are configured to have a base mount 11 (not the tower crane 10B), a tower 12, and a crane body 13. In this tower crane 10A, 10B, 10C, a plurality of mast blocks 12a are stacked to form a tower 12, and a crane main body 13 is placed on the top of the tower 12, and the tower is constructed according to the number of stacked mast blocks 12a. The height of 12 is adjusted. The mast block 12a is a component of the assembling tower 12 for adjusting the "hanging height Hh" directly related to the height of the tower 12 by the number of stacks.

This tower crane 10A, 10B, 10C is a mast climbing in which the crane main body 13 is raised while sequentially adding the mast block 12a to the tower 12 and the crane main body 13 is lowered while sequentially removing the mast block 12a from the tower 12. A device 14 is preferably provided.

That is, as the tower cranes 10A, 10B, and 10C, a tower crane of a type that raises and lowers the crane body 13 with the assistance of an auxiliary crane when the crane body 13 is raised and lowered may be used. It is more preferable to use a tower crane of a self-elevating type that elevates and lowers the crane body 13 by using the mast climbing device 14 without requiring assistance from the crane.

With this, the crane main body 13 can be lifted and lowered only by using the equipment and mechanism provided without using an auxiliary crane, so an auxiliary crane for lifting and lowering is not required, and the weight and deck space can be saved accordingly. Further, the tower 12 can be quickly assembled to a predetermined height.

A self-elevating type tower crane or an auxiliary crane may be used to incorporate the mast block 12a, but this auxiliary crane has a smaller capacity than the auxiliary crane for elevating the crane body 13. A crane is enough.

The tower cranes 10A, 10B, and 10C form a tower 12 by stacking a plurality of mast blocks (crane masts: posts) 12a on a base pedestal 11 in a working water area (construction site). The crane main body 13 is placed on 12. The crane main body 13 is assembled by attaching a boom (jib: arm of crane) 13b and passing a wire 13e for raising and lowering the boom 13b and hoisting and lowering a suspended load. After that, the climbing height Hh of a desired height is obtained by repeating climbing using the mast climbing device 14 to raise the crane body 13 and raise it while adding the mast block 12a.

The crane main body 13 of these work lanes 10A, 10B, and 10C includes a swing mechanism 13a, a suspension mechanism having a boom 13b, a front strut 13c, a rear strut 13d, and a wire 13e, and an operator's cab 13f. In this crane body 13, the front strut 13c and the rear strut 13d on the opposite side are balanced so that the overturning moment generated in the tower 12 by the load W of the suspended load is minimized. The boom 13b, the front strut 13c, and the rear strut 13d are a truss structure for weight reduction, and particularly, a lattice (lattice) structure that is a rhombic structure in which members are continuously connected in a pin shape with a joint structure as a pin structure. ) Structure is preferred.

The mast climbing device 14 is a device for raising the crane body 13 while incorporating the mast block 12a without using an auxiliary crane. As a climbing method using the mast climbing device 14, there are a method using expansion and contraction of a hydraulic cylinder, a method using tension of a lifting wire rope, and the like.

The mast climbing device 14 is composed of, for example, an upper lifting frame having an upper lift, a lower lifting frame having a lower lift, and a lifting cylinder, and the upper and lower lifts alternately support the entire mass of the crane body 13. The climbing method includes a method using a hydraulic cylinder, an electric cylinder, an electric chain block, a wire rope (used in combination with a hoisting device), and the hydraulic cylinder method is the mainstream for large cranes.

The crane main body 13 can move up and down the tower 12 by the expansion and contraction movement of the hydraulic cylinder. The lifting cylinders are equipped with "Kanuki" (bars) that engage through the holes of both members: Sekiki and Kanoki at the top and bottom. ing.

First, set the lower "Kanuki", extend the hydraulic cylinder, lift the crane body 13 together, and set the upper "Kanuki" at the specified height. When the crane body 13 is supported by the upper "Kanuki", the lower "Kanuki" is folded and the extended cylinder is contracted. When the hydraulic cylinder is fully compressed, set the lower "Cannuki" again and fold the upper "Cannuki" to extend the hydraulic cylinder. In this way, the crane main body 13 is alternately supported by "kanuki" and the crane main body 13 is moved up and down by repeatedly expanding and contracting the hydraulic cylinder.

As for the size of this tower crane 10A, it is already known that, for example, as a crane that can support assembling a super-large wind turbine of 5 MW or more in a port and maintenance in a working water area (it is also possible to assemble), the lifting load It has a boom length of 70 m, a maximum freestanding height of about 190 m, a maximum hook height (height related to the suspended load height) of about 170 m, and a weight of about 580 t. For comparison, a jib crane of equivalent capacity requires 1200t class, and its own weight is three times (1740t) or more. Further, regarding the mast block 12a that constitutes the tower 12 portion of this exemplified tower crane 10A. The outer shape of the cross section is about “3.5 m × 3.5 m” and the height is about “7.8 m”. These mast blocks 12a are bolted together. The maximum hook height is 170 m in a state where the tower 12 is self-supporting without a tie-in (support at an intermediate height also called a tie-back) from an offshore wind turbine or the like. The deck area required for installing the tower crane 10A is “16 m × 18 m” in the case of the structure in which the deck 3 receives the load of the tower crane 10A and the load W of the suspended load.

