Abstract:
A method for stowage of cargo items ( 7, 18, 100 ). In a cargo container ( 12, 20, 103 ) wherein spaces around the cargo items and within the cargo container are at least partly filled with spacer elements ( 1, 19, 104 - 106, 109 - 112 ) so as to substantially prevent movement of the cargo items in the cargo container, characterized in that dynamic forces on the cargo items associated with motion of the cargo container and/or weight forces on the cargo items are transmitted to the container structure through the spacer elements, and wherein at least one spacer element transmitting such forces comprises a shaped block of expanded plastics foam material, preferably polystyrene. The invention is applicable to comparatively heavy loads such as those transported in shipping containers and in such land vehicles as rail cars and road transport vehicles.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional of U.S. patent application Ser. No. 11/989,504 filed on Mar. 6, 2009. This application is a National Stage of International Application No. PCT/AU2006/001040 filed on Jul. 27, 2006. This application claims the benefit and priority of AUSN2005904009 filed Jul. 27, 2005. The entire disclosures of each of the above applications (are) incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The invention relates to improvements in methods and apparatus for the stowage of cargo for the transport of cargo so stowed. 
       BACKGROUND 
       [0003]    Enormous quantities of goods, including manufactured goods, produce and materials, are daily shipped around the world by land, sea and air in containers of various types. Standard shipping containers as used on seagoing ships, for example, are a familiar sight at sea and on land. The loading of cargo items into such containers and their subsequent unloading, is a major activity involving much expenditure of labour and money. An important problem facing all those involved in shipping of goods is containing the cost of such loading and unloading. 
         [0004]    Much of the cost of loading and unloading arises from the need to secure cargo items in their containers securely, to avoid damage in transit. Given the wide variety of goods that must be transported, this can be a skilled process consuming much time and effort. 
         [0005]    It is also important in many cases that cargo items not move within their containers during transit. In sea transport, for example, any inadvertent shifting of cargo due to ship motions can have adverse effects on ship stability and hence safety. 
         [0006]    Some cargoes comprising multiple discrete items that can be loaded in a container in layers also present a problem in that no number of complete layers closely matches the load carrying capacity of the container, yet partial layers can be difficult to secure against undesired movement. 
         [0007]    Materials such as timber used to secure heavy loads in containers can present quarantine and disposal problems at their destinations. 
         [0008]    An issue widely recognized in the sea transport industry, at least, is that there can be a mismatch between cargoes and container sizes on particular journey legs. For example, where cargo movements are such that “40-foot” containers arrive at a particular port in numbers greater than are required for cargoes leaving that port, there can be excessive numbers of “dead legs” for such containers, i.e. journey legs where the containers are carried empty. Enhancing the ability of such containers to be loaded with other cargo items could in such a case lead to substantial cost savings by reducing dead legs. 
         [0009]    More generally, it is always desirable to enhance the flexibility of loading of containers. For example, making it easier to use a small container where a large one was previously required, or vice versa, allows better matching of cargoes and container availability. 
       SUMMARY 
       [0010]    The invention has as its purposes and benefits easier, quicker and cheaper packing and unpacking of shipping and other transport containers, with efficient use of available space and avoidance of movement of cargo items within the container, than is available using conventional packing methods. The surprising finding that certain plastics foam materials can be used for the support end restraint of items of significant weight carried in cargo containers has led to the invention. 
         [0011]    In a first aspect, the invention provides a method and apparatus for stowing cargo items in a structure in which the cargo is to be transported. The structure can comprise a cargo container adapted for movement by a seagoing vessel or defines a cargo carrying space of a vessel. Alternatively, the invention may find application in transport modes where cargo items are contained by the structure of a carrying vehicle—for example where cargo items are carried between decks in ships, or in rail or road vehicles. 
         [0012]    In another aspect of the invention, there is provided a method for stowing cargo items in a structure. The method can include placing, on a floor surface within the structure, a first plurality of cargo items and a plurality of spacers, such that each of the spacers is positioned on the floor surface adjacent to cargo items of the first plurality of cargo items. A second plurality of cargo items can be placed on the plurality of spacers, whereby the cargo items of said second plurality are supported above the floor surface by the spacers so as to be partly raised relative to the cargo items of the first plurality of cargo items. A third plurality of cargo items can then be placed on the first plurality of cargo items, whereby each cargo item of said second plurality engages cargo items of said first and third pluralities. 
