In the field of shipping containers, containers are locked to the deck of a ship or other containers in a vertical stack or to rail wagons or road trailers through their corner fittings using inter box connectors (IBCs) also known as twistlocks. These IBCs are of the semi-automatic twistlock form (SATs), fully automatic twistlock form (‘FATs’) and other forms including locator cones. Examples of FATs are shown in DE102012201797 and US 20150203287. These FATs have a head to lock into the sockets in the underside of lower corner fittings of the container and when the containers are being lifted they have a hook shaped tail which project downwards out of the fittings to engage with a socket in the top side of a container corner fitting. The IBCs are not part of the container equipment often having different owners, so it is more or less the rule that the IBCs are removed from the containers before they are moved on.
To remove the IBCs men conventionally step forward under the handling machine or crane and remove them by hand. Whilst complex sorting, fitting and removing twistlocking machines have been devised these are slow, expensive and unreliable with the process still requiring manual intervention. The machines are purpose built mostly needing a power source and not easily adapted to the varying locations and layouts of many existing ports. They must be placed under the ship to shore crane and thus take up the valuable quayside space further delaying the speed of processing containers. The variety of IBC designs also leads to complications and requires complex changes to machinery when different IBC designs are used. Time is of the essence in processing the container ships and the time taken to have the IBCs removed or fitted is critical to speedy efficient operations, regardless of safety issues. The known twistlocking machines have been designed to work with one container at a time and because the cycle time of the ship to shore crane is typically more than 90 seconds, the cycle time for the machine can be relaxed. However more and more cranes are now able to lift two or more containers at a time and this means that faster twistlocking machines are needed.
Known twistlocking machines are made as large single assemblies and are not easily adapted for variations in IBC designs, lengths of containers and are bulky to ship to their port of use and to move around at the port. Such known machines being heavily mechanised and of sophisticated operation, reliability is a concern and spare machines may be needed in case of break down that might delay the ship. In short they lack versatility. Examples of such known machines can be found in, for example, U.S. Pat. No. 8,562,265 and WO2011/096877.
25% of all containers around the world are moved empty. Some ports handle as many as 70% of empty containers. If empty containers were lifted in vertical tandem lift (VTL) whereby one container is stacked on top of another, connected to it via four inter box connectors of the SAT type, and the pair of containers lifted together as one with a lifting crane spreader connected only to the top of the upper container the advantage of this manoeuvre would be that a container ship could be loaded with empty containers twice as fast than if it were being loaded with containers one at a time.
VTL is allowed by regulation but this is being held back by concerns about the lifting strength of the upper container being able to lift the lower container through the bottom corner fittings of the upper container because containers in themselves were not designed specifically to be lifting devices. Containers are tested and certified to loads well in excess of the lifting load needed for VTL and experience loads well in excess of the lifting load needed when secured on board ship particularly when the ship is rolling and heaving in heavy seas.
Although containers are tested and certified to obtain design and structural type approval, they are not individually tested regularly as a crane or lifting device might be. A crane spreader would be tested to simulate 1.25 g acceleration every 2 years to certify its strength. Containers and IBCs are inspected visually and regularly but not proof tested as is a crane. Time taken for any task is always a problem for busy ports so it would be an advantage if the proof testing could be carried out very quickly immediately prior to shipping.
The present invention thus provides a method of testing a shipping container for use as an upper container in a vertical tandem lift configuration the method comprising supporting the container other than by the lower corner fittings, connecting couplers in the lower corner fittings of the container to be tested and then applying a proof load on the couplers to confirm that the container and/or the couplers can sustain the forces which will be experienced during use in a vertical tandem lift.
This proof testing of the container and couplers can be carried out rapidly within the supply chain of containers immediately before use to confirm that the container can be used in a vertical tandem lift configuration. Evidence that the containers and IBCs have been proof tested correctly is essential if all those in the supply chain from Nigeria to USA, Vladivostok to Rio are to have confidence in the system. The method of testing of the present invention provides this certainty that a pair of containers can be lifted in VTL connected by their IBCs.
