WO2012171962A1

WO2012171962A1 - Composite shipping container

Info

Publication number: WO2012171962A1
Application number: PCT/EP2012/061216
Authority: WO
Inventors: VAN Ludo SCHEPDAEL; Berend Albert Drogt; Rudolf Machiel WESSELS
Original assignee: Dsm Ip Assets B.V.
Priority date: 2011-06-14
Filing date: 2012-06-13
Publication date: 2012-12-20
Also published as: WO2012171961A1

Abstract

Composite shipping container (2) comprising: - a plurality of walls (4) that form, in use, at least a top wall (4A), a floor wall (4B), and a plurality of side walls (4C) of the shipping container (2), and - a frame (6) that comprises a bottom side rail (6A). At least one of the side walls (4C) comprises a fibre-reinforced composite wall material. The bottom side rail (6A) comprises a base part including a standing portion for fixing the floor wall (4B) thereto, said standing portion extending along the bottom side rail (6A) and along an, in use, upward direction. The standing portion has an inner side to which the floor wall (4B) of the shipping container (2) is attached, and has an outer side opposite to the inner side, wherein the bottom side rail (6A) further comprises a plurality of reinforcement elements. A mutual distance between neighbouring reinforcement elements is in a range from 25 to 180 centimeter.

Description

COMPOSITE SHIPPING CONTAINER

Field and background

The invention relates to a shipping container comprising: - a plurality of walls that form, in use, at least a floor wall and a plurality of side walls of the shipping container, and - a frame for mechanically fixing at least one of the side walls and the floor wall thereto. The invention also relates to a bottom side rail. The invention also relates to an assembly comprising a bottom side rail and at least one side wall.

Shipping containers are often used for transport of goods over sea or land. Cargo ships can be loaded with many shipping containers. In a harbour, these shipping containers can be transferred to e.g. trucks, inland navigation vessels, and/or naval vessels. During such transfer, a hoisting crane may be used for lifting the shipping containers from the ship and depositing the shipping containers on land, on a truck, or on another ship.

During transport on sea or when stored on land, shipping containers may be stacked on top of each other. A shipping container may therefore experience a substantial load from other shipping containers that are present on top of said shipping container. In addition, during lifting a shipping container by means of a hoisting crane, significant stresses may be experienced by the shipping container. In order to withstand these different types of loads, walls of known shipping containers are usually made of corrugated steel. Steel walls of the known shipping containers are strong enough to be able to withstand these loads.

However, known steel shipping containers also have disadvantages. One of these is that such shipping containers are relatively heavy. Shipping containers may be filled with goods which may form a significant part of the total weight of a filled shipping container. However, a known steel shipping container itself usually forms a significant part of said total weight as well. A relatively large weight of the shipping container introduces various possible problems. It may for example increase fuel costs during transport of the shipping container over sea, land, or rail, or may limit an amount of shipping containers placed on a ship.

In order to decrease a weight of a shipping container, it has recently been proposed in US 7,059,488 to use a fibre-reinforced material (or, in other words, a composite material) for manufacture of walls of a shipping container. Such material couples a relatively low weight to a relatively high strength. However, when actually building a shipping container using composite material, a number of problems may arise, for example, due to the flexibility of the composite side-walls, a much higher outward pointing bending moment than with corrugated steel walls, is introduced on the bottom side wall under loads. In particular, known ways of fixing a wall of a shipping container to a frame of the shipping container, such as welding, may not be used when said wall comprises a composite material. Thus, fixing a wall comprising a composite material to a frame of the shipping container and realising a construction that is strong enough to resist the relatively heavy loads during handling of the shipping container in practice, may be problematic.

It is therefore an object of the invention to provide an improved shipping container that at least partly meets a problem mentioned above.

Summary of the invention

Accordingly, the invention provides a shipping container, preferably a composite shipping container, comprising: - a plurality of walls that form, in use, at least a floor wall, a plurality of side walls, and preferably a top wall of the shipping container, and - a frame for mechanically fixing at least one of the side walls and the floor wall thereto, wherein the frame comprises a bottom side rail arranged for fixing thereto the floor wall and the at least one of the side walls so that the at least one of the side walls extends from the bottom side rail in a side wall direction in use directed upwards, preferably towards the top wall; wherein the at least one of the walls comprises a fibre- reinforced composite wall material, in particular a fibre-reinforced plastic wall material, wherein the bottom side rail comprises a base part including a standing portion for fixing the floor wall thereto, said standing portion extending along the bottom side rail and along an, in use, upward direction, the base part further comprising a first transverse portion extending from the standing portion in a transverse direction that is transverse to the side wall direction and points away from the floor wall, the first transverse portion being arranged for receiving the at least one side wall, wherein the standing portion has an inner side to which the floor wall of the shipping container is attached, and has on outer side opposite to the inner side, wherein the bottom side rail further comprises a plurality of reinforcement elements that are spaced apart along the bottom side rail, said reinforcement elements being fixed to the standing portion on the outer side of the standing portion, and being fixed to the first transverse portion of the base part, wherein, preferably, a mutual distance between neighbouring reinforcement elements is at least 25 centimeter and/or at most 180 centimeter, in particular is in a range from 25 centimeter to 180 centimeter. More preferably, a mutual distance between neighbouring reinforcement elements is at least 25 centimeter and/or at most 60 or 120 centimeter, in particular is in a range from 25 centimeter to 60 or 120 centimeter. Preferably, the floor wall and the at least one of the side walls are fixed to the bottom side rail. Preferably, the frame comprises steel.

