METHOD FOR LOADING PIECE GOODS, SUPPLIED ON PALLETS, INTO A HOLD, PARTICULARLY A HOLD OF A VESSEL

Abstract: In accordance with the method of the invention for loading piece goods (10), supplied on pallets (12), into a hold of a vessel, the interrelationship among the piece goods (10) is main­ tained until within the hold. The pallet (12) together with the piece goods (10) stacked thereupon is rotated 180° in a clamped state. Then the pallet (12) is removed and the piece goods (10) are transported in a reversed state to a desired location within the hold. The interrelationship among the piece goods (10) is maintained during all the operations. The transport of the piece goods load (11) into the hold can be carried out by means of a cage (24), a C-shaped hook (33) or slings (40).

Description: This invention relates to a method for loading piece goods, supplied on pallets into a hold, particularly a hold of a vessel, with the interrelationship among the piece goods being maintained until within the hold. In accordance with the invention by hold is to be undestood the hold of a transporting means such as vessel, freighter, train, truck etc., which hold is suited for receiving cargo. Hereafter this invention will be described in connection with the hold of a vessel. A known method for loading piece goods, supplied on pallets, into the hold of a vessel comprises removing the pallets stacked with piece goods, from a transporting means, such as a truck or train, by means of a forklift truck, which places the loaded pallets onto the dock. Thereupon dock-workers attach so-called pallet-rods to the pallet which in turn is hoisted on board the ship by a crane or the ship's gear. Then the palletized bags or cases are removed from the pallets and stacked in the hold one by one by workers manually. Finally, the empty pallets are returned to the dock. This known method, however, has the disadvantage of being very labour-intensive, since taking off and lifting the piece goods from the pallet, transporting them and subsequently putting them down and/or stacking said piece goods in the hold should be performed by hand. Therefore, the speed at which the hold is loaded depends to a high degree on the performance and endurance of the workers. A further disadvantage is, that this method requires an additional stacking of the piece goods in the hold, which, at a high filling rate of the hold, is difficult to accomplish. When taking off the piece goods of the pallet by hand, said goods may slide over the pallet. This sliding over the mostly wooden pallets could cause damages to the bags or cases. This damages may arise when nails, bolts or splinters protrude and when the wood-work is broken. By damaging the bags or cases, also the contents of said piece goods may be damaged or may get lost as a result of the damaged packaging. It is an object of the present invention to provide a method as described in the preamble, which efficiently removes these disadvantages. In accordance with the present invention this method is characterized in that the pallet together with the piece goods stacked thereupon is rotated 180° in a clamped state, whereafter said piece goods are transported in a re­ versed state to a desired location within the hold without breaking the interrelationship among them. The method according to the invention offers great advantages with respect to the prior art method. After ro­ tating the pallet with the piece goods stacked thereupon 180°, the pallet rests freely on the piece goods, so that the pallet can be simply removed from the piece goods. This simple operation enables the piece goods to be stowed in a desired location without further manual labour; the actual moving of the piece goods load is done mechanically. By em­ ploying the method according to the invention a higher pro­ ductivity per worker is obtained; the hold may be loaded quicker with less man-power being required, which results altogether in great savings for the stevedore, the ship-­ owner as well as for the buyer and seller of the piece goods. It is also very favourable, that all the time the interrelationship among the goods is maintained. Once the piece goods having been stacked well upon the pallet, this stacking albeit in a reversed state, can be maintained until within the hold, thereby avoiding the above-mentioned disad­ vantages of the known method. In a preferred embodiment of the method according to the invention, the pallet is taken off of the piece goods before the piece goods are transported into the hold. This advantageously prevents the pallets to be hoisted aboard together with the piece goods and subsequent­ ly the empty pallets to be hoisted back ashore. When a hold is loaded with sling bundled piece goods, ship-owners are willing to give a discount on the ship-load for ships having certain destinations, because the unloa­ ding at the place of destination proceeds in a much simpler and quicker way. In another preferred embodiment, prior to rotating the pallet with the piece goods stacked thereupon, slings are crossed over the piece goods load with the ends of said slings being attached to each other after said rotating and removing of the pallet. Thus packing the piece goods, without the pallet, together into a bundle by means of crossed straps or slings, thereby maintaining the shape of and interrelationship among the piece goods load, is of particular advantage, since in this manner it is no longer necessary to break the interrelationship among the piece goods by means of manual labour in order to bundle them. On the other hand, the conventional