In the above method the couplers in the lower corner fittings of the container may be inserted into respective corner units of a test rig, the rig and container being moved relative to each other to generate the proof load.
The rig and container may be moved relative to each other by lifting the container away from the test rig.
The rig and container may be moved relative to each other by applying mechanical/hydraulic force between the rig and the container. Alternatively, the rig may be moved relative to the container by loading the rig with a test force sufficient to apply the proof load and then lifting the container via its upper corner fittings.
The test force may be off set from the couplers to apply additional leveraged load on the couplers more than the value of the test force. The test force may be applied as a dead weight.
The rig may be held down and load cells fixed to a machine for lifting the container to measure the force on the couplers and lower fittings.
As part of the method, data regarding the test is recorded and stored for future reference and proof of the fitness of the container for use in a vertical tandem lift.
The recorded test data may include one or more of the following parameters namely date of the test, container number and its known statistics, test load, inspector identification, container and coupler condition and approval, the data so collected forming formal verification that the proof test and inspection has been carried out correctly.
The invention also provides a rig for carrying out the method of testing described above and/or for connecting or disconnecting couplers to or from the lower corner fittings of a shipping container, the rig comprising two pairs of corner units, the corner units of each respective pair being held in the required transverse spacial relationship with the lower corner fittings at each respective end of the container, the two pairs of corner units also being held in the required longitudinal spacial relationship relative to the corner fittings of the container so that all the corner fittings of the container can be worked on simultaneously. Each corner unit also preferably has an indexing means for rotating tail portions of any couplers inserted into the units.
The corner of each pair may be held in the required transverse spacial relationship with the lower corner fittings at each respective end of the container by a structure extending between the units of each pair to form separate end modules.
The rig may have a box for containing the dead weight sufficient to apply the proof load or for storing couplers or housing a prime mover of the rig is supported from the structure which extends between the two corner units or comprises the structure itself.
The two pairs of corner units may be to a common base member in the required longitudinal spacial relationship. This common base member may be a trailer having sockets and/or connectors built into its frame to secure the corner units in the required spacial relationship.
Alternatively, the two pairs of corner units may be held in the required longitudinal relationship by side rails which extend longitudinally between the pairs of corner units. These side rails or trailer arrangement may allow different longitudinal spacing of the two pairs of corner units to cater for containers of different lengths.
The rig may include more than one pair of corner units at each end of the rig, different pairs of corner units being used for different types of coupler or for carrying out different operations on couplers placed in the corner units.
The corner units of the rig may be positioned to accommodate containers of different lengths.
The rig may also be transportable to its port of use in sections for assembly at the port.
The invention further provides a corner unit for use in a rig as described above in which indexing means is provided for holding a semi-automatic twistlock (SAT) coupler inserted into the unit in at least one of its three positions namely head locked/tail locked, head locked/tail unlocked, and head unlocked/tail locked, the indexing means being manually moveable between these positions to allow proof testing of the container and/or coupler and/or also to allow connection or disconnection of couplers to or from the lower corner fittings of the container.
There is also provided a corner unit for use in a rig as described above in which bias means biases a lever against a stop to hold the tail of any coupler in the unit in an unlocked position with its head in a locked position, as the container is lowered onto the corner unit a plunger moves the stop to allow the bias means to rotate the indexing means to unlock the coupler from the overhead container and lock the coupler to the unit to allow the container to be lifted without the coupler.
In the above corner unit the indexing means can be rotated away from the stop initially against the bias means until the bias means goes over centre and begins to assist the further rotation of the indexing means away from the stop to lock the coupler to the unit and to the container to allow proof testing. The plunger can be deactivated to prevent locking of the coupler to the unit so that the container can be raised with the coupler attached to its lower corner fitting.
In a further form of corner unit for semi-automatic twistlocks (SATs) when a coupler is lowered into the unit on a container an actuating member of the SAT, which when pulled rotates its head and tail against internal torsional springing, engages an abutment on an end of a pivoted lever, the lever is arranged to be moved against bias means by a plunger which is moved by the tail of the coupler as it enters the unit, the plunger contacts the lever to move the lever against the bias means and thus pull the actuating member to rotate the head and tail of the coupler to the head unlocked/tail locked position allowing the container to be raised without the coupler.