Experiments and numerical simulations carried out by the inventors showed that fixing the at least one side wall comprising the laminate structure to one of various known constructions of a bottom side rail, yielded a structure that was not strong enough. In particular, standardised tests were not passed. Relevant standards may be for example: ISO 668:1995 Freight containers, classification dimensions and ratings; ISO 830:1999 Freight containers, vocabulary; NEN ISO 1496, structural integrity and testing standards for containers; NEN ISO 1 161 , corner fittings and strength requirements; and/or COMMITTEE DRAFT ISO/CD 18185-6 seal

requirements. In such tests, i.a. bending of a side wall was observed, together with excessive deformation of a known bottom side rail. After application of the

reinforcement elements, an effective strengthening of the bottom side rail could be reached. Said distance between neighbouring reinforcement elements enables an effective strengthening of the bottom side rail, so that standard tests can be passed. Thus, by means of the reinforcement elements, fixing said at least one side wall comprising the fibre-reinforced composite wall material to the frame of the shipping container and realising a construction that is strong enough to resist loads during handling of the shipping container in practice, may be enabled.

A smaller mutual distance between neighbouring reinforcement elements may enable a stronger container. However, when the distance is too small, an increase in strength may be relatively small or may even be absent, e.g. as a result of weakening of the bottom side rail due to possible welding the reinforcement elements to the bottom side rail.

Preferably, the at least one of the walls comprises a laminate structure comprising two outer laminate layers, wherein at least one, preferably both, of said laminate layers are, at least partly, formed by the fibre-reinforced composite wall material. Preferably, the laminate structure further comprises a core layer arranged in between, and in mechanical load transferring contact with, the laminate layers, said core layer in use supporting the laminate layers. Thus, in an embodiment, the at least one of the side walls comprises a laminate structure comprising two outer laminate layers that are both, at least partly, formed by the fibre-reinforced composite wall material, wherein the laminate structure further comprises a core layer arranged in between, and in mechanical load transferring contact with, both outer laminate layers, said core layer in use supporting the outer laminate layers. It was found by the inventors that for a side wall having such a laminate structure, the reinforcement elements were especially valuable.

Preferably, the reinforcement elements are formed by reinforcement plates. Preferably, a thickness of the reinforcement plates is at least 2 millimeter and/or at most 10 millimeter.

In an embodiment, the floor wall of the shipping container comprises a plurality of cross-members that are attached to the bottom side rail at attachment positions that are located on the inner side of the standing portion of the base part. In an embodiment, at least a part, preferably all, of the plurality of reinforcement elements is positioned near, e.g. opposite to, attachment positions of the cross members.

Without wanting to be bound by any theory, then, in use, a load exerted on the shipping container may be introduced into the cross members effectively. Alternatively, at least a part, preferably all, of the plurality of reinforcement elements is positioned in between neighbouring ones of the attachment positions of the cross members. In an embodiment, a part of the plurality of reinforcement elements is positioned in between neighbouring ones of the attachment positions of the cross members and a part of the plurality of reinforcement elements is positioned near, e.g. opposite to, attachment positions of the cross members.

Preferably, a mutual distance between neighbouring reinforcement elements is approximately equal to a mutual distance between neighbouring cross members or to a multitude of the mutual distance between neighbouring cross members.

In an embodiment, the base part further comprises a second transverse portion extending from the standing portion along the transverse direction. The first and second transverse portions may be spaced apart along the side wall direction so that the base part has a substantially C-shaped cross section. Preferably, the reinforcement elements are further fixed to a lower transverse portion. Such a second transverse portion, preferably with the reinforcement elements fixed thereto, may give additional strength to the bottom side rail. According to one embodiment, the bottom side rail further comprises a first flange that extends from the first transverse portion of the base part along the side wall direction, and that is supported on the first transverse portion, the first transverse portion being arranged for receiving the at least one side wall. In this embodiment, the at least one side wall comprises a first face and a second face, the first face in use being contiguous to said first flange and the second face being opposite of said first face relative to said at least one side wall, wherein the second face in use extends over said standing portion, for fixing at least said second face to said standing portion. It has been found that fixing the at least one side wall in this manner to the bottom side face allows for optimal distribution of load from the side wall to the frame.

In another embodiment, the bottom side rail further comprises a first flange and/or a second flange that extend from the first transverse portion of the base part along the side wall direction, and that are preferably supported on the first transverse portion, the first transverse portion thus being arranged for receiving the at least one side wall, wherein the first flange and/or the second flange are arranged for fixing thereto the at least one side wall. Preferably, the at least one of the side walls is fixed to the first flange and/or the second flange.

Said first and second flange enable the realisation of a mechanical connection between the bottom side rail and the at least one side wall. Said mechanical connection may withstand relatively large loads that can in use be applied on the shipping container. The mechanical connection by means of the first and second flange enables fixing the at least one side wall to the bottom side rail in such a way that a probability for significant bending or buckling of the bottom side rail is be reduced. Such has been confirmed by experiments and simulations carried out by the inventors.

In an embodiment, the first transverse portion of the base part has a first end located away from the floor wall and preferably pointing in the transverse direction, wherein the first flange extends from the first end of the first transverse portion. Thus, extension of the first transverse portion in the transverse direction and away from the first flange portion, may be substantially prevented. A maximum width, measured in a direction perpendicular to the at least one side wall, of a type of known shipping containers is usually standardised. Also, a minimum distance between the at least one side wall and another, opposite, side wall is usually standardised. Thus, the first transverse portion extending in the transverse direction may decrease a thickness available for the side wall portion in between the first and second flange. In this embodiment, such a decrease of available thickness may be substantially prevented.