Next, a work pontoon (hereinafter, a work pontoon) including the crane according to the first embodiment of the present invention will be described. As shown in FIGS. 1 to 3, this work pontoon ship 1A comprises a drainage type work berth ship and a tower crane 10A of a deck mount type. This work pontoon 1A is a drainage type work pontoon that obtains buoyancy when the lower part of the hull 2 sinks below the surface of the water. Maintain position.

In this deck-mounting tower crane 10A, a base platform 11 that is firmly fixed to the deck 3 of the work table ship 1A is provided. The base mount 11 supports a tower 12 formed by vertically stacking mast blocks 12a, and bears the load of the tower crane 10A and the load of suspended load.

In the configuration of FIG. 1, in the work platform 1A, the deck (deck) 3 of the hull 2 is provided with a pair of arm-shaped structures formed of a pair of protrusions 4 projecting to the stern side, and a fork-shaped ( A U-shaped work mechanism is provided, an upper structure 5 serving as a bridge or a living area is provided on the bow side, and a tower crane 10A is provided on a portion of the deck 3 in the front-rear direction of the hull from the center to the rear side. ing. If necessary, a propeller for self-propelled vehicles and a propulsion system such as a rudder are mounted, but illustration of these propulsion systems is omitted.

2, the number of mast blocks 12a in the tower crane 10A can be reduced so that the height of the tower crane 10A can be equipped with the mast climbing device 14 and the crane main body 13 can be used. Is the minimum height that can be placed on the tower 12.

Normally, in order to save the work of assembling the crane main body 13, the tower 12 is lowered while the tower crane 10A is assembled as shown in FIG. 2, but the crane may be moved as necessary. The main body 13 may be removed from the tower 12, the tower crane 10A may be disassembled, and the tower crane 10A may be placed on the deck 3 to lower the overall height and sail.

Then, as shown in FIG. 3, when arriving at the work area and performing the crane work, the work platform 1A is moored with the anchor and the anchor rope 6a and the mooring rope 6b. In this case, the mooring system or the like that holds the ship position (position of the work table 1A) while adjusting the length and tension of the mooring line 6b and the like with a winch holds the ship position at the work point. Further, an automatic ship position holding system (DPS) using a side thruster, an azimuth thruster or the like may be equipped to hold the ship position at the work point.

In this displacement-type work pontoon 1A, the construction of lifting legs (legs, spuds) that go up and down by jacking up like SEP (self-elevating work boat) described later is unnecessary. This drainage type work pontoon ship 1A is suitable for crane work in a work area where the wind, waves and tidal currents are relatively small and the work berth receives less disturbance.

Before starting the crane work, the mast climbing device 14 is used to repeatedly raise the crane body 13 while incorporating the mast block 12a to raise the tower 12 to obtain a desired "hanging height Hh". At this time, as shown in FIG. 3, the air draft He2 becomes significantly higher than the air draft He1 during navigation shown in FIG.

In addition, during crane work, in the work pontoon 1A, the attitude of the hull 2 is adjusted in response to changes in the load of the tower crane 10A and changes in the boom length by means of pouring and draining ballast water and a mooring system. To maintain. Therefore, the tower crane 10A is preferably installed near the center of the hull in the left-right direction of the hull. Regarding the front and rear direction of the hull, the tower crane 10A should be installed in consideration of the mounting position of an offshore structure (not shown) to be installed during transportation, the weight distribution before and after the hull 2, the arrangement of ballast tanks, and the like. The location is set.

Next, a work pontoon (hereinafter, a work pontoon) including the cranes according to the second and third embodiments of the present invention will be described. As shown in FIGS. 4 to 6, the work pontoon boat 1B of the second embodiment comprises a half SEP type work pontoon boat equipped with a deck-mounted tower crane 10A. As shown in FIGS. 4, 5 and 7, the work pontoon ship 1C of the third embodiment is a full SEP type work pontoon ship equipped with a deck-mounted tower crane 10A. In the work pontoons 1B and 1C, as in the work pontoon 1A of the first embodiment, the deck-installed tower crane 10A is installed on the deck 3.

This half SEP type work pontoon 1B and full SEP type work pontoon 1C are types of work pontoons called SEP (Self Elevating Platform), jack-up boat, etc. A few lifting legs (legs, spuds) 20 arranged around work pontoons 1B and 1C (four in this embodiment, four legs arranged in four corners) and the lifting legs 20 are lowered, and An elevating leg elevating system (jack up system) 21 for elevating the hull 2 by equipping the water bottom (sea bottom) B with its tip (bottom) is provided.

Each of these work pontoons 1B, 1C is equipped with a pair of fixed stern-side lifting legs (spads) 20 near the stern and a kick-type bow-side lifting leg 20 in front. This fixed-type lift leg is a type of kick-type lift that restrains the relative swing between the lift leg and the pontoon and the degree of freedom in the horizontal direction when the amount of protrusion of the lift leg to the lower part of the carrier is fixed. The legs are allowed to swing relative to each other around the pins while the amount of protrusion of the lift legs to the lower part of the pedestal is fixed by the support by horizontal pins. By pushing and pulling in a horizontal direction relative to the pedestal, the elevating leg tilts like a pendulum, and the pedestal can be moved to walk on the seabed with the elevating leg. Is not allowed and remains vertical, but it is also possible to move the ship by sliding it horizontally with respect to the ship using a hydraulic cylinder.