In the above corner unit further movement of the plunger can be arranged to disengaged the cam means to allow the lever to be moved back by the bias so that the actuating member goes slack and the coupler rotates to its head locked/tail locked position thus locking the container to the unit.
In a corner unit for a fully automatic twistlock (FAT) and for use in a rig as described above an indexer is arranged to receive a FAT placed into the unit and bias means biases a lever against a stop to hold the head of the FAT in an unlocked position, as a container is lowered onto the corner unit a plunger moves the stop to allow the bias means to rotate the indexing means to lock the head of the FAT to the lowered container and to allow the container to be lifted with the coupler.
In such an arrangement the bias means can be reversed so that when a container with a FAT is lowered onto the unit, the indexer holds the FAT in the head locked position, as the container is lowered the plunger moves the stop to allow the bias to rotate the indexer to the head open position to allow the container to be lifted away without the coupler.
In an alternative corner unit arrangement for use in the above described rigs the indexing means may comprises one or more resiliently biased elements located under the top plate which when the tail of a SAT passes through the thickness of the top plate press on the sides of the tail and rotate the tail against its internal torsional springing to engage the tail under the top plate and put the head in the release position to allow the container to be lifted away without the coupler.
The invention also provides a corner unit for use in the above described rigs in which the unit is arranged to receive and support a SAT placed into the unit in a position where its toggle wire is accessible to an operator to allow the operator to move the SAT to all three of its positions namely head locked/tail locked, head locked/tail unlocked, and head unlocked/tail locked by use of the toggle wire.
Some of the above rig and corner unit arrangements can be used to both proof test the container and coupler and also connect and disconnect couplers from containers. Also the rig constructions described above are particularly economical to transport to their port of use as they can transported as pairs of corner units connected by their associated interconnecting structure or can be broken down further to their individual corner units with their separate associated interconnecting structure allowing several test rigs to be transported in a single shipping container.
The corner units described are also suitable for fitting and removing most types of SATs and FATs and should special features in the operation or shape of the SAT or FAT need to be accommodated the moving parts of the for corner units can quickly be exchanged for tailored mating parts.
The corner units can also be set up to use a plunger activated by movement of the container to trigger the corner unit to discharge the SATs and FATs into storage areas.
The present invention will now be described, by way of example, with reference to the accompanying drawings in which:
Referring to the drawings in
In
The positions 2A, 2B, 2C correlate to the diagrammatic section seen in
SATs have 3 modes of operation facilitated by rotation about the vertical axis 61 of its head and tail. At the free end of the wire rope 36 is a toggle 35 to allow the operator to pull the wire with his hand. To hold the rotation against the spring 64, there is a ferrule 63 fixed at an intermediate position along the wire which can be engaged with one or more catches holding the head and tail in one of 3 positions 2A, 2B and 2C. In this example it is assumed that the torsion spring is biased in a way to drive the head, shaft and tail assembly in a clockwise direction seen from above. When the toggle wire is pulled out from the body of the SAT the toggle can be pulled out and down to engage the ferrule 63 with a catch 66 or pulled further out and up to catch 65 above it. The degree of rotation varies from one SAT to another. The full rotation of a head and tail is normally within 90 to 110 degrees (say ¼ turn) carried out in two stages of about an ⅛ turn (about 45 degrees) each. The angle of relative orientation of the head and tail seen from above in plan view is about 110 degrees typically. The 3 positions are summarised as
When the head and tail are rotated to position 2A driven by spring 64 part of the lock 58 comprising head 24, tail 25 and shaft 60 encounter a stop such as stop 57 which in this example prevent the head from rotating any further and thus keep the head and tail in the important locked position. Likewise when the head and tail are rotated against the spring to position 2C they contact a stop 57 to prevent the head from over rotating out of profile of the aperture through which the head must pass retained thereby the catch 65 and ferrule 63 as described earlier. Stops 57 are known to be located inside or outside the SAT assembly.