         [0013]    In still another aspect of the invention, a structure containing cargo items stowed therein for transportation includes a first plurality of cargo items positioned on a floor surface within the structure. A plurality of spacers are also positioned on the floor surface, wherein each of the spacers is positioned adjacent to cargo items of the first plurality of cargo items. A second plurality of cargo items are positioned on the plurality of spacers, such that they are supported above the floor surface and thus partly raised relative to the cargo items of the first plurality of cargo items. A third plurality of cargo items are positioned on the first plurality of cargo items whereby each cargo item of the second plurality of cargo items engages cargo items of said first and third pluralities. 
         [0014]    Advantageously, at least one of the spacer elements can comprise a shaped block of an expanded plastics foam material, preferably expanded polystyrene foam. 
         [0015]    It is to be understood in this specification that the term “set” used in respect of a set of spacer elements, can mean one spacer element or a plurality. Similarly and intentionally in this specification, the term “set”, used in respect of a set of cargo items, can mean one cargo item or a plurality. It is not intended to imply, where there are several members of either type of set, that all such members need be identical. 
         [0016]    The term “cargo item”, as used herein, can mean a single element or assembly of elements, or a plurality of elements. Similarly, “cargo item” could mean one or several items secured to or on a support or handling element, such as a crate or a pallet. 
         [0017]    The term “standard shipping container” is here to be taken to include in particular containers of the type used in large numbers for transport of goods by sea. The containers in question are the subject of International Standards Organisation (ISO) standards and are available in various sizes, of which common external sizes are:
       (a) length: 20 feet (6096 mm); width 8 feet (2438 mm); height 8 feet 6 inches (2591 mm) or 9 feet 6 inches (2896 mm); (b) length: 40 feet (12192 mm); width 8 feet (2438 mm); height 8 feet 6 inches (2591 mm) or 9 feet 6 inches (2896 mm).       
 
         [0019]    Such shipping containers are of various types and in addition to general purpose containers, the invention is potentially applicable to suitable specific purpose and specific cargo container types, for example refrigerated containers. Containers of this general type are available in a number of other different lengths. 
     
    
     
       DRAWINGS 
         [0020]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0021]      FIG. 1  is a perspective view of a cargo support according to an exemplary embodiment of the invention, supporting a coil of steel strip (shown in phantom lines); 
           [0022]      FIG. 2  is a side view of four cargo supports as shown in  FIG. 1 , in use in the interior of a container (shown in phantom lines); 
           [0023]      FIG. 3  is a perspective view of two coils of steel strip on pallets and (in phantom lines) a cargo support according to another exemplary embodiment of the invention; 
           [0024]      FIG. 4  is a set of three views of the cargo support shown in  FIG. 3 , namely (a) side elevation, (b) end elevation, (c) view from below, 
           [0025]      FIG. 5  is a perspective view of five cargo supports and coils as shown in  FIG. 3 , in use in the interior of a container (shown in phantom lines); 
           [0026]      FIG. 6  is a set of three views of a cargo support according to an exemplary embodiment of the invention namely (a) side view, (b) bottom view, and (c) (left half) an end view and (right half) a cross sectional view, the spacer element being shown in views (b) and (c) covering loads of plate material on stillage elements; 
           [0027]      FIG. 7  is a perspective view of two spacers which are used according to form, with cargo supports, a packed arrangement in a shipping container in accordance with one example (the spacers being shown in phantom lines); 
           [0028]      FIG. 8  is a plan view of a possible packing arrangement for a layer of cylindrical cargo items in a container in accordance with a preferred embodiment of the invention; 
           [0029]      FIG. 9  is a plan view of a load of cargo items and spacer elements in accordance with a preferred embodiment of the invention, in the interior of a container (shown in phantom lines); 
           [0030]      FIG. 10  is a side view of a part of the load of cargo items and of the spacer elements as shown in  FIG. 8 , the part shown being the containers between planes marked “P” and “Q” in  FIG. 8 ; 
           [0031]      FIG. 11  is a perspective view of a shipping container interior space (represented by phantom lines) with coil-type cargo items stowed therein according to an exemplary embodiment of the invention; 
           [0032]      FIG. 12  is a perspective view of the shipping container interior space shown in  FIG. 11 , now with one only of the three cargo items shown in  FIG. 11  in place; 
           [0033]      FIG. 13  is a side view of a forklift vehicle, portion of a container and an apparatus for assisting in loading the container; and 
           [0034]      FIG. 14  is a plan view of a container internal space containing three cargo items, shoring timbers and spacers. 