The bottom plate of this lifting leg 20 is equipped with a bottom plate that is used as necessary in consideration of geological features of the seabed. This bottom plate has a structure for receiving a force applied to the lifting legs 20, and as a work platform, as shown in FIG. 22, there is an openable-closed bottom plate 22b in addition to the fixed bottom plate 22a. The openable bottom plate 22b is widely opened to cope with soft ground such as loose sand or cohesive soil, or the bottom plate 22b is flipped up to invalidate the support by the bottom plate 22b, and the sharply formed tower tip 22c is removed. It is constructed so that it can be stabbed in solid ground.

Furthermore, it is more preferable to equip the work pontoons 1B and 1C with an automatic ship position holding system so that they can be used not only for offshore wind power generation but also for various projects.

Then, as shown in FIG. 5, when the work pontoons 1B and 1C stop the operation of the tower crane and sail, the lift legs 20 are moved away from the water bottom B so that the lowest part of the lift legs is the bottom. Raise it to a certain height, and keep the descending legs fixed to the deck of the work platform. In this navigation state, as in the navigation state of the drainage type work pontoon ship 1A, the lower portion of the hull 2 sinks below the water surface to obtain buoyancy.

On the other hand, when performing a crane operation, as shown in FIGS. 6 and 7, the elevating legs (legs, spuds) 20 are lowered to reach the bottom B of the water, and the elevating legs 20 are further extended. The work pontoons 1B and 1C are fixedly supported by the lifting legs 20. When the hull 2 floats on the water surface S in this state, it is called a half SEP, and when the entire hull 2 is lifted above the water surface S in this state, it is called a full SEP.

Then, in the half SEP type work pontoon 1B, as shown in FIG. 6, when the hull 2 is lifted, a part of the hull 2 is placed under the water surface S. In this state, a part of the weight of the hull 2 is supported by the lifting legs 20, so that the position and the posture of the hull 2 are maintained. In this state, a part of the weight of the hull 2 is borne by the buoyancy of the hull 2, but a part of the hull 2 is lifted above the water surface S by the elevating legs 20 or the amount of ballast water injected is increased or decreased. By increasing or decreasing the weight of the hull 2, the load applied to the lifting legs 20 is increased or decreased.

In this half SEP, the hull floats above the water when a part of the lifting legs is submerged, so it is easy for the hull to move due to waves, but the buoyancy of the hull can handle changes in the load. It is possible to avoid tilting the tower and tower greatly. Therefore, this half SEP work pontoon is suitable for operation in the medium sea area. It should be noted that in this half SEP, the lifting legs 20 and the lifting leg lifting system 21 are not large-capacity objects such as full SEPs capable of lifting the dead weight and the load weight, but are partially used for a dredging barge. It is sufficient that the buoyancy is supplemented and the hull 2 can be stably supported.

On the other hand, in the full SEP type work pontoon 1B, as shown in FIG. 7, when the hull 2 is lifted, the entire hull 2 is placed above the water surface S. In this state, the elevating legs 20 support the entire weight of the hull 2 to hold the position and posture of the hull 2. In this state, the load applied to the elevating legs 20 and the attitude of the hull 2 are adjusted by adjusting the descending amount of the elevating legs 20 by the elevating leg elevating system 21. In this full SEP, by setting this state, it is possible to operate in the high sea area, and work efficiency and construction accuracy can be improved.

Further, according to the work pontoons 1A, 1B, and 1C of the first to third embodiments, since the deck-installed tower crane 10A is fixedly supported on the deck 3, the following effects are obtained. Can be demonstrated. Regarding the fixing of the tower crane 10A to the work pontoons 1A, 1B and 1C, the tower crane 10A may be moved on the deck 3 or disassembled and assembled before and after the crane work. Good. For example, even when the base platform 11 is movably provided on the rails laid on the decks 3 of the work pontoons 1A, 1B, and 1C, it cannot move on the rails when performing the crane work. It just needs to be fixed.

According to these work pontoons 1A, 1B, and 1C, the structure of the base pedestal 11 that supports or fixes the tower 12 of the tower crane 10A mainly receives the load in the vertical direction. Structurally easier than the supporting structure (base structure) of a crane with a large moment. That is, since the overturning moment acting on the tower 12 and the base pedestal 11 is small and most of the loads are vertical loads, the structural strength required for the base pedestal 11 as the base is smaller than that of other types of cranes. .. As a result, since the tower crane 10A can be fixedly supported by a relatively simple structure, the member weight and deck area required for the support structure of the tower crane 10A are the work benches equipped with other types of conventional cranes. It will be less than a ship. Therefore, it is possible to prevent the work pontoon from increasing in size.

Due to the structure of the tower crane 10A, the lifting capacity hardly depends on the height, and the installation heights He1 and He2 and the "hanging load height Hh" can be easily adjusted according to the height of a super-large wind turbine. Therefore, when performing a crane operation, the "crane height" can be easily increased by increasing the number of stacked mast blocks 12a. Therefore, it is easy to increase the "hanging load height" (the height related to the maximum hook height, which is the height of the highest position of the hook), which can lift the hanging load of the preset hanging load. it can.

On the other hand, at the time of navigation, by reducing the number of stacked mast blocks 12a, the air draft He1 can be lowered and it becomes possible to navigate under a bridge with a height restriction. Note that the air draft as a whole of the work pontoons 1A, 1B, 1C is related to the height of the offshore structures when the offshore structures are mounted on the work pontoons 1A, 1B, 1C for navigation. , It is not always necessary to have the tower 12 at a minimum height.