way is to spread out crosswise the slings on the dock, followed by stacking thereupon the piece goods from the pallet one by one, which involves the above-mentioned disadvantages. Hence it is of great economic advantage with respect to the conventional method, to prepare these bundles in the above-mentioned way and to transport them subsequently into the hold. In a particularly preferred embodiment of the present invention, the pallet loaded with piece goods is rotated in a rotating device having a top wall and a bottom wall, each being provided with inwardly opened grooves, which top and bottom wall are movable towards and apart from each other. By using a rotating device thus constructed the great advantage is obtained to engage a load of piece goods from below without subjecting the piece goods load to a sliding or stinging contact with relatively sharp projections of a lifting device. On the other hand, in order to lift piece goods supported by a smooth surface, a lifting device should be shoved underneath the piece goods load, which results in damaging the load, caused by the projections of the lifting device, considering also the great mass represented by the piece goods load and therefore the great mass resting on the undermost piece goods. In a particularly advantageous embodiment of the method according to the present invention, before transporting the piece goods into the hold, the piece goods are transferred into a hoistable loading means with the help of a lift-transport device equipped with forks fitting into the grooves of the top or bottom wall respectively of the rotating device. Using a hoistable loading means enables the loose piece goods load to be transported in a simple manner into the hold while maintaining the interrelationship among the piece goods. The forks of the lift-transport device, being adapted to the grooves of the top and bottom walls of the rotating device, can be shoved freely under the piece goods load, thereby preventing damaging of this load, which load then easily can be discharged into a loading means provided with corresponding grooves. In a further embodiment of the method according to the present invention, the lift-transport device equipped with forks is provided with a push off device. This embodiment is advantageous, especially when a loose piece goods load is to be discharged onto a support surface which is not provided with grooves corresponding to the forks of the lift-transport device. In a further advantageous embodiment of the method according to the invention, a cage is used as loading means, having a floor with a construction corresponding with the top and bottom walls of the rotating device. Transferring the piece goods load into a cage having such a floor construction brings on that the above described advantage, namely engaging the load from below, applies also within the hold of the vessel. In this connection a cage can be used having two compartments seperated by a partition, each compartment be­ ing suited for receiving one load of piece goods. This cage structure enables the simultaneous intro­ duction of two loads, each one load into each side of the cage. In this way, one hoist operation transports two loads into the hold, thereby speeding up the loading. In a very favourable embodiment of the method accor­ ding to the invention after hoisting the loaded cage into the hold, the piece goods are lifted out of the cage by a further lift-transport device, equipped with corresponding forks and a push off device, and subsequently being trans­ ported and discharged. Using such a lift-transport device within the hold has, apart from the advantages mentioned hereinbefore in connection with such device, also the favourable effect, that the hold can be filled very efficiently. Because of the maintained interrelationship among the piece goods such loads can be stacked very well up to the ceiling of the hold. Such filling cannot be obtained equally well with known methods, as with a high filling rate of the hold the working space for the workers is so small that heavy piece goods cannot be handled easily. The combination of such a lift-transport device and a cage provided with a grooved floor also enables sling bundled piece goods to be engaged from below within the hold. According to the known method one tries, on the one hand, to get the sling bundled piece goods on the desired location in the hold by means of a crane, which is not always succesful because of the struc­ ture of the ship's hatches, and on the other hand, to trans­ port these sling loads through the hold by inserting the forks of a forklift truck through a number of loops on top of the sling load, that is engaging the load from above. In order to engage a load from above a certain working space above the forks is required, which is not the case by enga­ ging from below resulting in the achievement of a higher stacking in the same hold when the cargo is engaged from below. Therefore a more efficient stowage of the hold is obtained. In another preferred embodiment of the method according to the present invention a C-shaped hook is used, equipped with a fixed base and a respective hydraulic push off device as well as with wheels, suited for receiving one load of piece goods. When the hold has been filled in such a way as to leave too little space to manoeuvre a lift-transport device, there exists a need for a combined loading and unloading means. This combined means preferably is the mentioned C-­ shaped hook, which requires no separate unloading device and only very little working space. In another embodiment