JP2008149819A - Vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vessel capable of reducing lowering of voyage performance by interference of anchor and waves by moving the position of the anchor when lifting the anchor in a bow part of an enlarged vessel to an upper side. <P>SOLUTION: A pull-up position of a lower end of the anchor when anchoring in the bow part in the enlarged vessel is made a rear side of a fore perpendicular and a front side of a bow collision bulkhead with respect to a vessel length direction, and is made higher than a position higher than a rising position of a water surface during navigation in a full load draft state by 0.25%Lpp (a length between perpendiculars) and a range lower than a gunwale side line of a deck installed with an anchor windlass with respect to the vertical direction, in side view. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a ship capable of reducing a decrease in navigation performance due to interference between a dredging and a water surface.

  Recently, in order to improve the propulsion performance of large ships such as large tankers, bulk carriers, ore carriers, crushing resistance due to wave collapse, resistance due to reflection of incident waves to the front, Wave resistance due to exercise has attracted attention, and propulsion resistance has been reduced as much as possible to improve navigation performance.

  On the other hand, as shown in FIG. 3 and FIG. 4, in the conventional ship 1X, equipment for lifting and mooring operations such as a lifting machine (windlas) 8 is arranged at the bow, Among them, the anchor 5 is lifted by a lifting machine 8 on the bow deck 4 and is connected to the tip of the anchor chain 9 passing through the chain pipe 7 and the bell mouth 6 provided outside the bow flare 3. Has been. When mooring, the anchor chain 9 is extended and the anchor 5 is lowered to the seabed to moor the ship 1X. At the time of navigation, the anchor chain 9 is wound up by the lifting machine 8 and stored in the anchor locker (chain locker) 10 and the anchor 5 is bellmouth 6 Has been raised. The anchor 5 at the time of lifting is lifted above the water surface (full water line) WL outside the bow flare 3.

  With respect to the position of lifting the dredger, the conventional watercraft did not take into account the rise in water level during navigation. For this reason, even when the dredger is in a position where no waves hit the dredger at the time of the stoppage, at the bow part of the enlarged ship, the water level rises around the stagnation point of the hull center line of the bow part. If a wave rides on the surface of the water or the bow moves up and down due to hull movement, there may be interference between the dredging and the surface of the water, such as a wave hitting the dredging or the dredging of the dredging. In addition to causing damage to the lifting equipment such as the anchor chain and the bell mouth, there is a problem that the propulsion performance is lowered and the fuel consumption is deteriorated because the resistance is increased due to interference between the anchor and the water surface.

  As a countermeasure against waves hitting this dredger, a wave breaker is provided from the bow side of the outer plate of the place where the dredger chain is stored to diagonally below, so that waves do not collide with the dredger when converging, There has been proposed a ship with a wave breaker that prevents damage to peripheral skins, chain pipes (hose pipes), windlass, and the like (see, for example, Patent Document 1).

  However, in this ship with a wave breaker, the waves do not collide directly with the anchor, but the wave breaker collides with the waves, and the propulsion resistance increases due to the waves hitting the wave break, so the navigation performance is rather deteriorated. There is a problem of doing.

  In addition, in a ship with a large spherical bow at the bow, it avoids the anchor and anchor chain from coming into contact with the bow, removes the restriction of the bow shape due to the anchor, and increases the degree of freedom in designing the bow shape. In order to improve navigation performance due to an increase in the number of anchors, an anchor recess is provided at the bottom of the bow to store the dredger, and a space that penetrates from the upper deck to the bottom of the hull is provided at the center of the hull. A storage structure for an anchor to be taken in and out has been proposed (see, for example, Patent Documents 2 and 3).

In the case of this structure, since the dredging enters and exits from the bottom of the ship, the waves do not collide with the dredging, but since the doorway of the dredging opens to the bottom of the ship, this opening increases the driving resistance. . Further, since a space for seawater to enter is provided in the center of the bow, a structure for maintaining the hull strength is required, and there is a problem that the bow structure is complicated.
JP 08-183493 A JP-A-2005-112201 JP 2005-132179 A

  The present invention has been made in order to solve the above-mentioned problems, and its purpose is to devise the position of the dredging at the bow of the enlargement ship so as to interfere with the dredging at the time of navigation and the water surface. An object of the present invention is to provide a ship capable of suppressing the increase in propulsion resistance due to the cruising and improving the navigation performance.