Regarding the stability performance of the work pontoons 1A, 1B, and 1C, the height of the tower crane 10A becomes lower, and the center of gravity of the work berths 1A, 1B, and 1C becomes lower, so that good stability performance can be easily achieved. Can be secured. Further, by disposing the disassembled and removed mast blocks 12a on the deck 3, an auxiliary ballast for maintaining the attitude (trim, heel) of the hull 2 of the work pontoons 1A, 1B, 1C during navigation. Can be used as As a result, the capacity of the ballast tank required to secure the restoration performance can be reduced, and the work pontoons 1A, 1B, and 1C can be prevented from increasing in size.

Further, by constructing the tower crane 10A in a self-elevating type, the tower crane 10A can be quickly assembled without using an auxiliary crane, so that the efficiency of the assembly work of the tower crane 10 can be improved.

Next, the work pontoons 1D, 1E, and 1F of the fourth to sixth embodiments equipped with the bottom-mounted tower crane 10B will be described. As shown in FIGS. 8 to 10, the work pontoon boat 1D of the fourth embodiment is the same displacement type work pontoon boat as the work pontoon boat 1A of the first embodiment. Further, as shown in FIGS. 12 to 14, the work pontoon boat 1E of the fifth embodiment is the same half SEP type work pontoon boat as the work pontoon boat 1B of the second embodiment. The work pontoon 1F of the sixth embodiment is, as shown in FIGS. 12, 13, and 15, a work pontoon 1C of the third embodiment and a full SEP type work pontoon.

In these work pontoons 1D, 1E, and 1F, a tower crane 10B is provided with a leg portion 15 formed by assembling a leg block 15a at a lower portion of a tower 12 formed by assembling a mast block 12a. In addition, the tower lifting system 16 for lowering the legs 15 into the water is provided. Further, the tower lifting system 16 for lowering the legs 15 of the tower crane 10B and the lifting leg lifting system for lifting the lifting legs 20 are separate systems. In the SEP work pontoons 1E and 1F, the hull 2 can be stably supported only by the lifting legs 20 without depending on the legs 15 of the tower crane 10B.

In this bottom-mounted tower crane 10B, when performing a crane operation, the portion above the hull 2 is composed of the tower 12 formed by assembling the mast block 12a, and the portion below the hull 2 is the leg. The legs 15 are formed by assembling the partial block 15a. Further, the leg 15 continuously provided to the tower 12 is passed through a through hole provided on the deck 3 or the hull 2 or a notch or a recess provided on a side portion of the deck 3 or the hull 2 to elevate the tower. It is lowered by the system 16 to reach the bottom B. Due to the bottom of the leg portion 15, the load of the tower crane 10B and the load for suspension are received by the water bottom B.

In this configuration, the external shape of the cross section of the mast block 12a and the external shape of the cross section of the leg block 15a are the same, that is, the leg block 15a that enters the water below the deck 3 is It is preferably formed with the same outer dimensions as the mast block 12a arranged above. Furthermore, by making the leg block 15a of the leg portion 15 and the mast block 12a of the tower 12 commonly usable, the tower 12 and the leg portion 15 are indistinguishable from each other in a series, and the space between the tower 12 and the leg portion 15 is eliminated. The base stand 11 is not present. In this case, in the illustrated tower crane 10B having a suspension weight of 125 tons, the sizes of the deck 3 and the opening of the hull 2 through which the mast block 12a or the leg block 15a penetrates are, for example, 3.5 m x 3.5 m ".

By doing so, the operation can be simplified by sharing the leg block 15a of the member that becomes the underwater portion and the mast block 12a of the member that becomes the aerial portion. Further, even if the water depth in the crane working water area changes a little, it is not necessary to replace the mast block 12a and the leg block 15a each time. The leg block 15a that enters the water is preferably made of a material that is superior in strength and corrosion resistance to the mast block 12a in the air.

In the SEP work berths 1E and 1F, the legs 15 of the bottom-mounted tower crane 10B are provided separately from the lifting legs 20 for lifting the hull 2. With this configuration, it is more preferable that the outer shape of the cross section of the mast block 12a and the outer shape of the cross section of the elevating leg 20 have the same shape. As a result, the operation of the work pontoons 1E and 1F can be simplified by sharing the member of the lifting leg 20 with the mast block 12a. In addition, if necessary, the place where the bottoming-up type tower crane 10B is installed is replaced with the place of the lifting leg 20, so that the tower crane 10B can be easily installed on the bow side or the stern side. The position of the tower crane 10B can be easily changed.

Further, it is preferable that the tower lifting system 16 for lowering the legs 15 of the tower crane 10B into the water is configured to be compatible with the lifting leg lifting system 21. This makes it possible to more easily replace the installation location of the tower crane 10B with the installation location of the lifting legs 20, so that the installation location of the tower crane 10B can be changed and moved to the bow if necessary. Or move to the stern and set up. Further, by constructing the lifting systems 16 and 21 for both the legs 15 and the lifting legs 20 of the tower crane 10B with a common jack-up system, not only when the tower crane 10B and the lifting legs 20 are equipped, It is possible to simplify the operation of the systems 16 and 21 in parts procurement, maintenance and inspection.

In addition, the work platform 1E, 1F can be jacked up with only three lifting legs 20 so that it can be stably supported, and instead of the remaining lifting legs 20, a bottom-mounted tower crane 10B is installed. It is also possible to do it. In this case, the bottom-mounted tower crane 10B can be installed by a modification to reinforce the leg structure of the existing work platform 1E, 1F having the four lifting legs 20.

