Patent Publication Number: US-2017369237-A1

Title: Cover for a Forklift Pocket of a Shipping Container

Description:
The present application relates to a shipping container and to a cover for covering a forklift pocket of the shipping container. 
     Shipping containers have been used for many years to transport goods. They are provided in standard sizes which allow them to be transported using appropriately configured ships, trucks or railway carriages. A shipping container may be transferred, for example, from a ship to an oil rig using a crane. A shipping container may also be transferred between storage locations using a forklift truck. In order to facilitate transport by forklift truck each shipping container is provided with forklift pockets which are configured to receive forklift tangs (which may also be referred to as prongs) of the forklift truck. 
     A problem associated with forklift pockets is that an object may enter the forklift pocket and may present a hazard at some future point in time. For example, a worker may put a spanner or screwdriver in a forklift pocket for convenience when working nearby and then forget to remove it. In another example, an object such as an empty drinks can could be blown by wind into the forklift pocket. During subsequent transfer of the shipping container (e.g. from a ship to an oil rig) the object may be blown out of the forklift pocket by wind (or may fall out due to tilting of the shipping container). This could cause injury to a worker. 
     It is an object of the present invention to address the above problem or another problem associated with known forklift pockets. 
     According to a first aspect of the invention there is provided a cover for a forklift pocket of a shipping container, the cover comprising a base and at least one resilient flap which is secured to the base, the at least one resilient flap extending from the base and being configured to substantially close the forklift pocket. 
     The cover reduces the likelihood of objects entering the forklift pocket. In addition, the cover prevents an object from falling out of the forklift pocket (or reduces the likelihood of the object falling out of the forklift pocket). 
     The at least one resilient flap may be sufficiently stiff that it projects upwardly from the base. 
     The at least one resilient flap may be sufficiently stiff to withstand a force of up to around 30N applied against it. 
     The at least one resilient flap may be sufficiently flexible that it will be deflected by a forklift tang of a forklift truck, and sufficiently resilient to return to its initial orientation after the forklift tang has been removed. 
     The at least one resilient flap may be held in a slot provided in the base. 
     The slot may be T-shaped in cross-section and a foot of the at least one resilient flap held in the slot may be T-shaped in cross-section. 
     The slot may be open at one end and closed at an opposite end. 
     The base may be a single piece of material. 
     The base may be a single piece of steel. 
     A plate may extend from one side of the base, the plate being configured to deflect a forklift tang away from the base. 
     The base may be provided with a sloping face. 
     The base may be provided with an additional sloping face on an opposite side. 
     The base may extend either side of the at least one resilient flap. 
     The base may be higher on one side of the at least one resilient flap than on the other side of the at least one resilient flap, the difference in height being greater than the thickness of the at least one resilient flap. 
     Corners of the at least one resilient flap distal to the base may be cut or rounded. 
     A target may be provided on the at least one resilient flap. 
     The at least one resilient flap may be brightly coloured. The at least one resilient flap may be orange. 
     The at least one resilient flap may be configured to substantially close the forklift pocket in combination with the base. 
     According to a second aspect of the invention there is provided a shipping container comprising a plurality of forklift pockets, each forklift pocket being fitted with a cover comprising a base and at least one resilient flap which is secured to the base, the at least one resilient flap extending from the base and substantially closing the forklift pocket. 
     The base may be secured to the floor of the forklift pocket and the at least one resilient flap may extend upwardly from the base. 
     There may be a gap between the at least one resilient flap and walls of the forklift pocket. 
     The gap may be less than 1 cm. 
     The gap may be around 5 mm. 
     The base may be secured to the floor of the forklift pocket and be provided with a sloping outer face which slopes upwardly in the direction of the at least one resilient flap. 
     An outer edge of the sloping outer face may be welded to the shipping container. 
     The at least one resilient flap may be sufficiently stiff to withstand a force of up to around 30N applied against it. 
     The at least one resilient flap may be sufficiently flexible that it will be deflected by a forklift tang of a forklift truck, and sufficiently resilient to return to its initial orientation after the forklift tang has been removed. 
