JP2011168073A - Access trunk structure of tanker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an access trunk structure having sufficient rigidity in an access trunk, having the effect of reducing stress concentration and satisfying CSR (Common Structural Rules), in a tanker such as a chemical tanker or a product tanker. <P>SOLUTION: In this access trunk structure, a flat structural material 3 having prescribed plate thickness, arranged with a vertical ladder 5 in its inside, and including an opening part 6 having a size in which a person wearing a self-contained respirator and protection equipment can pass without a hindrance is arranged horizontally to the access trunk 4, in the access trunk 4 provided in an intersect part of a corrugated vertical bulkhead 1 of a vertical corrugated structure and a corrugated transverse bulkhead 2 of a vertical corrugated structure in a cargo tank section of the tanker. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an internal structure of an access trunk provided at an intersection of a corrugated vertical partition wall of a vertical corrugated structure and a corrugated horizontal partition wall of a vertical corrugated structure in a cargo tank section of a tanker such as a chemical tanker or a product tanker.

Conventionally, in tankers such as chemical tankers and product tankers, when luggage is staggered in cargo tanks, the trunk is greatly deformed into a diamond shape, and around corrugated bulkheads of corrugated vertical bulkheads and corrugated horizontal bulkheads, There was a problem that very large stress was generated at the foot of the partition wall.
Therefore, the present applicant has already proposed a technique disclosed in Japanese Patent Application Laid-Open No. 2004-314741 as a technique for solving such a problem.

  The thing disclosed in Japanese Patent Application Laid-Open No. 2004-314741 relates to the invention name “corrugated bulkhead crossing structure of a liquid cargo loading ship”, and “corrugated bulkheads of the crossing portion of the vertical and horizontal bulkheads constituting the cargo tank of the liquid cargo loading ship. Dispersing the intersections at four points without concentrating the intersections at one point alleviates the stress concentration acting on the intersections, and does not cause high tensile stress to act on the weld toes. For the purpose of providing a cargo bulkhead structure for a liquid cargo-carrying ship that prevents leakage of cargo due to cracks, does not cause any line contact between cargoes, and has no restrictions on loading. (See paragraph No. 0008 of the gazette specification), “vertical and horizontal corrugations of a liquid cargo-carrying ship corrugated bulkhead and constituting a cargo tank of a liquid cargo-carrying ship At the intersection of the walls, the crests and troughs of the corrugated vertical bulkhead 1 extending from the bow side and the stern side are arranged oppositely, and the crests of the corrugated horizontal bulkhead 2 extending from the starboard side and port side And the troughs are arranged opposite to each other, and the four corners of the access trunk structure having a rectangular cross section are joined to the end portions of these crests and troughs (see the summary solution section of the publication), Reduces stress concentration at the intersection, prevents cargo from leaking due to the occurrence of cracks in this area, and ensures the safety of the cargo. , Eliminates restrictions on loading, improves cargo handling efficiency, and enables a substantial amount of cargo to be loaded from the past ". 0029).

FIG. 5 is a diagram showing an outline of the cargo partition structure of the liquid cargo-carrying ship disclosed as the first embodiment in the above Japanese Patent Application Laid-Open No. 2004-314741 (FIG. 1 of the same publication). FORE is the bow direction, AFT is the stern direction, A to D are each cargo tank, 101 is a corrugated vertical bulkhead, 102 is a corrugated horizontal bulkhead, 101 ₁ and 101 ₂ are corrugated ( Colgate) vertical barrier rib _ends, 102 1, 102 _2, waveform (corrugated) transverse bulkhead end 101a, 102a is a waveform (corrugated) ridges of the vertical barrier ribs 101, 101b, 102b is a waveform (corrugated) transverse bulkhead Reference numeral 102 denotes a trough, 103 ₁ , 103 ₂ , 103 ₃ , and 103 ₄ denote intersections, and 104 denotes an access trunk.

As shown in FIG. 5, a vertical ladder (not shown in FIG. 5) is suspended in the access trunk 104 in the corrugated bulkhead crossing structure of the liquid cargo loading ship shown in FIG. Was not installed. Therefore, it is inevitable that a very large stress is generated in the lower part of the partition wall around the intersections 103 ₁ , 103 ₂ , 103 ₃ , and 103 ₄ where the corrugated partition walls 101 and 102 intersect.

  In recent years, the International Federation of Classification Societies (IACS) has adopted a new hull structure standard, Common Structural Rules (hereinafter referred to as “CSR: Common Structural Rules”). There is a demand for a hull structure with even greater safety. In other words, a hull structure with higher strength is required, and in order to satisfy this new standard CSR, it is necessary to increase the thickness of the hull, leading to a significant cost increase.