Furthermore, it is preferable to provide a support structure for supporting the relative displacement of the tower crane 10B with respect to the hull 2 of the work pontoons 1D, 1E, 1F during crane work. That is, during the crane operation, the deck 3 and the tower crane 10B are configured to have an elastic support structure with an elastic member interposed therebetween or a flexible support structure using a crank mechanism. It is preferable that the shaking and vibration of the above is not transmitted to the tower 12 and the leg 15 of the tower crane 10B. For example, when the crane work is not performed, the tower crane 10B is configured to be firmly fixed to the deck 3 by the clamp device (fixing device) 17, and when the crane work is performed, the clamp device 17 is opened to be flexible. Switch to good support.

According to the work pontoons 1D, 1E, 1F of the fourth to sixth embodiments, in addition to the effects of the work pontoons 1A, 1B, 1C of the first to third embodiments described above, The following effects can be exhibited.

In the bottom-mounting tower crane 10B, when performing a crane operation, the tower lifting system 16 causes the legs 15 to land on the bottom B of the water, and the load of the tower crane 10B and a part or all of the load of the suspended load are masted. The water can be transmitted to the water bottom B via the block 12a and the leg block 15a and can be supported by the water bottom B.

Therefore, the hull 2 side of the work pontoons 1D, 1E, 1F may bear or may not bear a part of the load of the tower crane 10B and the load of the suspended load, so that the support structure for supporting the tower crane 10B is provided. Will be easier in terms of strength. As a result, the supporting load on the work pontoons 1D to 1F can be reduced, the supporting structure of the tower crane 10B can be simplified, and the increase of the weight of steel materials for the supporting structure and the expansion of the deck area can be suppressed, It is possible to prevent the work pontoons 1D, 1E, and 1F from increasing in size.

In the drainage type work pontoons 1D and the half SEP work pontoons 1E, the hulls 2 of the work pontoons 1D and 1E incline due to the load of the suspended load acting on the tower crane 10B and the boom length. Since this can be prevented, ballast adjustment is unnecessary, and the work efficiency and safety of crane work can be improved.

Then, when the crane work is provided with a support structure that supports the tower crane 10B in a state in which the relative displacement of the tower crane 10B is allowed with respect to the hull 2 of the work pontoons 1D, 1E, 1F, the tower crane 10B Since the load and the load applied to the tower crane 10B are not transmitted to the work pontoons 1D, 1E, 1F side, almost all of the load can be borne by the water bottom B, and the loads received by the work pontoons 1D, 1E, 1F. Can be significantly reduced. At the same time, it is possible to solve the problem of interference in which shaking and vibration on the side of the work pontoons 1D, 1E, and 1F are propagated to the tower crane 10B and the crane work is affected.

That is, when the tower crane 10B is fixed to the work pontoons 1D, 1E, and 1F, and part or all of the load of the tower crane 10B and the suspended load is borne by the work pontoons 1D, 1E, and 1F. Then, since the hull postures (trim, heel) of the work pontoons 1D, 1E, 1F fixing the tower crane 10B change due to changes in the load of the tower crane 10B and changes in the boom position, etc. Depending on the progress of work, it is necessary to plan or periodically adjust the draft by ballast operation and jack-up operation. Since changes in the hull posture and draft due to this draft adjustment affect the crane work of the tower crane 10B, there is a problem that the crane work is interrupted and the work efficiency of the crane is significantly reduced.

The problem of this interference is that, in the half SEP type (semi SEP type) work table boat 1E, during crane work, the buoyancy changes due to the tidal range and the weight of the suspended load, and the work table due to waves and wind. This is a more important issue, as the ship will be upset.

In addition, in the full SEP type work berth 1F in which the hull 2 is completely lifted above the water surface by jacking up the lifting legs 20, in the full SEP type work table 1F, shaking of the hull 2 caused by the influence of wind or other equipment on board. There is a problem that the work efficiency of the crane work is lowered because the vibration and the like due to the operation of (1) propagate to the tower crane 10B and are amplified. This full SEP type work pontoon 1F generally works under severer sea conditions and meteorological conditions than the half SEP work pontoon 1E, and therefore it is important to solve this problem.

Regarding the problem of this interference, when performing clay work, by removing the structural connection between the tower crane 10B and the work pontoons 1D, 1E, 1F side or by making a flexible connection, these work pontoons It is possible to suppress the movement of the 1D, 1E, and 1F sides from being transmitted to the tower crane 10B side. As a result, work efficiency and safety can be improved during crane work, particularly during lifting work.

Further, in the work pontoons 1D, 1E, and 1F equipped with the tower crane 10B for landing the legs 15, the tower crane 10B remains firmly fixed to the hull 2 even when performing crane work. In the case of such a configuration, a solid support structure for fixing the tower crane 10B to the hull 2 is required, but the leg portion 15 of the tower crane 10B can be used as a substitute for the lifting leg 20. Therefore, one of the lifting legs 20 can be omitted, the deck area can be saved, and the cost of one lifting leg 20 can be reduced. Further, the working time for raising and lowering the hull 2 and the working time for lowering the legs 15 of the tower crane 10B in the on-site sea area can be saved by the reduction of the lifting legs 20.

Further, in the work pontoons 1D, 1E, and 1F equipped with the tower crane 10B that bottoms the legs 15, flexible support that allows relative movement and firm support that does not cause relative movement are selected when performing crane work. With such a structure, the legs 15 can be reinforced by supporting the state of the water bottom B in which the work platform 1D, 1E, 1F cannot be safely supported by only the lifting legs 20. Therefore, the crane work can be performed in a wider water bottom B state.

