JP2012201374A - Forty foot container conforming to iso standard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfy strength conditions specified in the ISO (International Organization for Standardization) standards while highly maintaining workability when carrying in and out cargoes.SOLUTION: In a container 1 having a cargo compartment 2 in which the cargoes are loaded, and an opening part to which a door 3 is attached to be openable/closable, the opening part is disposed at least in a longitudinal side face of the cargo compartment 2, and the longitudinal length of the opening part of the cargo compartment 2 is set to be 60% to 95% of the longitudinal length of the cargo compartment 2.

Description

  The present invention relates to a 40-foot container conforming to the ISO (International Organization for Standardization) standard.

  A container that complies with the ISO standard satisfies a predetermined external dimension, a predetermined total gross weight, a predetermined strength condition, and the like defined by the ISO standard. This enables efficient container transportation, such as the ability to stack a number of containers of the same shape during sea or land transportation, and also provides cargo maintenance and cargo transportation by having a predetermined strength. The safety of the ship or vehicle is ensured.

  On the other hand, apart from containers conforming to the ISO standard, as seen in Patent Document 1, for example, there is a case in which workability at the time of loading and unloading cargo is emphasized and a door is provided on a side surface when viewed from the longitudinal direction of the container. . According to this, when it is desired to carry in / out a predetermined cargo, it is possible to open the door nearest to the cargo and carry in / out only the cargo or a small number of cargo around the cargo.

EP1136291A1

  In a container compliant with the ISO standard, a door used for loading and unloading cargo is located at the rear as viewed from the longitudinal direction. In this case, it is difficult to carry out only the cargo in the innermost part (frontmost part) of the container conforming to the ISO standard. Unable to carry out desired cargo. Also, if you have forgotten to load the cargo that should originally be loaded in the innermost part (frontmost part), it is difficult to load it in the innermost part if other cargo has already been loaded. It is. However, since the container conforming to the ISO standard is configured by the panel member of the wall surface except for the rear door, the predetermined strength condition defined by the ISO standard can be easily satisfied.

  On the other hand, the container of Patent Document 1 has high workability when loading and unloading cargo, but has a large opening for attaching a door, and has a lower strength than a container defined by the ISO standard. You may not be able to meet.

  Thus, good workability and strength at the time of loading and unloading cargo in the container are in a trade-off relationship.

  The present invention has been made under such a background, and conforms to the ISO standard that can satisfy the strength conditions defined in the ISO standard while maintaining good workability when loading and unloading cargo. The aim is to provide a compliant 40 foot container.

  The 40-foot container conforming to the ISO standard of the present invention is a 40-foot container conforming to the ISO standard having a cargo compartment in which cargo is loaded and an opening to which a door can be freely opened and closed. Provided on the side surface in the longitudinal direction of the cargo chamber, the length of the opening in the longitudinal direction of the cargo chamber is 60% to 95% of the length in the longitudinal direction of the cargo chamber. More preferably, the width of the opening is 75% to 90% of the entire length in the longitudinal direction.

  In addition, the length in the short direction, which is the width of the cargo compartment, is a dimension that can mount at least two rows of flat pallets for integrated transport that are 1100 millimeters in length and width according to JIS (Japanese Industrial Standard) Z0105 standard. The length in the longitudinal direction, which is the entire length of the cargo compartment, is preferably such a dimension that at least 10 rows of flat pallets for integrated transportation can be mounted.

  Furthermore, a door is comprised by the 1st, 2nd door used as a double door, and the 1st, 2nd door can each be made to be foldable in multiple steps | paragraphs.

  According to the present invention, a 40-foot container conforming to the ISO standard (hereinafter simply referred to as a container) that can satisfy the strength conditions defined in the ISO standard while maintaining good workability when loading and unloading cargo. Can be provided).