     According to a third aspect of the invention there is provided a shipping container comprising a plurality of forklift pockets, each forklift pocket being fitted with a cover comprising a plurality of bases each provided with at least one resilient flap, the resilient flaps extending from the bases and substantially closing the forklift pocket. 
     The cover may comprise two bases each of which is provided with at least one resilient flap. 
     The second and third aspects of the invention may include features mentioned above in connection with the first aspect of the invention. 
    
    
     
       Embodiments of the invention will now be described by way of example only, with reference to the accompanying figures, in which: 
         FIG. 1  schematically depicts a shipping container with forklift pockets that have been fitted with covers according to an embodiment of the invention; 
         FIGS. 2 and 3  depicts a cover and forklift pocket in more detail; 
         FIG. 4  depicts the cover and forklift pocket viewed from one side together with a forklift tang of a forklift truck; 
         FIGS. 5-7  are perspective views of the cover; 
         FIG. 8  is a perspective view of a cover according to an alternative embodiment of the invention; 
         FIG. 9  is a perspective view of part of a base of a cover according to an alternative embodiment of the invention; 
         FIG. 10  is a cross-sectional perspective view of a cover and forklift pocket according to an alternative embodiment of the invention; 
         FIG. 11  is a cross-sectional perspective view of the cover shown in  FIG. 10 ; 
         FIG. 12  is a perspective view from above of the base of the cover shown in  FIGS. 10 and 11 ; and 
         FIG. 13  is a perspective view from underneath of the base of the cover shown in  FIGS. 10 and 11 . 
     
    
    
       FIG. 1  schematically depicts a shipping container  1  provided with forklift pockets  2  according to an embodiment of the invention. The forklift pockets  2  are provided in pairs with a separation between them which corresponds with the separation been two forklift tangs of a forklift truck. Two forklift pockets  2  are visible at one end of the shipping container  1 . These forklift pockets run along the entire length of the shipping container  1 . Two further forklift pockets  2  are visible on one side of the shipping container  1 . These extend through to an opposite side of the shipping container. The forklift pockets  2  allow a forklift truck to lift the shipping container from either end or from either side. 
     When the shipping container  1  is lifted from one side rather than from the end, the tangs of the forklift truck may extend fully through the forklift pockets  2  and project out of the opposite side. In general, forklift truck tangs will not extend fully from one end of a shipping container to the other. However, this may occur if the shipping container is shorter than the conventional length, in which case the tangs may project out of the opposite end of the shipping container. 
     The forklift pockets  2  are fitted with covers  4 . The covers  4  are resiliently biased to a closed position which substantially closes the forklift pockets  2 . This prevents or inhibits entry of objects into the forklift pockets. The covers  4  may be pushed to an open position by tangs of a forklift truck. This allows the tangs of the forklift truck to enter the forklift pockets  2  in the usual way, and thus allows forklift transportation of the shipping container. The covers  4 , in addition to being moveable to allow forklift tangs to enter forklift pockets  2 , are also moveable to allow forklift tangs to project through and out of forklift pockets. That is, the covers  4  can open inwardly to allow entry of a forklift tang into a forklift pocket, or can open outwardly to allow a forklift tang to project out of a forklift pocket. Thus, the covers  4  prevent or inhibit objects from entering the forklift pockets  2 , whilst at the same time allowing the shipping container  1  to be handled in a conventional manner by a forklift truck. 
       FIG. 2  shows a cover  4  according to an embodiment of the invention in situ in a forklift pocket  2 .  FIG. 3  is a perspective view of the cover  4  and the forklift pocket  2 . The cover  4  comprises a base  6  and a resilient flap  8  which projects upwardly from the base. The dimensions of the resilient flap  8  are such that it substantially closes the forklift pocket  2 . As may be seen from  FIG. 2 , a gap exists between the resilient flap  8  and walls of the forklift pocket  2 . The gap may for example be less than 1 cm. The gap may for example be greater than 2 mm. The gap may for example be between 3 mm and 7 mm, and may for example be around 5 mm. The gap is provided to avoid rubbing of the resilient flap  8  against walls of the forklift pocket  2  (such rubbing could inhibit closure of the flap following removal of a forklift tang). The size of the gap takes into account the fact that over time some rust may accumulate on inner walls of the forklift pocket and may cause bubbling which moves the walls towards the resilient flap  8 . 