       
    
    
     DETAILED DESCRIPTION 
       [0035]      FIG. 1  shows a cargo support  1  according a first example. Cargo support  1  is generally rectangular, having end faces  2 , side faces  3 , a bottom face  4  and a top face  5 . An upwardly-facing recess  6  has the form of a half-cylinder. Shown in phantom lines in  FIG. 1  is a coil  7  of strip steel that is received and supported in recess  6 . Coil  7  is an example only of a cargo item able to be supported by cargo support  1 . Cutouts  8  are provided to provide access to a central hole  9  of coil  7  for an elongate “sling” (not shown) as is typically used by material handling equipment for lifting and moving coils of steel strip. Also, longitudinal recesses  15  extend along the length of bottom face  4  and are spaced and sized to enable tines of a forklift (or the like; not shown) to lift the cargo support  1  and contained coil  7  together. 
         [0036]      FIG. 2  shows a side view of four spacer elements  1  and coils  7  positioned, in the interior of a standard shipping container  12 . Container  12  is represented schematically in  FIG. 2  by showing in phantom lines only the edges of its internal surfaces, so that only the container&#39;s interior space is shown. 
         [0037]    Cargo supports  1  are sized so that four of them snugly fit in container  12 , being restrained from longitudinal movement by the inner end surfaces  13  and from lateral movement the inner side surfaces  14  of container  12 . Such movements may be caused by ship motions at sea and need to be resisted for ship stability and safety. The width between side faces  3  of cargo support  1  is close to the width between inner side surfaces  14  and the length of the four cargo supports  1  in combination is close to the length between inner end surfaces  13 . With this mode of stowing the heavy and unwieldy cargo items  7 , it is quicker and easier to load a shipping container and to unload it, with no need for lashing the items  7  to the interior of the container  12  itself. 
         [0038]    The cargo supports  1  are formed integrally from a foamed cellular plastics material such as, for example only, “RMAX Geofoam” polystyrene foam, available under the name “Isolite EPS” in Australia from a division of Huntsman Chemical Company Australia Pty Ltd. 
         [0039]    This rigid cellular polystyrene material is available in a range of six density classes, with different compressive strengths, and is manufactured to Australian Standard AS1366 Part 3-1992. Grades used by applicants to date are “SL” (nominal density 11 kg/cubic metre and 70 kPa compressive stress at 10% deflection) and “M” (nominal density 19 kg/cubic metre and 105 kPa compressive stress at 10% deformation). However, it is of course desirable to use a material with a suitable density for the particular application, having regard to the cargo item weights and sizes, likely movements of the container, and the like. Selection does not of itself require inventive effort. 
         [0040]    Forming of the cargo supports  1  is preferred to be by foaming in a simple mould (not shown), and more preferably this is done on or close to the site where the coils  7  are to be loaded in container  12 . This could be at a steel warehouse or at a container loading facility. Alternatively, the polystyrene foam can simply be purchased in blocks from the manufacturer and cut to shape using suitable known methods (e.g. hot wire cutting). 
         [0041]    Cargo supports  1  may be reinforced—where necessitated by the load to be carried—by providing at appropriate points inserts (not shown) of material(s) more resistant to deformation from concentrated loads than foamed plastics. For example, the recesses  15  could be defined and their surfaces reinforced by inverted channel sections formed from sheet metal placed in the mould before foaming. However, it has surprisingly been found that in many practical cases, and with suitable choice of material, no such reinforcement is needed even for heavy loads. 
         [0042]    Other suitable expanded plastics foam materials may be used, and spacer elements with the functionality of elements  1  may even be fabricated from several components in suitable cases. 
         [0043]    The clearances to be provided between the elements  1  and the inner surfaces  13  and  14  of container  12  are chosen by suitable trial to suit the weights of the cargo items involved, the skill of the persons stowing and unloading the containers, and the equipment available to them. 
         [0044]      FIG. 3  shows two coils  16  of steel strip, each secured on a suitable pallet  17 , each coil  16  and its pallet  17  comprising a cargo item  18 . Shown in phantom lines is a further cargo support  19  that can facilitate the stowage of cargo items  18  in shipping containers. Cargo such as cargo items  19  are commonly required to be loaded into shipping containers and are sometimes referred to as “top hats”, due to their shape. 
         [0045]      FIG. 5  shows five cargo supports  19  being used to stow ten cargo items  19  in a shipping container interior space  20  (whose edges are shown in phantom lines, just as in  FIG. 2 ). As with cargo supports  1 , cargo supports  19  are sized and shaped so as to fit snugly (i.e. with clearances small enough to sufficiently limit load movement under likely ship motions and large enough for easy loading and unloading) between inner side surfaces  21  of container interior  20  and so that five in combination fit snugly between inner end surfaces  22  of interior  20 . 