Some dimensions of the SATs and related twistlocks are defined by ISO 1161 standards and can be 55.5 mm wide entering into equally defined apertures of width 65 mm spaced apart by a dimension that can vary another 3 mm. The theoretical positional variation of a SAT in an apertures can vary 13 mm but in reality damage, wear and tear and errors in manufacture only serve to increase these figures. The shape of the tails can vary considerably from one IBC or SAT to another and so too the angle of rotation up to the stops 57 can vary. Thus to engage and rotate the tail fully in any direction until the stops 57 are engaged requires acceptance of the variations in geometry and position of the SATs.
Speed is an essential part of port operations and so any mechanism or device than needs energising during container handling and needs time to be energised can cause an unwelcome delay to the processing of the containers. Any sophisticated mechanism is prone to breakdown. So to be certain that a container 10 is the one that is safe to lift another container 20, it needs to be proof tested and reliably so immediately prior to being lifted onto a ship.
In
The handles 23, 23′ of corner units 6, 6′ (examples of which are described below with reference to, for example,
Container 10 is shown being lifted up by the spreader 19. In this embodiment, the rig is weighted with, for example, water tanks or concrete blocks carried in a weight box (not shown) supported from beam 70 of each module 133 to provide a deadweight equal to the lifting proof load required on container 10. This if the proof load be 5 tonnes per fitting 15, then a dead weight of 4×5=20 tonnes gross would be provided for the rig 1. Since the load cannot be exceeded, the container cannot be overloaded and all that is required for the test is that the lifting machine 40 has the capacity to lift such a load. No hydraulics, electronics or other sophistications are needed if a dead weight is used and the simple manually operated corner unit shown in
An operating system for use with straddle carriers 40 might have rig 1 of
The proof test on the container need only be as described perhaps 5 tonnes per corner. However the SAT to be used might be required to be proof tested to a higher load. A SAT can have a typical working load of 25 tonnes. But to lift each corner to provide such a load would exceed the lift capability of a lifting machine and the top container itself. So in
In
Other methods of testing are envisaged such as applying vertical downward tensile loads through the bottom fittings 15 of a restrained or supported container 10. The loads can be applied by gravity, hydraulic rams, jacks, and so on and the loads verified by instrumentation in the twistlocks of the lifting spreader or hydraulics or whatever is suitable and known. The method of testing is envisaged to be carried out by this or any other way to prove the container as a lifting device and/or the SATs to go with it.
It will be appreciated that the proof testing is applicable primarily to the top container 10 to be used as the lifting element, and the SATs that are fitted to its four bottom fittings 15. So immediately once proof tested, a recording system and then simultaneously or soon after a data base is created to store the data. It is envisaged that a handheld computer or smart phone be used as a data input device with internet connection to a data server which can be accessed by authorised companies and personnel. The data relating to the container 10 and SATs 18 proof tested is generated including at least some of the following date of test, container number and its known statistics, test load, inspector identification, container and coupler condition and approval. The data so collected and approved by the inspector then forms or generates a formal certificate verifying that the proof test and inspection has been carried out correctly.
Most important is that the receiving port in the far away destination can then check the certificate generated to verify that the two coupled containers 10, 20 can be safely lifted off the ship in vertical tandem lift by the top container 10 through its SATs. Thus the system of proof testing prior to shipping, coupling two containers one on another in VTL, shipping, and discharging of the containers in a safe and efficient manner in VTL has been achieved, and immediately so prior to its shipping.