In an embodiment, the first transverse portion of the base part has a second end located adjacent to the floor wall and preferably pointing in a direction opposite to the transverse direction, wherein the standing portion is connected to the first transverse portion via the second end of the first transverse portion. Thus, extension of the first transverse portion in the transverse direction and away from the second flange portion, may be substantially prevented, over at least part of the bottom side rail.

In an embodiment, the first transverse portion is provided with a recess for receiving a part of the floor wall therein. Thus, limitation of a size of the floor wall by means of the bottom side rail may, at least partly, be prevented. In an embodiment, the at least one side wall has an inside surface and an outside surface, wherein the first flange is fixed to the outside surface and the second flange is fixed to the inside surface of the at least one side wall.

In an embodiment, the first flange, the second flange, and the first transverse portion together form a substantially U-shaped cavity that extends along the bottom side rail, and is arranged for receiving and fixing therein the at least one side wall. Preferably, the base part, the first flange, and the second flange form one piece (i.e. a single piece bottom side rail).

In an embodiment, the at least one side wall has an, in use, lower side wall portion and an, in use, upper side wall portion, said lower side wall portion being fixed to the first and second flange and extending along the side wall direction to the upper side wall portion, wherein a thickness of the lower side wall portion is smaller than a thickness of the upper side wall portion. Preferably, a thickness of the first flange, the second flange, and the lower side wall portion, is similar to a thickness of the upper side wall portion. Since optionally, the lower side wall portion may be fixed to the first and second flange using an adhesive layer, in that specific case a thickness of the first flange, the second flange, the lower side wall portion, and the one or more optional adhesive layers may be similar to a thickness of the upper side wall portion. Numerical simulation carried out by the inventors showed that an increased thickness of the at least one side wall is beneficial for reducing a possibility of significant bending, or even buckling, of the at least side wall. However, standardised dimensions (e.g. according to an ISO standard) may limit a maximum thickness of the at least one side wall. In this embodiment, a thickness of the upper and/or lower side wall portion may both be optimised. A reduction in thickness of the lower side wall portion used for accommodating the first and second flange within the available thickness for the at least one side wall, may at least partly be prevented in the upper side wall portion.

The invention also provides the bottom side rail, the at least one side wall, and an assembly comprising the bottom side rail and the at least one side wall. Thus, there is provided an assembly for assembling a shipping container, preferably a composite shipping container, the assembly comprising:- a plurality of walls that form, in use, at least a floor wall, a plurality of side walls, and preferably a top wall of the shipping container, and - a frame for mechanically fixing at least one of the side walls and the floor wall thereto, wherein the frame comprises a bottom side rail arranged for fixing thereto the floor wall and the at least one of the side walls so that the at least one of the side walls extends from the bottom side rail in a side wall direction in use directed upwards, preferably towards the top wall; wherein the at least one of the walls comprises a fibre-reinforced composite wall material, in particular a fibre-reinforced plastic wall material, wherein the bottom side rail comprises a base part including a standing portion for fixing the floor wall thereto, said standing portion extending along the bottom side rail and along an, in use, upward direction, the base part further comprising a first transverse portion extending from the standing portion in a transverse direction that is transverse to the side wall direction and points away from the floor wall, the first transverse portion being arranged for receiving the at least one side wall, wherein the standing portion has an inner side to which the floor wall of the shipping container is attached, and has an outer side opposite to the inner side, wherein the bottom side rail further comprises a plurality of reinforcement elements that are spaced apart along the bottom side rail, said reinforcement elements being fixed to the standing portion on the outer side of the standing portion, and being fixed to the first transverse portion of the base part, wherein, preferably, a mutual distance between neighbouring reinforcement elements is at least 25 centimeter and/or at most 180 centimeter, in particular is in a range from 25 centimeter to 180 centimeter. More preferably, a mutual distance between neighbouring reinforcement elements is at least 25 centimeter and/or at most 60 or 120 centimeter, in particular is in a range from 25 centimeter to 60 or 120 centimeter. Preferably, the at least one of the walls comprises a laminate structure comprising two outer laminate layers, wherein at least one, preferably both, of said laminate layers are, at least partly, formed by the fibre- reinforced composite wall material. Preferably, the laminate structure further comprises a core layer arranged in between, and in mechanical load transferring contact with, the laminate layers, said core layer in use supporting the laminate layers. Thus, in an embodiment, the at least one of the side walls comprises a laminate structure comprising two outer laminate layers that are both, at least partly, formed by the fibre- reinforced composite wall material, wherein the laminate structure further comprises a core layer arranged in between, and in mechanical load transferring contact with, both outer laminate layers, said core layer in use supporting the outer laminate layers.

It may be appreciated that in particular in those embodiments wherein the wall portions are fixed to the first and second flange, the bending moment plays an important role in the integrity of the bottom side rail. In particular in the u-shaped configuration of the flanges and the first transverse portion, wherein the side wall is fixed within the u-shaped cavity, the end point of the first transverse portion contiguous or adjacent the floor wall may be subject to large stress loads due to the bending moment. Notwithstanding the advantage of the features of the present invention in general, the reinforcement elements of the present invention play a particular important role with respect to these embodiments. The reinforcement elements in these embodiments reduce the potential amount of stress load on the end point of the first transverse portion near the floor wall (i.e. the corner portion between the standing portion and the transverse portion), taking away this part of the base part as being a structural weak part thereof.

