JPH05105180A - Ballast tank member for ship of double hull construction - Google Patents

Abstract

PURPOSE: To obtain the subject element contrived to chiefly improve the stabil ity, by providing at least both the double-bottom ballast tank of a half breadth of which a tank access trunk is located within a double side part of a hull, and the side ballast tank which is located within the double hull and is adjacent to the tank access trunk. CONSTITUTION: A double hull vessel is constructed with a double bottom ballast tank having a half breadth, that is, a J-shaped unit. The vessel is also provided with a side ballast tank which is located within a double hull, that is, an S- shaped unit. In this case, the tank access trunk is located within in the double side part in the hull, and also the side ballast tank is located next to the tank access trunk. Moreover, the tank access trunk has at least one frame breadth designed. The vessel uses at least one pair of ballast tank elements, the pair being faced opposite at the adjacent position. The one pair of ballast tank elements are used in conjunction with double hull ballast tank elements having no internal subdivisions, that is, a U-shaped unit.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a double hull ballast tank element for ships.

[0002]

BACKGROUND OF THE INVENTION Single-hull vessels are commonly used to carry liquid cargo such as gasoline, crude oil and various other liquid chemicals. If the hull is destroyed in an accident, leakage of liquid into the surrounding sea can cause pollution.

Because of the international sentiment caused by oil spills,
Various schemes have been proposed to minimize the risk of leaks from oil carriers. Usually, the solution is in a double-hull ship, the design of which is that if an accident damages the structure of the outer hull, the inner hull retains its integrity and the liquid cargo held in it. It is possible to prevent the leakage.

[0004]

Unfortunately, double-hull vessels are less stable because the center of gravity of the load is higher in double-hull vessels than in single-hull vessels. Even if only a few of the compartments of a double-hull ship are destroyed due to the subdivision configuration, the resulting load imbalance can cause the ship to capsize, resulting in the loss of the entire ship. There is.

[0005]

SUMMARY OF THE INVENTION The present invention resides in a double-hull ship that has a high survivability when damaged. This high survivability results from the new ballast tank elements, each ballast tank element being (a) a half-width double bottom ballast tank ("J" shaped unit) with a tank access trunk;
(B) It has a side ballast tank (“S” shaped unit) positioned in the double hull. The tank access trunks of the "J" type unit are positioned within the double sides of the hull, and the side ballast tanks are next to the tank access trunks. The tank access trunk can have at least one frame space width. Preferably, at least a pair of ballast tank elements are used, these elements being adjacent and facing each other. These pairs of ballast tank elements can be used with dual hull ballast tank elements ("U" shaped units) that do not have internal subdivisions.

[0006]

The advantages of this construction include both the inner and outer hulls as the cargo tank body while it retains acceptable full stability during loading and unloading of cargo and ballast water. Provides survivability in all damage conditions. This is a more general configuration of the present invention, "L, L, L,
2 (a) to FIG. 7 (d) for comparison with a "L, L, L, L, L, L" configuration arrangement.

Good access and ventilation of all ballast tanks is maintained without having to provide an access trunk to the double bottom through the cargo tank.

In this specification, different types of ballast tanks ("L" type, "J" type, "S" type and "U" type) are considered. The "L" shaped unit is a ballast tank positioned in the double hull and having its inward boundary at the center of the ship and its outward boundary at the upper deck level ((d) of Figure 1). Shown). The "J" type unit is a semi-width double bottom ballast tank with a tank access trunk (shown in Figures 1a and 1c).
The "S" type unit is a side ballast tank positioned in the double hull and is in close proximity to the tank approaching trunk of the "J" type unit (FIGS. 1 (a) and 1 (c)).
Shown in). The "U" shaped unit is a double hull ballast tank without internal subdivisions (shown in Figure 1 (b)).

To facilitate an understanding of the present invention, reference is made to the accompanying drawings of a preferred embodiment of the invention. The drawings are for illustration purposes only and should not be construed as limiting the invention.

[0010]

DETAILED DESCRIPTION OF THE INVENTION In its broadest aspect, the present invention comprises a double-hull ship having increased survivability when damaged. Its enhanced survivability is due to the semi-width double bottom ballast tank ("J" shaped unit) with tank approaching trunk and the side ballast tank ("S" shaped unit) positioned in the double hull. Obtained with novel ballast tank elements including and. The tank approaching trunk of the "J" type unit is positioned within the double side of the hull proximate to the "S" type unit. Together, the "J" shaped unit and the "S" shaped unit form a ballast tank element ("J / S" shaped element) novel to the present invention.