With the tail 25 in the unlocked position, and the head 24 locked inside the fitting 15, the container 10 can now be lifted up and away from the rig 1, as shown in
However, when it is required that the SAT is locked to the bottom fitting 15 and plate 26 as described earlier for proof testing, the handle 23 of the indexer 11 is released from the retainer 34 and rotated to position 23″ shown in
In a return trip when a container 10 or 20 is to have its SATs 18 removed before transporting it on road and rail which might require no SATs to travel with it, the SATs can be removed manually using the same corner units 6, 6′ and indexers as seen in
It is envisaged that operation of the handle and removal and fitting of the SATs onto the stub post can be done by robot with the SAT bins being fitted out with racks to orientate the SATs for the robot to pick up and/or store in an orderly manner rather than randomly. The purpose of the handles 23 as illustrated is to provide levers for rotation as described. However it is envisaged that the handles could be located within the body of the corner unit 6 or module 133 and provide levers driven remotely in simple terms by a linkage such as bar 142 and pole 166 or by a prime mover, for example electro-hydraulic motor and actuator, acting on a linkage to a handle/lever in the form of a spigot, gear drive and/or torsion spring as described later, or other mechanical rotator. Similarly the operation of handles/levers 23 described below could also be by a prime mover rather than manual operation.
In an alternative form of corner unit seen in
Further lowering of the container and SAT is seen in
In
In
In
Once the container and the SAT are removed the corner unit 6 can be set to automatically pick up SATs set upon it by lowering a container 10 without manual or mechanical intervention. To set the post 6 the catch assembly 73 is pushed downwards to rotate about pivot 74 until free of the bottom of the plunger 72. The bridge 77 is then flipped over about 180 degrees to reveal the slot 76. The catch assembly is then allowed to rise up driven by spring 75 and thus holding handle 23 against the action of spring 79, and the plunger drops down through the slot 76 by passing the catch assembly and avoiding contact with tail 25 of an SAT. A SAT can now be placed within the plate 26 without triggering the catch 84 thus keeping the handle and head and tail of the SAT steady and ready to be picked up by the lowering of a container down onto it and lifted off. The guide 85 supports and prevents the ferule 63 getting trapped by catch 66 or 65 which would otherwise prevent the lock 58 rotating to position 2A.
If no bridge 77 is included in the embodiment, then the plunger 72 can be removed such as by lifting it out through the top socket 21 so that the tail 25 of a SAT does not activate the catch 84 and thus the indexer remains in position 2B held by the catch and the handle 23.
In
In
The position of the indexer 44 with socket 164 is such that head 91 of the FAT 90 is aligned with the socket 17 in the fitting 15 so that as the container 10 is lowered the head enters the socket 17. There is provided a torsion spring 158 wrapped around the shaft 30 and which in this position biases the bracket 71 with indexer and handle 23′ to rotate counter clockwise, prevented in doing so by the handle 23′ bearing on catch 84 being part of catch assembly 73 mounted and operated as described earlier. The spring 158 is fixed to the bracket 71 at one end and a gear box comprising gear 163 and 162 driven by handle 161 fixed by conventional means not shown here to the structure 70 of corner unit 6 at the other.
In
In
In
As the base 160 makes contact with top 159 the tail 94 enters the socket 164 and plunger 72 is driven down to release catch 84 allowing the handle 23, shaft 30 and indexer 44 to rotate clockwise rotating the FAT 90 clockwise and aligning its head 91 with the socket 17 in the fitting 15. The back 157 of the FAT is driven around to make contact with or come close to stop 156. Container 10 can now be lifted away from the corner unit without the FAT. Friction and jamming of the FAT in the socket 17 might tend to lift the FAT 90 up with the container 10 so to hold the FAT down within the corner unit 6, hook 95 is held within the socket 164 by the location of stop 156 sufficient to prevent the hook sliding out from within the socket yet enabling the FAT 90 to tilt and move to free itself from contact with socket 17 urged on by the direction and support of spring 165.
In
In operation to lock SATs 18 to the post 6 as might be needed when receiving a container with SATs off a ship and needing to lock the container to a trailer or frame automatically for safe transport, the container is lowered towards the post. The tail 25 of the SAT enters the socket 21 and the projecting toggle 35 and wire 62 is guided into the clevis 124. As the lowering continues the toggle and/or wire come to rest on the guide 85 urging the wire and/or toggle upwards drawing the ferrule 63 out of engagement with catch 66. The tail 25 encounters the plunger 125 as seen in
Should it be so required to use the corner unit for removing SATs from containers, the cam 127 can be extended by an extension 130 preferably with a detent recess to hold the follower from slipping and so that the indexer remains held in the outward position and thus the SAT in position 2C where the head 24 of the SAT is in the open position thus enabling the container to be lifted off the SAT leaving it locked to the post 6.