  In the one shown in FIG. 5 disclosed as the first embodiment in the above Japanese Patent Application Laid-Open No. 2004-314741 proposed by the applicant of the present application, the stress concentration is reduced as compared with the access trunk structure before that, The difficulty of construction is high, and it takes time, and the access trunk does not have sufficient rigidity to meet the new CSR standards, so it is not enough to alleviate stress concentration and have no other adverse effects. There is a problem that it is enough.

While the applicant of the present invention has proceeded in detail with the structural analysis of the stress concentration of the conventional access trunk structure in which only the vertical ladder is suspended and the structure is not installed therein, the four corners of the access trunk 104 are provided. By carrying out detailed structural analysis of the intersecting portions 103 ₁ , 103 ₂ , 103 ₃ , and 103 ₄ , the inventors have found that the above problem can be solved by avoiding stress concentration in this portion.

Japanese Patent Laid-Open No. 2004-314741

  In a tanker such as a chemical tanker or a product tanker, an object of the present invention is to provide an access trunk structure that has an influence on relaxation of stress concentration in an access trunk at an intersection of bulkheads and satisfies CSR.

In order to achieve the above object, an invention according to claim 1 of the present application is directed to an access trunk structure of a tanker at an intersection between a corrugated vertical partition wall of a vertical corrugated structure and a corrugated horizontal partition wall of a vertical corrugated structure in a cargo tank section of a tanker. The access trunk has a predetermined thickness, a vertical ladder is arranged inside, and an opening of a size that allows a person wearing a self-contained breathing apparatus and protective equipment to pass through without any hindrance. The flat structural material is horizontally disposed with respect to the access trunk.
The invention according to claim 2 of the present application. In the access trunk structure of the tanker according to the first aspect, the flat structure material is a flat plate, and the opening is at least 600 mm × 600 mm × 100R.
The invention according to claim 3 of the present application is characterized in that, in the access trunk structure of the tanker according to claim 1, two or more flat structure members are arranged in the access trunk.

Since this invention is comprised as mentioned above, there exists the following effect.
(1) In tankers such as chemical tankers and product tankers, since the flat structural material 3 is installed in the access trunk, the access trunk has sufficient rigidity and has the effect of reducing stress concentration. .
(2) Also, the stress relaxation can satisfy the new CSR standard.
(3) Further, it is conceivable to increase the thickness of the partition wall as one of the measures for reducing the stress at the lower part of the partition wall. However, it is possible to reduce the reinforcement weight rather than taking such a thickening measure. It is possible to increase the efficiency of work at the site and reduce the cost.
(4) In a chemical tanker using stainless steel for the partition walls, the members in the access trunk do not come into contact with the load. Therefore, ordinary steel may be used, so that further cost reduction can be achieved.

FIG. 1 is a perspective view schematically showing Example 1 of a tanker access trunk structure which is the best mode for carrying out the tanker access trunk structure according to the present invention; The figure which shows the outline of the shape of the said flat structure material 3 which concerns on Example 1. FIG. 3 is a schematic perspective view of the access trunk structure of the tanker according to the second embodiment. FIG. 4 is a schematic plan view of an access trunk structure of a tanker according to the second embodiment. FIG. 5 is a diagram showing an outline of a cargo partition structure of a liquid cargo-carrying ship disclosed as a first embodiment in Japanese Patent Application Laid-Open No. 2004-314741.

  The best mode for carrying out an access trunk structure of a tanker according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view schematically showing Example 1 of a tanker access trunk structure which is the best mode for carrying out the tanker access trunk structure according to the present invention.
As shown in FIG. 1, in the access trunk structure of the tanker according to the first embodiment, a flat structural member 3 having a predetermined thickness is arranged horizontally with respect to the access trunk 4 at an appropriate position in the access trunk 4. It is a thing.
In FIG. 1, reference numeral 1 denotes a corrugated vertical partition wall, which is composed of a peak portion 1a and a valley portion 1b. Similarly, reference numeral 2 denotes a corrugated horizontal partition wall, which is similarly composed of a peak 2a and a valley 2b. Reference numeral 3 denotes a flat structure material used in the access trunk structure of the tanker according to the first embodiment, 4 denotes an access trunk, 5 denotes a vertical ladder, and 6 denotes an access opening provided in the flat structure material 3. It is. In FIG. 1, the symbol FORE indicates the bow direction, and AFT indicates the stern direction.

  As shown in FIG. 1, the access trunk structure of the tanker according to the first embodiment has a flat structural member 3 installed in the access trunk 4 and an access opening 6 is provided in the flat structural member 3. The vertical ladder 5 is disposed in the opening 6 and serves as a passage for workers.

