JPH10181682A - Wave-resistant type grabdredger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wave-resistant type grabdredger which can be stably operated even in a sea zone with strict environmental conditions, and in which mooring of a soil transportation vessel is possible. SOLUTION: In a front part of a base vessel 10 in which a rotary crane 3 for suspending and elevating a grab bucket 2 is disposed, a direct through hole 60 in which a grab bucket 2 passes to be elevated to dredge soil and sand on the sea bottom is formed to extend the front part of the base vessel 10, and the rotary crane 3 is disposed roughly at a center of the base vessel 10. It is favorable that majour accessories 50 necessary for a grab-dredger are disposed on the back of the rotary crane 3, and that a side part of the base vessel 20 on the opposite side where a soil transport boat 4 gets to stop is protruded outward for enabling the vertical through hole 60 to be enlarged along the width. Vertical and axial oscillation of the base vessel 20 is thus reduced, and vertical oscillation of a tip 3b of a crane jib 3a can be largely reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glove dredger equipped with a swiveling crane having a lifting grab bucket suspended therein, and in particular, has a small swing with respect to a long-period (long-wavelength) wave, and is suitable for marine conditions. The present invention relates to a wave-resistant grab dredger capable of operating stably even in severe sea areas.

[0002]

2. Description of the Related Art Conventionally, as a grab dredger, as shown in FIGS. 8 and 9, a swing type crane 3 in which a grab bucket 2 is suspended so as to be lifted up and down is mounted on the bow portion (front side) of a barge 1. It is known that the grab bucket 2 grasps and lifts the earth and sand at the bottom of the sea, and the crane 3 rotates to transfer the earth and sand to the earth carrier 4 which is laterally attached to the carrier 1.
This dredger is widely used because it is capable of dredging and excellent in versatility irrespective of the properties of soil and water depth. Reference numerals F and R indicate a bow side (front) and a stern side (rear), respectively.

[0003]

However, in the above-mentioned conventional dredger, when the amount of vertical movement of the tip 3b of the jib 3a of the crane 3 exceeds 0.5m due to the waves, it is difficult to perform dredging efficiently. I can't. Therefore, in general, the period is 8
If the significant wave height, which is a statistically representative value, exceeds 0.6 m in a wave having a long cycle of 10 to 10 seconds (wavelength of 100 to 150 m), dredging becomes difficult, and in a sea area where sea conditions are severe. There is a disadvantage that the operation rate is significantly reduced.

Further, the mooring position of the earth transport vessel 4 with respect to the barge 1 of the grab dredger is limited to the bow, which is the position where the tip 3b of the jib 3a of the crane 3 reaches, and has the largest amount of motion. For this reason, the length L of both berths is limited and shortened, and there is a disadvantage that mooring in waves is extremely difficult.

Therefore, it is an object of the present invention that the vertical shaking of the tip of the jib of a crane causes vertical movement (Heave) in which the ship as a whole fluctuates up and down and vertical pitching (Pitch) in which the front and rear portions alternately fluctuate up and down. Based on the fact that it is based on, in order to eliminate the disadvantages of the prior art described above,
Vertical movement and vertical movement are reduced by extending the ship in front of the crane, and the horizontal distance between the rocking center of the ship and the tip of the crane jib is shortened, resulting in vertical movement. It is intended to provide a wave-resistant grab dredger capable of stable operation even in a sea area where the sea conditions are severe, and in which mooring of an earthmoving ship is easy, because vertical fluctuation of the tip of the crane jib is significantly reduced.

[0006]

In order to achieve the above object, a wave-resistant glove dredger according to the first aspect of the present invention is provided with a slewing crane (3) for suspending a grab bucket (2) so as to be able to move up and down. A grab bucket (2) passes and ascends and descends in front of the barge (1) thus formed, thereby extending the front of the barge (1) by forming a vertical through hole (60) capable of dredging earth and sand on the sea floor. In addition, the swiveling crane (3) is arranged substantially at the center of the barge (1).

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the main equipment (50) required for the grab dredger is provided by a barge on which the swivel crane (3) is arranged. It is arranged rearward.

[0008] The invention according to claim 3 is the invention according to claim 1 or 2.
In addition to the configuration of the invention described in (1), the barge on the side of the side opposite to the side where the earth transport vessel (4) berths so that the vertical through hole (70) can be expanded in the width direction of the barge (20). A part of (20) is expanded outwardly. The main equipment (50) is a general term for a residential area, an engine room provided with a main engine / generator, etc., a mooring windlass, a bucket storage space, and the like. Further, the symbols in parentheses described in the means for solving the above problems correspond to the symbols described in the drawings and the embodiments of the invention described later.