     References to the resilient flap  8  being dimensioned to “substantially close” the forklift pocket  2  may be interpreted as meaning that the forklift pocket is sufficiently closed that an object such as a spanner or a screwdriver cannot easily fall out of the forklift pocket, or is sufficiently closed that an object such as an empty drinks can cannot be blown into the forklift pocket. The term “substantially closed” is not intended to mean that there is no gap between the resilient flap  8  and walls of the forklift pocket  2 . Instead, as shown in  FIG. 2 , a gap may be present but the gap is sufficiently small to prevent most potentially harmful objects falling out of the forklift pocket  2 , or to prevent potentially harmful objects being blown into the forklift pocket. 
     The size of the gap between the resilient flap  8  and the forklift pocket is thus a compromise between keeping the gap small to prevent objects falling out of the forklift pocket and keeping the gap sufficiently large to prevent rubbing of the resilient flap against walls of the forklift pocket. 
     The resilient flap  8  may for example have a height of around 145 mm. The height of the resilient flap  8  may be such that an upper end of the flap is adjacent to an upper surface of a conventionally dimensioned forklift pocket. The resilient flap  8  may for example have a width of around 335 mm. The width of the resilient flap  8  may be such that sides of the flap are adjacent to sides of a conventionally dimensioned forklift pocket. A conventionally dimensioned forklift pocket may for example have a height of 150 mm and a width of 350 mm. A forklift pocket may have other dimensions, in which case the size of the resilient flap may be selected accordingly. 
     The resilient flap  8  may for example be formed from butyl rubber. The butyl rubber may for example have 65° Scale A Shore hardness (+/−5°). The butyl rubber may for example have a thickness of around 6 mm. Butyl rubber with this hardness and thickness is relatively inflexible and the flap  8  is thus resiliently biased to the closed position. The resilient flap  8  is sufficiently stiff that it extends upwardly from the base  6  (i.e. it does not bend downwardly under its own weight). The force required to push the resilient flap  8  away from the closed position is considerable, and may be around 30N. Thus, an object such as an empty drinks can being blown along by the wind would not exert sufficient force to push open the resilient flap  8  and enter the forklift pocket  2 . However, the force applied by a tang of a forklift truck in normal operation is considerably greater than the force required to push the resilient flap  8  away from the closed position, and thus the forklift tang will enter the forklift pocket in the normal way. The flap  8  is resiliently deformable in either direction, and thus allows passage of a forklift tang irrespective of the side of the flap upon which the forklift tang is incident. Therefore, the resilient flap  8  can be pushed open to accommodate entry of a forklift tang into a forklift pocket, and can be pushed open to accommodate projection of a forklift tang out of a forklift pocket. Because the flap  8  is resilient it returns to its closed configuration when the forklift tang is removed from the forklift pocket. 
     It might be possible for a worker to push the resilient flap  8  open and place an object such as a spanner or screwdriver in the forklift pocket  2 . If the spanner or screwdriver is left in the pocket then it will be retained by the cover  4  in the forklift pocket during subsequent transfer of the shipping container. For example, during transfer of the shipping container from a ship to an oil rig wind may move the spanner or screwdriver to one end of the forklift pocket  2  (or this may happen due to tilting of the shipping container). However, the spanner or screwdriver will then hit the base  6  of the cover  4  (and possibly also the flap  8 ), and will thereby be prevented from falling out of the forklift pocket  2 . Thus, potential injury to a worker will be avoided. The base  6  acts as a lip which prevents an object from sliding out of the forklift pocket  2  (or reduces the likelihood of this happening). If the spanner or screwdriver were to hit the resilient flap  8  and not the base  6 , then the flap  8  is sufficiently stiff to prevent the spanner or screwdriver from falling out of the forklift pocket (or reduce the likelihood of this happening). A very heavy object might have sufficient weight to bend the resilient flap  8  to an open position, e.g. to apply a force in excess of around 30N. The object would then fall out of the forklift pocket. However, such a heavy object is unlikely to be accidentally left in a forklift pocket. 