The flat structural member 3 is sufficient if the thickness of the flat structural member 3 is equal to or greater than the peripheral thickness of the trunk. In the tank access trunk structure according to the first embodiment, the thickness of the flat structural member 3 is 28 mm. The opening 6 has a clear opening shape of 600 mm × 600 mm, and the four corners 6a, 6b, 6c, 6d of the access opening 6 of the flat structure material 3 are disclosed in the above-mentioned JP-A No. 2004-314741. Each of the intersecting portions 103 ₁ , 103 ₂ , 103 ₃ , and 103 ₄ has a structure in which a chamfering of 100R is performed, which is 600 mm × 600 mm × 100 mmR.
FIG. 2 is a diagram showing an outline of the shape of the flat structure material 3 determined in this manner. Reference numeral 3 denotes the flat structure material, 6 denotes the access opening, 6a, 6b, 6c, 6d. Are corners of the four corners of the access opening 6 of the flat structural member 3.
By disposing the flat structure material 3 having such a shape in the access trunk 4 of the tanker under the above-described construction conditions, the stress concentration of the access trunk 4 of the tanker can be reduced.

Next, the best mode for carrying out the access trunk structure of a tanker according to the present invention will be described in detail with reference to the drawings of Embodiment 2 of the access trunk structure.
That is, in the access trunk structure of the tanker according to the second embodiment, not only one but also a plurality of flat structural members 3 are arranged in the access trunk 4 under the tanker construction conditions, and the access trunk is arranged. As a result, in the access trunk structure of the tanker according to the second embodiment, the upper and lower flat structure members 3 are arranged.

  3 and 4 are diagrams showing an outline of an access trunk structure of a tanker according to the second embodiment, FIG. 3 is a schematic perspective view thereof, and FIG. 4 is a plan view thereof. 3 and 4, reference FORE is the bow direction shown in FIG. 1, AFT is the stern direction, A to D are the cargo tanks, and the same reference numerals as those shown in FIGS. The same member as the access trunk structure of the tanker according to the first embodiment is shown. The other reference numeral 7 is the upper deck, 8 is the double bottom, 9 is the bottom of the ship, 10 is the ballast tank, 11 is the stool of the corrugated vertical bulkhead 1, and 12 is the corrugated ( Colgate) A stool for the horizontal partition wall 2.

The access trunk structure of the tanker according to the second embodiment shown in FIGS. 3 and 4 is a tanker constructed in conformity with the above-described tanker construction conditions, and the access opening 6 is provided in the access trunk 4 4. The flat structure members 3a, 3b, 3c, and 3d are installed.
These four flat structural members 3a, 3b, 3c, and 3d have the same shape and thickness as the flat structural member 3 used in the access trunk structure of the tanker according to the first embodiment.

  As in the case of determining the flat structure material 3 in the access trunk structure of the tanker according to the first embodiment, stress is applied when a plurality of flat structure materials 3 having the same shape and thickness are arranged in the access trunk 4. This is the result of analyzing the most suitable number for avoiding concentration and the arrangement position thereof by the above-described three-dimensional model stress analysis.

  The present invention is used for an access trunk of a tanker.

DESCRIPTION OF SYMBOLS 1 Corrugated vertical partition 1a Peak part 1b Valley part 2 Corrugated horizontal partition wall 2a Peak part 2b Valley part 3, 3a, 3b, 3c, 3d Flat structure member 4, 104 Access trunk 5 Vertical ladder 6 Access opening 6a, 6b, 6c, 6d Corner part 7 Upper deck 8 Double bottom 11, 12 Stool 101 Vertical partition wall 102 Horizontal partition wall 1031 Crossing part FORE Bow direction AFT Stern direction a Flat part b Inclined part c Flat part d Inclined part

Claims (3)

  The tank has a predetermined thickness in the access trunk provided in the intersection of the corrugated vertical corrugated bulkhead and the vertical corrugated horizontal corrugated bulkhead in the cargo tank compartment of the tanker, and a vertical ladder is arranged inside. An access trunk structure for a tanker, characterized in that a flat structure material having an opening of a size that allows a person wearing a stored breathing apparatus and protective equipment to pass through without any trouble is disposed horizontally with respect to the access trunk. .   2. The access trunk structure for a tanker according to claim 1, wherein the flat structure material is made of a flat plate, and the opening is at least 600 mm × 600 mm × 100R. 2. The access trunk structure for a tanker according to claim 1, wherein two or more flat structure members are disposed in the access trunk.

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