It is a figure which shows the container of embodiment of this invention, and the vehicle which conveys this. It is the figure which looked at the container of FIG. 1 from the side. It is the figure which looked at the container of FIG. 2 from the upper surface. It is a figure which shows the opening part which removed the door of the container. It is a perspective view of the container of the state which removed the door. It is a figure which shows the state which opened the door of the container of FIG. It is a figure which shows the state with which the cargo (pallet) was loaded in the container of FIG. It is a figure which shows the mode of carrying in / out of the cargo (pallet) of the container of FIG. It is a figure which shows the mode of the carrying in / out of the cargo (pallet) set | placed on the back of the wall surface (opening ratio 85%) of the container of FIG. It is a figure which shows the mode of the carrying in / out of the cargo (pallet) set | placed on the back of the wall surface (75% of opening ratio) of the container of FIG. It is a figure which shows the mode of the carrying in / out of the cargo (pallet) set | placed on the back of the wall surface (opening ratio 60%) of the container of FIG. It is a figure which shows the structure of each flame | frame and each pillar of a container. It is a figure which shows the triangular reinforcement member attached to a container. It is a figure which shows the state of a displacement of the lower side frame at the time of applying a loading weight to a container. It is a figure which shows the space | interval of two containers in the loading form in which two containers are stacked in the vertical direction. It is a figure which shows the relationship between the opening dimension of a container, and the displacement of a lower side frame corresponding to the change of an aperture ratio. It is a figure which shows the state in which cargo (pallet) is loaded into the container which has a door in the rear part as a comparative example.

(Container 1 configuration)
The configuration of the container 1 will be described with reference to FIGS. 1, 2, and 3. FIG. 1 is a diagram showing a container 1 and a vehicle 10 that carries the container 1. FIG. 2 is a side view of the container 1. FIG. 3 is a view of the container 1 as seen from above. In the following, the top view as shown in FIG. 3 shows a state in which the ceiling panel and the corner bracket 5 are not shown for easy understanding of the state of the doors 3 and 3B.

  The container 1 according to the embodiment of the present invention is carried on a vehicle 10 or a ship (not shown) as shown in FIG. Here, a 40 ft (feet) container conforming to the so-called ISO standard will be described. The 40 ft container conforming to the ISO standard has an external dimension of 9 ft 6 in (inch) (2896 mm (millimeters)) × width 8 ft (2438 mm) × length 40 ft (12192 mm) and a maximum total mass of 30480 kg (kg). . The corner bracket 5 is for connecting the frames and the pillars constituting the container 1 to each other by welding, and slightly protrudes from the full length, the full width, and the full height of the cargo compartment 2. Therefore, the total length of the container 1 for calculating the aperture ratio described later does not need to include the protruding portion of the corner metal fitting 5. Therefore, in the following, when calculating the aperture ratio, 12000 mm is adopted as the total length (L1 described later) of the container 1.

  As shown in FIGS. 1 to 3, the container 1 has a rectangular parallelepiped cargo chamber 2, a door 3 on the side wall surface in the longitudinal direction, and 2 in the short direction perpendicular to the side wall surface in the longitudinal direction. One side wall surface (hereinafter referred to as a rear portion) of the two side wall surfaces has a door 3B. The door 3 includes small doors 3R-1, 3R-2, 3L-1, 3L-2. The small doors 3R-2, 3L-2 and the door 3B are attached to the main body of the container 1 by a hinge 4 so as to be freely opened and closed. Further, the small door 3R-1 and the small door 3R-2, and the small door 3L-1 and the small door 3L-2 are rotatably connected by a hinge 4, respectively. Further, corner metal fittings 5 are disposed at the corners of the cargo compartment 2.

(About the opening 30 and 30B of the container 1)
FIG. 4 is a view showing the openings 30 and 30B from which the doors 3 and 3B of the container 1 are removed. FIG. 5 is a perspective view of the container 1 with the doors 3 and 3B removed. Thus, the doors 3 and 3B are attached to the openings 30 and 30B.

  As shown in FIGS. 4 and 5, the container 1 has openings 30 and 30B for attaching the doors 3 and 3B. The upper diagram in FIG. 4 shows the container 1 having the doors 3 and 3B in the cargo compartment 2, and the lower diagram in FIG. 4 shows the openings 30 and 30B from which the doors 3 and 3B are removed. Note that the ratio [(L2 / L1) × 100] (%) of the length L2 of the opening 30 that appears when the door 3 is opened to the total length L1 of the container 1 is referred to as an opening ratio.

  Further, wall members 7F and 7R are disposed on both sides of the opening 30 in the longitudinal direction. Since there is no door in the front part of the container 1, strength can be ensured compared with the rear part which has the opening part 30B of the door 3B. Therefore, the area of the wall surface 7F may be smaller than the area of the wall surface 7R. However, in order to reduce the number of parts of the container 1, it is preferable to use the same panel member on the wall surfaces 7F and 7R. Therefore, here, the areas of the wall surfaces 7F and 7R are equal left and right.