In order to achieve the above object, the ship of the present invention has a maximum ship speed Vs (m / s) when navigating in a full draft state in a ship having a square coefficient of 0.8 to 1.0 in the summer full load draft line. ), an intersection point between the gravitational acceleration g (m / s ²⁾ and the water head ^{ho = Vs 2 / 2g (m} ) an amount corresponding load line from above the horizontal line and the forward perpendicular when the first position, between vertical line length The crossing point between the vertical line 5% Lpp behind the bow perpendicular line when Lpp is Lpp and the full load water line is the second position, and the intersection point between the bow collision bulkhead and the full load water line is the third position. In the side view, the position of the lower end is rearward from the bow perpendicular line and forward from the bow bulkhead, and the first position, the second position, and the third position are connected in order with respect to the vertical direction. Higher than the line segment by 0.25% Lpp It is comprised so that it may become the range which is higher than an installation and lower than the shore side line of the deck which installed the lifting machine.

  When the square coefficient (Cb) in the full waterline is smaller than 0.8, the degree of enlargement at the bow is small, and there is little interference between the soot and the water surface due to the rising of the water surface at the bow, so the effect of the present invention is small. Further, a ship having a square factor larger than 1.0 has poor navigation performance and is not practical. Therefore, the target ship is a ship having a square coefficient of 0.8 or more and 1.0 or less in the full load waterline.

  As for the position of the lower end of the anchor (anchor) at the time of lifting, the bow flare structure protrudes forward, the anchor locker (chain locker) and the lifting position when placed in front of the bow perpendicular (FP). Arrangement of dredgers etc. becomes difficult and the structure of the bow part becomes complicated, so it is located behind the bow perpendicular line. In addition, since a tank and a hold (hull) are arranged on the stern side of the bow collision bulkhead (head collision bulkhead), it is not preferable to dispose the kite behind the bow collision bulkhead because the tank and the hold part are reduced. . In addition, when the bow collision bulkhead is disposed on the stern side by 8% Lf (Lf: freeboard length) or more from the bow perpendicular or the like, special approval of the classification is required.

With respect to the vertical direction, hydrocephalus at the stagnation point of sailing in maximum ship speed Vs (water rise height) ho becomes Vs ^2/2 g. In other words, during navigation of the ship, the bow and water (seawater) move relatively at Vs, and when viewed in a coordinate system fixed on the ship, water flows into the bow at a flow velocity Vs. I will do it. On the other hand, since the water flow velocity Vo is zero at the stagnation point of the bow, when the density of water is ρ, the relationship between the water head ho at the stagnation point and the water head hs in the distance is ρ × g × ho + ρ ^{× Vo 2/2 = ρ ×} g × hs + ρ × Vs 2/2 becomes, when Vo = 0, hs = 0, the ho = Vs ² / 2g. That is, the water head ho indicating the amount of water increases at the stagnation point of the bow section, a maximum ship speed Vs (m / s), when the gravitational acceleration ^{g (m / s 2),} Vs 2 / 2g (m) and Become. For example, in a ship having a boat speed of 15 kt (knots), Vs = 7.72 (m / s), and the water head ho is about 3.0 (m).

  Therefore, the actual submerged portion where the ship is navigating is at a position that is higher than the full load water line by the water head ho in the vicinity of the bow. The rising height of the water surface decreases as it goes to the side of the hull, that is, away from the stagnation point. In consideration of this change in the water surface based on experimental results and calculation results, the range above the line segment connecting the first position and the second position is selected as a range not affected by the rise of the water surface in a side view. Further, it is assumed that the influence of the rising of the water surface is small between the second position and the third position, and the line above the line connecting the second position and the third position (full load draft line) is selected in a side view. Then, as a lower limit, an allowance of ha = 0.25% Lpp is given in consideration of the amount of change in the vertical direction of the bow due to the hull motion when a wave rides on the raised water surface. As for the upper limit, the heel side line of the deck on which the lifting machine is installed is the upper limit of the lower end of the heel.

  According to this configuration, the dredging position is kept away from the rising part of the wave at the bow, and the dredging is temporarily submerged under the surface of the water during navigation to promote vortex resistance and wave resistance. In order to reduce the chance of generating resistance, the storage position of the bag is moved upward to a position where there is little possibility of interference between the bottle and the water surface. In other words, by setting the lifting position during dredging within a range that takes into account the rise of the water surface of the bow, interference between the dredging and the water surface that causes waves to hit the dredging or submerge the dredging during navigation. Reduce the chance of occurrence. Therefore, it is possible to reduce the damage caused by the waves in the dredging and the dredging device, and it is possible to reduce the increase in propulsion resistance due to the interference between the dredging and the water surface, thereby improving the propulsion performance and the voyage performance.

