JPH04212692A - Cargo oil spillage preventing tanker - Google Patents

Abstract

PURPOSE:To offer such a tanker that is made so as to keep off any spillage of cargo oil from an inboard cargo oil tank in the case where some damage has occurred in a hull shell plating part. CONSTITUTION:Each double hull construction 4 is installed at both sides of a cargo oil tank in a tanker, while a deck 3 partitioning off the cargo tank up and down is installed therein, and height H from a ship's bottom 8 at the deck 3 is properly set up, whereby pressure at the cargo oil side being imposed on a hull shell plate is made so as not to be higher than seawater pressure, through which any possible spillage of the cargo oil is made preventable from occurring at a time when the hull is damaged by stranding or bumping.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tanker, and more particularly to a tanker capable of preventing cargo oil from spilling when the hull is damaged due to grounding or the like.

0002

[Prior Art] In accordance with the requirements stipulated by the Oil Pollution Prevention Act, conventional tankers are equipped with designated separate ballast tanks (tanks that are not used as cargo oil tanks) in the cargo area of the ship, and their placement is limited to stranded tanks. and compartments other than oil tanks, such as separate ballast tanks, are arranged to protect cargo oil tanks in defined areas of the ship's side and bottom skins in order to limit the spillage of oil in the event of a collision. .

FIGS. 4 to 10 show the tank arrangement of a conventional tanker. 4, 5, and 6 show a tanker in which ballast tanks 10 are arranged alternately with cargo oil tanks 12 on the side of the ship.In this system, damage to the cargo oil tanks 12 on the side of the ship due to collision or other damage is avoided. If this occurs, cargo oil will flow out from the tank 12. Furthermore, regarding the bottom of the ship, if the cargo oil tank 12 is damaged, cargo oil will flow out from the tank 12.

[0004] Figures 7 and 8 show a tanker equipped with a double side structure, and a ballast tank 4 is disposed over the entire side of the ship, which can prevent cargo oil from spilling out in the event of damage to the side of the ship. , in the event of damage to the bottom of the ship corresponding to the cargo oil tank 12, spillage of cargo oil is unavoidable.

FIGS. 9 and 10 show a tanker with a double bottom structure, in which a ballast tank 11 is arranged over the entire bottom of the ship, so that in the event of damage to the bottom of the ship, cargo from the cargo oil tank 12 will be removed. It can prevent oil spills, but
In case of damage to the ship's side, spillage of cargo oil is unavoidable.

As mentioned above, conventional tankers cannot effectively prevent the spillage of cargo oil in the event of damage to the side or bottom of the ship.As an alternative, tankers with a double hull structure or horizontal Tankers with bulkheads have been developed.

FIGS. 11 and 12 show a tanker with a double-hull structure, in which the inside of the double-hull structure is used as a ballast tank 13, and the side and bottom parts of the ship are designed to cover the cargo oil tank 12. The whole area is protected by a ballast tank 13. However, since the range of the ballast tank 13 becomes wider, the thickness between the double shells of the double hull structure to cover the necessary amount of ballast can be thin. Furthermore, from the economic point of view of ship construction and operation, the thickness between the double shells will be the minimum value within the prescribed regulations, and the thickness of the tank 13 specified in the current Oil Pollution Control Law will be adopted. The thickness is
The thickness should be at least 1/15 of the ship's width or 2 m, whichever is smaller, and the thickness should be selected to meet these conditions.

[0008] Normally, in a double hull structure, the thickness between the double shells is thinner than the thickness of the double sides in a conventional tanker double hull structure. Therefore, even though the sides and bottom of the ship are all protected by the ballast tank 13, because of its thin thickness, in the event of damage due to a large impact, not only the side and bottom skins but also the double ballast tank 13 The possibility of damage extending to the inner shell of the ship's hull increases, and if the damage extends to the inner shell, spillage of cargo oil from the cargo oil tank 12 is unavoidable.

FIGS. 13 and 14 show a tanker in which a cargo oil tank is provided with a deck 3 as a horizontal bulkhead. FIG. 13 shows an example of a conventional tanker of the type shown in FIG. 4, in which the cargo oil tank is provided with a deck 3 as a horizontal bulkhead. is accommodated.

FIG. 14 shows an example in which, among the tanks on the side of the ship, only the upper part separated by the deck 3 serving as a horizontal bulkhead is used as a ballast tank 15, and the remaining sections 16 to 18 are all tanks for storing cargo oil 14. It shows.

In the case of these conventional tankers with internal decks, the deck 3 is installed at a position below the full load water line 19 so as to approximately bisect the depth in the transverse section of the hull. (in the case of Figure 13) or simply below the load water line 19 (in the case of Figure 14)
An inappropriate decision-making method was used.

[0012] When considering the actual operation of a ship, there are cases where cargo oil is loaded only in a part of the cargo oil tank during operation, and in that state the water line becomes shallower than the full water line 19.
It is also common for ships to operate in water that is less than half the ship's depth. In this case, even if deck 3 is installed below the full load water line 19 or at a position that roughly bisects the depth of the ship, the water line during actual operation will be lower than the position of deck 3. If the bottom of the ship is also lowered, the deck 3 will not contribute to preventing the cargo oil 14 from flowing out when the bottom of the ship is damaged.

Furthermore, in the case of a conventional tanker with an inner deck, the tanker shown in FIG. 13 only has a means for preventing cargo oil 14 from spilling out in the event of damage to the bottom of the ship, and measures to prevent cargo oil 14 from spilling in the event of damage to the side of the ship. Cannot be prevented.

The tanker shown in FIG. 14 is as effective as the tanker shown in FIG. 13 when the bottom of the ship is damaged, but when the side of the ship is damaged, it is particularly effective against damage to the side of the lower cargo oil tank. If this occurs, cargo oil 14 will flow out.

FIG. 15 shows that when damage occurs to the side part of the lower cargo oil tank 16 in the tanker shown in FIG.
4 shows each process by which 4 flows out.

Immediately after the damage occurs, as shown in the initial state A in FIG. 15, the pressure of seawater at the damaged location is higher than the pressure of the cargo oil 14 in the damaged cargo oil tank 16, and the seawater flows into the cargo oil tank. 16. The cargo oil 14 in the cargo oil tank 16 is pushed upward through the vent pipe 5 by the pressure of seawater. In intermediate state B, when time T1 has elapsed after the damage occurred, when the pressure of the seawater that has flowed into the bottom of the tank 16 and the pressure of the cargo oil that has been pushed up to the vent pipe 5 are equal, air is released through the opening of the damaged part. , the replacement of cargo oil 14, which has a light specific gravity, with seawater, which has a heavy specific gravity, begins. Then, in the terminal state C after time T2 has elapsed, when the seawater level reaches the upper end of the damaged part opening in the tank 16, the outflow of the cargo oil 14 is stopped and an equilibrium state is reached.

In the case of FIG. 15, since the water line 19 before the damage occurs is above the position of the deck 3, a part of the cargo oil 14 in the cargo oil tank 16 does not leak out to sea even after the damage occurs. However, as mentioned before, if the water line is below the position of the deck 3, the entire amount of cargo oil 14 in the cargo oil tank 16 will flow out.

[0018]

[Problem to be Solved by the Invention] As mentioned above, conventional tankers have the problem that even if various measures are taken, it is not possible to sufficiently prevent cargo oil from spilling when the hull is damaged. be.

[0019] The present invention is an attempt to solve these problems, and employs a double side structure to cope with impacts from the sides of the ship, and also to deal with damage to the bottom of the ship appropriately. To provide a cargo oil spill prevention type tanker which can sufficiently prevent cargo oil from spilling when the hull is damaged by appropriately setting the installation height of a deck that partitions a cargo oil tank into upper and lower parts. The purpose is to

[0020]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the cargo oil spill prevention type tanker of the present invention has a cargo oil tank provided inside the ship, and a cargo oil spill from the cargo oil tank to the outside of the ship. In order to prevent spillage, the cargo oil tank is equipped with a double ship side structure installed on each side, and a deck is provided to divide the cargo oil tank into an upper cargo oil tank and a lower cargo oil tank. The upper limit of the height from the bottom of the ship is set to less than half the height of the cargo oil tank.