         [0046]      FIG. 4  shows cargo support  19  in three views. Cargo support  19  is generally in the form of a rectangular prism and has two holes  23  within which coils  16  are received, and a rectangular recess  24  within which pallets  17  are received. In use, and by contrast to cargo support  1  whose load is lowered into recess  6 , cargo support  19  is lowered over two cargo items  18  from above and partially surrounds items  18 . Cargo support  19  thereafter maintains the desired relative positions of the items  18 . A forklift (not shown) can pass its tines into recesses  25  in the base of cargo support  19  to access pallets  17  and lift the complete combination of items  8  and cargo support  19  for placement into container interior  20 . 
         [0047]    As with cargo supports  1 , cargo supports  19  are conveniently formed from an expanded foam plastics material, which may be lightweight, but without implying any limitation to this material type or construction. 
         [0048]    It is not essential that the cargo items  18  protrude through the top of cargo support  19 . This arrangement simply happens to economize on the material used to form cargo support  19 . A similar cargo support (not shown) could simply cover the items  19  completely (except at the bottom), if required. 
         [0049]      FIG. 6  shows a cargo support  30  that is also open-bottomed and in use lowered over a cargo item  31  from above. Cargo item  31  comprises three layers  32  of flat material (e.g. metal plates or billets for hot rolling) supported on stillage elements  33  in known manner. Cargo support  30  is generally rectangular in overall form, having opposing side faces  33 , end faces  34 , a top face  35  and a bottom face  36 . A recess  37  is formed in bottom face  36  and is shaped and sized for close-fitting containment of cargo item  31  as shown. Recesses  38  are provided also in bottom face  36  for tines of a forklift or the like, so that once cargo support  30  has been positioned over and lowered onto cargo item  31  the complete combination of cargo support  30  and cargo item  31  can be lifted and conveniently loaded into and unloaded from, a shipping container. The side faces  33  are spaced apart so as to fit between opposing inner side faces of a shipping container (not shown) with clearances small enough to limit undesired movement during transit of the container. Similarly the end faces are spaced so that a specified number of cargo supports  30  can be placed longitudinally in the container with sufficiently small clearance to resist undesired movement in transit. 
         [0050]    From the above descriptions of cargo supports  1 ,  19  and  30 , it will be apparent that a very wide variety of cargo items—beyond the specific items used as examples—can be conveniently stowed in containers so as to resist undesired movement therein during transit of the containers. By making the cargo supports at the point of loading, especially by the use of lightweight foamed plastics, an efficient stowing and restraining system can be provided. 
         [0051]    Cargo supports  1 ,  19  and  30  all partially surround their respective cargo items  7 ,  18  and  31  in use.  FIG. 7  shows another possibility. A container interior  40  is partially filled with spacers  41 , which in this embodiment are provided as spacer elements each comprising single block of substantially rigid expanded plastics foam, so that cargo spaces  42  and  43  are defined by the spacers  41  and the interior surfaces of the container interior  40 . This arrangement permits cargo items, taking up only part of a container interior to be stowed in such a way that their potential movement in the container is limited by the inner sides, floor and (if desired) roof surfaces and (in the longitudinal direction) by the container inner end surfaces and the spacers  41 . In this case, the general principle is again followed of substantially filling gaps between opposing inner surfaces of the container is followed, so as to limit undesired cargo movement, but without actually surrounding the cargo items by the spacers  41 . In this embodiment, each spacer  40  comprises side faces which are spaced apart to bear against inner surfaces of the container interior  40 . 
         [0052]    Spacers  41  have recesses  44  for tines of handling equipment to ease the task of locating them in the container interior  40 . 
         [0053]    Spacers  41  are solid blocks in this embodiment, but could be provided with openings (not shown), where the nature of the particular cargo items permits, to minimize weight and usage of expanded, plastics foam in the spacers  41 , to provide for airflow (especially in the case of refrigerated containers), etc. 
         [0054]    One possible variation, not shown, is to bevel, round off, or taper upright corner edges of cargo supports  1 ,  19 ,  30  and/or spacers  41  to ease the process of passing them through close fitting load openings (e.g. doors) in containers, some care in alignment being needed. 