  Further, in the above-mentioned ship, the direction connecting the position of the rear end of the dredging and the lifting machine (windlass), that is, the direction of the anchor chain (anchor chain) is 30 from the bow direction toward the dredging direction. Arrange the lifting machine so that it has an angle of ~ 90 degrees. The rear end of the kite is where the kite chain is connected. According to this configuration, the lifting machine can be arranged behind the bow as long as the arrangement of the devices on the deck on which the lifting machine is installed is allowed. At the same time, the protruding length of the protruding part (raised bell mouth) from the hull to secure the required length of the anchored pipe (hose pipe) can be suppressed. Can be high.

  If this angle is less than 30 degrees, it will be difficult to lower the dredger to the rear of the hull, and if it exceeds 90 degrees (lateral direction: left-right direction), it will wind up from the stern side to the bow side, and as much as possible It becomes impossible to secure a large volume of the tank and hold by arranging it in front. Therefore, the range of 30 degrees to 90 degrees is preferable.

  Further, in the above-mentioned ship, the direction connecting the position of the rear end of the dredger at the time of dredging and the dredger, that is, the direction of the anchor chain has an angle of 40 degrees to 60 degrees from the bow direction toward the dredging direction. So arrange the lifting machine. If it is outside the range of 40 degrees to 60 degrees, there is a strong possibility that the dredging work and the mooring work will be disturbed. Therefore, it is more preferable that the range is within the range of 40 degrees to 60 degrees.

  Because of the arrangement of these lifting machines, the anchor and the lifting machine are provided on both anchors, so that the two lines of the anchor chain connecting the anchor and the lifting machine are opened on the front side of the hull. With this arrangement, the dredging position (storage position) of the dredger is located behind the hull, compared to the conventional arrangement of dredging in front of the dredger. It becomes the part which became. Therefore, the distance between the position of the kite during lifting and the raised water surface can be made larger than in the conventional case.

  In addition, considering the flare shape of the bow and the hull shape with the bow valve, the rearward position is a higher position for raising the dredger. It becomes easy to arrange the raising position of the heel high. That is, it is not necessary to provide a structure for raising the eaves raising position.

  Furthermore, with this arrangement, even if the dredging position is provided on the stern side of the conventional position, the lifting machine need not be provided on the stern side of the conventional position, so the bow collision bulkhead is moved to the stern side. There is no need. That is, the bow collision partition wall can be arranged on the bow side.

  The above configuration is particularly effective when the ship is a tanker or a bulk carrier. This is because these bow types often have round bows. In particular, in a tanker, a rule that a cargo tank and a lifting device must be separated from each other by a certain distance may be applied, so that the present invention often has a large effect.

  According to the ship of the present invention, the position of the dredging at the bow of the ship is arranged rearward and upward in consideration of the water surface rising at the bow, so the interference between the dredging and the water surface during navigation of the ship The decrease in the propulsion performance of the ship due to this interference can be reduced, and the navigation performance can be improved. Moreover, since it can reduce that a wave hits a kite, the damage by the wave of a kite or a lifting device can be reduced.

  Hereinafter, embodiments of a ship according to the present invention will be described with reference to the drawings. This ship is a ship having a square coefficient Cb of 0.8 or more and 1.0 or less in the summer full load waterline WL.

  As shown in FIGS. 1 and 2, in the bow portion of the ship 1 having the bow valve 2, the anchor 5 passes the bell mouth 6 and the anchor pipe (hose pipe) 7 above the bow flare 3. 9 are connected to each other. The anchor chain 9 is wound around a lifting machine (windlass) 8 installed on the upper deck 4 at the time of lifting, and the anchor chain (chain locker) provided in front of the bow collision bulkhead FB. 10. In addition, the kite 5 is pulled up to the bell mouth 6 during the lifting.

  And in this invention, the raising position of the lower end 5a of the anchor (anchor) 5 at the time of lifting is set behind the bow perpendicular line FP and ahead of the bow collision partition wall FB in the captain direction. If it arrange | positions ahead of a bow perpendicular line (FP) FP, the structure of the bow flare 3 protrudes ahead, arrangement | positioning of the anchorage 10, the lifting machine 8, etc. becomes difficult, and the structure of a bow part becomes complicated. Further, since the tank (or hold (hull)) 11 is disposed on the stern side from the bow collision partition wall FB, it is not preferable to dispose the rod 5 behind the bow collision partition wall FB because the volume of the tank 11 is reduced. In addition, if the bow collision bulkhead FB is placed more than 8% Lf (Lf: length of freeboard) from the bow perpendicular line FP or the like, special approval of the classification is required. The lower end 5a of the lower end is also disposed forward of 8% Lf.