Further, the cargo oil spill prevention type tanker of the present invention includes a cargo oil tank provided inside the ship, and a cargo oil tank provided on both sides of the cargo oil tank to prevent the cargo oil from leaking outward from the cargo oil tank. A deck that divides the cargo oil tank into an upper cargo oil tank and a lower cargo oil tank is provided almost horizontally, and the height position of the deck from the bottom of the ship is However, when operating with cargo oil loaded in the cargo oil tank, in the shallowest stagnant state, when cargo oil is loaded in the lower cargo oil tank from the bottom of the ship to the vicinity of the deck, it acts on the bottom of the ship. The pressure on the cargo oil side, that is, the pressure due to the weight of the cargo oil plus the maximum pressure setting value of the pressure control valve in the vent pipe for the lower cargo oil tank, becomes equal to the pressure of the seawater acting on the bottom of the ship. It is characterized by being set below the position.

Furthermore, the cargo oil spill prevention type tanker of the present invention has a cargo oil tank provided inside the ship, and a cargo oil tank provided on both sides of the cargo oil tank to prevent the cargo oil from spilling outward from the ship. A deck is provided that divides the cargo oil tank into an upper cargo oil tank and a lower cargo oil tank, and the height position of the deck from the bottom of the ship is When operating with cargo oil loaded in cargo oil tanks, in the shallowest stagnant state, when cargo oil is loaded from the bottom of the ship to the deck above, the pressure of the cargo oil acting on the bottom of the ship and the pressure acting on the bottom of the ship. It is characterized by being set below and near the position where the pressure of seawater is equal to that of the seawater.

Further, the cargo oil spill prevention type tanker of the present invention includes a cargo oil tank provided inside the ship, and a cargo oil tank provided on both sides of the cargo oil tank to prevent the cargo oil from leaking outward from the cargo oil tank. The deck that divides the cargo oil tank into an upper cargo oil tank and a lower cargo oil tank is provided with a slope, and the height from the bottom of the ship at the highest point of the deck is However, in the shallowest stagnant state when operating with cargo oil loaded in the cargo oil tank, if the cargo oil is loaded in the lower cargo oil tank from the bottom of the ship to near the highest point of the deck, the ship Set below the point where the seawater pressure acting on the bottom of the ship is equal to the pressure due to the weight of the cargo oil acting on the bottom, plus the maximum pressure setting value of the pressure control valve in the vent pipe for the lower cargo oil tank. It is characterized by being

Furthermore, the cargo oil spill prevention type tanker of the present invention includes a cargo oil tank provided inside the ship, and a cargo oil tank provided on both sides of the cargo oil tank to prevent the cargo oil from leaking outward from the cargo oil tank. A deck is provided that divides the cargo oil tank into an upper cargo oil tank and a lower cargo oil tank, and the height position of the deck from the bottom of the ship is When operating with cargo oil loaded in cargo oil tanks, in the shallowest stagnant state, when cargo oil is loaded from the bottom of the ship to the deck above, the pressure on the cargo oil side that acts on the bottom of the ship and the pressure that acts on the bottom of the ship The inner shell of the double ship side structure is formed by the side wall of the upper cargo oil tank and the side wall of the lower cargo oil tank. It is a feature.

[0025]

[Function] In the cargo oil spill prevention type tanker of the present invention described above,
In the event of damage to the ship's side, the cargo oil tanks inside the ship are protected by the double ship side structure, which prevents cargo oil from spilling out.

[0026] In addition, in the event of damage to the bottom of the ship, the deck that divides the cargo oil tank into an upper compartment and a lower compartment may be formed horizontally or slanted and placed at an appropriate height. Therefore, the effect of preventing cargo oil from flowing out is properly performed.

Furthermore, the inner shell of the double side structure is formed by the side walls of the upper cargo oil tank and the lower cargo oil tank, and these side walls may be constructed of vertical flat plates or inclined flat plates, or the inner shell By joining at the flat portion, the above-mentioned cargo oil spill prevention effect can be performed more accurately.

[0028]

[Embodiments] Examples of the present invention will be explained below with reference to the drawings. Fig. 1 is a cross-sectional view of the hull of a cargo oil spill prevention type tanker as a first embodiment of the present invention, and Fig. 2 is a vertical distance from the bottom of the ship. Alternatively, it is a characteristic diagram showing the relationship between the liquid level and the pressure acting on the bottom of the cargo oil tank.

As shown in FIG. 1, a deck 3 is provided as a horizontal bulkhead that divides the cargo oil tank provided at the center in the transverse direction into a lower cargo oil tank 1 and an upper cargo oil tank 2.
In addition, in order to prevent cargo oil from leaking outward from the cargo oil tanks 1 and 2, a double ship side structure is provided on both sides of the cargo oil tanks 1 and 2, each with a ballast tank or empty space inside. 4 is provided. The position of deck 3 in the height direction from the bottom of the ship, that is, the position having a height H, is such that cargo oil can be carried from the bottom of the ship to deck 3 in the shallowest stagnant state when operating with cargo oil loaded in the cargo oil tank. It is set below and near the position where the pressure of cargo oil acting on the bottom of the ship is equal to the pressure of seawater acting on the bottom of the ship when the ship is loaded. In FIG. 1, reference numeral 5 indicates a vent pipe communicating with the lower cargo oil tank 1, 6 indicates an inert gas hatch, 7 indicates an inert gas/vent main pipe, 8 indicates a ship bottom, and 9 indicates a ship side.

Next, it will be explained that by setting the height H of the deck 3 from the bottom of the ship as described above, the deck 3 is effective in preventing cargo oil from spilling out when the bottom of the ship is damaged. The specific gravity of cargo oil varies depending on the type of cargo oil, and is difficult to determine when building a ship. However, it is possible to determine the range of the design specific gravity of cargo oil in advance when building a ship. When a range is set for the design specific gravity of cargo oil, there is a maximum value and a minimum value of the specific gravity.

Straight line a shown in FIG. 2 shows the relationship between the liquid level of the cargo oil with the smallest specific gravity and the pressure (internal pressure) acting on the bottom of the cargo oil tank, and straight line b shows the relationship between the liquid level of the cargo oil with the smallest specific gravity and the pressure (internal pressure) acting on the bottom of the cargo oil tank. The straight line c shows the same relationship as above in the case of It shows. In addition, each symbol in FIG. 2 is as follows. dmax...Ship water dmin at the ship's full load water line...Minimum water flow H0 when operating with cargo oil loaded...
A cargo oil liquid in which the seawater pressure acting on the bottom of the cargo oil center tank is equal to the cargo oil pressure inside the tank at the minimum water drop when carrying cargo oil with the highest specific gravity among the cargo oil scheduled to be loaded. Range A...Inner deck installation height range where cargo oil spills due to damage to the ship's bottom, regardless of the specific gravity of the water and cargo oil. Range B...Prevents spillage of cargo oil by placing appropriate limits on the water and specific gravity of the cargo oil. Possible inboard deck installation height range C... Inner deck installation height that can prevent spillage of cargo oil regardless of the specific gravity of the cargo oil. Since there is a high probability that the ship will be damaged, it is more effective to install the inboard deck in the upper part of range C as much as possible.