         [0055]      FIG. 11  shows three large coils  100 ,  101  and  102  (e.g. of steel strip) stowed in a shipping container internal space  103  in another example. Internal space  103  is represented by chain-dotted lines as before. The coils are stowed with their axes longitudinally oriented in space  103 . They are supported from below on cargo supports  104 ,  105  and  106  which are cut away to closely conform with the cylindrical shapes of coils  100 - 102  and which closely fit the gap between opposing sidewalls  107  and  108 . Four spacers  109 ,  110 ,  111  and  112  are provided firstly to separate coils  100  and  101  and  101  and  102  and secondly to separate coils  100  and  102  from respective end walls  113  and  114 . The entire assembly of coils  100 - 102 , spacers  109 - 112  and cargo supports  104 - 106  is closely confined between end walls  113  and  114 . No separate restraint of coils  100 - 102  is provided. 
         [0056]      FIG. 12  is a similar view of container internal space  103  partly loaded, through end doors  115 . Spacer  109  and cargo support  104  are in position, and spacer  110  is being moved longitudinally (as shown by arrow  116 ) towards its final position. Coil  100  has been placed on cargo support  104 , by means described below, after placement of cargo support  104  in position. Similarly, coils  101  and  102  will be placed on their respective supporting cargo supports  105  and  106  in the same way, after placement of spacers  105  and  106  in space  103 . 
         [0057]    A difficulty with stowing in the way shown in  FIG. 12  is that it can be impossible for a suitably sized forklift to enter space  103 .  FIG. 13  shows a way in which this problem can be overcome. A wheeled apparatus  121  is provided which can be attached to a forklift  120  and which has a chassis  123 , the chassis  123  being mounted on wheels  124 , and a support in the form of an elongate sling  122  that can pass through coils such as coil  100 . The chassis has a lifting means, in the form of a hydraulic cylinder  125 , whereby sling  122  can be raised and lowered (as shown by arrow  126 ). A rearwardly-extending elongate coupling, in the form of a beam  127 , is mounted to sling  122 , in this embodiment at a pivot  128 , and is coupled at its opposite (rear) end to a counterweight  129 . Coupling of beam  127  to counterweight  129  allows a degree of relative movement between them. Counterweight  129  is adapted to be raised and lowered by forklift  120 , which extends its tines  130  into cooperating openings (not shown) in counterweight  129 . Hydraulic power for operating cylinders  125 , and in this embodiment a cylinder  131  that allows some relative pivoting of beam  127  about sling  122 , is taken from forklift  120 . Accordingly, raising and lowering of the support  122  can be effected by operation of the tines  130  and the cylinder  125 . 
         [0058]    As shown in  FIG. 13 , the chassis  123  and support  122  are positioned forwardly of the tines  130  to be maneuverable by the forklift vehicle  120 , whereby the apparatus  121  can be used to lift heavy weights such as coil  100  and maneuver them into (or out of) a container  132  without the forklift vehicle  120  itself having to enter container  132 . Apparatus  121  allows the use of a forklift smaller than would otherwise be necessary for placement of coil  100  into container  132 , counterweight  129  reducing the weight to be lifted by forklift  120  when handling coil  100 , with wheels  124  acting as a fulcrum. This is very helpful, because many dock facilities do not have such large machines. 
         [0059]    The polystyrene cargo supports and spacers have the unexpected advantage of surprisingly high friction when in contact with container interior surfaces. Thus, lateral forces on coils  100 - 102  would be transmitted to the floor  133  of space  103  by shear in cargo supports  104 ,  105  and  106  and friction at their contacts with floor  133 , as well as by direct bearing of end faces such as faces  134  on walls  107  and  108 . Generally clearances between cargo supports such as  104 - 106  and opposing walls such as  107  and  108  should be as small as practicable, even to the extent of actual contact between the cargo supports and the walls on both sides. However, the effect of friction where cargo items such as coils  100 - 102  are supported from below is to alleviate any ill effects of positive clearances. Clearances can if desired or found necessary be closed by sliding any suitable thin laminar material between spacer elements and walls. 
         [0060]    An important point of difference among the various cargo supports described herein is that some are used to resist both the weight of cargo items and lateral forces arising from motions during transport of the cargo container, whereas others resist only the latter type of forces. Cargo supports  1  and  104 - 106 , for example, support the weight of cargo items (respectively items  7  and  100 - 102 ) and also restrain movement of those cargo items in generally horizontal directions in their containers, which movements can arise from dynamic forces associated with motion in a seaway for shipping containers or cornering and acceleration loads in land applications. By contrast, cargo supports  19  primarily restrain cargo items against generally horizontal forces, as do spacers  109 - 112 , while the weight of the cargo items is taken directly by the floors of their respective containers. 