According to the first aspect of the present invention, the addition of the vertical through-hole extends the front of the barge in front of the swivel crane as compared with the conventional example, so that the barge can be moved up and down (Heave). ) Is reduced and pitch (Pit) is reduced.
ch) is greatly reduced as compared with that of the conventional example. In addition, since the distance between the center of shaking of the barge and the tip of the jib of the crane is short, for example, in waves in a wave cycle of 8 to 10 seconds, the vertical direction of the tip of the jib of the crane due to the vertical movement of the barge. Is reduced to 1/5 to 1/3 of that of the conventional example, and the operation rate is greatly improved. In addition, since the barge was extended, the tilt of the barge due to the load movement of the crane (Trim
And Heel), the work becomes easier, and the length of berthing to the soil carrier is increased, so that a stable and easier mooring of the soil carrier is possible as compared with the conventional grab dredger.

According to the second aspect of the present invention, in addition to the functions and effects of the first aspect, if the part of the barge ahead of the crane is cut off, the main equipment necessary for the grab dredger is provided. Since the goods are left behind, after dredging work in severe sea area, it can be easily converted to a conventional glove dredger that can be used for inland sea or harbor dredging. Conversely, a conventional glove dredger (or a dredger whose front part is cut off) may be additionally provided with a front part provided with a vertical through hole, and may be converted into a wave-resistant dredger of the present invention.

Further, according to the third aspect of the present invention,
In addition to the operation and effect of the first or second aspect of the present invention, since the range of movement of the grab bucket in the left-right direction (width direction of the barge) is expanded, the number (frequency) of barge position movements is reduced.

[0012]

Embodiments of the present invention will be described with reference to the drawings. 1 is a side view showing a wave-proof glove dredger according to an embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a wave-proof glove according to another embodiment of the present invention. It is a top view which shows a dredge. The symbols F and R indicate the bow side and the stern side, respectively.

As shown in FIGS. 1 and 2, a wave-resistant glove dredger according to an embodiment of the present invention includes a swing type crane 3 which suspends a grab bucket 2 so as to be able to move up and down.
The grab bucket 2 passes and goes up and down in front of the swiveling crane 3, and a vertical through hole 60 (generally called a well) is added so as to be able to dredge the seabed sediment. It is formed and the front of the barge 10 is extended. The earth carrier 4 is moored to the front of one side of the pier 10.

Furthermore, it is preferred that the main equipment 50 required for the grab dredger is arranged behind the swivel crane 3. The main equipment 50 is the residential area 5.
1, an engine room 52 provided with a main engine, a generator, etc., a mooring windlass 53, a bucket storage space 54, etc. In addition, as another embodiment, as shown in FIG. 3, the pier 2 on the side of the port on the opposite side to the side on which the earthmoving ship 4 is berthed.
It is preferable that a part of 0 be expanded outwardly and the vertical through hole 70 be expanded in the width direction of the pier 20.

In the wave-resistant glove dredger according to the embodiment of the present invention, a hatched portion S in front of the crane 3 is extended and a vertical through-hole (partly) is provided as compared with the conventional example shown in FIGS. It can be said that a well 60 is provided, and a part thereof is formed in a twin-body type.

In the case of dredging, the grab bucket 2 suspended from the tip 3b of the jib 3a of the crane 3 has a vertical through hole 6
It was dropped to the bottom of the sea through 0, and when it grasped the sediment of the bottom of the sea,
The gib bucket 2 is lifted and the jib 3a is rotated.
The earth and sand captured by is transferred to the earth carrier 4.

The wave-resistant glove dredger has a jib 3 of the crane 3 as the barge 10 is shaken by the waves.
The tip 3b of a moves up and down. 4 and 5,
For the conventional example (captain 80m) and the wave-resistant grab dredger (captain 115m) according to the embodiment of the present invention, the wave period that affects the pitching and pitching amplitude per unit wave height in the longitudinal wave of the long-wave irregular wave. Shows the effect of. According to them, although the amount of reduction of the vertical motion of the barge 10 is smaller than that of the conventional example, the vertical vibration is reduced to half that of the conventional example. In addition,
The long wave top wave is a wave whose wave direction is substantially one direction like a swell. The longitudinal wave is a wave approaching in the longitudinal direction of the barge.

FIG. 6 shows the influence of the wave period on the vertical swing of the tip 3b of the jib 3a of the crane 3 during the longitudinal wave.
According to this, since the distance between the center of shaking of the barge 10 and the tip 3b of the jib 3a of the crane 3 is smaller than that of the conventional example, the vertical movement of the barge 10 causes the jib 3a of the crane 3 to move vertically. The shaking is greatly reduced as compared with that of the conventional example, and is reduced to 1/5 to 1/3 of that of the conventional example in waves having a wave period of 8 to 10 seconds.