     Providing the base  6  on the floor of the forklift pocket  2  is advantageous compared with providing the base for example on the ceiling of the forklift pocket. This is for two reasons. The first reason is that, as explained above, the base  6  acts as a lip which may stop an object from sliding out of the forklift pocket  2 . The second reason arises from the fact that an object which is incident upon the resilient flap  8  is most likely to be incident upon it close to the base  6  if the base is on the floor of the forklift pocket. For example, if the object has slid along the forklift pocket floor and over the base  6  then it will be incident upon the resilient flap  8  close to the base. The moments of force exerted by the object on the resilient flap  8  are significantly lower than the moments of force that would be exerted on the resilient flap if the object was incident upon the end of the resilient flap which is furthest from the base  6 . If the base  6  were to be provided on the ceiling of the forklift pocket  2  then the object would be most likely to be incident upon the end of the resilient flap which is furthest from the base. The moments of force exerted by that object would be significantly higher, and the resilient flap would be bent open more easily. That is, an object close to the floor of the forklift pocket which is not sufficiently heavy to bend open the resilient flap  8  when the base  6  is on the floor of the forklift pocket  2  may be sufficiently heavy to bend open the resilient flap when the base is on the ceiling of the forklift pocket. Similarly, if the base  6  were to be provided on one side of the forklift pocket, then if the object were to be incident upon the resilient flap  8  on an opposite side of the forklift pocket it would bend open the resilient flap relatively easily (compared with the case if the base is on the floor of the forklift pocket). Thus, although the base  6  may be provided on the ceiling or a wall of the forklift pocket, it is advantageous to provide it on the floor of the forklift pocket. 
     Although the resilient flap may be formed from butyl rubber, any suitable resilient material may be used (e.g. any suitable elastomeric material, e.g. any suitable rubber). Silicon or neoprene (or some other synthetic rubber) may be used. The resilient flap  8  should be sufficiently stiff that it projects upwardly from the base, but sufficiently flexible to allow insertion of forklift tangs. 
       FIG. 4  shows the cover  4  viewed from one side in situ in a forklift pocket  2  of a shipping container. Also shown is part of a tang  16  of a forklift truck. The tang is shown twice, first at a central height (depicted by solid line  16 ) which allows straight-forward entry of the tang into the forklift pocket, and second at a lower height (depicted by dashed line  16   a ) which will allow entry of the tang via deflection from the base  6 . 
     As will be appreciated from  FIG. 4 , the base  6  occupies some volume in the forklift pocket  2 , thus reducing the vertical height of the forklift pocket which is open to receive the forklift tang  16   a . This potential disadvantage is mitigated by the presence of a sloping face  18  on an outwardly facing side of the base  6 . The sloping face  18  acts as a deflector that upwardly deflects a forklift tang  16   a  which is incident upon it. Thus, if the forklift tang has a low height  16   a  as it approaches the forklift pocket  2 , the tang is pushed upwards by the sloping face  18  and thereby slides into the forklift pocket. The usable vertical height of the forklift pocket  2  therefore substantially corresponds with the usable vertical height that would be available if the cover  4  was not present. 
     The sloping face  18  is formed from a material which is sufficiently strong to receive and deflect the forklift tang  16   a  without suffering significant damage. The sloping face  18  may for example be formed from nylon 6-6 (also referred to as nylon 6,6). The material may be provided with a lubricant which promotes interfacial sliding between the forklift tang  16   a  and the sloping face  18 . For example, molybdenum disulphide powder may be added to nylon 6-6 when forming the sloping face. The molybdenum acts as a lubricant at the surface of the nylon 6-6. 
     The base  6 , including the sloping face  18 , may be formed from nylon 6-6 or any other suitable material. For example, the base may be formed from any suitable plastic, such as a suitable polyamide. Nylon or some other polyamide such as Kevlar may be used. The base  6  may be provided with any suitable lubricant (e.g. molybdenum). 
     The construction of the cover  4  will now be described in more detail with reference to  FIGS. 4 to 7 .  FIGS. 5 and 6  are perspective views from the front and rear of the cover  4 .  FIG. 7  is a perspective view from underneath of ends of the cover  4 . The base  6  comprises a sloping front face  18  and a vertical rear wall  24 . Bottom ends of the sloping front face  18  and the vertical rear wall  24  are connected by a bottom surface  22 , and upper ends of the sloping front face and the vertical rear wall are connected by an upper surface  26 . Ends of the base  6  are closed by end walls  32 . The base  6  may be formed from a single piece of nylon 6-6 (or other suitable material), for example using injection moulding. 