The invention will now be described, in a non-limiting way, with reference to the accompanying drawings, in which:

Brief description of the drawings

Figure 1 schematically shows a perspective view of a shipping container, in a first embodiment according to the invention;

Figure 2 schematically shows a perspective view of a cross-sectional detail of a shipping container, indicated in figure 1 ;

Figure 3 shows a part of an inside surface of a side wall and a bottom side rail of a shipping container, in a second embodiment according to the invention;

Figure 4 shows a bottom side rail in a cross-section indicated in figure

3; Figure 5 shows a perspective view of at least part of a floor wall; Figure 6 shows a cross-section of a bottom side rail in the second embodiment;

Figure 7 shows, in a third embodiment, a cross-section of a bottom side rail and at least one side wall;

Figures 8A shows a side view of an example of a reinforcement plate;

Figure 8B shows the example of the reinforcement plate in a back view of the reinforcement plate; and

Figure 9 illustrates a further example of a bottom side rail in cross section, including a floor plate and a side wall.

Detailed description

Unless stated otherwise, like reference numerals refer to like elements throughout the drawings.

Figure 1 schematically shows a perspective view of a shipping container 2, in a first embodiment according to the invention. The shipping container 2 comprises a plurality of walls 4. The plurality of walls 4 form, in use, at least a top wall 4A, a floor wall 4B, and a plurality of side walls 4C of the shipping container. The shipping container 2 further comprises a frame 6 for mechanically fixing at least one, e.g. two, of the side walls 4C, and the floor wall 4B thereto. Thus, two or more, e.g. all, walls 4 of the shipping container may be fixed to said frame 6.

The frame 6 comprises at least a bottom side rail 6A (or in other words, a lower side rail 6A) to which the floor wall 4B and the at least one of the side walls 4C are fixed. As a result, the at least one of the side walls 4C extends from the bottom side rail 6A in a side wall direction 8 towards the top wall 4A. The side-wall direction 8 may be substantially parallel with a surface, e.g. an outside surface 10, of the at least one side wall 4C, in particular of an upper part of the at least one side wall 4C.

Figure 2 schematically shows a perspective view of a cross-sectional detail I of the shipping container 2, indicated in figure 1. The at least one of the side walls 4C comprises a laminate structure 12. The shipping container 2 may thus be a composite shipping container. More in general, the term 'composite shipping container' may be used for indicating a shipping container comprising a fibre-reinforced composite wall material. The laminate structure 12 comprises a first and a second, i.e. at least two, outer laminate layers 14A respectively 14B. At least one of said outer laminate layers 14A, 14B, preferably both of said outer laminate layers, are at least partly formed by a fibre-reinforced composite wall material. A typical of the laminate structure thickness ranges between 3 and 5 cm with a core material of for example light polymer foam of between 40 - 120 kg/m3. In a variation, the fibre-reinforced composite wall material is formed by another composite structure, such as a pultrudate.

Pultradates are formed by means of a pultrusion process, which process is known as such to the skilled person. Examples (non-limiting) of core materials could be; PVC, PET, PA, PL⁾, -foams. For reefer applications, the walls may be even thicker, for example, up to 100 mm.

The laminate structure 12 further comprises a core layer 16 arranged in between, and in mechanical load transferring contact with, both outer laminate layers 14A, 14B. In use, the core layer 16 supports the outer laminate layers 14A, 14B. The core layer may e.g. comprise a polymer foam. As a result of the core layer, a vulnerability of the laminate structure 12 for impacts on the at least one side wall 4C is reduced. The use of a laminate structure for building walls 4, e.g. side walls, of shipping containers 2 may result in a substantial weight decrease of such shipping containers 2, compared to the traditional shipping containers having corrugated steel sheet walls.

More in general, all side walls (e.g. four side walls) of the shipping container 2, and optionally the top wall of the shipping container 2, may comprise the laminate structure 12. Thus, a relatively large weight decrease can be realised.

The bottom side rail 6A comprises a base part, indicated in figure 2 by an imaginary dashed box 18 that contains said base part. The base part 18 includes a standing portion 18A for fixing the floor wall thereto. The standing portion 18A extends along the bottom side rail 6A. The standing portion 18A also extends along an, in use, upward direction 1 1. The base part 18 may typically be provided from a blank steel plate in a hot or cold rolled process, wherein the base part 18 is formed as a metal profile.

Said upward direction may be parallel with the side wall direction 8 or may make an angle with the side wall direction 8. That means that the standing portion 18A may extend in parallel with the side wall direction 8 or may make an angle with the side wall direction. Said angle may be smaller than e.g. 30 degrees, preferably smaller than 15 degrees. If said angle is relatively small, the base part may be relatively strong as it may better sustain a load in a direction opposite to the side wall direction 8.

The base part 18 further comprises a first transverse portion 18B. The first transverse portion 18B extends from the standing portion 18A in a transverse direction 20. Said transverse direction 20 is transverse, e.g. approximately parallel, to the side wall direction 8 and points away from the floor wall 4B. The first transverse portion is arranged for receiving the at least one side wall. Thereto the bottom side rail 6A further comprises a first flange 22 and/or a second flange 26. The first flange 22 extends, from the first transverse portion 18B of the base part 18, along the side wall direction 20, or at least upwards. The at least one side wall 4C may be fixed to the first flange 22. For example, the at least one side wall 4C is glued to the first flange 22. The bottom side rail 6A may further comprise the second flange 26 that extends, in use, upwards, e.g. along the side wall direction 8, from the first transverse portion 18B of the base part 18. Thus, the first and second flange may extend along the side wall direction 8, and along a longitudinal direction 9 of the bottom side rail, approximately in parallel. The at least one side wall 4C may be fixed, e.g. glued, to the second flange 26.