of the method according to the invention a forklift truck is used as lift-transport device, the forks of which being movable in a horizontal plane sub­ stantially perpendicular to the push off or discharge direction of the piece goods. In this way the advantage is obtained that, in cases the forklift truck cannot be manoeuvred right in front of the discharge location of the piece goods load, this load still can be discharged at the right location by a lateral movement of the forks of the forklift truck. In a very preferred embodiment of the present inven­ tion the above described method can be simplified by rota­ ting the pallet, stacked with piece goods, in the rotating device which is mounted on a lift-transport device, the top wall and bottom wall of said rotating device each consisting of a set of forks which are movable towards and apart from each other. In this way, the pallet, with the piece goods stacked thereupon, is lifted by one set of forks of the lift-trans­ port device, whereafter both sets of forks are moved towards each other, thereby clamping the load, followed by rotating the load. Meanwhile the lift-transport device can be driven towards a loading means. The rotation being completed, the two sets of forks are moved apart, so that the pallet comes to hang on the uppermost set of forks, whereafter said pal­ let can be removed. Before or after removing this pallet, the load of piece goods can be discharged into the loading means. This discharge operation is carried out by lowering the undermost set of forks into the grooves of the loading means and subsequently withdrawing them thereout, and/or by using a push off device installed on the lift-transport de­ vice. The loaded loading means is then hoisted into the hold in the manner described hereinbefore. In a last aspect of the method according to this invention, in all operations of this method the piece goods are supported by and/or slided over smooth surfaces. By this measure the rise of damaging the packaging of the piece goods is remarkably reduced. Hereafter the invention will be elucidated with reference to the accompanying drawings showing three embodiments of the method according to the invention by way of example. Fig. 1 is a schematic illustration of the different steps of a first embodiment of the method according to the invention; Fig. 2 is a schematic representation of a number of steps of a second embodiment of the method according to the invention; and Fig. 3 is a schematic representation of two stadia of a third embodiment of the method according to the invention. With reference to fig. 1 a method for loading a ship's hold is showed, by which piece goods, supplied on pallets, are loaded into a ship's hold. Products usually transported in bags are for instance potatoes, sugar, fertilizer, cereals, milk powder, flour, rice, onions etc., the bags usually consisting of jute or synthetic material. Instead of bags, of course, also cartons, bales or cases etc. may be used, the packaged products mostly being tins or cans and frozen products such as butter, meat, fish, chicken etc. Fig. 1a shows a pallet 12 positioned on a loading platform or dock or in a transporting means and loaded with piece goods 10, the piece goods 10 together forming the piece goods load 11, in the openings 13 of which pallet 12 are inserted two forks 14 of a forklift truck not shown. With the aid of forks 14 the pallet 12 together with the piece goods load 11 is lifted and then positioned into a rotating device 15, after which the forks 14 are withdrawn out of openings 13 of pallet 12. The situation thus obtained is shown in fig. 1b. The rotating device 15 is equipped with a bottom wall 16, supporting pallet 12 together with the piece goods load 11, a top wall 17, a side wall 18 and a not-shown back wall. The bottom wall 16 and top wall 17 each are provided with inwardly open grooves 19, 20 respectively. Rotating device 15 is mounted in a frame work 21 and supplied with the necessary energy by a generator (not shown). The rota­ ting device also can be mounted on a lift-transport device as described hereinbefore. In fig. 1b bottom wall 16 and top wall 17 have been moved towards each other over such a dis­ tance as to clamp pallet 12 with the piece goods load 11 resting thereupon. Both walls are moved towards each other simultaneously and uniformly. The force with which both walls clamp together the load is adjustable and may vary in dependence of the load. A side wall only then is re­ quired, when the top 17 and bottom wall 16 cannot be pres­ sed together enough to hold the pallet and piece goods in a clamping engagement, because this pressing might damage the cargo. Then a side wall 18 is used to prevent the load from slipping away. Then the rotating device 15 is rotated 180° in a substantially vertical plane, the fixed metal side wall 18 of rotating device 15 supporting the load during rotation, preventing it from slipping away, while functioning again as side wall 18 after the rotation. The rotation being comple­ ted, top wall 17 is found to be below bottom wall 16. Next top wall 17 and bottom wall 16 are moved apart, pallet 12 thereby resting freely upon piece goods load 11. The thus reversed piece goods load 11 resting freely upon top wall 17 has the same interrelationship among piece goods 10 as when stacked upon pallet 12. After rotating and removing the piece goods load 11 and pallet 12, top wall 17 may serve as bottom wall 16 during the introduction of a further piece goods load 11, and vice versa. Referring to fig. 1c forks 22 of a forklift truck (not shown) are