     The base  6  includes five stepped bores  34  which are configured to receive bolts  36 . The bolts  36  are used to securely fasten the base  6  to the floor  38  of the forklift pocket  2 . Other numbers of openings and bolts may be used to secure the base  6  to the forklift pocket  2 . In general, the base may be provided with any suitable configuration which allows it to be securely attached to a wall of the forklift pocket  2 . 
     A rod (not visible) extends along the interior of the base  6 , and is secured to end walls  32  of the base using bolts  40 . The rod may for example be formed from metal. A clamping plate  42  is provided at an opposite surface of the resilient flap  8  from the rear wall  24  of the base  6 . Bolts  44  pass through openings in the clamping plate  42 , pass through openings in the resilient flap  8  and the rear wall of the base  24 , and are received in threaded bores in the rod. The bolts are tightened into the threaded bores, thereby securing the resilient flap  8  between the rear wall  24  and the clamping plate  34 . 
     The bottom surface  22  of the base  6  is provided with channels  46  which extend from the front to the back of the base. Four channels  46  are present and these separate the bottom surface into five parts. Other numbers of channels may be provided. Grooves are  48  are cut into the sloping face  18 , the grooves being aligned with the channels  46  in the bottom surface  22 . This prevents outer ends of the channels  46  being closed by the sloping face  18 . The channels  46  allow liquid to flow out of the forklift pocket  2 . Thus, for example, a worker may use a jet washer to clean a shipping container. The worker may push the resilient flap  8  open with the jet washer to allow water to enter the forklift pocket  2 . Some water may enter the forklift pocket  2  via gaps between the resilient flap  8  and walls of the forklift pocket  2 . Water which has entered the forklift pocket will flow back out of the forklift pocket  2  along the channels  46 . The water may carry with it dirt and small pieces of debris, thereby cleaning these out of the forklift pocket  2 . 
     Referring to  FIG. 4 , it can be seen that the clamping plate  42  stops short of the upper surface  26  of the base  6 . As a result of this construction, when a forklift tang  16   a  is in contact with the base  6  on entering the forklift pocket  2 , the resilient flap  8  can bend away from the rear wall  24  of the base  6  (the flap  8  bends about the clamping plate  42 ). Because the clamping plate  42  stops short of the upper wall  26  of the base  6 , the resilient flap  8  can bend out of the way of the forklift tang  16   a , and is not compressed against the clamping plate  42  by the forklift tang  16   a . An upper end of the clamping plate  42  may stop short of the top surface  26  of the base  6  by a distance which is greater than the thickness of the resilient flap  8 . 
     In general, the resilient flap  8  may be fixed to the base  6  at a point below the upper surface of the base. This may be at least one flap thickness below the upper surface of the base. This is advantageous when a forklift tang  16   a  slides over the base  6  as it enters the forklift pocket  2  because it avoids the resilient flap  8  being compressed by the forklift tang (the flap bends out of the way). It is also advantageous in situations in which the shipping container is inverted during use (e.g. if the shipping container is a mud skip), because again it avoids the resilient flap  8  being compressed by the forklift tang. 
     Referring again to  FIG. 2 , it may be seen that upper corners  14  of the flap  8  have been cut at a 45° angle. This is done to reduce the likelihood of a corner of the flap  8  becoming stuck inside a corner of a forklift pocket  2 . Although the corners  14  are cut at 45° in  FIG. 2 , the corners may be cut or rounded in any suitable manner. 