[0032] The stuttering of a ship differs depending on the loading condition, and when the ship is loaded with cargo oil, the pressure outside the bottom of the ship at the minimum hush dmin is Pmin, and the outside bottom pressure at the maximum hush dmax is Pmax. The relationship between Pmax and Pmin is

[Equation 1] Pmax>Pmin Let H be the cargo oil level in the cargo oil tank, and let P be the internal pressure acting on the bottom of the ship in that case. P varies depending on the specific gravity of the cargo oil even at the same liquid level H. In order to prevent cargo oil from spilling in the event that the bottom of the lower cargo oil tank 1 is damaged during any type of swamping during ship operation,

[Equation 2] P must be selected so that P≦Pmin. P is determined by the specific gravity of the cargo oil and the liquid level, and the larger the specific gravity of the cargo oil and the higher the liquid level, the larger the value. Therefore, Equation 2 is satisfied and the upper limit of the liquid level of the cargo oil is the minimum when the specific gravity of the cargo oil is maximum. The cargo oil level in this case is assumed to be H0. H
The deck 3 shown in Fig. 1 is installed at a position H below the 0 position, and the cargo oil level in the lower cargo oil tank 1 is adjusted to the height H of the deck 3.
Even if the bottom of the lower cargo oil tank 1 is damaged, it is possible to prevent the cargo oil from flowing out, regardless of the specific gravity of the cargo oil and the stuttering of the ship. In other words

[Math 3]
The relationship H≦H0 holds true.

On the other hand, regarding the lower limit of H, if H approaches 0, that is, if the distance between the bottom of the ship and deck 3 is shortened, the probability that damage will extend to deck 3 in the event of damage to the bottom of the ship due to a large impact increases. It gets expensive. Therefore, along with the formula [Math. 3],

[Equation 4] The condition that H≈H0 is required. In the tanker of this embodiment that meets these conditions, even if the bottom of the ship is damaged, the spillage of cargo oil is sufficiently prevented, and if the side of the ship is damaged, the double side structure 4 prevents the cargo from spilling. Oil leakage is sufficiently prevented.

In reality, cargo oil is not loaded up to the deck 3 in the lower cargo oil tank 1, and even when the cargo oil is fully loaded, a space 26 remains between the cargo oil surface and the deck 3. 26 is supplied with inert gas under pressure. Therefore,
PC is the pressure due to gravity of cargo oil only, PI is the pressure of inert gas [in design, the maximum pressure setting value at the pressure control valve 27 (see Fig. 3) of the vent pipe 5 leading to the lower cargo oil tank],
When the height of the space 26 is h, the above equations [Math. 2], [Math. 3], and [Math. 4] become as follows.

[Math. 5] P=PC+PI≦Pmin

[Math. 6] H≦H0+h

[Equation 7] H≈H0+h Here, assuming that the specific gravity of seawater is SSW and the specific gravity of cargo oil is S0, the height H of the deck 3 is determined by the following formula.

[Formula 8] H≦SSW/S0・(dmin-PI/SSW
)+h

Next, a specific design example will be explained based on FIG. 3.The specific gravity of seawater is 1.025, the maximum value of the specific gravity of cargo oil is 0.9, and the range of fluctuation of inert gas pressure during operation is determined by atmospheric pressure. 1.4 mAq (pressure control valve 27
maximum pressure setting value) to -0.5 mAq (pressure control valve 27
(minimum pressure setting value), ship width 58 m, width of double side structure 4 5.8 m, hull height 31.5 m, full load water dm
When ax is 20.6 m and minimum water dmin is 14.2 m, the height H of the deck 3 in the lower cargo oil tank 1 is as follows. (a) When the inert gas pressure is atmospheric pressure + 1.4 mAq

[Equation 9] H≦1.025/0.9・(14.2−1.4/1
．． 025) + h = 14.6 m + h (b) When the inert gas pressure is atmospheric pressure

[Formula 10] H≦1.025/0.9・14.2+h=16.2m+
h(c) When the inert gas pressure is atmospheric pressure -0.5mAq

[Equation 11] H≦1.025/0.9・(14.2+0.5/1
．． 025)+h=16.7m+h and the upper space 2 of the lower cargo oil tank 1 when the lower cargo oil tank 1 is fully loaded
The height h of 6 is usually 1.5 m to 0.3 m, preferably 1
m or less, and the height H of deck 3 is at least the value when the inert gas pressure PI is at its maximum during the operation (
The maximum pressure setting value of the pressure control valve 27 in the ventilation pipe 5) may be adopted, and the maximum pressure setting value may be set to 15.6 m or less. In other words, it is less than half the height of the cargo oil tank.

Note that the height h of the upper space 26 differs depending on the operation. Therefore, it is safer to determine the height H of the deck 3 by setting the height h of the upper space 26 in the lower cargo oil tank 1 to 0. That is, according to formula [Equation 9], the height H of the deck is 14.6 m or less. In this way, even if the height H of the deck 3 is determined by setting the height h of the upper space 26 to 0, when actually filling the lower cargo oil tank 1 with cargo oil, it is still necessary to The tank 1 is loaded with an upper space 26 left. In this state, the relationship between the cargo oil side pressure acting on the bottom shell plate and the seawater pressure is expressed by the following equation.

[Formula 12] P<Pmin If the bottom of the lower cargo oil tank 1 is damaged in this state, seawater will flow into the lower cargo oil tank from the relationship in equation [12], and the pressure will be expressed by the following equation. The inflow of seawater continues until balance is achieved, and since the specific gravity of seawater is greater than the specific gravity of cargo oil, the infiltrated seawater forms a layer at the bottom of the lower cargo oil tank.

[Equation 13] P=PC+Ps+PI=Pmin Here, Ps represents the pressure due to the weight of the seawater in the seawater layer formed by the seawater that has entered the lower cargo oil tank 1. This seawater layer effectively prevents the movement of the ship due to waves after damage to the ship's bottom, and the secondary outflow of cargo oil from holes in the ship's bottom due to tidal currents. In addition, the lower limit of the height H of deck 3 has been set to the minimum standard value of the height of the double bottom, which is conventionally provided to prevent cargo oil from spilling due to damage to the ship's bottom, that is, 1/15 of the ship's width.
If the length is smaller than 2m, there is a high probability that damage will extend to deck 3 in the event of damage to the bottom of the ship due to a large impact. Therefore, the lower limit of the height of the deck 3 should be set higher, preferably a value near the water line during ballast voyage.

FIG. 16 shows a cross section of the hull of a cargo oil spill prevention type tanker as a second embodiment of the present invention. In addition to having the same configuration as the first embodiment, the second embodiment is provided with a cargo oil pipe device similar to a conventional tanker only in the lower cargo oil tank 1 as a cargo handling means for cargo oil. That is, in the lower cargo oil tank 1, the cargo oil main pipe 20,
A cargo oil pipe system consisting of a cargo oil branch pipe 21 and a stop valve 22 with a cargo oil branch pipe is provided. Further, a bulkhead valve 23 is installed on the deck 3 to allow the upper cargo oil tank 2 to communicate with the lower cargo oil tank 1 only during cargo handling.

In the case of this embodiment, since the upper and lower cargo oil tanks 1 and 2 are in communication with each other when the cargo oil has been loaded, the upper cargo oil also flows into the ventilation pipe 5 communicating with the lower cargo oil tank 1. oil tank 2
The cargo oil will infiltrate to a height equal to the cargo oil level. and,
After loading, the bulkhead valve 23 is closed, and at that time, the cargo oil level inside the vent pipe 5 connected to the lower cargo oil tank 1 is
If the water level is higher than the above-mentioned H0 and the bottom of the lower cargo oil tank 1 is damaged in this state, the cargo oil in the vent pipe 5 between the liquid level in the vent pipe 5 and the liquid level of H0 will damage the bottom of the ship. It flows out from the department. However, the cross-sectional area of the vent pipe 5 is small, and the amount of oil spilled is
It is minute. Furthermore, after the loading of the cargo oil tank is completed and the bulkhead valve 23 is closed, the cargo oil in the lower cargo oil tank 1 is transferred to another tank by the amount that has entered the ventilation pipe 5. The liquid level in the cargo oil tank becomes H, which makes it possible to prevent cargo oil from spilling in the event of damage to the bottom of the ship. Further, as in the case of the first embodiment, the double side structure 4 contributes to preventing the spillage of cargo oil when the side of the ship is damaged.