When the tower crane 10B is stopped and sailing, the legs 15 are moved away from the bottom of the water and the legs 15 are moved until the lowest part of the legs 15 is near the surface of the water, like the lifting legs 20. And one or both of the tower 12 and the legs 15 of the tower crane 10B are fixed to the hull 2, and the tower crane 10B is fixed to the work pontoons 1D, 1E, and 1F for navigation.

Next, the work pontoons 1G and 1H of the seventh and eighth embodiments will be described. The work pontoons 1G of the seventh embodiment are, as shown in FIGS. 15 to 17, half SEP type work pontoons which are the same as the work pontoons 1B and 1E of the second and fifth embodiments. As shown in FIGS. 15, 16 and 18, the work pontoon 1H of the eighth embodiment is the same full SEP type work as the work pontoons 1C and 1F of the third and sixth embodiments. It is a barge. Each of these work pontoons 1G and 1H is configured to mount a tower crane 10C of a lifting leg mounting type.

In the tower crane 10C of the lifting leg mounting type, the base pedestal 11 is provided on the lifting leg 20A for bottoming and supporting the SEP work pontoons 1G, 1H, and the base pedestal 11 on the lifting leg 20A is used. The mast block 12a supports the tower 12 formed by vertically stacking it, receives the load of the tower crane 10C and the load of the suspended load, and transmits this load to the lifting legs 20A that have bottomed on the bottom B of the water. The bottom B of water. In this case, the lifting legs 20A equipped with the lifting leg-mounting tower crane 10C also support the hulls 2 of the work pontoons 1G and 1H, so a part of the weight of the hull 2 and the load of the tower crane 10C. And it will support the load of the suspended load. Therefore, it is composed of a structure having higher strength than the other lifting legs 20B.

In these work pontoons 1G and 1H, the elevator leg-mounting tower crane 10C is configured in the same manner as the deck-mounting tower crane 10A, except that the base platform 11 is placed on the elevator legs 20A. There is.

According to the work pontoons 1G and 1H of the seventh and eighth embodiments configured as described above, on the hull 2 side of the work pontoons 1G and 1H, the lifting legs 20A for mounting the tower crane 10C are reinforced, By increasing the strength of the lifting / lowering leg lifting system 21 of the lifting / lowering leg 20A, a part or all of the load of the tower crane 10C and the load of the suspended load are newly provided without providing the tower lifting / lowering system 16 for the tower crane 10C. Can be transmitted to the water bottom B via the elevating legs 20A and supported by the water bottom B. In addition, since the tower crane 10C is arranged at the portion of the lifting leg 20A, the deck area for installing the tower crane 10C can be reduced, and the work pontoons 1G, 1H can be prevented from increasing in size.

Further, as compared with the work pontoons 1D, 1E, and 1F equipped with the tower crane 10B having the tower lifting system 16 provided separately from the lifting legs 20, the leg portion 15 of the tower crane 10C is also used as the lifting legs 20A. Since the tower block 15a of the tower crane 10C and the tower lifting system 16 are not necessary, the cost is reduced, and the bottoms of the legs 15 of the tower crane 10B on the work berths 1D, 1E, and 1F in the field sea area are settled. The work can be omitted, and the work time for this can be reduced in the work pontoons 1G and 1H.

Next, a crane operating method (hereinafter, referred to as “crane operating method”) of a work pontoon ship equipped with the crane according to the embodiment of the present invention will be described. This crane operating method is a crane operating method in the work pontoons 1A to 1I equipped with the above cranes.

In this crane operation method, when the offshore structure is loaded on the work berth 1A from the quay or port of the factory, the crane set on the quay or harbor is usually used, but it is loaded on the work berth 1A. It is also possible to assemble the working tower crane 10A as shown in FIG. 3 and use the tower crane 10A to mount an offshore structure on the work pontoon 1A by crane work. Alternatively, the offshore structure may be placed in the recess D (FIG. 1) formed by the protrusion 4 by utilizing the protrusion 4 at the stern of the work platform 1A.

Before the next navigation or at the first stage during navigation, as shown in FIG. 19, from the state of FIG. 3, the number of assembled mast blocks 12a of the tower crane 10A is reduced to lower the tower 12. As a result, the tower 12 is lowered to the state shown in FIG. For example, during normal navigation, the mast block 12a is reduced to about 4 blocks in consideration of sway and especially when traveling under the bridge. As a result, the crane body 13 also descends to a lower position accordingly. As a result, the upper end of the crane is about 30 m above the water surface.

Further, the crane body 13 is removed from the tower 12 so that it is placed on the deck 3 as shown in FIG. Then, the height of the tower crane 10A is lowered to lower the air draft of the work pontoon 1A, and the restoration performance is improved, and the boat is sailed. In this case, an auxiliary crane for assembling the crane body 13 to the tower 12 is required. Further, during a project in which a crane is not necessary, the crane main body 13 can be removed and the crane can be unloaded from the work pontoon ship 1A, but attachment and detachment of the crane requires assistance from another crane. In this case, the crane at the base can be used.

This navigation will be self-propelled if it has a propulsion system, and will be towed by another ship if it does not have a propulsion system. In addition, in the SEP work pontoons 1B, 1C, 1E, 1F, 1G, 1H, at the time of navigation, as shown in FIG. 5, FIG. 9, FIG. 12, and FIG. 15 is pulled up to a height around the bottom of the hull 2. The height of the crane can be kept low during navigation, especially when passing under a bridge.