Furthermore, the first and second flange may be supported on the first transverse portion. Such may increase a strength of the at least one bottom side rail 6A. The use of a fibre-reinforced wall material may cause a problem in fixing the side wall to the bottom side rail. By means of the first and second flange, such a problem may be solved. Without wanting to be bound by any theory, it was recognized by the inventors that the first and second flange may decrease a probability for excessive bending of a side wall comprising a fibre-reinforced wall material.

With regard to the prior art it is noted that US 5,741 ,042 relates to a shipping container having a laminate structure comprising a fiber-reinforced wall material. However, US 5,741 ,042 does not disclose i.a. that the first and second flange extend from the first transverse portion along the side wall direction, and are supported on the first transverse portion. It is further noted that US 4,325,488 relates to an air cargo container having a bottom side rail having a first and second flange that extend from a first transverse portion along the side wall direction, and are supported on said first transverse portion. However, US 4,325,488 does not disclose i.a. a laminate structure comprising a fiber-reinforced composite wall material. The bottom side rail with side wall disclosed in US 5,741 ,042, and the bottom side rail with side wall disclosed in US 4,325,488, are of a different structure. Furthermore, US 5,741 ,042 and US 4,325,488 relate to different types of containers, i.e. a shipping container respectively an air cargo container. Hence, the skilled person would not combine US 5,741 ,042 and US 4,325,488.

The first flange 22, the second flange 26, and the first transverse portion 18B may together form a substantially U-shaped cavity that extends along the bottom side rail 6A. Said cavity is arranged for receiving therein, and for fixing, e.g. gluing, therein, the at least one side wall 4C. More in general, the base part 18, the first flange 22, and the second flange 26 may preferably form one piece. E.g., the base part 18, the first flange 22, and the second flange 26 may be made out of one piece, e.g. by means of extrusion. As another example, the first flange 22 and the second flange 26 may be welded or glued to the base part 18. As yet another example, the base part and one of the first and second flange, e.g. the first flange or the second flange, may be made out of one piece, and the other one of the first and second flange may be attached, e.g. welded or glued, to the base part 18. In particular, the base part and the first flange may be formed from a sheet of metal, e.g. by means of a laminating mill. The second flange may be attached to said sheet after forming the base part and the first flange.

Without wanting to be bound by any theory, the inventors recognized that the first flange and the second flange may form an adhesive bonding surface for introducing shear stresses from the side wall into the bottom side rail 6A. Such a solution differs significantly from a known way of connecting a side wall made of corrugated steel sheet to a known bottom side rail, which is carried out by applying a single welding line. Experiments carried out by the inventors showed that the first and second flange are beneficial for preventing collapse of the bottom side rail 6A in a standardized test. Numerical simulations carried out by the inventors showed that the at least one side wall 4C may bend outwards and/or may buckle, when a relative large load is applied on the shipping container 2 in a downward direction (e.g. in a direction opposite to the sidewall direction 8) and/or on the side wall in or opposite to the transversal direction. A probability for such bending and/or buckling may be reduced by applying the second flange 26 in addition to the first flange 22. Without wanting to be bound by any theory, the inventors recognized that the second flange 26 may cause a better introduction of a load on the at least one sidewall 4C into the base part of the bottom side rail. The shipping container 2 may be a 45 foot shipping container, or may have another, preferably standardized, size. A maximum width, measured in a direction perpendicular to the outside surface 10 the at least one side wall 4C, of a type of shipping container may usually be standardised, e.g. according to an ISO standard. Relevant standards may be for example: ISO 668:1995 Freight containers,

classification dimensions and ratings; ISO 830:1999 Freight containers, vocabulary; NEN ISO 1496, structural integrity and testing standards for containers; NEN ISO 1 161 , corner fittings and strength requirements; and/or COMMITTEE DRAFT ISO/CD 18185-6 seal requirements. Also, a minimum distance between the at least one side wall 4C and another, opposite, side wall is usually standardised, e.g. according to the ISO standard. Thus, a maximum wall thickness of the at least one side wall may be defined by a difference between said maximum thickness and said minimum distance. To prevent a possibility of significant bending, or even buckling, of the at least side wall, it may be beneficial to have a relatively large thickness of the at least one side wall. Thus, preferably, parts protruding out of bottom side rail along the transverse direction, may be substantially prevented. Then, a relatively large thickness of the at least one side wall may be realised, while the ISO standard can still be met.

In a variation of the first embodiment, as indicated in figure 2, the first transverse portion 18B of the base part 18 has a first end 24A located away from the floor wall 4B. The first flange may extend from the first end 24A of the first transverse portion 18B. The first transverse portion 18B of the base part 18 may optionally have a second end 24B located adjacent to the floor wall. The second end 24B of the first transverse portion may be connected to the standing portion 18A. Thus, the standing portion 18A may be connected to the first transverse portion 18B via the second end 24B of the first transverse portion 18B. Said first end 24A and said second end 24B generally extend along the at least one bottom side rail 6A.

Additionally, or alternatively, in said variation the at least one side wall 4C has the outside surface 10 and the first flange is fixed to the outside surface 10 of the at least one side wall 4C. Additionally, or alternatively, in said variation the base part 18 may further comprise a second transverse portion 18C extending from the standing portion along the transverse direction 20. The first and second transverse portions 18B respectively 18C are spaced apart along the side wall direction. As a result, the base part 18 may have a substantially C-shaped cross section. It is noted that, more in general, the first flange, the second flange, the first transverse portion, and/or a lower transverse portion extend along the bottom side rail 6A.