FIG. 17 shows a cross section of the hull of a cargo oil spill prevention tanker according to a third embodiment of the present invention. The third embodiment also has the same configuration as the first embodiment, but the cargo handling means includes a cargo oil pipe 20 constituting a cargo oil pipe system similar to that of a conventional tanker, An oil branch pipe 21 and a cargo oil branch pipe stop valve 22 are provided in the lower cargo oil tank 1, and a cargo oil branch pipe 25 is provided for cargo handling in the upper cargo oil tank 2, which is independent from that for cargo handling in the lower cargo oil tank 1. and a stop valve 22 are provided. In this third embodiment, it is possible to carry out cargo handling in the lower cargo oil tank 1 and the upper cargo oil tank 2 separately, and when loading cargo oil into the lower cargo oil tank 1, the cargo oil liquid level is adjusted to the deck. It is easy to control up to position H of 3. In the case of the third embodiment of the present invention described above, the same effect as in the case of each of the above-described embodiments can be obtained with respect to preventing cargo oil from flowing out when the hull is damaged. The above-mentioned deck 3 does not necessarily have to be completely horizontal, and even if it is slightly inclined, there is no problem as long as the highest part of the deck 3 is below the above-mentioned height H. An example in which the inboard deck is inclined will be described below. In addition, from FIG. 18 onward, the inboard deck is indicated by the reference numeral 118.

In the cargo oil spill prevention type tanker as a fourth embodiment of the present invention shown in FIG. The double ship side structure 104 is formed so as to be sloped linearly so as to gradually become higher toward the ship side.
In the vicinity of the connection to the inner shell, there is a locally flat highest portion 102 having a maximum height H above the bottom of the ship. The maximum height H is the maximum height H when the cargo oil 107 is loaded into the lower cargo oil tank 105 from the bottom of the ship to near the highest position of the deck 118 in the shallowest water dmin state when the cargo oil tank is loaded with cargo oil and the vessel is operated. When loaded, the pressure due to the weight of the cargo oil 107 that acts on the bottom of the ship plus the maximum pressure setting value of the pressure control valve 113 in the vent pipe 112 for the lower cargo oil tank 105 acts on the bottom of the ship. The height is set close to the point where the pressure of the seawater is equal to the pressure of the seawater. In addition, in FIG. 18, reference numeral 101 is the deck slope, 106 is the upper cargo oil tank, 107 is the cargo oil in the upper cargo oil tank, 108 is the bottom shell, 109 is seawater, 110 is the water surface, 1
Reference numeral 11 indicates the gas pressure in the lower cargo oil tank, and reference numeral 114 indicates an inert gas/cargo oil tank ventilation pipe. As described above, by providing the deck 118 with an inclination, in this fourth embodiment, the cargo oil 107 loaded in the upper cargo oil tank 106 can be
In addition to improving the efficiency of oil collection and dredging, deck 1
The effect of reducing the amount of sludge that accumulates in the tank 108 and reducing the scope of sludge removal work can be obtained, and furthermore, the degassing of the lower cargo oil tank 105 during loading can be carried out smoothly. It's also effective.

FIGS. 19 and 20 show that according to this embodiment,
This is a description of a situation in which sludge 115 is concentratedly deposited in the lowest part 103 of the deck 118 and in a range extending from the lowest part 103 to the slope part 101. In particular, FIG. 20 shows an enlarged view of the vicinity of the lowest deck part 103, and shows that sludge 115 can be suctioned and removed together with cargo oil 107 from the suction pipe opening end 116 during cargo unloading. There is. The inclination of the deck 118 such that the hull centerline side is lower is such that the sludge 115 that settles during operation with cargo oil 107 loaded in the upper cargo oil tank 106 is removed from the lowest part of the deck 118 forming the bottom surface of the upper cargo oil tank. 103, that is, it has the effect of concentrating on the hull centerline side. Generally, the opening end of the suction pipe of a tank is normally provided at the lowest position of the tank, and this embodiment also assumes that the opening end 116 of the suction pipe for the upper cargo oil tank 106 is provided at the lowest position of the tank 106. It is said that Based on this premise, when considering the unloading of the cargo oil 107 loaded in the upper cargo oil tank 106, as a matter of course,
Because the bottom surface of the tank, that is, the deck 118 is sloped, the sludge 115 described above can be efficiently removed by suction together with the cargo oil, and even when the liquid level in the upper cargo oil tank 106 decreases, the sludge 115 can be efficiently removed from the vicinity of the opening end 116 of the suction pipe. 107
Since these materials gather together, suction efficiency improves and unloading time can be shortened.

Furthermore, in tankers, work is carried out to remove the sludge accumulated in the cargo oil tank to the outside of the tank before docking. Since the area where 115 is accumulated remains in a narrow area centered on the lowest position of the intermediate deck, the scope of sludge removal work before docking is reduced, and moreover, sludge 115 can be efficiently removed during unloading operations during normal operations. At the same time, the amount of work itself can be reduced. On the other hand, if the deck 118 that forms the top plate of the lower cargo oil tank 105 does not have an inclination, the loading rate will be temporarily lowered before the cargo oil loading is completed, and the loading rate will be lowered once until the gas in the tank is sufficiently released. It is necessary to carry out loading operations slowly. In particular, when the hull member with the deck 118 is disposed below the deck 118, air pockets are likely to occur. In this embodiment, since the deck 118 is raised toward the side of the ship, the lower cargo oil tank 10
When loading cargo into the tank, as the liquid level in the tank rises, the gas in the upper part of the cargo oil smoothly escapes upward along the slope of the deck 118, and flows through the tank from the ventilation pipe 112 located at the highest part 102 of the deck 118. It is expelled to the outside. Therefore, air pockets do not occur and loading can be carried out efficiently.

Note that FIG. 21 shows a modification in which a partial horizontal part is not provided on the inboard deck, and a linear inclined part 101 is provided between the highest deck part 102 and the lowest deck part 103. Further, FIG. 22 shows a combination of a straight section a, a partial horizontal section b, and an arcuate section c on the inboard deck to form an inclined section 101 with a highest deck section 102 having the above-mentioned height H and a lowest deck section 10.
3 is shown.

FIGS. 23 and 24 show the highest deck portion 102 having the height H described above in a tanker similar to that described above.
This shows a fifth embodiment of the present invention in which the
The same effects as in the example can be obtained. Note that the symbols a, b, and c in FIG. 24 respectively indicate a straight portion, a partial horizontal portion, and a circular arc portion, similarly to FIG. 22.

In the sixth embodiment of the present invention shown in FIGS. 25 and 27, the inboard deck 118 is inclined in the ship's ship direction within the range of each upper cargo oil tank 106, and each deck 118 is located at the bow side. It has the above-mentioned highest height H at the end, and has the lowest height H' at the end on the stern side. A partial flat part is formed in the lowest part 103 of the deck. In addition, the code|symbol 117 in a figure shows a transverse bulkhead, (alpha) shows a trim angle, and (beta) shows the inclination angle of the deck 118 in the ship's direction.

FIG. 27 shows the angle that the deck 118 makes with the horizontal plane and the state of the cargo oil 107 and sludge 115 in the upper cargo oil tank 106 just before the end of the cargo unloading operation, with trim attached during unloading. The remaining situation is compared with the case where the deck 118 has no slope shown in FIG. 26. In the tanker of this embodiment shown in FIG. 27, compared to the case of FIG. 26, the angle between the deck 118 and the horizontal plane can be made larger by the inclination angle β of the deck 118 even when the trim angle α is the same. Freight oil 107 as the angle of inclination is large
The sludge 115 is more likely to collect near the opening end 116 of the suction tube. This improves the efficiency of cargo unloading and the ability to remove sludge. moreover,
Specifically, in a tanker, a pump room is generally arranged on the stern side of a cargo oil tank compartment, and suction pipes are piped from each cargo oil tank toward the pump room on the stern side. Therefore, when carrying out unloading operations, it is common practice to trim the hull to the stern position in order to improve suction efficiency. In this case, the bottom surfaces of the cargo oil tanks are inclined so that the stern side of each tank is lower with respect to the horizontal plane depending on the trim of the hull. By providing the deck 118, which is the bottom surface of the upper cargo oil tank 106, with an inclination so that the stern side is lower, the inclination of the deck during unloading work is reduced due to the synergistic effect with the stern trim described above. It becomes larger relative to the horizontal plane. Therefore, the efficiency of unloading the upper cargo oil tank can be further improved, and the sludge 1 during unloading can be further improved.
The suction and removal efficiency of No. 15 can also be further improved.

