JP6752682B2 - How to install a suspended load by a crane vessel - Google Patents

Description

The present invention relates to a method of installing a suspended load by a crane vessel.

In order to install a large-sized suspended load at a predetermined position by a hoist ship, for example, the suspended load is suspended with a beam body interposed above and below the crane hook and the suspended load (see Patent Document 1). If the weight of the suspended load is heavy, a crane vessel with multiple jib arranged in parallel is used.

By the way, the crane vessel is easily shaken by waves, wind, etc., and this shaking becomes an obstacle when the suspended load is installed at a predetermined position. In particular, rolling of a ship is a major obstacle. As a countermeasure against such a problem, a device for preventing the suspension hook from shaking by using a substantially V-shaped bifurcated arm has been proposed (see Patent Document 2).

Japanese Unexamined Patent Publication No. 2011-247048 Japanese Unexamined Patent Publication No. 8-119572

In the suspension hook anti-sway device proposed in Patent Document 2, in order to prevent the suspension hook from swinging, the work of connecting the legs of the bifurcated arm to both sides of the jib via a universal joint, two A large amount of man-hours are required, such as the work of connecting the tips of the two legs of the fork arm with a pin and the work of connecting the tips of the two legs with the hanging hook. In addition, the number of parts is large and the structure is complicated.

An object of the present invention is to provide a method for installing a suspended load by a crane vessel, which can suppress the shaking of the suspended load due to the shaking of the crane vessel without using a complicated mechanism.

The method of installing the suspended load by the crane ship of the present invention for achieving the above object is the method of installing the suspended load by the crane ship in which the suspended load is installed at a predetermined position by using a plurality of jib arranged in parallel on the ship. The hooks suspended from each of the jib and the beam extending in the parallel direction of the jib are connected by a plurality of beam suspension wires, and the hook suspended from each of the jib and the suspended load are connected. Are arranged at intervals in the extending direction of the beam body, and are connected by a plurality of suspension wires for adjusting the position by penetrating the beam body vertically and suspended from the adjacent jib. A state in which the hooks adjacent to each other in the width direction of the crane ship are connected by a rigid connecting body, and the hooks adjacent to each other in the length direction of the crane ship suspended from the same jib are not connected to each other. Then, the connecting body, the connecting body formed by the hooks connected to the connecting body, the beam body, and the suspended load are suspended vertically at intervals to obtain the beam body. The beam body is made to function to dampen the sway of the suspended load by making the sway of the suspended load in the ship width direction opposite, and the suspended load is lifted by the plurality of jib and moved to a predetermined position. It is characterized by being installed.

According to the method of installing a suspended load by a crane vessel of the present invention, the distance between hooks is kept constant by a simple configuration in which hooks suspended from adjacent jib are connected by a rigid connecting body. The swing of each hook is regulated. Therefore, it is possible to reduce the sway of the suspended load due to the sway of the crane vessel.

Further, when the crane vessel is shaken, it can be expected that the beam body is shaken between the upper and lower parts of the connecting body and the suspended load so as to offset the shaking of the suspended load. That is, it becomes possible to dampen the shaking of the suspended load by the shaking of the beam body.

It is a side view which illustrates the suspended state of the suspended load by this invention. It is explanatory drawing which illustrates the suspended state of FIG. 1 from the front view. It is explanatory drawing which illustrates the suspended state of FIG. 1 in a plan view. It is explanatory drawing which illustrates the suspended state immediately after the rolling motion occurred in the crane vessel of FIG. 2 from the front view. It is explanatory drawing which illustrates the time-dependent change of the suspended state of FIG. It is explanatory drawing which illustrates the time-dependent change of the suspended state of FIG.

Hereinafter, a method of installing a suspended load by a crane vessel of the present invention will be described based on the embodiment shown in the figure. As illustrated in FIGS. 1 to 3, the present invention uses a crane vessel 10 provided with a plurality of jib 11. In the drawings, the length direction, the width direction, and the vertical direction are indicated by arrows X, Y, and Z, respectively.

