JPH04221288A - Oil tanker - Google Patents

Abstract

PURPOSE:To ensure easy access to a lower cargo oil tank by forming a ship's side as a double hull with a longitudinal bulkhead extended from an upper deck to a ship's bottom for use as ballast tanks, further forming a lower cargo oil tank between the ballast tanks, setting an upper deck in such a way as keeping the internal pressure of the lower cargo oil tank at a level lower than external pressure due to draft, and independently installing an upper cargo oil tank. CONSTITUTION:A ship's side is so constituted as to have a double hull with longitudinal bulkheads 4 extended from an upper deck 2 to a ship's bottom 3, and the compartments of ballast tanks 5 are thereby formed. In addition, a lower cargo oil tank 6 is formed between the ballast tanks 5. The height of the upper deck 2 is so set as to keep the internal pressure of the lower cargo oil tank 6 lower than external pressure due to draft, according to given draft. Furthermore, an upper cargo oil tank 7 having less width than the lower cargo oil tank 6 is independently provided on the upper deck 2, thereby supplementing a capacity shortage resulting from the lower cargo oil tank 6 alone.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil tanker used for transporting cargo oil.

0002

[Prior Art] When an oil tanker transporting cargo oil suffers damage to its hull due to an accident such as colliding with another vessel or running aground while underway, the cargo oil leaks out of the hull, causing marine pollution. It becomes a problem.

[0003] Therefore, even if the hull of an oil tanker is damaged due to an accident such as running aground, in order to prevent the problem of marine pollution from occurring by suppressing the leakage of cargo oil from the tank to the outside of the hull, Various efforts have been made and research has been made on this, and one example is an oil tanker ship with a structure in which the hull a has a double shell structure on both the sides and the bottom, and a cargo oil tank b is partitioned inside, as shown in Figure 2. Proposed.

However, in the case of an oil tanker having the structure shown in FIG.
However, due to the double-shell structure, the weight of the steel material and the painted area will increase, and the area outside the tank b will be flooded. Inspection work is difficult and there is a risk that flammable gas may accumulate; in the event of a grounding, seawater will flow into the area outside tank B, causing hull A to sink, making it difficult to leave the ship aground; In the case of a large-scale accident, there are problems such as the possibility of damage to the internal cargo oil tank b.

On the other hand, as shown in FIGS. 3 and 4, the ship side of the hull a has a double structure with a longitudinal bulkhead c, and the ship side is a ballast tank d, and the cargo oil tank provided between the ballast tanks d is used for carrying cargo. There has also been proposed a type in which the tank is divided into an upper and lower oil tank g and a lower oil tank h by a horizontal bulkhead f at a height below the minimum water drop line e during oil loading.

According to this oil tanker, even if the ship's side shell is damaged due to a collision, the cargo oil will not leak out because the ship's side is the ballast tank d, and even if a hole occurs in the bottom due to grounding, etc. However, if the cargo oil is loaded in the lower cargo tank h so that the cargo oil level is such that there is some space at the bottom of the horizontal bulkhead f, seawater will not enter the lower cargo tank h through the hole. Since the cargo oil is pushed up, it is possible to prevent the cargo oil from flowing out from the lower cargo oil tank h.

[0007]

However, in the case of the oil tanker shown in FIGS. 3 and 4, the upper oil tank g and the lower oil tank h are separated by a horizontal bulkhead f, so that the lower oil tank h It is difficult to install liquid level gauges, cleaning machines, etc. Therefore, it is necessary to take measures such as installing a trunk that passes through the lower oil tank h to the upper oil tank g to reach the upper deck, but by providing a trunk, it becomes possible to access the lower oil tank h. However, it is still difficult to install liquid level gauges and cleaning machines.

[0008] Therefore, the present invention provides an oil tanker which prevents cargo oil from spilling based on the principle of head difference as shown in Figs. The purpose is to make it easier to install machines, etc.

[0009]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a structure in which a longitudinal bulkhead extending from the upper deck to the bottom of the ship forms a double ballast tank on the ship's side, and a lower load is placed between the ballast tanks. An oil tank is formed, and the upper deck is set at a position where the internal pressure of the lower oil tank is less than the external pressure due to water intake, and an independent upper oil tank with a width narrower than the lower oil tank is provided on the upper deck. The configuration is such that the

0010

[Operation] Since the width of the upper oil tank installed on the upper deck is narrower than the lower oil tank, a part of the lower oil tank faces the upper deck, and this part can be used to access the lower oil tank. Access is now possible, making it easier to install liquid level gauges, cleaning machines, etc.