In a seventh embodiment of the present invention shown in FIG. 28, in a tanker similar to the above-mentioned tanker, the inboard deck has a local area in the middle part of the upper cargo oil tank 106 in the longitudinal direction within the range of each upper cargo oil tank 106. The lowest part of the deck 103 which is horizontal
The transverse bulkhead 117 has straight portions 101 that gradually become higher toward the bow and the stern.
The deck has the highest part 102 set at the maximum height H mentioned above at the part connected to the deck. Note that the lowest deck portion 103 is provided slightly rearward of the center of the length of the upper cargo oil tank 106 in the longitudinal direction. In this seventh embodiment, almost the same effects as in the sixth embodiment described above can be obtained, but in addition, when the inboard deck is viewed from the bow and stern direction, the middle part is low and the front and rear parts are high, so that the lowest part 103
No matter where in the bow and stern direction, the positions of the front and rear ends in the height direction can be made equal. Therefore, the height of the inboard deck can be made the same before and after the transverse oiltight bulkhead 117 between a series of upper cargo oil tanks that extend in the longitudinal direction of the ship, improving reliability in terms of structural strength and requiring the required steel materials. It also leads to improved economic efficiency, such as reduced weight and ease of construction.

In an eighth embodiment of the present invention shown in FIG. 29, in a tanker similar to the one described above, the inner deck has a linear inclination in the ship's direction, and in the transverse direction of the hull there is a tanker as shown in FIG. 18. It has a similar shape. That is, the inboard deck is formed low near the centerline of the ship, has a straight portion 101 that gradually becomes higher toward the ship, and has flat plate-like portions at both ends thereof. The inboard deck has the highest deck part 102 having the above-mentioned maximum height H on the bow side of the ship, and has the lowest deck part 103 in the center part on the stern side. In this eighth embodiment, since the inclination of the inboard deck in the lateral direction of the ship and the inclination in the ship's direction are combined, the lowest deck part 10, which is the lowest part of the bottom of the upper cargo oil tank 106,
3 becomes one narrow spot. Therefore, the cargo oil and sludge in the upper cargo oil tank 106 gather at the lowest part 103 along the inclination of the ship's internal deck in the longitudinal direction and in the lateral direction of the ship, thereby further improving the unloading efficiency and the sludge removal efficiency.

In a ninth embodiment of the present invention shown in FIGS. 30 to 36, a tanker similar to that described above has a double side structure 10.
The inner shell 119 of No. 4 is formed by the side wall of the upper cargo oil tank and the side wall of the lower cargo oil tank. The inner shell 119 is formed of a vertical flat plate that is continuous in the vertical direction and extends between the upper cargo oil tank and the lower cargo oil tank. In the thin part of the hull skin at the front and rear of the cargo oil tank compartment, as shown in Figure 37, the side skin comes closer to the center of the hull, and at the same time the bottom skin plate flat part 1
The range of 21 is also getting smaller. In such parts,
If the inner shell 119 of the double side structure 104 is placed on the same plane as the position of the inner shell in the center of the hull, the double side structure cannot be obtained as shown in FIG. 37. In other words, a part of the ship's side outer plating is not a double ship's side. With such a bulkhead structure, there is a possibility that even slight damage to the side bottom of the ship could cause cargo oil to leak out.

FIG. 37 schematically shows the spillage of cargo oil when the bottom of the ship's side is damaged in the above-mentioned portion. In order to prevent these cargo oils from spilling in the above areas, as shown in Figure 30, the inner shell 119 formed by a vertical flat plate is bent toward the hull centerline on the bow and stern sides when viewed from above. It has become.

[0051] In the ninth embodiment of the present invention, by employing continuous vertical flat plates in the vertical direction for the inner shell of the double side structure, the side outer plate near the center of the hull is a vertical flat plate. To a certain extent, the double side structural blocks can be rectangular parallelepipeds, except for the bilge section of the side bottom. When building a ship, the current mainstream method of ship construction is to divide the hull into several blocks, have each block assembled at a factory, and then join the blocks together at the dock or on the slipway. ing. Rectangular parallelepiped blocks are easy to work both when assembling the blocks and when joining blocks together, making it easy to apply automation equipment and making it easy to control work accuracy. Therefore, this embodiment in which the double ship side structural blocks can be made into rectangular parallelepipeds leads to ease of construction and improved efficiency.
Improves economic efficiency during construction. Furthermore, regarding the thin parts of the hull outer panels at the front and rear of the cargo oil tank compartments, the inner shell of the double hull structure can be bent toward the hull center line while maintaining the vertical flat plate at the center of the hull, as described above. Since the lower end of the vertical flat plate can always be joined to the flat part of the bottom shell, oil leakage due to damage to the bottom shell can be avoided as shown in FIG. 37. At the same time, the inner shell is composed of a vertical flat plate, and when assembling blocks or joining blocks together, the vertical flat plate can be used as a reference plane, making construction easier.

As a tenth embodiment of the present invention, FIG. 38 shows a cross-sectional view of the center of the hull, FIG. 39 shows a horizontal cross-sectional view of the hull showing the arrangement of the upper cargo oil tank, and FIG. 40 shows the arrangement of the lower cargo oil tank. FIG. 41 is a vertical sectional view along the hull center line showing the arrangement of the upper and lower cargo oil tanks. In this tenth embodiment, the shape of the hull deck 118 shown in FIG. 18 is adopted, and the inner shell 119 of the double hull structure 104 is formed by combining a vertical flat plate and a horizontal flat plate. In other words, a vertical flat plate is provided in the range that touches the side of the upper cargo oil tank 106, and it is placed close to the ship's side shell plate 20, and a horizontal flat plate 22 is provided at the position of the deck 118, and the side of the lower cargo oil tank 5 and The contact area is a vertical flat plate, and it is placed at a distance from the ship's side outer plate 20. When damage to the ship's side occurs due to a collision, the double ship side structure 104 can prevent cargo oil from spilling as long as the damage does not reach the inner shell 119, but if the energy of the collision is large, the damage will reach the inner shell 119. The greater the thickness (width) of the double side structure 104, the lower the probability that damage will reach the inner shell 119. However, increasing the thickness of the double side structure 104 over the entire surface of the cargo oil tank section will lead to a decrease in the cargo oil tank volume if the ship shape is constant; This leads to larger sizes and less economic efficiency. Moreover, the inside of the double side structure 104 is normally used as a ballast tank, but the internal volume of the double side structure 104 is too large for the amount of ballast required when operating a tanker. This will create a section that is unnecessary for flight operations. In contrast, the thickness of the double side structure 104 is made thicker in areas where damage is likely to occur due to collision or where oil spills are likely to occur on a larger scale when the inner shell 119 is damaged, and the thickness is increased in other areas. By making it thinner, it is possible to further enhance the oil spill prevention effect, and to minimize the wasted space inside the double side structure 104 as described above, thereby effectively securing the cargo oil tank volume. It becomes possible. As a result, the hull shape is minimized and economical efficiency increases. The lower cargo oil tank 105 has a double side structure 10 in its area.
4 is thicker and safer from damage to the ship's side. Therefore, as shown in FIGS. 39, 40 and 41,
Regarding the lower cargo oil tank 105, the upper cargo oil tank 106
The number of horizontal oil-tight bulkheads 117 at the front and rear of the tank is reduced, and the number of lower cargo oil tanks 105 is reduced compared to the upper cargo oil tank 10.
It is half the number of 6.