On the crane vessel 10, two jib 11s are rotatably fixed to the front end of the pontoon 12 using a hinge 13 about the Y direction, and are arranged in parallel in the Y direction. Each jib 11 hangs two hooks 21 from the top thereof using a crane wire 20 at intervals in the X direction. Since the hooks 21 suspended by the respective jib 11 are spaced apart in the Y direction, the crane vessel 10 has four hooks 21 arranged as illustrated in FIG. The hook 21 has a main body 21a and a hanging portion 21b arranged below the main body 21a. The hanging portion 21b is rotatably connected to the main body 21a about the axis in the Z direction.

A beam 14 and winches 15a and 15b are arranged at the rear end of the crane vessel 10. The beam 14 is connected to the top of each jib 11 by an undulating wire 16. The winch 15a raises and lowers the jib 11 by winding and feeding the undulating wire 16. Another winch 15b moves the hook 21 up and down by winding and unwinding the crane wire 20. Two anchor wires 17 are connected to each of the bow (right end in the X direction) and the stern (left end in the X direction) of the crane vessel 10 so as to spread in the width direction (Y direction). At the bow, the anchor wires 17 are dropped onto the bottom ground 1 toward the front outside without crossing each other. At the stern, the anchor wires 17 are crossed with each other and dropped onto the bottom ground 1 toward the rear outside. The number of anchors, the presence or absence of intersection of anchor wires 17, etc. are appropriately set according to the site.

Below each hook 21, a beam body 23 extends in the parallel direction (Y direction) of the jib 11. The beam body 23 has a function of adjusting the position of the suspension wire 22a for suspension so that the suspension wire 22a for suspension connected to each hook 21 is located directly above the connection portion provided on the upper surface of the suspension 24. Has. More specifically, in the beam body 23, a plurality of through holes 23a penetrating vertically are formed at intervals in the Y direction. The size of the through hole 23a is such that the suspension wire 22a for suspension can be slightly idled. Each wire 22a is connected to the connection portion of the suspended load 24 via the corresponding through hole 23a. Further, each hook 21 and the four corners of the upper surface of the beam body 23 are connected by a beam body suspension wire 22b.

The beam body 23 is a flat plate-like body made of steel. The length of the beam body 23 in the X direction may be equal to or shorter than the distance between the hooks 21 suspended from the same jib 11 in the X direction, but is formed longer in this embodiment. The length of the beam body 23 in the Y direction may be equal to or shorter than the distance between the hooks 21 suspended from each jib 11 in the Y direction, but is formed longer in this embodiment. In this embodiment, the length of the beam body 23 in the Y direction is longer than the length of the suspended load 24, but may be equal to or shorter than the suspended load 24. The length of the beam body 23 in the Z direction is smaller than the length in the X direction and the Y direction, but has a sufficient length to suppress bending deformation of the beam body 23. As the beam body 23, a rigid body having a small bending deformation even when the load of the suspended load 25 acts may be used, and the shape is not particularly limited, but if it is excessively heavy, the load on the crane vessel 10 becomes large. Therefore, the specifications should be as light as possible and have high flexural rigidity. For example, an H-shaped steel or a combination of a plurality of H-shaped steels and the like can be used as the beam body 23. A suspended load 24 such as a caisson is arranged below the beam body 23.

In the present invention, a rigid connecting body 30 for connecting hooks 21 suspended from adjacent jib 11 is used. The two connectors 30 have basically the same specifications. The shape and material of the connecting body 30 are not particularly limited as long as they have rigidity that does not easily deform. The cross-sectional shape of the connecting body 30 may be round, elliptical, annular, or square, and for example, a steel pipe or H-shaped steel can be used as the connecting body 30. One end of the hook 21 is connected to the right side surface of the main body 21a of the hook 21 suspended from one jib (left jib in FIG. 2) 11, and the hook is suspended from the other jib (right jib in FIG. 2) 11. The other end is connected to the left side surface of the main body 21a of 21. The connection of the end of the connecting body 30 to the hook 21 can be made non-rotatable by welding or the like, or can be made rotatable via a pin or the like.