(About opening and closing the doors 3 and 3B of the container 1)
The opening / closing mechanism of the doors 3 and 3B of the container 1 will be described with reference to FIG. FIG. 6 is a diagram illustrating a state in which the door of the container 1 is opened. As shown in FIG. 6, the doors 3, 3 </ b> B of the container 1 are opened and closed by a hinge 4, and the small doors 3 </ b> R- 1, 3 </ b> R- 2, 3 </ b> L- 1, 3 </ b> L- 2 are folded by the hinge 4. In FIG. 6, the small door 3L-2 is not opened.

(About loading and unloading of cargo in container 1)
Carrying in / out of cargo in the container 1 will be described with reference to FIGS. 7 and 8. FIG. 7 is a diagram illustrating a state in which cargo (pallet 6) is loaded on the container 1. FIG. 8 is a diagram illustrating a state in which the cargo (pallet 6) in the container 1 is carried in and out.

  As shown in FIG. 7, the container 1 can be loaded with cargo such as a pallet 6. In addition, the pallet 6 assumes the flat pallet for the consistent transport based on JISZ0105 standard, The dimension is 1100 mm long x 1100 mm wide x 144 mm in height. As a result, 20 pallets 6 in a maximum of 10 × 2 rows can be loaded in the container 1.

  Carrying in / out of the pallet 6 and the like to / from the container 1 can be performed from both the side door 3 and the rear door 3B. As shown in FIG. 8, the pallet 6 loaded in the container 1 has small doors 3R-1, 3R-2, 3L-1, 3L-2 (FIG. 8 shows a closed state). By opening, it becomes possible to carry in / out from the side of the container 1. Further, by opening the door 3B, it is possible to carry in and out from the rear part of the container 1.

(About the opening ratio of the side wall surface and ease of carrying in and out of the pallet 6)
The carrying in / out of the pallet 6 in the front part of the container 1 will be described with reference to FIGS. 9, 10, and 11. 9 to 11 schematically show the front portion of the container 1 having different opening ratios of the side wall surfaces in the longitudinal direction. In FIG. 9, the aperture ratio is 85%, in FIG. 10, 75%, and in FIG. 11, the aperture ratio is 60%. The aperture ratio is calculated assuming that the total length of the container 1 (L1 in FIG. 4) is 12000 mm.

  When unloading the pallet 6 (the pallet 6 indicated by the dotted line in the figure) in the back of the front of the container 1, it is necessary to pull it out to the opening 2 beyond the wall surface 7F. Moreover, when carrying in, it is necessary to push in from the opening part 2 to the back of a front part. In the example of FIG. 9, the aperture ratio is 85%, and the areas of the wall surfaces 7F and 7R are made uniform, so the length of the wall surface 7F is 900 mm. Since the length of the pallet 6 is 1100 mm, about 900 mm of the length of the pallet 6 is hidden by the wall surface 7F, so that the pallet 6 can be moved in and out from the side surface of the container 1 by horizontally moving the pallet 6 by about 900 mm. Become.

  On the other hand, in the example of FIG. 10, since the aperture ratio is 75% and the areas of the wall surfaces 7F and 7R are made uniform, the length of the wall surface 7F is 1500 mm. Since the length of the pallet 6 is 1100 mm, one part of the pallet 6 is hidden by the wall surface 7F, so that the pallet 6 can be carried in and out from the side surface by horizontally moving the pallet 6 by the length of that one piece. Become. In the example of FIG. 11, the opening ratio is 60%, and the areas of the wall surfaces 7F and 7R are made uniform, so the length of the wall surface 7F is 2400 mm. Since the length of the pallet 6 is 1100 mm, two pallets 6 are hidden by the wall surface 7F. Therefore, the pallet 6 is moved horizontally by the length of the two pallets 6 to carry in and out from the side of the container 1. Is possible.