The standing portion 18A may have an inner side 30 to which the floor wall of the shipping container can be attached, and has on outer side 32 opposite to the inner side 30. The bottom side rail 6A may further comprise a plurality of reinforcement elements 34. The bottom side rail 6A may e.g. comprise at least 20 and/or at most 60 reinforcement elements 34, typically approximately 40 reinforcement elements 34. Said reinforcement elements 34 are spaced apart along the bottom side rail 6A. The reinforcement elements 34 are fixed to the standing portion 18A on the outer side 32 of the standing portion 18A. The reinforcement elements are also fixed to the first transverse portion 18B of the base part 18. A mutual distance X between neighbouring reinforcement elements is in a range from 30 to 60 centimeter. Said distance may be measured from a center 36A of a first reinforcement element 34A to a center 36B of a second reinforcement element 34B. Reinforcement elements (or other parts) are 'neighbouring' if no other reinforcement elements are located in between said neighbouring reinforcement elements (or respectively in between said other parts).

In this example, a reinforcement element is positioned near every cross member. Hence, a mutual distance between neighbouring reinforcement elements may be approximately equal to a mutual distance between neighbouring cross-members. .A mutual distance between neighbouring reinforcement elements, and/or between neighbouring cross members, may be in a range from 25 to 60 centimeter. However, in other examples, a reinforcement element may be positioned near every other cross member. Hence, a mutual distance between neighbouring reinforcement elements may be approximately equal to a multitude, in this example two times, of the mutual distance between neighbouring cross-members. Then, the mutual distance between neighbouring reinforcement elements may be in a range from 25 to 120 centimeter. Or, a reinforcement element may be positioned near one out of three cross members. Then, said multitude may be equal to three times and the mutual distance between neighbouring reinforcement elements may be in a range from 25 to 180 centimeter

The reinforcement elements 34 may be formed by reinforcement plates, e.g. may be reinforcement plates. A thickness D₂ of the reinforcement plates may be at least 2 or 3 millimeter and/or at most 5 or 10 millimeter. The reinforcement elements may further be fixed to a lower transverse portion 18C. In particular, the combination of the reinforcement elements and the first and second flange provide a relatively strong bottom side rail 6A. The combination of the U-shaped cavity and the reinforcement plates may effectively withstand a load caused by the bending of the side wall, thus limiting said bending.

The reinforcement elements will provide additional strength to the bottom side rail 6A. When in use the shipping container is under a heavy downward load or sideward load, the reinforcement plates may decrease a possibility of yielding of the base part. As a result of said yielding, a C-shaped base part 18 may "close", e.g. by the first transverse portion and a lower transverse portion coming closer together.

Figure 3 shows a part of an inside surface 10' of a side wall 4C and a bottom side rail 6A of a shipping container 2, in a second embodiment according to the invention. Figure 4 shows a bottom side rail 6A in a cross-section B-B' indicated in figure 3. Figure 4 shows the bottom side rail 6A, the base part 18, the standing portion 18A having the inner side 30 and the outer side 32, the first transverse portion 18B having the first and second end 24A respectively 24B, a lower transverse portion 18C, and the first flange 22. Said elements shown in figure 4 may be arranged similarly as corresponding elements shown in figure 2. The first transverse portion may be provided with a recess 38 for receiving a part of the floor wall therein.

By way of a non-limiting example, dimensions of the bottom side rail 6A are indicated in figure 4. A height H₁ of the first flange 22 may be in a range from 3 to 10 centimeter, typically approximately 5 centimeter. A depth H₂ of the recess 38 may be in a range from 20 to 40 millimeter, typically approximately 27 millimeter. The depth H₂ of the recess 38 may, more in general, be approximately equal to a thickness of a floor plate, e.g. made of wood, forming part of the floor wall 4B. A height H₃ of the standing part 18A may be in a range from 1 1 to 15 centimeter, typically approximately 13 centimeter. A width W₁ of the first transverse portion 18B may be in a range from 6 to 10 centimeter, typically approximately 8 centimeter. A width W₂ of a lower transverse portion may be at least 2 centimeter and/or at most 9 centimeter, e.g. approximately 3 centimeter. A width W₃ of the recess 38 may be in a range from 2 to 5 centimeter, typically approximately 3 centimeter. A thickness D₁ of a lower transverse portion may be in a range from 3 to 6 millimeter, e.g. approximately 4 millimeter. A thickness D₂ of the standing portion 18A, a thickness D₃ of the first transverse portion 18B, a thickness D₄ of the first flange, and/or a thickness D₅ of the second flange may be in a similar range, e.g. may be at least 3 millimeter and/or at most 6 millimeter. All such dimensions have been found advantageous in numerical simulations carried out by the inventors.