     Also visible in  FIG. 2  is a target  50  which has been provided on the resilient flap  8  of the cover  4 . The target  50  in this embodiment is a circle, but any suitable shape, pattern or other marking may be used. The target  50  is a visual aid towards which the forklift truck driver can aim a tang of the forklift truck. The target  50  may be provided in a colour which contrasts with the colour of the resilient flap  8 . For example, if the resilient flap  8  is black then the target  50  may be white. The target  50  may for example be formed using fluorescent paint. The target  50  may be particularly useful if, for example, the resilient flap  8  has a colour which is similar to the colour of the shipping container such that the resilient flap is difficult to see. It is also advantageous compared with conventional open forklift pockets, which are often dark and may be difficult to see in some circumstances (e.g. if they are provided in a shipping container that has a dark colour and/or the shipping container is stacked on top of several other shipping containers). 
     In an alternative approach, instead of being provided with a target  50  the resilient flap  8  may be brightly coloured. For example, the resilient flap  8  may be orange (e.g. high visibility orange). 
       FIG. 8  shows an embodiment of the cover  4  in perspective view seen from the rear. The cover  4  generally corresponds with the cover shown in the preceding figures, but includes a deflection plate  60  which extends from the rear of the base  6 . The deflection plate  60  may for example be integrally formed with the base  6  (e.g. using injection moulding). The deflection plate  60  may be formed from steel or any other suitable metal. 
     The deflection plate  60  comprises a first substantially horizontal portion  62  which extends from the base  6 , a second portion  64  which slopes upwardly and away from the first portion  62 , and a third portion  66  which slopes downwardly and away from the second portion  64 . A distal end  68  of the deflection plate tapers downwardly to an edge. The configuration of the deflection plate  60  is such that the distal end  68  of the deflection plate  60  is adjacent to or in contact with the floor of a forklift pocket when the cover  4  is in situ. The deflection plate  60  may be configured such that the distal end  68  of the deflection plate presses against the floor of the forklift pocket when it is in situ. 
     In use, when a forklift tang travels towards the rear of the cover  4  and is in contact with or just above the floor of the forklift pocket, the deflection plate  60  deflects the forklift tang upwards before it reaches the flap  8 . The deflection is provided by the downwardly sloping third portion  66  of the deflection plate  60 , and in addition may be provided by the tapering end  68  of the deflection plate. The deflection plate  60  prevents the forklift tang from being incident upon the rear wall  24  of the base  6  or upon the clamping plate  42  (or associated bolts  44 ). Thus, damage which might be caused by the forklift tang is avoided. 
       FIG. 9  shows in perspective view, seen from underneath, part of an alternative base  80  which may be used instead of the base  6  shown in preceding figures. The base  80  is a solid block provided with openings configured to receive components. The base  80  may be formed from nylon 6-6 or any other suitable material (e.g. using injection moulding). It may be provided with a lubricant such as molybdenum. 
     The base  80  has the same general exterior shape as the base  6  shown in preceding figures. A through-bore  82  passes from a bottom surface  84  of the base  80  through to a sloping face (not visible) of the base. The through-bore  82  is stepped and is dimensioned to receive a bolt (not shown) which may be used to secure the base  80  to a forklift pocket. A rectangular opening  86  extends partway into the base  80  from the bottom surface  84  of the base. A blind bore  88  with a circular cross-section extends into the base  80  from a rear surface  90  of the base and intersects with the rectangular opening  86 . A hexagon-headed nut (not shown) is inserted into the rectangular opening  86  such that it is aligned with the blind bore  88 . This allows a bolt (not shown) to be inserted through the blind bore  88  and secured in the hexagon-headed nut (the nut is prevented from rotating by walls of the rectangular opening). The bolt may be used to fix a flap and clamping plate to the base  80  in a manner which corresponds with that shown in  FIG. 4 . A square-headed nut or other suitable bolt receiving means may be used instead of the hexagon-headed nut. 
     A channel  94  is provided in the base  80 . The channel allows fluid to flow out of the forklift pocket, for example during cleaning of a shipping container (in the manner described further above). 
     Although only one end of the base  80  is shown in  FIG. 9 , it will be appreciated that the features shown in  FIG. 9  repeat along the base in a manner which generally corresponds to that shown, for example, in  FIG. 5 . 
     An advantage of the base  80  shown in  FIG. 9  over the base  6  shown in the preceding figures is that it does not require a bar to receive and secure the bolts which clamp the flap and clamping plate to the base. Since the bar is a bespoke component it is relatively costly. The base  80  shown in  FIG. 9  uses standard hexagon-headed nuts (or other standard bolt receiving means) to perform the same function, thereby avoiding the requirement for a bespoke component and reducing the cost of the cover. 