  9, 10, and 11, comparing the workability when loading and unloading the pallet 6, one of the pallets 6 is shown in FIG. 9 (opening ratio 85%) and FIG. 10 (opening ratio 75%). The operation | work which moves about the length of a piece in the container 1 in a horizontal direction is required. On the other hand, in FIG. 11 (opening ratio 60%), it is necessary to move the length of about two pallets 6 in the container 1 in the horizontal direction. Thus, it can be seen that a larger aperture ratio is preferable from the viewpoint of workability. In particular, if the aperture ratio is less than 75%, the moving distance of the pallet 6 during loading / unloading exceeds one pallet 6, so the aperture ratio is preferably 75% or more. Further, if the opening ratio is less than 60%, the moving distance of the pallet 6 during loading / unloading further exceeds two pallets 6 and the workability is remarkably deteriorated. % Is appropriate.

(About the structure of each frame and each pillar of container 1)
The configuration of each frame and each pillar of the container 1 will be described with reference to FIG. FIG. 12 is a diagram illustrating a configuration of each frame and each pillar of the container 1.

  As shown in FIG. 12, the container 1 includes a lower side frame 50, an upper side frame 51, a rear side pillar 52, and a front side pillar 53. Each of these members is joined by welding an end portion thereof to the corner metal fitting 5.

(About strength evaluation of container 1)
Evaluation of the strength of the container 1 will be described with reference to FIGS. 12, 13, and 14. FIG. 12 is a diagram illustrating the configuration of each frame and each pillar of the container 1 as described above. FIG. 13 is a view showing a triangular reinforcing member 60 attached to the container 1. FIG. 14 is a diagram illustrating a state of displacement of the lower side frame 50 when the loaded weight is applied to the container 1.

  As a comparison object, a 40-foot container (hereinafter referred to as a conventional container) that does not have a door on the side and has a door only at the rear and conforms to a conventionally well-known ISO standard (hereinafter referred to as a conventional container) is used. The strength of the container 1 was evaluated by comparing with the strength of the container 1. That is, evaluation was performed by applying the same force to the container 1 and the conventional container and measuring the difference in displacement. In addition, since the structure of each frame and each pillar of the conventional container is basically the same as that of the container 1, the same reference numerals as those of the container 1 are used for convenience.

  The strength is evaluated by the displacement of the lower side frame 50 that supports the floor of the container 1 and the conventional container, the displacement of the upper side frame 51 that supports the ceiling of the container 1 and the conventional container, the displacement of the corner bracket 5, and the door 3 (this Is evaluated for each of the displacement of the rear side pillar 52 adjacent to the opening 30 of 3B (which does not have a conventional container) and 30B. The front side pillar 53 of the container 1 has a structure combined with a front panel member (not shown) to ensure strength performance. Therefore, the displacement of the front side pillar 53 is always less than the displacement amount of the rear side pillar 52. . For this reason, the front side pillar 53 is excluded from the object of strength evaluation.

  Regarding the displacement of the lower side frame 50, a heavy object was loaded on the container 1 and the conventional container, and the displacement was measured.

  About the displacement of the corner metal fitting 5 and the upper side frame 51, the container-shaped heavy article was piled up on the container 1 and the conventional container, and the displacement was measured.

  Furthermore, about the displacement of the corner metal fitting 5 and the rear side pillar 52, force was applied from the longitudinal direction and the short direction orthogonal to the longitudinal direction, respectively, and the displacement was measured.

  According to the evaluation of the strength of the container 1 performed as described above, the stress due to the force from the short direction of the corner bracket 5 and the rear side pillar 52 is concentrated on the upper part of the rear frame corner. As shown in FIG. 13, by inserting the triangular reinforcing member 60, it was possible to obtain a displacement amount equivalent to that of the conventional container. Moreover, about the displacement by the force from the longitudinal direction of the corner metal fitting 5 and the rear side pillar 52, it was the displacement amount equivalent to the conventional container. Further, the displacement of the upper side frame 51 was the same as that of the conventional container.

  Moreover, about the displacement of the lower side frame 50 of the container 1, it turned out that the amount of displacement changes depending on the magnitude | size of the opening part 30 which a conventional container does not have. At this time, it was also found that the amount of displacement of the lower side frame 50 exceeds the amount of change defined in the ISO standard at a predetermined aperture ratio. That is, as shown in FIG. 14, between the upper side frame 51 and the lower side frame 50, panel members of wall surfaces 7F and 7R that connect them are interposed. Therefore, the upper side frame 51 can bear a part of the load applied to the lower side frame 50 by the wall surfaces 7F and 7R. For this reason, it has been found that the areas of the wall surfaces 7F and 7R change depending on the size of the opening 30, and the amount of displacement of the lower side frame 50 also changes accordingly.