The lifting position of the lower end 5a of the anchor 5 at the time of lifting is as follows in consideration of the head (water surface rising height) ho at the stagnation point during navigation at the maximum ship speed Vs (m / s) in the vertical direction. Set as follows. Incidentally, the water head ho, from Bernoulli's theorem, when the gravitational acceleration and g (m / s ^2), the Vs ² / 2g (m).

  The actual submerged portion when the ship 1 is navigating in still water is higher than the full-length water line WL by the water head ho in the vicinity of the bow. Since the rising height of this water surface decreases as it goes to the side of the hull, the intersection of the horizontal line above the full waterline WL and the bow FP line is set as the range not affected by the rising of the water surface. 1 position A, the intersection of the vertical line 5% Lpp behind the bow perpendicular line FP when the length between the vertical lines is Lpp and the full load water line WL is the second position B, and in the side view, the first position A and the second Select above the line segment connecting position B. Note that the intersection of the bow collision bulkhead FB and the full load water line WL is the third position C, and the influence of the rise of the water surface is small between the second position and the third position. Select above the line connecting the positions (full load water line).

  And as a lower limit of the raising position of the lower end 5a of the anchor 5 at the time of lifting, when the wave rides on this raised water surface (ABC), the amount of change in the vertical direction of the bow due to the hull motion In consideration of the above, a margin corresponding to ha = 0.25% Lpp is provided. Further, the upper side is the heel side line 4a of the deck 4 on which the lifting machine 8 is installed, and this heel side line 4a is the upper limit of the lifting position of the lower end 5a of the heel 5 at the time of lifting.

  That is, the position of the lower end 5a of the anchor 5 at the time of lifting at the bow portion is a rear view from the bow perpendicular line FP and forward from the bow collision bulkhead FB in the ship length direction, and in the vertical direction, It is higher than the line segment connecting the first position A, the second position B, and the third position C in order, and is higher than the position higher by ha = 0.25% Lpp, and the deck on which the lifting machine 8 is installed (here The upper deck 4 is configured to be lower than the heel side line 4a. In addition, since the deck 4 of the ship 1 is usually provided with a camber whose central portion is convex, the side line 4a of the deck 4 is lower than the hull center line portion of the deck 4.

  Furthermore, the arrangement of the lifting equipment on the upper deck 4 of the ship 1 is determined by the position of the rear end 5b of the anchor 5 and the lifting machine 8 at the time of the lifting, which is substantially the same position as the deck flange that is the entrance of the anchor chain 7. The lifting machine 8 is arranged so that the connecting direction θ has an angle α of 30 degrees to 90 degrees from the bow direction toward the anchor side direction, and preferably an angle β of 40 degrees to 60 degrees. A hook chain 9 is connected to the rear end 5 b of the hook 5.

  In other words, the direction θ of the anchor chain 9 to the lifting machine 8 is arranged with an angle α of 30 ° to 90 °, preferably 40 ° to 60 ° with the angle β from the ship's direction to both sides, and the arrangement is Protrusion length of the projecting part (raised bell mouth) from the hull to secure the necessary length of the anchor chain 7 while at the same time achieving the rearward arrangement of the bow of the dredger 8 and dredger 5 to the extent possible Suppresses the height and achieves the position of the dredging higher from the water surface. This is because if the direction θ is less than 30 degrees, the effect of lowering the ridge 5 backward is small, and if the direction θ is 90 degrees or more, it is impossible to arrange the ridge 5. Further, by setting the direction θ to 40 degrees to 60 degrees, it is possible to prevent almost any trouble in the lifting work and the mooring work. In other words, the mooring equipment (not shown) can be placed in consideration of the mooring work so that the mooring work is not hindered. It is easy to maintain good workability.

  According to this configuration, the lifting machine 8 can be arranged behind the bow as long as the arrangement of the devices on the deck 4 on which the lifting machine 8 is installed is allowed. At the same time, the lifting position of the ridge 5 can be raised from the water surface. If this direction θ is less than 30 degrees, it will be difficult to lower the anchor 5 to the rear of the hull, and if it is greater than 90 degrees (lateral direction: left-right direction), it will wind up from the stern side to the bow side, and the bow collision bulkhead FB It is not possible to secure a large volume of the tank (or hold) 11 by arranging it as far as possible. Therefore, the direction θ is preferably in the range of 30 degrees to 90 degrees. Further, if the direction θ is outside the range of the angle β of 40 degrees to 60 degrees, there is a high possibility that the dredging work and the mooring work will be disturbed. It is more preferable to use the inside.