inserted into the grooves 20 of top wall 17 below the piece goods load 11. Piece goods load 11 then is lifted and removed out of rotating device 15, after which pallet 12 may be taken off of the piece goods load 11 (not shown). Taking off the pallet 12 may for instance be done by hand or by means of a forklift truck. Piece goods load 11 is moved by forks 22 of the forklift truck (not shown) into a cage 24 comprising two compartments 26, 27 respectively se­ parated by a partition 25. The bottom 28 of cage 24 is pro­ vided with grooves 29 matching the grooves 19 and 20 of the rotating device 15. With reference to fig. 1d the piece goods load 11 is placed into compartment 26 against the partition 25 of the cage 24, forks 22 being moved downwards in the grooves 29, and subsequently being taken out of the grooves 29 by driving the not-shown forklift truck backwards from the cage 24. The cage 24 is constructed in such a way as to receive two piece goods loads 11 simultaneously in compartments 26 and 27 from both sides. The number of forks 22 of the not-­ shown forklift truck, as well as the number of grooves 19, 20 and 29 respectively of bottom wall 16 and top wall 17 of the rotating device 15 and the floor 28 of the cage 24 res­ pectively may be varied in dependence of the sort of cargo. This number is preferably nine. In the case of for instance bagged potatoes, the total mass in such a double cage 24 may amount to about 3600 kg (2 × 36 bags of 50 kg each). It may also be desirable to use a single cage, for receiving one load of piece goods. This is desired, especially when the hold and/or the ship's hatches are relatively small, and also when light cranes are used, such as the ship's gear, which are not able to hoist a double load. Then the loaded cage 24 is attached to a hoisting device (not shown) via fastening points 30 of the cage 24 and hoisted into the ship's hold (not shown). Hoisting de­ vices include for example dock cranes, mobile cranes or the ship's gear, the latter not always being equipped for hoisting such a heavy load. In the hold the cage 24 is emptied in the way described before by means of a further forklift truck (not shown) equipped with corresponding forks 22 and a push off device 23. After detaching the loaded cage 24 a second cage (not shown), meanwhile emptied, is hoisted out of the hold. The piece goods load 11 resting on the forks 22 of the forklift truck, the interrelationship of which being the same as in the palletized state, is trans­ ported to a desired location within the hold, where it is unloaded. This situation is illustrated in fig. 1e. The un­ loading of the piece goods load 11 in the hold takes place by bringing the forks 22 of the not-shown forklift truck above the desired location 32 and subsequently lowering the forks 22 until they come to rest upon the location 32. While the not-shown forklift truck then is being driven backwards, thereby withdrawing the forks 22 from under the piece goods load 11, the push off device 23 is simultaneous­ ly moved forwards with a velocity corresponding to that of the truck in such a way as to maintain the piece goods load 11 at the desired location 32. The device 31, to which the forks 22 and the push off device 23 are connected, being movable in a horizontal plane substantially perpendicular to the direction in which the piece goods load 11 is being pushed off, enables the piece goods load 11 to be stacked upon the desired location 32 without further operations such as moving the forklift truck itself. In the second embodiment of the method according to the invention the pallet 12 stacked with piece goods 10 is subjected to the same series of operations as described above in connection with fig. 1a - 1c. However, instead of using a cage 24 as loading means, in the present embodiment a C-shaped hook 33, equipped with a fixed base 34 and a res­ pective hydraulic push off device 35 as well as with wheels 36 and a lever 37, is used. The rotated piece goods load 11, without pallet 12, is positioned, in the way mentioned be­ fore, onto the metal base 34 of the C-shaped hook 33 with the help of a not-shown forklift truck equipped with forks 22 and push off device 23. The push off plate 38 of the hy­ draulic push off device 35 is pushed back to its starting position by placing the piece goods load 11 onto the metal base 34. Referring to fig. 2a the C-shaped hook 33, via lever 37, is hoisted into the hold by a crane, thereby moving lever 37 upwards from its starting position, indicated at 39, thus building up a hydraulic pressure in the push off device 35 via the lever mechanism, so that a pressure is created suf­ ficient for pushing off the piece goods load 11 of the metal base 34. This latter operation is carried out when the C-­ shaped hook 33 has been positioned onto the desired location within the hold, where the push off device 35 pushes, so to speak the C-shaped hook 33 away from under the piece goods load 11. This is illustrated in fig. 2b. This preferred method especially can be applied, when the space in the hold is insufficient or not suited any more to manoeuvre a forklift truck. In this case, the des­ cribed C-shaped hook 33 offers the advantage of not requi­ ring a separate device in order to take off the load of the C-shaped hook 33 and put it down again at a desired location in the hold. With reference to fig. 3 some aspects of a third embodiment of the method according to the invention are shown. The piece goods load 11 can be bundled by means of crossed slings or straps 40. For that purpose, see fig. 3a, slings 40 are crossed over the pallet 12 