(About the allowable range of displacement of the lower side frame 50)
The allowable range of the amount of displacement of the lower side frame 50 will be described with reference to FIG. FIG. 15 is a diagram illustrating an interval between two containers 1-1 and 1-2 in a stacking form in which the two containers 1-1 and 1-2 are stacked in the vertical direction.

  The loading form as shown in FIG. 15 is a loading form generally adopted when the container 1 is transported by sea. The containers 1-1 and 1-2 are shown in FIG. 15 even if the corner fittings 5-1 and 5-2 are connected by a fixing device called a twist lock so that the container 1-1 may be shaken during transportation. The loading form can be kept. At this time, the distance between the container 1-1 and the container 1-2 is about 12.5 mm. Here, according to the provisions of the ISO standard, the container 1-1 should not interfere with other containers 1-2 even if it is the maximum load capacity. Accordingly, the amount of displacement allowed for the lower side frame 50 must be less than 12.5 mm.

(Relationship between aperture ratio and displacement of lower side frame 50)
An example of the relationship between the opening ratio of the opening 30 of the container 1 and the amount of displacement of the lower side frame 50 is shown in FIG. FIG. 16 is a diagram showing the relationship between the opening dimension of the container 1 (length in the longitudinal direction of the opening 30) and the displacement of the lower side frame 50 in correspondence with the change in the opening ratio.

  The lower side frame 50 used in the example has a height of 200 mm × width of 100 mm and a thickness of 6 mm, the upper side frame 51 has a height of 100 mm × width of 150 mm and a thickness of 6 mm, and the rear side pillar 52 has a height of 150 mm × The front side pillar 53 has a width of 150 mm and a thickness of 9 mm. The front side pillar 53 has a height of 90 mm × a width of 173 mm and a thickness of 6 mm. These materials are all rolled steel for general structure (JIS G3101: type symbol is SS400). Further, the inner dimensions of the container 1 are a total length of 12030 mm, a width of 2250 mm, and a height of 2400 mm. In addition, although the external dimension of the container 1 is based on the ISO standard, the opening ratio was calculated by setting the total length to 12000 mm. Further, the areas of the wall surfaces 7F and 7R were made equal. The loading capacity of container 1 was 15 tons. Note that the total mass of the container 1 at this time is less than the maximum total mass of 30480 kg defined by the ISO standard 40-foot container.

  As shown in FIG. 16, when the aperture ratio is 75%, the displacement amount is 5.7 mm, when the aperture ratio is 80%, the displacement amount is 7.0 mm, and when the aperture ratio is 83%, the displacement amount is 5.7 mm. When the aperture ratio is 88%, the displacement is 9.1 mm. When the aperture ratio is 93%, the displacement is 11.0 mm. When the aperture ratio is 95%, the displacement is 12.4 mm. Yes, at an aperture ratio of 98%, the displacement was 12.6 mm. When the aperture ratio is 98%, the areas of the wall surfaces 7F and 7R are zero (that is, there are no wall surfaces 7F and 7R).

  Accordingly, since the upper limit of the allowable range of the displacement amount of the lower side frame 50 is less than 12.5 mm, it can be seen that the displacement amount of the lower side frame 50 is within the allowable range up to an aperture ratio of 95%. Therefore, the upper limit of the aperture ratio is 95%. However, in consideration of the actual usage situation of the container 1, considering a vibration during the transportation of the container 1, etc., if 2.5 mm (20% of 12.5 mm) is subtracted from 12.5 mm as a certain safety margin, 10.0 mm It is. From this result, the opening ratio up to 90% may not deviate from the allowable range of the displacement amount of the lower side frame 50 even in consideration of the actual use situation of the container 1. Moreover, if the opening ratio is less than 75%, as described above, the workability of loading and unloading the pallet 6 is deteriorated. Therefore, it is appropriate that the aperture ratio is 75% to 90%. Further, when the opening ratio is less than 60%, as described above, the workability of loading and unloading the pallet 1 is remarkably lowered. Therefore, it is appropriate that the lower limit of the opening ratio is 60%. Therefore, the maximum range that the aperture ratio can take is 60% to 95%.