  As shown in FIG. 2, the kite 5 is lifted as shown in FIG. 2 rather than the conventional kite 5 as shown in FIG. In the configuration arranged diagonally forward of the machine 8, the lifting position (storage position) of the anchor 5 is located behind the hull, so that the lifting position of the anchor 5 is the height of the rise of the water surface as shown in FIG. Is the smaller part. Therefore, the distance between the position of the kite 5 during lifting and the raised water surface can be made larger than in the conventional case.

  Considering the shape of the flare 3 at the bow and the shape of the hull having the bow valve 2, the lifting position of the anchor 5 is higher when the anchor 5 is disposed rearward. As a result, the lifting position of the flange 5 is rearward, so that it is easy to arrange the lifting position of the flange 5 high. Therefore, it is not necessary to provide a structure for raising the lifting position of the flange 5. Further, with this arrangement, even if the lifting position of the anchor 5 is provided on the stern side from the conventional position, it is not necessary to provide the lifting machine 8 on the stern side from the conventional position. No need to move to. That is, the bow collision partition wall FB can be arranged on the bow side.

  According to the ship 1 having this configuration, the storage position of the dredger 5 is arranged in consideration of the rising surface of the water surface at the bow portion. Opportunities to generate propulsion resistance such as wave resistance can be reduced. Therefore, it is possible to reduce the damage caused by the waves in the dredging 5 and the lifting gears 6, 7, and 8 and to reduce the increase in propulsion resistance due to the interference between the dredging 5 and the water surface, thereby improving the propulsion performance and the voyage performance. In particular, even when navigating in stormy seas, the probability that waves will collide with the anchor 5 and cause a drop in ship speed is reduced, so that the navigation performance in actual seas is improved.

  In addition, the arrangement of the lifting devices can be disposed rearward without increasing costs, and there is almost no adverse effect on the lifting and mooring operations. According to this arrangement configuration, since the lifting device can be arranged further forward, the bow collision partition wall FB can also be arranged further forward. Thereby, the volume of the tank (or hold) 11 can be secured more widely than that of the conventional ship. In other words, this arrangement can solve the problem of deterioration in navigation performance due to the interference of the water surface of the dredger 5 caused by arranging the bow collision bulkhead FB more forward, so that the volume of the tank 11 is larger than that of the conventional ship. It can be secured more widely. As a result, more cargo can be transported with less fuel than conventional ships, and economical ship operations are possible.

It is a side view of the bow part which shows the position of the dredging at the time of dredging of the ship of embodiment of this invention. It is a top view of the bow part which shows arrangement | positioning of the lifting machine of the ship of embodiment of this invention. It is a side view of the bow part which shows the position of the dredging at the time of dredging of the ship of a prior art. It is a top view of the bow part which shows arrangement | positioning of the lifting device of the ship of a prior art.

Explanation of symbols

1 Vessel 2 Bow Valve 3 Bow Flare 4 Upper Deck (Deck with Lifting Machine)
5 Anchor
5a Position of the lower end of heel 6 Bell mouth 7 Chain pipe (hose pipe)
8 Lifting machine (windlass)
9 Anchor chain
10 Chain locker (chain locker)
11 Tank or hold (Funakura)
A 1st position B 2nd position C 3rd position O Stagnation point BL Base line FP Bow perpendicular FB Bow collision bulkhead (bow collision bulkhead)
ho head of stagnation point ha lower margin Lf length for freeboard Lpp length between vertical lines Vs maximum boat speed WL summer full load water line

Claims (3)

The maximum ship speed when navigating in the full draft state is Vs (m / s) and the gravitational acceleration is g (m / s ² ) for a ship with a square coefficient of 0.8 to 1.0 in the summer full load draft line. Hourly head ho = Vs ² / 2g (m) As much as the intersection of the horizontal line above the waterline and the bow perpendicular is the first position, and the length between the perpendiculars is Lpp, 5% Lpp behind the bow perpendicular The intersection of the vertical line and the full load water line is the second position, and the intersection of the bow collision bulkhead and the full load water line is the third position. , Rearward of the bow perpendicular line and forward of the bow bulkhead, and in the vertical direction, only 0.25% Lpp than the line segment connecting the first position, the second position, and the third position in order. A deck that is higher than the high position and is equipped with a lifting machine Ship, characterized in that the lower range than broadside line.   Arranging the lifting machine so that the direction connecting the position of the rear end of the anchor and the lifting machine at the time of lifting has an angle of 30 degrees to 90 degrees from the bow direction toward the anchor side. The ship according to claim 1, wherein   The lifting machine is arranged so that the direction connecting the position of the rear end of the kite during lifting and the lifting machine has an angle of 40 degrees to 60 degrees from the bow direction toward the anchor side. The ship according to claim 2, wherein

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