Figure 5 shows a perspective view of at least part of the floor wall 4B. Figure 5 shows two bottom side rails 6A, 6B. Figure 5 also shows reinforcement elements 34. The floor wall 4B of the shipping container comprises a plurality of cross members 40. The cross members 40 may be attached, e.g. welded, to the inner side 30 of the standing portion 18A of the base part 18. At least part, e.g. all, of the reinforcement elements 34 are positioned opposite to a cross member, preferably to introduce a load on the shipping container in an effective manner from the bottom side rail into the cross-members. Thus, reinforcement elements 34 may be positioned so that they are aligned with the cross members. The plurality of cross members 40 are attached to the bottom side rail 6A at attachment positions 41 located on the inner side 42 of the standing portion of the base part. The plurality of reinforcement elements 34 is positioned near, in this example opposite to, the attachment positions 41 of the cross members 40. When the reinforcement elements are located near the cross members, there may be limited deformation of the bottom side rail due to inserted heat from welding the reinforcement elements to the bottom side rail. Furthermore, the shipping container may have an improved stiffness if the reinforcement elements are positioned near the cross members. Alternatively, at least part, e.g. all, of the plurality of reinforcement elements may be positioned in between neighbouring attachment positions of the cross members. Then, reinforcement elements 34 may be positioned so that they lack alignment with the cross members. More in general, the term 'floor' may be interpreted broadly, and may comprise merely the cross members or may comprise the cross-members in combination with other parts, e.g. a (e.g. wooden) floor plate. Thus, instead of the term 'floor wall', the term 'bottom structure' may be used.

Figure 6 shows a cross-section of the bottom side rail 6A in the second embodiment, an attachment position 41 , the inner side 42 of the standing portion of the base part, and the floor plate 40A. Figure 6 also shows one of the cross members 40 and one of the reinforcement plates 34. Figure 6 shows the floor plate 40A received by the recess 38. Figure 6 also shows the cavity 34.

Figure 7 shows, in a third embodiment of a shipping container, a cross-section of the bottom side rail 6A and the at least one side wall 4C. The side wall 4C comprises the laminate structure that comprises the first outer laminate layer 14A, the second outer laminate layer 14B, and the core layer 16. Figure 7 also shows glue layers 44 with which the side wall 4C is fixed to the first and second flange 22 respectively 26.

The at least one side wall 4C may have an, in use, lower side wall portion 4C and an, in use, upper side wall portion 4C". Analogously, the laminate structure 12 may have a lower laminate structure portion 12' and an upper laminate structure portion 12". The lower side wall portion 4C may be fixed to the first flange 22 and may extend along the side wall direction 8 that is directed along the sidewall direction 8, e.g. upwards, to the upper side wall portion 4C". A thickness D₆ of the lower side wall portion may be smaller than a thickness D₇ of the upper side wall portion. Preferably, the sum of the thickness D₄ of the first flange, a thickness D₅ of the second flange, the thickness D₆ of the lower portion of the at least one side wall, and the thickness of the adhesive layers 44 is similar, e.g. approximately equal, to the thickness D₇ of the upper part 4C" of the at least one side wall 4C.

Figure 8A shows a side view of an example of a reinforcement plate 34. Figure 8B shows the example of the reinforcement plate in a back view of the reinforcement plate, seen in parallel with a width direction 48 of the reinforcement plate indicated in figure 8A. Said back of the reinforcement plate is indicated with reference number 49. By way of a non-limiting example, dimensions of the example of the reinforcement plate 34 are indicated in figures 8A and 8B. A height H₄ of the reinforcement plate may be in a range from 12 centimeter to 18 centimeter, typically approximately 15 centimeter. A maximum width W₄ of the reinforcement plate may be in a range from 1 centimeter to 5 centimeter, typically approximately 2.5 centimeter. A maximum width W₅ of the reinforcement plate may be in a range from 5 centimeter to 9 centimeter, typically approximately 7 centimeter. A thickness D₈ of the reinforcement plate may be at least 2 millimeter and/or at most 10 millimeter, typically approximately 6 millimeter. All such dimensions have been found advantageous in numerical simulations carried out by the inventors. More in general a reinforcement element, in particular a reinforcement plate 34, may be provided with a reinforcement element recess, in particular a reinforcement plate recess 50, for accommodating the recess 38 for receiving a part of the floor wall 4B, and/or for receiving therein the part of the floor wall 4B.

Figure 9 illustrates a further embodiment wherein the bottom side rail 6A comprises standing portions 18A and first transverse portions 18B. The

embodiment of Figure 9 further illustrates a reinforcement flange 34 in accordance with the principles of the present invention. A floor plate 40A rests on the lower part of first transverse portion 18B of the bottom side rail 6A. From the outer end of the upper part of first transverse portion 18B, a first flange 22 extends in the direction of the surface of the side wall 4C. Side wall 4C comprises a fibre reinforced composite plastic panel being made of a core 16 and outer laminates 14A and 14B. Outer laminate 14B forms a first face of the side wall 4C, and outer laminate 14A (on the inner side of the container) forms a second face of the side wall 4C.

As fixed to the bottom side rail 6A, the first face 14B of the side wall 4C is contiguous to the first flange 22 of the bottom side rail 6A. In addition, the second face 14A of the side wall 4C extends partly over the standing portion 18A of the bottom side rail 6A, providing an overlapping portion 60 allowing portion 60 to be fixed to the standing portion 18A. Fixing of the side wall 4C to the bottom side rail 6A is preferred for gaining structural integrity, but it is not essential. As will be appreciated, embodiments may exist wherein the overlapping part 60 is not fixed to the standing portion 18A, while the construction as a whole provides sufficient strength by itself. If fixing is applied, the skilled person will appreciate that any suitable fixing means such as bolt or rivets, but most preferentially a glue, resin or kit (e.g. providing a watertight or airtight seal) may be used for fixing the side wall 4C to the bottom side rail 6A.