(About effect)
As a comparative example, FIG. 17 shows a container 101 that conforms to the ISO standard with the door 100 at the rear. In the container 101 compliant with the ISO standard, when carrying out the hatched pallet 6, it can be carried out only after all the other pallets 6 are carried out.

  On the other hand, according to the container 1 having the door 3 on the side surface, it is possible to easily carry out the cargo to be carried out. Moreover, since carrying in of the pallet 6 etc. to the container 1 can be loaded from the door 3 of the side, arbitrary cargo can be easily loaded into arbitrary loading locations. Moreover, the width of the opening 30 can be 60% to 95%, preferably 75% to 90% of the total length in the longitudinal direction of the container 1 conforming to the ISO standard. Can have. In particular, by setting the aperture ratio from 75% to 90%, the pallet 6 on the back surface of the wall surface 7F can be carried in and out by the moving distance of about one pallet 6, and from the ISO standard. It is possible to maintain sufficient strength.

  As a result, the same number of pallets 6 as the container 101 can be loaded, and a small quantity and various types of parts can be loaded into a plurality of pallets 6 and loaded freely at predetermined positions. it can. For example, even when a part is forgotten to be loaded on the container 1, by opening the door 3 on a predetermined side surface, only that part can be added and loaded at a predetermined position of the container 1 later. This is the same even when cargo is dropped from the container 1, and even if a part is forgotten to be dropped from the container 1, the door 3 on the predetermined side surface is opened so that it can be moved from a predetermined position on the container 1 later. Only that part can be dropped. Moreover, since the door 3 is divided into small doors 3L-1, 3L-2, 3R-1, 3R-2 and can be folded, the space around the container 1 required to open the door 3 can be reduced. .

(Other embodiments)
Various modifications can be made to the embodiment of the present invention without departing from the gist thereof. For example, by changing the material of each frame and each pillar of the container 1 to a stronger material, the above-described aperture ratio can be set to a larger value. For example, by making the material like a titanium alloy, the aperture ratio can be further increased.

  In the above-described embodiment, the pallet 1 is exemplified as the loaded cargo of the container 1, but the loaded cargo may be any type. For example, the cargo may be directly loaded on the container 1 without using the pallet 1, or the cargo loaded on the pallet 1 and the cargo loaded without using the pallet 1 may be mixedly loaded. Alternatively, in the above-described embodiment, the usage form in the height direction of the container 1 is not described in detail. May be.

  Moreover, in the above-mentioned embodiment, in order to reduce the number of parts of the container 1, the areas of the wall surfaces 7F and 7R are made equal to the left and right, but the area of the wall surface 7F may be smaller than the area of the wall surface 7R. According to this, even if the aperture ratio is less than 75%, it is possible to prevent a decrease in workability when the pallet 6 is carried in and out.

  DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Cargo compartment, 3, 3B ... Door, small door ... 3R-1, 3R-2, 3L-1, 3L-2, 6 ... Pallet (flat pallet for consistent transport of JIS Z0105), 30 ... Aperture

Claims (4)

In a 40-foot container conforming to the ISO standard having a cargo compartment in which cargo is loaded and an opening to which a door can be freely opened and closed,
The opening is provided at least on a side surface in the longitudinal direction of the cargo compartment,
The longitudinal length of the cargo compartment at the opening is 60% to 95% of the longitudinal length of the cargo compartment.
A 40-foot container conforming to the ISO standard characterized by A 40 foot container complying with the ISO standard of claim 1,
The width of the opening is 75% to 90% of the total length in the longitudinal direction.
A 40-foot container conforming to the ISO standard characterized by 40 feet container conforming to the ISO standard according to claim 1 or 2,
The length in the short direction, which is the width of the cargo compartment, is a dimension capable of mounting at least two rows of flat pallets for integrated transport that are 1100 millimeters in length and breadth according to JIS Z0105 standards. The length in a longitudinal direction is a dimension that can mount at least 10 rows of the flat pallets for integrated transportation.
A 40-foot container conforming to the ISO standard characterized by A 40-foot container conforming to the ISO standard according to any one of claims 1 to 3,
The door is composed of first and second doors that are double doors,
Each of the first and second doors can be folded into a plurality of stages.
A 40-foot container conforming to the ISO standard characterized by