stacked with piece goods 10, prior to the rotation as described with respect to fig. 1b and 1c. After the rotation the pallet 12 is removed and the ends 41 of the cross slings 40 are tied together to form a bundle or sling-load 42. Thereupon this sling-load 42 may be transferred into the hold by applying the prefer­ red methods described hereinbefore. It is also possible to hoist the piece goods bundle 42 directly into the hold onto the desired location without using a loading means. This is shown in fig. 3b, where the sling-load 42 is attached to hook 44 of a crane (not shown) by means of a hoisting bridle 43. The method for loading the sling-load 42 into the hold by the preferred methods, schematically illustrated in fig. 1 and 2, is mostly applied when ship-owners give a discount on bundled cargo's; whereas the method for loading the bundles 42 directly into the hold then is applied, when the hold is filled with cargo in such manner, that even a hy­ draulic C-shaped hook 33 does not have enough space to work in. The remaining unloaded space in the hold can then be filled with bundled piece goods 42, being hoisted into the hold by a crane. It will be understood by those skilled in the art that the method of the invention may be modified and varia­ ted in many ways without departing from the spirit and the scope of the invention. As described hereinbefore, the pre­ sent method may be applied to other transporting means than vessels, for instance freighters, trains, trucks etc. By means of illustration of the particularly great advantages of the present invention the following example is given. When loading bagged cargo, such as potatoes, into a ship's hold, a shift of 15 workers can stowe in 8 hours ap­ proximately 225 tons according to the known method. On the other hand, a shift of 8-10 workers can stowe in 8 hours approximately 650-800 tons according to the method of the present invention.

Claims: 1. Method for loading piece goods, supplied on pal­ lets, into a hold, particularly a hold of a vessel, with the interrelationship among the piece goods being maintained until within the hold, characterized in that the pallet (12) together with the piece goods (10) stacked thereupon is ro­ tated 180° in a clamped state, whereafter said piece goods (10) are transported in a reversed state to a desired loca­ tion within the hold without breaking the interrelationship among them. 2. Method according to claim 1, characterized in that the pallet (12) is taken off of the piece goods (10) before the piece goods (10) are transported into the hold. 3. Method according to claim 2, characterized in that, prior to rotating the pallet (12) with the piece goods (10) stacked thereupon, slings (40) are crossed over the load (11) of piece goods (10), with the ends (41) of said sling (40) being attached to each other after said rotating and removing of the pallet (12). 4. Method according to any of the claims 1 - 3, characterized in that the pallet (12) stacked with piece goods (10) is rotated in a rotating device (15) having a top wall (17) and bottom wall (16), each being provided with inwardly opened grooves (20 and 19 respectively), which top (17) and bottom wall (16) are movable towards and apart from each other. 5. Method according to claim 4, characterized in that the pallet (12), stacked with piece goods (10), is ro­ tated in the rotating device (15), which is mounted on a lift-transport device equipped with a push off device (23), the top wall (17) and bottom wall (16) of the rotating de­ vice (15) each consisting of a set of forks which are movable towards and apart from each other. 6. Method according to claims 4 and 5, characterized in that before transporting the piece goods (10) into the hold, the piece goods (10) are transferred into a hoistable loading means with the help of a lift-transport device equipped with a push off device (23) and with forks (22), fitting into the grooves (20 or 19 respectively) of the top (17) or bottom wall (16) respectively of the rotating device (15), the forks (22) being movable in a horizontal plane substantially perpendicular to the push off or discharge direction of the piece goods (10). 7. Method according to claim 6, characterized in that as a loading means, a cage (24) is used having a floor (28) with a structure corresponding with the top (17) and bottom walls (16) of the rotating device (15), which cage (24) loaded with piece goods (10) is hoisted into the hold, where the piece goods (10) are lifted out of the cage (24) by a further lift-transport device and subsequently transported and discharged. 8. Method according to claim 7, characterized in that a cage (24) is used having two compartments (26 and 27) separated by a partition (25), each compartment (26 or 27 respectively) being suited for receiving one load (11) of piece goods (10). 9. Method according to claim 6, characterized in that as a loading means, a C-shaped hook (33) is used, equipped with a fixed base (34) and a respective hydraulic push off device (35) as well as with wheels (36), suited for re­ ceiving one load (11) of piece goods (10), which C-shaped hook (33) loaded wth piece goods (10) is hoisted into the hold, where the piece goods (10) are pushed off of the base (34) by the respective push off device (35). 10. Method according to any of the claims 1 - 9, characterized in that in all operations of this method the piece goods (10) are supported by and/or slided over smooth surfaces.

Inventors: SNOEIJERS, JACOBUS MARIA
Applicants: FINOPORT STEVEDORING B.V.
Application year: 1986
Main classification: B65G1
IPC codes: B65G1