Embodiments of the invention are not limited to the foregoing description and drawings. E.g., the shipping container may lack a top wall. Equally all kinematic inversions are considered inherently disclosed and to be within the scope of the present invention. The use of expressions like: "preferably", "in particular", "especially", "typically" etc. may relate to optional features. The terms "comprising" and "including" do not exclude other elements. The term 'fixing' as used herein may comprise attaching, e.g. gluing. The indefinite article "a" or "an" does not exclude a plurality. Expressions like '"lower", "upper", "inside", "inner", "outside", "outer", "top", "bottom", "upwards", "downwards", "sidewards", "floor", and the like refer to a situation of normal use of the shipping container. Features which are not specifically or explicitly described or claimed may be additionally comprised in the structure according to the present invention without deviating from its scope.

Claims

Shipping container comprising:

a plurality of walls that form, in use, at least a floor wall and a plurality of side walls of the shipping container, and

a frame for mechanically fixing at least one of the side walls and the floor wall thereto, wherein the frame comprises a bottom side rail arranged for fixing thereto the floor wall and the at least one of the side walls so that the at least one of the side walls extends from the bottom side rail in a side wall direction, in use, directed upwards;

wherein the at least one of the walls comprises a fiber-reinforced composite wall material,

wherein the bottom side rail comprises a base part including a standing portion for fixing the floor wall thereto, said standing portion extending along the bottom side rail and along an, in use, upward direction, the base part further comprising a first transverse portion extending from the standing portion in a transverse direction that is transverse to the side wall direction and points away from the floor wall, the first transverse portion being arranged for receiving the at least one side wall,

wherein the standing portion has an inner side to which the floor wall of the shipping container is attached, and has on outer side opposite to the inner side, wherein the bottom side rail further comprises a plurality of reinforcement elements that are spaced apart along the bottom side rail, said reinforcement elements being fixed to the standing portion on the outer side of the standing portion, and being fixed to the first transverse portion of the base part.

Shipping container according to claim 1 , wherein a mutual distance between neighbouring reinforcement elements is in a range from 25 centimeter to 180 centimeter.

Shipping container according to claim 1 or 2, wherein the floor wall and the at least one of the side walls are fixed to the bottom side rail.

Shipping container according to any of the previous claims, wherein the at least one of the walls comprises a fibre reinforced plastic panel

Shipping container according to claim 4, wherein the plastic panel comprises a laminate structure comprising two outer laminate layers, wherein at least one, preferably both, of said laminate layers are, at least partly, formed by the fibre- reinforced composite wall material.

6. Shipping container according to claim 5, wherein the laminate structure further comprises a core layer arranged in between, and in mechanical load transferring contact with, the laminate layers, said core layer in use supporting the laminate layers.

7. Shipping container according to any of the previous claims, wherein the

reinforcement elements are formed by reinforcement plates.

8. Shipping container according to claim 7, wherein a thickness of the

reinforcement plates is at least 2 millimeter and/or at most 10 millimeter.

9. Shipping container according to any of the previous claims, wherein the floor wall of the shipping container comprises a plurality of crossmembers that are attached to the bottom side rail at attachment positions located on the inner side of the standing portion of the base part.

10. Shipping container according to claim 9, wherein at least a part of the plurality of reinforcement elements is positioned opposite to attachment positions of the cross members.

1 1. Shipping container according to claim 9 or 10, wherein a mutual distance between neighbouring reinforcement elements is approximately equal to a mutual distance between neighbouring cross members or to a multitude of the mutual distance between neighbouring cross members.

12. Shipping container according to any of the previous claims, wherein the base part further comprises a second transverse portion extending from the standing portion along the transverse direction, wherein the first and second transverse portions are spaced apart along the side wall direction so that the base part has a substantially C-shaped cross section, wherein the

reinforcements elements are further fixed to a lower transverse portion.

13. Shipping container according to any of the previous claims, wherein the first transverse portion is provided with a recess for receiving a part of the floor wall therein.

14. Shipping container according to any of the previous claims, wherein the

bottom side rail further comprises a first flange that extends from the first transverse portion of the base part along the side wall direction, and that is supported on the first transverse portion, the first transverse portion being arranged for receiving the at least one side wall, and wherein the at least one side wall comprises a first face and a second face, the first face in use being contiguous to said first flange and the second face being opposite of said first face relative to said at least one side wall, wherein the second face in use extends over said standing portion, for fixing at least said second face to said standing portion.

15. Shipping container according to any of the claims 1-13, wherein the bottom side rail further comprises a first flange and a second flange that extend from the first transverse portion of the base part along the side wall direction, and that are supported on the first transverse portion, the first transverse portion thus being arranged for receiving the at least one side wall, wherein the first flange and the second flange are arranged for fixing thereto the at least one side wall.

16. Shipping container according to claim 15, wherein the first transverse portion of the base part has a first end located away from the floor wall, wherein the first flange extends from the first end of the first transverse portion.

17. Shipping container according to one of claims 15-16, wherein the first

transverse portion of the base part has a second end located adjacent to the floor wall, wherein the standing portion is connected to the first transverse portion via the second end of the first transverse portion.

18. Shipping container according to one of claims 15-17, wherein the first flange, the second flange, and the first transverse portion together form a

substantially U-shaped cavity that extends along the bottom side rail, and is arranged for receiving and fixing therein the at least one side wall.

19. Shipping container according to one of claims 15-18, wherein the at least one side wall has an, in use, lower side wall portion and an, in use, upper side wall portion, said lower side wall portion being fixed to the first and second flange and extending along the side wall direction to the upper portion, wherein a thickness of the lower side wall portion is smaller than a thickness of the upper side wall portion.

20. Shipping container according to claim 19, wherein a sum of a thickness of the first flange, the second flange, the lower side wall portion, and optionally one or more adhesive layers, is similar to a thickness of the upper side wall portion.