Next, a procedure for installing the suspended load 24 at a predetermined position according to the present invention will be described. The vertical movement of the suspended load 24 by the hoisting vessel 10 is carried out by winding the crane wire 20 while rotating the winch 15b with the jib 11 in an appropriate undulating state and keeping the Z-direction positions of the hooks 21 the same. Do. The horizontal movement of the suspended load 24 to a predetermined position after being lifted by the crane vessel 10 is performed by winding and unwinding each anchor wire 17 so as to position the top of the jib 11 above the predetermined position.

The swaying states of the hook 21, the beam 23, and the suspended load 24 when the crane vessel 10 sways due to the influence of waves or the like will be described with reference to FIGS. 4 to 6. .. FIGS. 4, 5 and 6 schematically show changes over time in the suspended state of the suspended load 24 by the crane vessel 10.

In this series of changes over time in the suspended state, since the hooks 21 adjacent to each other in parallel are connected by the connecting body 30, the swing of each hook 21 is regulated while the distance between the hooks 21 is kept constant. To. Therefore, the sway of the suspended load 24 due to the sway of the crane vessel 10 can be reduced.

In detail, if the adjacent hooks 21 in parallel are not connected by the connecting body 30, each hook 21 sways independently in its own direction and its own amplitude. However, each hook 21 connected by the connecting body 30 is forcibly maintained at a distance from each other to the length of the connecting body 30. Therefore, each hook 21 regulates the independent sway of the hook 21 on the other side, and sways while keeping the distance between them constant.

As a result, the sway of each hook 21 is remarkably suppressed, and the sway transmitted to the suspended load 24 is also reduced. Therefore, the suspended load 24 can be easily positioned above the predetermined position with high accuracy, and can be easily installed at the predetermined position.

In addition to the effects of the connector 30 described above, the following effects can also be expected. As shown in FIG. 4, immediately after the pontoon 12 is swayed by the waves and the hoisting vessel 10 is swayed, the hooks 21 of the adjacent jib 11 and the connecting body 30 are integrally formed. The combined body 31 sways in the Y direction (leftward in FIG. 4). At this time, the beam body 23 and the suspended load 24 are stopped, but as will be described later, the sway of the combined body 31 is transmitted to the beam body 23 and the suspended load 24 with a time lag.

As illustrated in FIG. 5, when a predetermined time elapses from the state of FIG. 4, the conjugate 31 sways in the direction opposite to the sway at the time of FIG. 4 (to the right in FIG. 5). At this time, the beam 23 in which the sway of the coupling 31 is transmitted via the suspension wire 22 with a time lag sways in the direction opposite to the sway of the coupling 31 (to the left in FIG. 5). At this time, the sway of the beam body 23 is not yet transmitted to the suspended load 24, and the suspended load 24 is in a stopped state.

As illustrated in FIG. 6, when a predetermined time elapses from the state of FIG. 5, the conjugate 31 sways in the direction opposite to the sway at the time of FIG. 5 (to the left in FIG. 6). At this time, the beam 23 in which the sway of the coupling 31 is transmitted via the suspension wire 22 with a time lag sways in the direction opposite to the sway of the coupling 31 (to the right in FIG. 6). At this time, the suspended load 24 in which the sway of the beam body 23 is transmitted via the suspension wire 22 with a time lag sways in the direction opposite to the sway of the beam body 23 (to the left in FIG. 6).

In the present invention, the hooks 21 are connected to each other by the connecting body 30 to form an integrated body 31. Therefore, a vibration system is formed in which the coupling body 31, the beam body 23, and the suspended load 24 are vertically connected by wires. In this vibration system, the three mass bodies (combined body 31, beam body 23, and suspended load 24) sway with a time lag, so that the swaying of the beam body 23 that sways in the middle is regulated by the lower suspended load 24. As a reaction to this, the sway of the suspended load 24 is regulated by the sway of the beam body 23 and becomes smaller. That is, it is possible to make the beam body 23 function to dampen the sway of the suspended load 24.

On the other hand, when the hooks 21 are not connected by the connecting body 30, each hook 21 sways independently, so that the beam body 23 and the suspended load 24 are regarded as a vibrating system in which they are vertically connected by wires. Can be done. In this vibration system, two mass bodies (beam body 23 and suspended load 24) vibrate with a time lag. Therefore, the effect of dampening the sway of the suspended load 24 cannot be expected so much by simply repeating the swaying of the two upper and lower masses in the opposite directions.