The indexer 120 can be fitted with a foot or hand pedal cantilevered out from the outer face to assist or carry out manual movement of the lever to pull the toggle 35.
To accommodate geometric variations in toggle positions, wire lengths, ferrule positions the indexer may need to be deflected not to geometric needs but by a pre-defined force greater than the highest manual hand force it has been designed for typically 15 kg to 30 kg. So the indexer, cam, extensions and plunger can all be made flexible and/or adjustable or the indexer might be driven by hydraulic or pneumatic rams applying a force limit to the indexer located in place of the spring 123 triggered by an electrical switch detecting plunger displacement.
In an alternative construction (not shown) the indexer 120 and the spring 123 could be incorporated into a single curved shaped spring steel strip with a clevis 124 at one end and which is secured to the unit 6 at its other end. In this arrangement the plunger 125 would act on the inside of the spring strip to bend the strip and thus pull on the toggle 35 to operate the SAT as described above.
It is known that other IBCs have been devised which operate with a toggle 35 and wire 62 (see, for example, the IBC described in the Applicant's own UK patent application No. 1903392.7) and it is envisaged that the toggle operating device described above would be adapted to operate such other IBCs.
In
In
It is envisaged that a rig 1 might be fitted to a trailer or indeed be fitted with wheels to become a trailer in its own right such that a container being lowered onto it can be locked to that trailer using the means described herein to safely transport it without toppling off.
In
Other modules 133 shown in
In
In
In order to fit a SAT using such a corner unit a thick plate with an aperture aligned with the socket in the unit is placed on the top plate of the unit so that a SAT can be placed into the unit with the aperture in the thick plate and socket in the top plate holding the tail in the open position. If a container is now lowered onto this SAT the head will automatically be deflected by the container lower socket to the open position against the internal spring loading of the SAT and will then snap back into the head locked position within the socket of the lowered container allowing the container to then be raised with the SAT locked in its the lower fitting socket. The thick plate can conveniently be hinged to the corner unit so it can be flicked on and off the top plate as required when switching between removing and fitting SATs.
It is envisaged that the levers 200 could be made and set up in similar geometry and operation to indexer 22 as described earlier and if applied without the plunger 72 and associated release mechanism yet partially closing off the socket as described above and being driven open by the tail entering the socket and then driven to lock the tail under the top plate once the tail is through the top plate.
To free the tail or to set the SAT 18 in position 2B handles and positional holding means would be added in principle as describer earlier with a means to hold the indexer steady for fitting and lifting off SATs 18 in position 2A.
It is also envisaged that a rig in accordance with the present invention may include more than one pair of corner units at each end of the rig, different pairs of corner units being used for different types of coupler or for carrying out different operations on couplers placed in the corner units. For example, each end of the rig might have three pairs of corner units one pair to attach couplers to containers, one pair to detach couplers from containers and the third pair to lock the container to the rig for proof testing. These couplers can be close together, and even combined into a single three aperture unit. The upper part of
In
It is an important feature of the present invention that the rig provided is quick in operation as the various corner units operate immediately the container is lowered onto the rig with the operation of the corner units being triggered by lowering of the container onto the rig. Thus an operator can place in the rig or remove from the rig couplers whilst the handling machine is picking up its next container giving a more or less continuous process.
A further important feature of the present invention is that the rig provided can be transported to its port of use in sections for assembly at the port.
Although the invention has been described above in relation to rigs used on the dock side or on a trailer it will be understood that the rigs could be used on a ship's deck to remove couplers from containers on board ship or could be used on containers or on structure connected to cranes or other lifting machinery.
Number | Date | Country | Kind |
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1807575.4 | May 2018 | GB | national |
1902005.6 | Feb 2019 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/GB2019/000067 | 5/8/2019 | WO | 00 |