After reaching the working water area, in the drainage type work pontoons 1A and 1D, as shown in FIGS. 3 and 10, mooring systems such as anchor ropes 6a and mooring ropes 6b, an automatic ship position holding system (DPS system), etc. Thus, the work pontoon ship 1A is held at the work position. Further, in the half SEP work pontoons 1B, 1E, and 1G, as shown in FIGS. 6, 13, and 17, the elevating leg elevating system 21 lowers the elevating legs 20 to reach the bottom B of the water. As a result, the work pontoons 1B, 1E, 1G are held at the work position while floating on the water surface S. Further, in the full SEP work pontoons 1C, 1F, 1H, as shown in FIGS. 7, 14 and 18, the elevating leg elevating system 21 lowers the elevating legs 20, 20A, 20B to reach the bottom B of the water. Bottom out. As a result, the work pontoons 1C, 1F, 1H are held at the work position in a state where they are above the water surface S. By these, the work pontoons 1A to 1H are held in stable positions.

Further, in the case of the work pontoons 1D, 1E, 1F equipped with the bottoming type tower crane 10B, the legs of the bottoming type tower crane 10B are further added before, after, or in parallel with the lifting work of the lifting legs 20. While assembling the partial blocks 15a to form the legs 15, the tower elevating system 16 lowers the legs 15 to the bottom to hold the work platform in a stable position.

On the work pontoons 1A to 1H, when the position holding is completed or in parallel with the position holding work, the tower cranes 10A, 1B, and 10C are assembled. In the work pontoon ship 1A, as shown in FIG. 20, when the crane main body 13 is disassembled, the crane main body 13 is assembled into the state shown in FIG. From the state of FIG. 2, as shown in FIG. 21, the crane main body 13 is jacked up by the self-elevating device of the tower crane 10A, the number of mast blocks 12a incorporated is increased, and the tower 12 is raised. As a result, as shown in FIG. 3, in the work pontoon ship 1A, a crane operation can be performed by the deck-mounted tower crane 10A. In addition, as shown in FIGS. 6 and 7, the work pontoons 1B and 1C are also in a state in which the deck-mounted tower crane 10A can perform crane work.

Also, in the work pontoons 1D, 1E, and 1F equipped with the leg lifting tower crane 10B, the position holding and the bottoming of the legs 15 of the leg lifting tower crane 10B are completed. Before or after this, or in parallel, the crane main body 13 is jacked up by the self-elevating device of the tower crane 10B to increase the number of incorporated mast blocks 12a and raise the tower 12.

When the clamp device 17 is configured to be able to release the fixed support during crane work and to flexibly support the tower crane 10B on the work pontoons 1D, 1E, and 1F while allowing relative displacement, The fixed support of the clamp device 17 is released. On the other hand, when the clamp device 17 has a structure in which the fixed support cannot be released, the clamped state is maintained as it is. As a result, as shown in FIGS. 10, 13, and 14, the tower lifting tower crane 10B is ready for crane work.

In addition, in the work pontoons 1G and 1H equipped with the lifting / lowering leg-mounting tower crane 10C, when the position holding is completed, the tower crane 10C mounted on the lifting / lowering leg 20A, as shown in FIG. In FIG. 17, the mast block 12a is incorporated to raise the tower 12 so that the crane work can be performed by the elevating leg-mounting tower crane 10C as shown in FIGS.

Then, when the crane work can be performed on the work pontoons 1A to 1H, as many mast blocks 12a as necessary are incorporated to make the height of the tower 12 suitable for crane work, if necessary. Perform crane work. In the case of the self-elevating type, the crane body 13 can be self-elevated by a hydraulic cylinder, and a hoist provided on the crane body 13 can lift and add an additional mast block 12a.

For example, according to the standard specifications of a tower crane that performs a crane work with a hook height of 170 m, a hoisting load of 125 t, and a hoisting speed of 6 m / min, each of the strike blocks 12a having a height of 7.8 m is required to reach the maximum freestanding height. In addition, it is necessary to increase the number by eight. In this tower crane, one assembly time is about one hour, so it takes about eight hours to reach the maximum freestanding height. Therefore, by assembling two mast blocks 12a in advance and loading the mast blocks 12a having a height of 15.6 m in about one hour, by repeating this four times, a short time can be obtained. Therefore, it becomes possible to obtain a suspension height capable of performing work of a 5 MW class wind turbine. In this standard specification mast block 12a, the block height per unit is determined in consideration of the transportation constraint on land, and on the ocean, there is no constraint on this transportation. It is possible to install the blocks together.

Further, during the crane work, while performing the mooring system and the ballast control for maintaining the attitude of the hull and the lifting adjustment of the lifting legs 20, 20A, 20B and the legs 15, and the hulls of the work pontoons 1A to 1H. Crane work such as installation of offshore structures is performed while maintaining the posture.

Then, when the crane work at the working position is completed, the mooring system is released or the elevating leg 20 is lifted to move to another working position in the working water area as necessary, and the mooring system is again set. Crane work is carried out by setting, raising and lowering legs 20, 20A, 20B, and leg portion 15 being lowered and bottomed and held at their working positions. This is repeated in the working area. Then, when a series of crane work in this work water area is completed and the work is moved to another work water area, the work berths 1A to 1H are used to carry out the operations shown in FIG. 2, FIG. 5, FIG. 9, FIG. The state shown in FIG. 16 is obtained.