The tenth embodiment of the present invention makes use of the idea of the ninth embodiment described above, that is, by adopting a combination of vertical flat plates and horizontal flat plates that are easy to construct, a double ship side structure 1 is constructed.
This is a means for changing the thickness of 04 in the vertical direction. By this means, for example, if the thickness of the double ship side structure in the area of the upper cargo oil tank 106 is made thin and the thickness of the double ship side structure in the area of the lower cargo oil tank 105 is made sufficiently thick, if damage to the ship side occurs due to a collision. However, the lower cargo oil tank 105 is not damaged because the double side structure 104 is sufficiently thick. Therefore, since the lower cargo oil tank 105 is safer from damage to the ship's side, damage to the ship's bottom, and oil spillage, the capacity of each tank may be increased, that is, it may be a large tank. . The lower cargo oil tank 105 is more difficult to remove sludge than the upper cargo oil tank 106, is gas free, and is difficult to inspect and maintain inside the tank. Therefore, by making the lower cargo oil tank 105 a larger tank and reducing the number of tanks by the above means,
This leads to a reduction in the number of fittings in the tank and maintenance work.

On the other hand, the upper cargo oil tank 106 is easily damaged by damage to the ship's side, so in order to stop the outflow of cargo oil on a small scale, it becomes necessary to subdivide the tank. As a result, the number of tanks increases, the number of fittings in the tank increases, and the maintenance work increases, but the fitting work and maintenance work for the upper cargo oil tank 106 is easier than for the lower cargo oil tank 105. Therefore, when looking at the entire ship, reducing the number of lower cargo oil tanks 105 and increasing the number of upper cargo oil tanks 106 makes the ship easier to use and more economical. Further, according to the tenth embodiment, in the thinned portion of the hull skin in the front and rear portions of the cargo oil tank compartment, the above-mentioned ninth
When the embodiment is applied, the width of the double side structure 104 tends to be unnecessarily wide above the side shell plate and narrow below it, resulting in unnecessary volume being taken up in the double side structure portion. However, the inner shell shape of the double hull structure 104 can be formed into a stepped shape along the shape of the hull outer plate. Therefore, it is not necessary to take unnecessary volume in the double ship side structure 104, and the volume of the cargo oil tank can be effectively secured accordingly. Assuming that the cargo oil tank volume is constant, by employing this tenth embodiment, the ship shape can be minimized and economical efficiency can be increased.

FIG. 42 shows a case where the concept shown in FIG. 38 is applied to the thinned portion of the hull outer plate at the front and rear of the cargo oil tank compartment. As shown in FIG. 42, the shape of the side outer plate 20 at the thinned portion of the outer plate of the hull becomes a smooth curve toward the center line of the hull as it approaches the bottom of the boat. In the inner shell 119,
As shown in FIG. 42, by combining the vertical flat plate and the horizontal flat plate, the range 123 shown by dotted hatching can be used as the upper cargo oil tank 106, compared to the case where only the vertical flat plate is used as the inner shell 119 (see FIG. 35). Can be used effectively.

As an eleventh embodiment of the present invention, FIG. 43 shows a cross section at the center of the hull. In the tanker shown in FIG. 43, the shape of the deck 118 shown in FIG. 18 is used, and the shape of the inner shell 119 is at an angle γ and an angle δ
A flat plate having two types of inclinations is adopted, and the inclination change position is the intersection line with the deck 118. And δ is larger than γ. In this eleventh embodiment, the upper cargo oil tank 106
The position where the thickness of the double side structure 104 is minimum in the range of
The thickness of the double side structure 104 is increased. In this embodiment, if a collision occurs on the side of the ship, the part of the inner shell 119 that is likely to be damaged is near the upper deck where the thickness of the double side structure 104 is the smallest. When the side surface of the upper cargo oil tank 106 is damaged, the amount of cargo oil that flows out is the amount of cargo oil loaded above the lowest level of the breach in the damaged part. Therefore, the effect of preventing cargo oil from spilling will be greater if the lower side of the side is not damaged than the upper side. In the embodiment shown in FIG. 43, by focusing on the above points, the effect of preventing oil leakage when the upper cargo oil tank 106 is damaged on the ship side is increased. The thickness of the double side structure 104 in the area of the lower cargo oil tank 105 is made thicker than in the area of the upper cargo oil tank 106,
The effect of preventing cargo oil spillage is greater than damage to the ship's side.

FIG. 44 is a cross-sectional view of the embodiment shown in FIG. 43 at the thinned part of the outer skin of the hull. The inclination and inclination change position of the inner shell 119 are the same as in the case of FIG. 43. According to this embodiment, in the thin part of the hull skin, the ship side skin 20
According to the shape, the volumes of the upper cargo oil tank 106 and the lower cargo oil tank 105 can be secured more effectively than in the embodiment shown in FIG. The eleventh embodiment of the present invention described above uses a combination of inclined flat plates in the shape of the inner shell 119 as a means for vertically changing the thickness of the double side structure described in the tenth embodiment. As mentioned above, it is obvious that this method is easy to construct because it is a combination of flat plates, but in addition, the inner shell of the double side structure has a bending part. However, since it has continuity as a surface, it is possible to share the shearing force in the longitudinal direction of the hull, making it an effective structural element in terms of structural strength. Therefore, there is no need for shear reinforcement, leading to improved economic efficiency such as a reduction in the weight of the hull. The effect produced by changing the thickness of the double ship side structure in the vertical direction by combining the inclined flat plates is the same as in the tenth embodiment described above. Furthermore, regarding the thinned parts of the hull skin at the front and rear portions of the cargo oil tank compartments, in this embodiment, the inner shell 119 of the double hull structure 104 can be formed along the hull skin, and the effect thereof is the same as described in the above-mentioned 10th section. This is the same as described for the embodiment.

As a twelfth embodiment of the present invention, FIG. 45 shows a cross section at the center of the hull, and FIG. 46 shows a cross section at the thinned part of the hull outer plate. In this embodiment, the inboard deck 118 shown in FIG. 18 is used, and the shape of the inner shell 119 is as follows.
It has a vertical flat plate at its upper end and lower end, and an inclined flat plate having two types of inclination angles at the middle part, and the inclination change position is the intersection line with the deck 118. This embodiment is based on the embodiment shown in FIGS. 43 and 44, and the inner shell 11
9 is bent vertically near the upper deck and near the bottom outer plate, and the upper cargo oil tank 106 is shown in Fig. 43.
The thickness of the double side structure 104 is thicker near the upper deck than that shown in FIG. however,
Since the volume of the upper cargo oil tank 106 is reduced by the thickness of the double ship side structure 104, the lower cargo oil tank 105 is
This is an attempt to secure the capacity of the cargo oil tank by reducing the thickness of the double ship side structure 104 near the bottom outer plate below the ship. When the side surface of the lower cargo oil tank 105 is damaged, the amount of cargo oil that flows out is the amount of cargo oil loaded below the level of the top end of the broken hole in the damaged part. Therefore, the effect of preventing cargo oil from spilling will be greater if the upper side of the side is not damaged more than the lower side. Focusing on this point, the oil spill prevention effect of the lower cargo oil tank 105 is equivalent if the thickness of the double side structure 104 above the side surface, that is, at the intersection with the deck 118 is the same. It can be considered. Therefore, by vertically bending the vicinity of the bottom outer plate of the inner shell 119, it is possible to secure the capacity of the cargo oil tank without impairing the cargo oil leakage prevention effect.

In the tanker shown in FIG. 46, a horizontal flat plate is provided near the bottom outer plate of the inner shell 119 so that the bottom outer plate flat portion 121 is at a position where the inner shell 119 contacts the outer plate. By providing these partial horizontal flat plate portions, vertical flat plate portions, and inclined flat plate portions, the necessary minimum thickness of the double ship side structure 104 is secured along the shape of the ship side shell plating 120, and the thickness of the cargo oil tank is The inner shell 11 is designed to effectively secure the volume.
It becomes possible to determine the shape of 9.