[0011]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which the ship side of the hull 1 is doubled by longitudinal bulkheads 4 extending from the upper deck 2 to the bottom 3, and ballast tanks 5 are partitioned on each side. At the same time, a lower cargo oil tank 6 is partitioned between the ballast tanks 5, and the upper deck 2 is arranged such that the internal pressure (pressure of the cargo oil) of the lower cargo oil tank 6 is lower than the external pressure (pressure of seawater) due to the hutching of the hull 1. Further, an upper oil tank 7 having a width narrower than the lower oil tank 6 is independently installed on the upper deck 2.

[0013] In the above, since the draught is usually given as a design condition, in the present invention, the height of the upper deck 2 is determined in accordance with the given draught. At that time, the capacity of the cargo oil tank 6 under the upper deck 2 is insufficient, so the upper deck 2
The basic idea is to further provide a cargo oil tank 7 on top. When loading cargo oil onto a ship designed in this way, the stutter changes depending on the specific gravity of the cargo oil, but the cargo is loaded so as not to exceed the set full load stowage. In other words, in the case of cargo oil with a light specific gravity, even if it is fully loaded, it will not reach the set water level, and conversely, in the case of cargo oil with a heavy specific gravity, if it is fully loaded,
This means that it cannot be fully loaded because it exceeds the set stuttering limit. In addition, in FIG. 1, only one tank in the bow and stern direction of the hull 1 is shown.

When the upper cargo oil tank 7 and the lower cargo oil tank 6 are loaded with cargo oil, for example, if the ship's bottom 3 is damaged due to grounding or the like and a hole is formed, the cargo oil will flow out from the lower cargo oil tank 6. However, by setting the height position of the upper deck 2, the internal pressure of the lower cargo oil tank 6 is lower than the external pressure caused by the water in the hull 1, so seawater flows from the hole to the lower cargo tank due to the principle of water head difference. By entering the oil tank 6 and balancing the pressure, cargo oil is prevented from flowing out. Therefore, the problems of a double-shelled oil tanker as shown in FIG. 2 do not occur.

In the above, the upper oil tank 7 is independent from the lower oil tank 6 and is installed on the upper deck 2 with a width narrower than the width of the lower oil tank 6.
A part of it will face the upper deck 2. Therefore, it becomes possible to access the lower cargo oil tank 6 from the portion facing the upper deck 2, and it is possible to easily install a liquid level gauge and a cleaning machine.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

[0017]

[Effects of the Invention] As described above, according to the oil tanker of the present invention, the lower cargo oil tank is formed between the double ship sides, and the internal pressure of the lower cargo tank is lower than the external pressure due to water intake by setting the position of the upper deck. As a result, even if the bottom of the ship is damaged, the spillage of cargo oil can be prevented by the principle of water head difference.Furthermore, the upper cargo oil tank, which is narrower than the lower cargo tank, is independent on the upper deck. Since it was installed, a part of the lower cargo oil tank will face the upper deck, and by using this part,
It provides excellent effects such as being able to access the lower cargo oil tank and easily installing a liquid level gauge and cleaning machine in the lower cargo oil tank.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of one tank of a hull showing an embodiment of an oil tanker according to the present invention.

FIG. 2 is a schematic diagram showing an example of an oil tanker that has been proposed recently.

FIG. 3 is a schematic diagram showing another example of an oil tanker that has been proposed recently.

FIG. 4 is a schematic diagram showing yet another example of an oil tanker that has been proposed recently.

[Explanation of symbols]

2 Upper deck 3 Bottom of the ship 4 Longitudinal bulkhead 5 Ballast tank 6 Lower cargo oil tank 7 Upper cargo oil tank

Claims (1)

[Claims] Claim 1: A longitudinal bulkhead extending from the upper deck to the bottom of the ship doubles the ship side to form a ballast tank, and a lower cargo oil tank is formed between the ballast tanks, and the upper deck is connected to the inner pressure of the lower cargo tank. Set at a position where the pressure is below the external pressure caused by stuttering,
Furthermore, the oil tanker is characterized in that it has a configuration in which an upper cargo oil tank having a width narrower than the lower cargo tank is independently installed on the upper deck.