As described above, according to the present invention, the hooks 21 suspended from the adjacent jib 11 are connected to each other by the rigid connecting body 30, and the distance between the hooks 21 is kept constant. The swing of the hook 21 is regulated. Therefore, the sway of the suspended load 24 due to the sway of the crane vessel 10 can be reduced. In addition, by making the beam body 23 function as a member for dampening the shaking of the suspended load 24, it is becoming more and more advantageous to suppress the shaking of the suspended load 24.

When the connecting body 30 is rotatably connected to the hook 21, there is an advantage that the connecting body 30 is not excessively bent or twisted as compared with the case where the connecting body 30 is rotatably connected. However, relative movement between the hooks 21 connected via the connecting body 30 is allowed. On the other hand, when the connecting body 30 is non-rotatably connected to the hook 21, the relative movement of the connected hooks 21 is restricted. As a result, the hooks 21 are swayed in substantially the same direction in synchronization with the same amplitude. Therefore, the effect of suppressing the sway of the hook 21 is further improved, which is advantageous for suppressing the sway of the suspended load 25.

The length of the connecting body 30 may be substantially the same as the distance between the hooks 21 suspended from the adjacent jib 11 in a neutral state. This neutral state is a state in which the hooks 21 are naturally suspended without being connected by the connecting body 30. For example, the length of the connecting body 30 is set to about 95% to 105% of the distance between the hooks 21. By setting the length of the connecting body 30 in this way, the load (tensile force, compressive force, etc.) acting on the connecting body 30 and the hook 21 can be reduced. Along with this, it is advantageous to maintain the hook 21 and the connecting body 30 in a healthy state and extend the service life.

In addition to the hooks 21 suspended from the adjacent jib 11, the hooks 21 suspended from the same jib 11 can be connected by the connecting body 30. This makes it easier to further reduce the sway amplitude of the coupling 31, which is advantageous for reducing the sway amplitude of the suspended load 24.

In this embodiment, two jib 11s are provided in parallel, but the number of jib 11s in parallel may be three or more, and may be at least two. The number of hooks 21 suspended from each jib 11 is not limited to a plurality, and may be a single number.

1 Underwater ground 10 Lifting machine ship 11 Jib 12 Carrier 13 Hinge 14 Beam 15a, 15b Winch 16 Undulating wire 17 Anchor wire 20 Crane wire 21 Hook 21a Main body 21b Suspended part 22a Suspended load suspension wire 22b Beam suspension wire 23 Beam body 23a Through hole 24 Suspended load 30 Crane 31 Crane

Claims (3)

In the method of installing a suspended load by a crane vessel that installs the suspended load in a predetermined position using multiple jib arranged in parallel on the ship.
A hook suspended from each of the jib and a beam extending in a parallel direction of the jib are connected by a plurality of beam hanging wires, and a hook suspended from each of the jib and the suspended load are connected. Are arranged at intervals in the extending direction of the beam body, and are connected by a plurality of suspension wires for adjusting the position by penetrating the beam body vertically and suspended from the adjacent jib. A state in which the hooks adjacent to each other in the width direction of the crane ship are connected by a rigid connecting body, and the hooks adjacent to each other in the length direction of the crane ship suspended from the same jib are not connected to each other. Then, the connecting body, the connecting body formed by the hooks connected to the connecting body, the beam body, and the suspended load are suspended vertically at intervals to obtain the beam body. The beam body is made to function to dampen the sway of the suspended load by making the sway of the suspended load in the ship width direction opposite, and the suspended load is lifted by the plurality of jib and moved to a predetermined position. A method of installing a suspended load by a hoist ship, which is characterized by being installed in a crane. The method for installing a suspended load by a crane vessel according to claim 1, wherein the connecting body is non-rotatably connected to the hook. The method for installing a suspended load by a crane vessel according to claim 1 , wherein the connecting body is rotatably connected to the hook .

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