     Embodiments of the invention may be retro-fitted to a shipping container by forming threaded bores in the floor of the forklift pocket  2  which receive bolts  36 . The bolts  36  secure the base to the floor of the forklift pocket  2  (see  FIG. 4 ). 
     Although a clamping plate  42  is used to fix the resilient flap  8  to the base  6 ,  80  in the illustrated embodiments, a clamping plate is not essential and the resilient flap may be secured to the base by any suitable securing means. 
       FIGS. 10-13  show an alternative embodiment of the cover  4 . The cover  4  provides the same general functionality as covers shown in the preceding Figures, but has a stronger construction and is thus more resilient to impact of forklift truck tangs. The cover  4  comprises a resilient flap  108  which extends upwardly from a base  106 . A deflection plate  160  extends from the rear of the base  106 . As shown in  FIG. 10 , the resilient bias of the resilient flap is such that it substantially closes a forklift pocket to which it is fitted. The base  106  extends either side of the resilient flap  108 . 
     The base  106  is formed as a single piece rather than an assembly of pieces. This is advantageous because it improves the strength of the base and thus its resistance to damage. The base  106  may be formed from steel, other metal or other suitable material. The steel may for example be wear-resistant steel. In order to reduce the weight and metal content (and thus cost) of the base  106 , cavities  107  are provided in the base. The cavities  107  are separated by ribs  109  which extend in a direction generally perpendicular to the resilient flap  108 . The ribs  109  increase the structural rigidity of the base  106  and improve its resistance to impact damage. Thus, the combination of cavities and ribs reduces the weight and expense of the base  106  without reducing the strength of the base below a level at which significant damage due to an impact might be expected. 
     The base is provided with a slot  111  which is configured to receive the resilient flap  108 . The slot  111  has an inverted T-shape in cross-section. The slot  111  has a closed end  113  and an open end  115  (see  FIG. 12 ). The resilient flap  108  is provided with a T-shaped foot which is received in the slot  111 . The interface between the T-shaped foot of the resilient flap  108  and the T-shaped slot  111  strongly secures the resilient flap to the base, thus preventing the flap from becoming detached from the base during use. The T-shaped arrangement provides increased engagement between the resilient flap  108  and the base  106  (compared with other illustrated embodiments) and thus reduces the risk of the resilient flap being separated from the base during use. In alternative arrangements the slot may have some other cross-sectional shape, with the foot of the resilient flap being provided with a corresponding shape. 
     During assembly of the cover  4 , the foot of the resilient flap  8  is pushed into the slot  111  through the open end  115 . The resilient flap  108  is pushed up against the closed end  113  of the slot  111  and is then glued into position. When the base  106  is located in a forklift pocket (as shown in  FIG. 10 ) the resilient flap  108  cannot slide sideways and out of the base because it is prevented from doing so by the walls of the forklift pocket. A small amount of movement of the resilient flap  108  along the slot  111  would be possible if the flap was not glued in place. This small amount of movement is undesirable because it could lead to the side of the resilient flap  108  which is at the open end  115  of the slot  111  coming into contact with a wall of the forklift pocket. This would inhibit movement of the resilient flap  108 . Gluing the resilient flap  108  in place in the slot  111  prevents this from happening. The closed end  113  of the slot  111  may provide a separation between the resilient flap  108  and the forklift pocket wall of, for example, around 5 mm when the resilient flap is pushed up against the closed end. 
     The width of the resilient flap  108  may be such that a corresponding gap is provided between the opposite side of the resilient flap and the forklift pocket wall when the resilient flap is in this position. 