[0060]

Effects of the Invention As detailed above, according to the cargo oil spill prevention type tanker of the present invention, the following effects can be obtained. (1) Since the cargo oil tank is protected by the double side structure,
This prevents cargo oil from spilling in the event of damage to the side of the ship, and furthermore, the height from the bottom of the deck that divides the cargo oil tank into an upper lower oil tank and a lower cargo oil tank is set appropriately, making it possible to create a double bottom. Even without adopting this structure, it is effective in accurately preventing the spillage of cargo oil in the event of damage to the bottom of the ship under all loading conditions during ship operation. (2) By tilting the ship's deck, the sludge in the upper cargo oil tank is concentrated and deposited in the lower part of the ship, allowing the sludge to be efficiently removed along with the cargo oil during unloading.
Can be removed by suction. (3) Even with regard to sludge that could not be removed during unloading, the distribution range is limited to the lower part of the sloping interior deck, so the sludge removal work is reduced. (4) Since not only sludge but also cargo oil is concentrated in a low position on the ship's deck, the efficiency of dredging in the final stage of unloading is improved and the unloading time is shortened. (5) When loading the lower cargo oil tank, by providing an incline to the ship's inboard deck, the gas in the tank above the oil level can smoothly escape to a higher position behind the ship's ship's deck, allowing air to flow to the top of the tank. There is no accumulation and the loading process is made more efficient. (6) In addition to the inclination of the inboard deck in the transverse direction of the hull, by trimming the hull in the stern direction during unloading, the inclination also occurs in the fore-and-aft direction of the hull, amplifying the above effect. (7) By sloping the inboard deck in the direction of the ship's ship, the inclination of the inboard deck in the longitudinal direction of the ship due to the hull trim during unloading operations can be made stronger, thereby amplifying the above effect. (8) By providing the lowest part of the deck in the middle part of the ship's internal deck in the longitudinal direction within the range of the upper cargo oil tank, in addition to the above effects, the height of the ship's internal deck can be used as a partition in the longitudinal direction of the cargo oil tank. It is now possible to match the front and rear of the horizontal oiltight bulkhead, improving reliability in terms of structural strength and improving economic efficiency. (9) The above-mentioned effects can be synergistically enhanced by having the inboard deck both sloped in the ship's direction and sloped in the transverse direction of the hull. (10) By adopting a vertical flat plate for the inner shell of the double side structure, design and construction are the easiest, it is easier to ensure accuracy during construction, and reliability is improved. (11) The inner shell of the double side structure selectively combines vertical flat plates, horizontal flat plates, and inclined flat plates, thereby reducing ship construction costs while maintaining the effect of preventing cargo oil from spilling against side damage and bottom damage. The effect of reducing this can be obtained. (12) By using a method that changes the width of the double ship side structure in steps, it is possible to achieve the effect of protecting a part of the cargo oil tanks from damage to the ship side, and to reduce the number of cargo oil tanks. In addition to making it possible to reduce (13) By using a means to continuously change the width of the double side structure with the sloping sidewalls, the inner shell can share the hull longitudinal shear force in terms of structural design, which reduces the hull weight. This results in a reduction in fuel consumption and improves economic efficiency. (14) While maintaining the oil spill prevention effect of the double side structure, even in the thin parts of the hull outer panels at the front and rear of the cargo oil tank compartments, areas that could not previously be fully used as cargo oil tanks can be used as cargo oil tanks. It can now be used effectively as a tank,
If a tanker with a fixed cargo oil tank capacity is compared, the ship shape can be made smaller, which has the effect of reducing construction costs and operating costs.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the hull of a cargo oil spill prevention type tanker as a first embodiment of the present invention.

FIG. 2 is an explanatory diagram for determining the installation position of a deck that partitions an upper cargo oil tank and a lower cargo oil tank in the tanker.

FIG. 3 is a cross-sectional view of the hull showing an example of use of the tanker.

FIG. 4 is a horizontal sectional view of a first example of a conventional tanker.

FIG. 5 is a sectional view taken along the line AA in FIG. 4;

FIG. 6 is a sectional view taken along the line BB in FIG. 4;

FIG. 7 is a horizontal sectional view of a second example of a conventional tanker.

8 is a sectional view taken along the line AA in FIG. 7. FIG.

FIG. 9 is a horizontal sectional view of a third example of a conventional tanker.

FIG. 10 is a sectional view taken along the line A-A in FIG. 9;

FIG. 11 is a horizontal sectional view of a fourth example of a conventional tanker.

FIG. 12 is a sectional view taken along the line AA in FIG. 11;

FIG. 13 is a cross-sectional view of a fifth example of a conventional tanker.

FIG. 14 is a cross-sectional view of a sixth example of a conventional tanker.

15 is an explanatory diagram showing the process of cargo oil spilling when the side of the tanker in FIG. 14 is damaged; FIG.

FIG. 16 is a cross-sectional view of the hull of a cargo oil spill prevention type tanker according to a second embodiment of the present invention.

FIG. 17 is a cross-sectional view of the hull of a cargo oil spill prevention type tanker as a third embodiment of the present invention.

FIG. 18 is a cross-sectional view of a cargo oil spill prevention type tanker according to a fourth embodiment of the present invention.

19 is a cross-sectional view of the hull of the tanker shown in FIG. 18, showing the state in which the upper cargo oil tank is used.

FIG. 20 is an enlarged cross-sectional view of the main parts of the tanker shown in FIG. 19;

FIG. 21 is a cross-sectional view of a partially modified hull of the tanker of the fourth embodiment.

FIG. 22 is a cross-sectional view of a partially modified hull of the tanker of the fourth embodiment.

FIG. 23 is a cross-sectional view of a cargo oil spill prevention type tanker according to a fifth embodiment of the present invention.

24 is a transverse cross-sectional view of a partially modified hull of the tanker of FIG. 23; FIG.

FIG. 25 is a longitudinal cross-sectional view of a cargo oil spill prevention type tanker according to a sixth embodiment of the present invention.

FIG. 26 is a vertical cross-sectional view showing a vertically inclined state of main parts of a conventional tanker.

27 is a longitudinal sectional view showing the main parts of the tanker of FIG. 25 in contrast to FIG. 26;

FIG. 28 is a longitudinal cross-sectional view of a cargo oil spill prevention type tanker according to a seventh embodiment of the present invention.

FIG. 29 is a perspective view showing the main parts of a cargo oil spill prevention type tanker as an eighth embodiment of the present invention.

FIG. 30 is a horizontal cross-sectional view of a cargo oil spill prevention type tanker according to a ninth embodiment of the present invention.

31 is a sectional view taken along the line A-A in FIG. 30. FIG.

32 is a sectional view taken along the line BB in FIG. 30. FIG.

33 is a sectional view taken along the line CC in FIG. 30. FIG.

34 is a sectional view taken along the line DD in FIG. 30. FIG.

35 is a sectional view taken along the line E-E in FIG. 30. FIG.

36 is a sectional view taken along the line FF in FIG. 30. FIG.

FIG. 37 is a cross-sectional view of the hull schematically showing an example of a problem when the ship's side bottom part is damaged.

FIG. 38 is a cross-sectional view of the center of the hull showing a cargo oil spill prevention type tanker as a tenth embodiment of the present invention.

39 is a horizontal sectional view of the upper cargo oil tank of the tanker of FIG. 38; FIG.

40 is a horizontal sectional view of the lower cargo oil tank of the tanker of FIG. 38; FIG.

41 is a longitudinal cross-sectional view of the tanker of FIG. 38 along the hull centerline; FIG.

42 is a cross-sectional view of the tanker in FIG. 38 at a thinned portion of the hull skin; FIG.

FIG. 43 is a transverse cross-sectional view of a cargo oil spill prevention type tanker according to an eleventh embodiment of the present invention.