"J" Type Unit The "J" type unit is a half width dual bottom ballast tank with a tank access trunk. "Half width" means half the width (or body width) of a ship. "Double bottom" means the space enclosed by the inside and outside bottoms of the ship.
"Ballast Tank" means a tank used solely for the transportation of water ballast.

The tank approaching trunk is positioned within the double side of the hull proximate to the "S" shaped unit. “Tank approaching trunk” means a watertight enclosure extending from the upper deck and containing a ladder. "Double sides of the hull" means the space enclosed between the inside and outside sides of the ship. Preferably, the tank access trunk has a width of at least one frame space. "One frame space" means the space extending between one transverse web frame and the next front or rear transverse web frame.

"S" Type Unit The "S" type unit is a side ballast tank positioned in the double hull and proximate the tank approaching trunk of the "J" type unit. "Side ballast tank" means a ballast tank positioned generally within the double side and extending from the upper deck to the inner bottom level.

"J / S" Shape Units-In general, the "J" shape units and the "S" shape units form "J / S" shape elements that occupy the same space as a conventional "L" shape unit. Preferably, these "J / S" type ballast tank elements are used in pairs, where the elements are closely adjacent to each other.

"U" Type Units A pair of "J / S" type units can be used with double hull ballast tank elements that do not have internal subdivisions ("U" type units). "No internal subdivision"
Means that there is no longitudinal watertight structure dividing the inside of the tank.

Although the present invention has been described in relation to particular embodiments, it is intended that the invention encompass various modifications and substitutions that can be made by those skilled in the art without departing from the spirit and scope of the claims. To be done.

[Brief description of drawings]

FIG. 1 (a) is a half-width double bottom ballast tank (“J” type unit) and side ballast tank (“S”).
Figure 2 is a schematic view of a ballast tank element of the present invention having a shaped unit). (B) is a cross-sectional view of a "U" shaped unit. (C) is a cross-sectional view of a "J" type unit and an "S" type unit. (D) is a cross-sectional view of the "L" -shaped unit.

FIG. 2 shows “L, L, L, L, L, L
FIG. 7 is a schematic diagram of computer simulation results showing the limit of survivability of a double hull design having an “L, L, L” configuration.

[Fig. 3] "U, U, U, U, J / in a fully loaded state"
FIG. 6 is a schematic diagram of computer simulation results showing the limits of survivability and different degrees of bottom damage for a double hull design having a “S, U, J / S, U” configuration.

[Fig. 4] "U, U, U, U, J / in a fully loaded state"
FIG. 6 is a schematic diagram of computer simulation results showing the limits of survivability and different degrees of bottom damage for a double hull design having a “S, U, J / S, U” configuration.

[Fig. 5] "U, U, U, U, J / in a fully loaded state"
FIG. 6 is a schematic diagram of computer simulation results showing the limits of survivability and different degrees of bottom damage for a double hull design having a “S, U, J / S, U” configuration.

[Fig. 6] "U, U, U, U, 40% unloaded state"
FIG. 6 is a schematic diagram of computer simulation results showing the limits of survivability and different degrees of side damage for a double hull design with a “J / S, U, J / S, U” configuration.

[Fig. 7] "U, U, U, U, 40% unloaded state"
FIG. 6 is a schematic diagram of computer simulation results showing the limits of survivability and different degrees of side damage for a double hull design with a “J / S, U, J / S, U” configuration.

[Explanation of symbols]

 J “J” type unit L “L” type unit S “S” type unit U “U” type unit

Claims (4)

[Claims] 1. A double-hulled vessel having at least one ballast tank element, comprising: (a) a tank-approaching trunk, the tank-approaching trunk being positioned within a double side of the hull. A double-hulled vessel that includes a double-bottomed ballast tank having a half width and (b) a side ballast tank positioned in the double-hulled vessel and adjacent to the tank approaching trunk. 2. The double hull ship of claim 1, wherein the tank approaching trunk has at least one frame space width. 3. The double-hull vessel of claim 1 including at least one pair of said ballast tank elements, said elements closely facing each other. 4. The double-hull type according to claim 3, comprising: (a) at least a pair of the ballast tank elements and (b) a double-hull ballast tank element having no internal subdivision. ship.