According to the above crane operating method, when performing crane work, the suspension height is adjusted by the number of mast blocks 12a forming the towers 12 in the tower cranes 10A to 10C, and when the crane work is stopped and sailing is performed, The number of mast blocks 12a to be piled up is made smaller than the number when the tower cranes 10A to 10C are operated, and the height of the tower 12 is lowered.

According to this crane operation method, when the crane work is performed, simply by increasing the number of the mast blocks 12a to be stacked, the installation height and the suspended load height can be correspondingly increased with respect to the height of the super-large wind turbine. Can be easily adjusted. Further, at the time of navigation, the height of the tower 12 can be easily lowered only by reducing the number of stacked mast blocks 12a, so that the air draft of the work pontoons 1A to 1H at the time of navigation can be lowered.

Therefore, when the tower 12 is added in the working water area according to the water depth, the crane height is adjusted according to the wind turbine when maintenance of the wind turbine is required, and the tower cranes 10A, 10B, and 10C are unnecessary and temporarily in a project. It will be possible to easily remove it.

According to the work pontoons 1A to 1H equipped with the crane having the above-described configuration and the crane operating method thereof, when used for offshore work in shallow water, especially for installation and maintenance work of a landing type offshore wind turbine generator. The height of the crane can be easily changed according to the height of the work object, and when navigating without crane work, the height of the crane can be lowered to lower the air draft. In addition, the overturning moment acting on the base of the crane is small, the scale of the base structure of the crane is small, and the hulls of the work pontoons 1A to 1H can be suppressed.

1A work boat (drainage type work boat equipped with deck-mounted tower crane)
1B workboat (half-SEP workboat with deck-mounted tower crane)
1C work boat (Full SEP work boat with deck-mounted tower crane)
1D work boat (drainage type work boat equipped with bottomed tower crane)
1E Work Vessel (Half SEP work vessel equipped with bottomed tower crane)
1F work boat (full SEP work boat equipped with bottomed tower crane)
1G work boat (Half SEP work boat equipped with a lifting tower-mounted tower crane)
1H work boat (Full SEP work boat equipped with a lifting tower-mounted tower crane)
2 hull (platform)
3 decks (deck)
10 tower crane (deck mounting type)
10B tower crane (bottom type)
10C tower crane (elevating leg mounting type)
11 base mount 12 tower 12a mast block 13 crane body 13b boom (jib: crane arm)
14 Mast Climbing Device 15 Leg 15a Leg Block 16 Tower Lifting System 17 Clamping Device (Fixing Device)
20, 20A, 20B Lifting leg (leg, spud)
21 Lifting leg lifting system 22a Bottom plate (fixed type)
22b Bottom plate (open-close type)
22c Tower tip B Water bottom D Recess He1 Air draft S Water surface

Claims (11)

1. In a work table equipped with a crane that uses a crane to install offshore structures,
   As the crane, a tower crane is formed by stacking a plurality of mast blocks to form a tower, and a crane body is placed on the top of the tower, and the height of the tower is adjusted according to the number of the mast blocks stacked. A work table equipped with a crane characterized by being equipped with.
2. The tower crane is a self-elevating type mast climbing device that raises the crane main body while sequentially connecting the mast block to the tower and lowers the crane main body while sequentially removing the mast block from the tower. A work pontoon equipped with the crane according to claim 1, characterized in that the work berth is provided.
3. The work pontoon is either a drainage type work pontoon, a half SEP in which the hull is floating on the water surface during crane work, or a full SEP in which the hull is above the water surface during crane work. It is one work pontoon, The work pontoon provided with the crane of Claim 1 or 2 characterized by the above-mentioned.
4. A work platform equipped with the crane according to any one of claims 1 to 3, wherein a base platform for supporting the tower is fixedly supported by the work platform during crane work.
5. The tower crane is configured to include a leg portion formed by assembling leg blocks at a lower portion of the tower formed by assembling the mast block, and a tower lifting system for lowering the leg portion into water. A work table equipped with the crane according to any one of claims 1 to 3, characterized in that
6. The crane according to claim 5, comprising a support structure for supporting relative displacement of the tower crane with respect to the hull of the work pontoon during crane work. A work table equipped.
7. The work boat equipped with the tower crane according to claim 5 or 6, wherein the external shape of the cross section of the mast block and the external shape of the cross section of the leg block are the same.
8. The work boat equipped with the tower crane according to any one of claims 5 to 7, wherein the outer shape of the cross section of the mast block and the outer shape of the cross section of the lifting leg are the same. ..
9. The work pontoon ship is a half SEP or a full SEP equipped with an elevating leg for elevating the hull by lowering it from the hull of the work pontoon and bringing it to the bottom and an elevating leg elevating system for elevating the elevating leg.
   The tower crane according to claim 7, wherein the tower lifting system for lowering the legs of the tower crane into the water is configured to be compatible with the lifting leg lifting system. Work boat.
10. The work pontoon ship is a half SEP or a full SEP equipped with an elevating leg for elevating the hull by lowering it from the hull of the work pontoon and bringing it to the bottom and an elevating leg elevating system for elevating the elevating leg.
    The work pontoon equipped with the crane according to claim 1 or 2, wherein the tower crane is mounted on one of the elevating legs during a crane operation.
11. A crane operating method for a work pontoon ship equipped with the crane according to any one of claims 1 to 10,
    When performing a crane operation, adjust the hanging height by the number of stacked mast blocks forming the tower in the tower crane,
    When sailing with the crane operation stopped, the number of stacked mast blocks is reduced from the number when working with the tower crane to lower the height of the tower. How to operate a crane on a ship.

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