FIG. 7 shows the influence of the wave period on the operating limit wave height when the allowable value of the vertical swing amplitude (significant value) of the tip 3b of the jib 3a of the crane 3 is 0.5 m. According to this, the operating limit wave height in waves having a long wave period of 8 to 10 seconds, for which dredging work was difficult, becomes 3 to 5 times that of the conventional example, and the operation rate is greatly improved. You.

If the hatched portion of the barge 10 is separated from the crane 3, the main equipment necessary for the grab dredger is left behind, so after dredging work in severe sea area, It can be easily converted to a conventional grab dredger that can be used for inland or harbor dredging that is frequently used. In addition,
Conversely, a conventional glove dredger (or a dredger having a front part cut away) may be additionally provided with a front portion provided with a vertical through hole, and may be converted into a wave-resistant dredger of the present invention.

Further, the side of the ship opposite to the side on which the earthing ship 4 berths is expanded in the width direction of the barge 20 so as to protrude, and the vertical through hole 6 is formed.
In the case where 0 is expanded in the width direction of the barge 10, the range of movement of the grab bucket 2 in the left-right direction (width direction of the barge) is expanded accordingly, so that the number of times (frequency) of the position movement of the barge 10 is reduced. .

[0022]

As described above, according to the first aspect of the invention, since the front of the barge is longer than the conventional crane, the vertical movement (Heave) of the barge is reduced. At the same time, pitch (Pitch) is greatly reduced as compared with that of the conventional example. In addition, since the distance between the center of shaking of the barge and the tip of the jib of the crane is short, for example, in waves in a wave cycle of 8 to 10 seconds, the vertical direction of the tip of the jib of the crane due to the vertical movement of the barge. Is reduced to 1/5 to 1/3 of that of the conventional example. Therefore, the operation limit wave height is 3 to 5 times that of the conventional example, and the operation can be stably performed even in the sea area where the sea condition is severe, and the operation rate is greatly improved.

Further, since the barge is extended, the lateral movement of the tip of the crane jib due to the bowing (Yaw) of the barge is reduced, and the inclination (Trim and Heel) of the barge due to the load movement of the crane is reduced. Reduced and work easier. The increased berthing length for the earthmoving vessel allows for more stable and easier mooring of the earthmoving vessel compared to conventional glove dredgers.

According to the invention described in claim 2, according to claim 1,
In addition to the effects of the invention, if the part of the barge in front of the crane is cut off, the main equipment necessary for the grab dredger is left behind, so the frequency is low and the construction period is as short as 1-2 years After the dredging work in severe sea area, it can be easily converted to a conventional glove dredger that can be used for dredging in inland seas and harbors where the frequency of use is gentle, which is frequently used. Conversely, a conventional grab dredger (or a dredger with the front part separated)
It is also possible to add a front part provided with a vertical through-hole to the water-resistant dredger of the present invention.

According to the third aspect of the present invention, in addition to the effect of the first or second aspect, the range of movement of the grab bucket in the left-right direction (the width direction of the barge) is expanded. The number of times (frequency) of position movements of is reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing a wave-resistant glove dredger according to an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a plan view showing a wave-resistant glove dredger according to another embodiment of the present invention.

FIG. 4 is a graph showing the influence of the wave period on the vertical oscillation amplitude per unit wave height in the longitudinal wave of the long crest irregular wave.

FIG. 5 is a graph showing an influence of a wave period on a pitch amplitude per unit wave height in a longitudinal wave of a long crest irregular wave.

FIG. 6 is a graph showing the effect of the wave period on the vertical swing of the tip of the crane jib during a longitudinal wave.

FIG. 7: Vertical swinging amplitude of crane jib tip (significant value)
9 is a graph showing the influence of the wave cycle on the operating limit wave height when the allowable value of the distance is 0.5 m.

FIG. 8 is a side view showing a conventional example.

FIG. 9 is a plan view of FIG.

[Explanation of symbols]

 Reference Signs List 1 barge 2 grab bucket 3 revolving crane 3a jib 3b tip 4 soil carrier 10 barge 20 barge 50 main equipment 51 living area 52 engine room 53 mooring windlass 54 bucket storage space 60 vertical through hole 70 vertical penetration Hole F Bow side R Stern side L Pier length

Claims (3)

[Claims] 1. A grab bucket is provided in front of a barge on which a revolving crane is suspended so as to be able to move up and down, so that the grab bucket passes and goes up and down to form a vertical through hole capable of dredging earth and sand on the seabed. A wave-resistant glove dredger extending the front of the barge and disposing the swiveling crane substantially at the center of the barge. 2. The wave-resistant glove dredger according to claim 1, wherein main equipment necessary for the glove dredger is arranged behind a barge on which the swiveling crane is arranged. 3. A part of the barge on the side of the ship opposite to the side on which the earth transport ship berths is extended outward so that the vertical through-hole is widened in the width direction of the barge. Claim 1.
Or the wave-resistant glove dredger according to 2.