         [0061]    Further, loads may be restrained against horizontal movement in a cargo container in one direction only or in two perpendicular directions. In  FIGS. 2 ,  5  and  11 , container spaces  12 ,  20  and  103  are shown as being completely filled except for space above the loads, so that both lateral and longitudinal movements are resisted by the cargo supports  1 ,  19  and  104 - 106  and spacers  109 - 112 . However, it is possible in principle that only movements in one direction be resisted by the cargo supports including expanded foam materials, with other means being provided to resist movement in a perpendicular direction. In  FIG. 14 , heavy cargo items  150 ,  151  and  152  are shown in a container internal space  153  (represented by chain-dotted lines) and are secured against longitudinal movement (i.e. in the direction of arrow  154 ) by timbers  155 . However, they could still move laterally to some degree, and so are restrained against lateral movement by cargo supports  156 . Any or all of the cargo items  150 - 152  could of course have their weight supported by cargo supports.  FIG. 14  is meant primarily to illustrate the above point rather than necessarily being a practical and preferred implementation. 
         [0062]    Preferred embodiments of the invention will now be described. The cargo items are not necessarily surrounded in these embodiments. 
         [0063]      FIG. 8  is a plan view of a container interior  60  (shown in phantom lines) with a single layer of 65 drum-type cargo items  61  therein. A problem of this arrangement is that the layer of items  61  is not constrained sufficiently by the interior surfaces of the container interior  60  to fully prevent movement of items in transit, with the possibility of damage or leakage. There is a space  62  into which cargo items  61  can move, but which cannot be neatly filled by one or more extra containers  61 . A further problem that often arises with cargoes of this type is that one layer does not fully utilize the weight carrying capacity of the container, whereas two full layers would exceed that capacity.  FIGS. 9 and 10  show how embodiments of the invention may allow for these problems to be avoided. 
         [0064]      FIG. 9  is a similar view to  FIG. 8 , showing how the container interior  60  can be stowed with an extra  25  cargo items to make 90 cargo items in all, all constrained against excessive movement during transit.  FIG. 10  shows this cargo as seen in side elevation looking in the direction of arrow “R” in  FIG. 9 , although for clarity only those cargo items between planes “P” and “Q” are shown. To prevent movement within the space  62 , a suitably shaped and sized spacer element  63  is positioned therein bearing against some of the cargo items  61  and inner end surface  64 . (A spacer element  63 , positioned in a designated position as a first step in loading a layer of cargo items  61 , has the additional advantage of guiding the building up of the layer with each item in its correct position, so that an intended or designed arrangement and number of items  61  in the layer is achieved.) 
         [0065]    In  FIG. 9 , circles without letters indicate cargo items  61  of the bottom layer. Circles with the letter “Y” indicate cargo items  61  that are raised partly out of the bottom layer by being positioned on top of suitably shaped and sized spacer elements  65 , of which four are shown in this case. A partial layer of 25 additional cargo items  61 , marked “X”, is then stacked on top of items  61  of the bottom layer. Undesired movement of the items  61  labeled “X” is prevented by the inner side surfaces  66  of container interior  60  and end barriers formed by the partly-raised cargo items  61  labeled “Y”. 
         [0066]    Each of spacer elements has the form of two cylinders  67  (that each sit under one cargo item  61 ) joined by an intermediate section  68 . However, this is optional. It will be clear to skilled persons that many other shapes would be possible. Another possibility is to provide spacer elements (not shown) that instead of lifting some cargo items partially out of one layer to form a barrier to movement of items in another layer, are held within one layer and also extend out of that layer to form a barrier against undesired movement of items of another layer. For example, elements having a shape that is a combination of the shape of elements  67  and the cargo items  61  shown above them in  FIGS. 9  and  10  could be used as an alternative to elements  67  to restrain movement of items  61  of the upper layer. 
         [0067]    As with the arrangement of  FIG. 7 , the arrangement of  FIGS. 9 and 10  involves a cargo being constrained against undesired movement by a combination of interior surfaces of a container and by spacer elements placed in the container. 
         [0068]    It should be understood that there is nothing specific to the particular packing arrangement shown in  FIGS. 8 ,  9  and  10  that limits the scope of the invention. What has been described is purely an example. 
         [0069]    Many variations and enhancements may be made without exceeding the spirit or scope of the invention. Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.