44 is a cross-sectional view of the thinned part of the hull of the tanker of FIG. 43; FIG.

FIG. 45 is a cross-sectional view of the center of the hull showing a cargo oil spill prevention type tanker as a twelfth embodiment of the present invention.

46 is a cross-sectional view of the tanker in FIG. 45 at a thinned portion of the hull skin; FIG.

[Explanation of symbols]

1 Lower cargo oil tank 2 Upper cargo oil tank 3 Deck 4 Double ship side structure 5 Ventilation pipe 6 Inert gas hatch 7 Inert gas/ventilation main pipe 8 Bottom 9 Ship side 10 Ballast tank 11 Double bottom structure 12 Cargo oil tank 13 Double hull structure 14 Cargo oil 15 Upper side ballast tank 16 Lower side cargo oil tank 17 Upper center cargo oil tank 18 Lower center cargo oil tank 19 Full load water line 20 Cargo oil main pipe 21 Cargo oil branch pipe for lower cargo oil tank 22 Cargo oil branch pipe included Stop valve 23 Bulkhead valve 24 Upper side cargo oil tank 25 Cargo oil branch pipe for upper cargo oil tank 26 Space 101 Inner deck slope 102 Inner deck highest part 103 Inner deck lowest part 104 Double side structure 105 Lower cargo oil tank 106 Upper part Cargo oil tank 107 Cargo oil 108 Bottom shell plate 109 Seawater 110 Water surface 111 Gas pressure in lower cargo oil tank 112 Inert gas/vent pipe for lower cargo oil tank 11
3 Lower cargo oil tank pressure control valve 114 Inert gas/cargo oil tank ventilation main pipe 115
Sludge 116 Suction pipe open end 117 Horizontal oiltight bulkhead 118 Inner deck 119 Inner shell 120 Ship side outer plate 121 Bottom outer plate flat part 122 Inner shell horizontal flat part 123 Freight oil tank volume increase range

Claims (15)

[Claims] [Claim 1] A cargo oil tank provided inside the ship, and a double ship side structure provided on each side of the cargo oil tank to prevent the cargo oil from leaking from the cargo oil tank to the outside of the ship. , a deck is provided that divides the cargo oil tank into an upper cargo oil tank and a lower cargo oil tank, and the upper limit of the height of the deck from the bottom of the ship is set to less than half the height of the cargo oil tank. A tanker that prevents oil from spilling. [Claim 2] A cargo oil tank provided inside the ship, and a double ship side structure provided on each side of the cargo oil tank to prevent the cargo oil from leaking from the cargo oil tank to the outside of the ship. , a deck that divides the cargo oil tank into an upper cargo oil tank and a lower cargo oil tank is provided almost horizontally, and the height of the deck from the bottom of the ship is such that the cargo oil is loaded into the cargo oil tank. When the lower cargo oil tank is loaded with cargo oil from the bottom of the ship to the vicinity of the deck in the shallowest stagnant state when the vessel is operated as The seawater pressure acting on the bottom of the ship is set at a level below where the pressure obtained by adding the maximum pressure setting value of the pressure control valve in the vent pipe for the lower cargo oil tank is equal to the pressure of the seawater acting on the bottom of the ship. A cargo oil spill prevention type tanker. [Claim 3] A cargo oil tank provided inside the ship, and a double ship side structure provided on each side of the cargo oil tank to prevent cargo oil from flowing out from the cargo oil tank to the outside of the ship. , a deck is provided that divides the cargo oil tank into an upper cargo oil tank and a lower cargo oil tank, and the position of the deck in the height direction from the bottom of the ship is such that the cargo oil tank is loaded with cargo oil during operation. When cargo oil is loaded from the bottom of the ship to the above-mentioned deck in the shallowest stagnant state when the ship is in its shallowest state, below the position where the pressure of the cargo oil acting on the bottom of the ship is equal to the pressure of seawater acting on the bottom of the ship. This oil spill prevention type tanker is characterized by being set up near the same location. [Claim 4] A cargo oil tank provided inside the ship, and a double ship side structure provided on each side of the cargo oil tank to prevent cargo oil from flowing out from the cargo oil tank to the outside of the ship. , the deck that divides the cargo oil tank into an upper cargo oil tank and a lower cargo oil tank is provided so as to be inclined, and the height of the highest point of the deck from the bottom of the ship is such that the cargo oil is transferred to the cargo oil tank. In the shallowest stagnant state when loaded and operated,
When the lower cargo oil tank is loaded with cargo oil from the bottom of the ship to near the highest point on the deck, a pressure control valve in the vent pipe for the lower cargo oil tank is used to control the pressure due to the weight of the cargo oil acting on the bottom of the ship. A cargo oil spill prevention type tanker, characterized in that the pressure is set below the point where the pressure of the seawater acting on the bottom of the ship is equal to the maximum pressure set value of the tanker. 5. The cargo oil spill prevention type tanker according to claim 4, wherein the deck is formed to be lowest near the hull center line and gradually become higher toward the ship side. 6. The cargo oil spill prevention type tanker according to claim 4, wherein the deck is formed to be highest near the hull centerline and gradually lower toward the ship side. 7. The cargo oil spill prevention type tanker according to claim 4, wherein the deck is provided so as to be inclined in the ship's ship direction within the range of the upper cargo oil tank. 8. The deck is formed to be lowest in the middle part of the upper cargo oil tank in the longitudinal direction of the upper cargo oil tank, and gradually become higher toward the bow and the stern. The cargo oil spill prevention type tanker according to claim 4, characterized in that the cargo oil spill prevention type tanker is formed. 9. The deck is inclined toward the ship's length within the range of the upper cargo oil tank, and is formed to be lowest near the hull centerline in a cross section of the hull and gradually become higher toward the ship side. The cargo oil spill prevention type tanker according to claim 4, characterized in that: 10. The deck is inclined toward the ship's length within the range of the upper cargo oil tank, and is formed to be highest near the hull centerline in a cross section of the hull and gradually become lower toward the ship side. The cargo oil spill prevention type tanker according to claim 4, characterized in that: [Claim 11] A cargo oil tank provided inside the ship, and a double ship side structure provided on each side of the cargo oil tank to prevent the cargo oil from leaking from the cargo oil tank to the outside of the ship. , a deck is provided that divides the cargo oil tank into an upper cargo oil tank and a lower cargo oil tank, and the position of the deck in the height direction from the bottom of the ship is such that the cargo oil tank is loaded with cargo oil during operation. In the shallowest stagnant state when cargo oil is loaded from the bottom of the ship to the above deck, the pressure of the cargo oil acting on the bottom of the ship is equal to the pressure of the seawater acting on the bottom of the ship. A cargo oil spill prevention type tanker, wherein the inner shell of the double side structure is formed by a side wall of the upper cargo oil tank and a side wall of the lower cargo oil tank. 12. The inner shell of the double ship side structure is formed of a vertical flat plate that is continuous in the vertical direction across the upper cargo oil tank and the lower cargo oil tank. An oil spill-proof tanker. 13. The inner shell of the double ship side structure is characterized in that the lower end of the side wall of the upper cargo oil tank and the upper end of the side wall of the lower cargo oil tank are connected by an inner shell flat portion. , the cargo oil spill prevention type tanker according to claim 11. 14. The inner shell of the double side structure is formed by an inclined side wall of the upper cargo oil tank and an inclined side wall of the lower cargo oil tank, and the inclination angle of the inclined side wall of the lower cargo oil tank is 12. The cargo oil spill prevention type tanker according to claim 11, wherein the angle of inclination of the inclined side wall of the upper cargo oil tank is set to be larger than the angle of inclination of the inclined side wall of the upper cargo oil tank. 15. The side wall of the upper cargo oil tank and the side wall of the lower cargo oil tank forming the inner shell of the double side structure selectively form at least two of the vertical side wall, the inclined side wall, and the inner shell flat portion. The cargo oil spill prevention type tanker according to claim 11, characterized in that it is formed in combination with.