     The deflection plate  160  may also be made from steel, which may be wear-resistant steel. The deflection plate  160  is glued into a recess  161  formed in a bottom surface of the base  106 . The recess  161  has dimensions which correspond with the dimensions of one end of the deflection plate  160 , as may be best seen in  FIG. 11 . The height of the recess  161  corresponds with the thickness of the deflection plate  160 . As a result, as may be best seen in  FIG. 10 , when the base  106  is in place on the floor of the forklift pocket there is no gap between the deflection plate  160  and the floor of the forklift pocket (in the region beneath the base). The deflection plate  160  has an apex  163  which is higher than the highest part of the base  106 . Thus, the deflection plate  160  will act to upwardly deflect a forklift truck tang passing from right to left in  FIG. 10  such that it does not impact upon the base  106 . A distal end of the deflection plate  160  is not glued to the floor of the forklift pocket but instead is free to move. This gives the deflection plate  160  some energy-absorbing resilience. 
     A sloping face  118  is provided on an outwardly facing side of the base  106 . As explained further above in connection with other embodiments, the sloping face will push a forklift tang upwards such that it slides into the forklift pocket. A further advantage of the sloping face  118  (and the sloping face of other embodiments) is that it prevents a worker from leaving an object on top of the base  106 , since the object will slide down the sloping face  118  and fall off the base. A sloping face  119  is also provided on an inwardly facing side of the base  106 . The height of this sloping face  119  is lower in order to provide space into which the resilient flap  108  can bend when it is pushed open by a forklift tang pushing on its outer face. The sloping inner face  119  of the base  106  thus provides some protection to the base  106 . In practice, the deflection plate  160  may be expected to deflect a forklift tang such that it is not incident upon the sloping inner face  119  of the base  106 . 
     Assembly and installation of the cover  4  shown in  FIGS. 10-13  may be as follows: the resilient flap  108  is inserted into the slot  111  and pushed up against the closed end  113  of the slot. The resilient flap  108  is then glued in place in the slot  111 . The deflection plate  160  is glued into the recess  161  in the base  106 . The base  106  and deflection plate  160  are then glued to the floor of a forklift pocket. The glue may for example be structural adhesive. An outermost edge of the base  106  is welded to the opening of the forklift pocket. The weld  121  provides a strong join between the base  106  and the forklift pocket which is resilient to impact of a forklift truck tang. Because the base  106  is glued to the forklift pocket floor, upward rotation of the base about the weld  121  which might otherwise occur during welding is prevented. The weld  121  may be a continuous weld or may be a series of spaced apart welds (this is commonly referred as a stitch weld). 
     The embodiment shown in  FIGS. 10-13  does not include channels corresponding to the channels  46 ,  94  provided in other embodiments. However, a gap between ends of the base  106  and walls of the forklift pocket may be sufficient to allow water and small pieces of debris to flow out of the forklift pocket (e.g. during cleaning). Alternatively, channels which correspond with the channels shown in other embodiments may be provided. 
     An advantage of the embodiment shown in  FIGS. 10-13  over other illustrated embodiments is that it does not include bolts or other relatively small fixings which could shear away during use and then subsequently pose a hazard to workers during movement of a shipping container. 
     Although in illustrated embodiments of the invention only one resilient flap extends from the base, two or more resilient flaps may extend from the base. The two or more resilient flaps may together substantially close the forklift pocket. For example, two resilient flaps may be provided side by side and arranged to substantially close the forklift pocket. 
     In an alternative embodiment (not illustrated) a base is provided on one side wall of the forklift pocket and a base is provided on the opposite side wall of the forklift pocket. A resilient flap extends from each base to the centre of the forklift pocket. This pair of resilient flaps closes the forklift pocket. This embodiment may include features described above in connection with other embodiments. More than two bases and associated resilient flaps may be provided. 
     Although the embodiment illustrated in  FIG. 1  is a dry goods shipping container, other embodiments of the invention may comprise other forms of shipping container (e.g. mud skip, waste transportation unit, container for transporting a chemical tank, drum basket, etc). 
     A shipping container may also be referred to as an offshore container. The DNV Standard for Certification No. 2.7-1 for Offshore Containers identifies at Guidance Note 2 the problem of loose items being retained in forklift pockets which could subsequently fall out during lifting operations. The Guidance Note suggests that openings should be provided in the bottom of forklift pockets to reduce this risk. However, as identified in the Guidance Note, such openings in the bottom of forklift pockets may be damaged by forklift trucks. The invention provides an alternative solution to the problem of falling objects whilst avoiding the disadvantages which arise from providing openings in the bottom of forklift pockets.