The present invention relates to a container handling system and method for the handling of shipping containers at shipping container terminals. More specifically, it relates to improving the throughput of container handling systems when compared with conventional systems.

Shipping containers have revolutionised international trade over the past decades. As container ships have got bigger, the processes for transferring containers between a container ship and a suitable container storage and sortation system of container handling systems have evolved so that a large container ship with over ten thousand containers may be loaded in around 24 hours. Nevertheless, delays or so-called “bottlenecks” in the container transfer process persist, increasing the idle time for the ship at the shipping container terminal and clogging up the throughput of the container handling system.

Inefficiencies also reside in some of the known storage and sortation systems themselves. These systems generally include a structure comprising a plurality of parallel shelving units for storing containers. In some cases, yard cranes are configured to move along the structure in-between adjacent shelving units, transferring containers to and from the shelving units in a sideways manner. This configuration has a number of disadvantageous. For example, the presence of the yard cranes, occupying the space between adjacent shelving units, takes away from the overall storing capacity of the storage and sortation system. A low storing capacity can of course slow down the process of transferring containers from container ships, but it also has cost implications since space close to a waterfront or river tends to be expensive. Another problem with such a configuration is that it requires the yard cranes to load and unload containers from the side of the shelving units. This causes a significant amount of torque to act on the yards cranes, particularly if a container is full, in which case it could weigh in the region of 30 tonnes. It is because of this that the yard cranes themselves need to be very heavy in order to compensate for the operational torque they experience, adding to their cost and taking away from their movability, for example.

There would be significant benefits if container ships could be unloaded and loaded even faster; not only would the idle time for the container ships be reduced, but more space could be made available in the shipping container terminal if the container ships could be handled faster. There is a perceived need for an alternative container handling system which would speed up the unloading and loading of container ships by seeking to address at least some of the problems of the prior art. The present invention accordingly provides, in a first aspect, a container handling system for a shipping container terminal, the container handling system comprising a container load handling device for transferring containers between a container vessel moored at the container terminal and a first transfer point; a container transport vehicle for transferring containers between the first transfer point and a second transfer point located below the horizontal grid structure; and, a container storage and sortation structure comprising a substantially horizontal grid structure, two substantially perpendicular sets of rails disposed on an upper surface of the grid structure and a workspace beneath the grid structure, the workspace being configured to store one or more containers; one or more robotic load handling devices operative on the grid structure, the robotic load handling devices each comprising a body mounted on wheels, a first set of wheels being arranged to engage with at least two rails of the first set of rails, a second set of wheels being arranged to engage with at least two rails of the second set of rails, wherein one of the first or second set of wheels is independently moveable and driveable with respect to the other of the first or second set of wheels such that when in motion only one set of wheels is engaged with only one set of rails at any one time, thereby enabling movement of the robotic load handling devices along the rails to any point on the grid structure by driving only the set of wheels engaged with the rails, and a lifting means for transferring containers between storage locations within the workspace and the second transfer point.

Preferably, the container handling system further includes a twistlock station for mounting twistlocks to or removing twistlocks from containers, the twistlock station being located between the first and second transfer points.

Preferably, the twistlock station is positioned under the grid structure so as to be accessible by the container transport vehicle and the robotic load handling devices.

Preferably, the second transfer point comprises a twistlock station for mounting twistlocks to or removing twistlocks from containers.

Preferably, the twistlock station is automated or, alternatively, may be manually operated.

Preferably, the container handling system further comprises a holding station located between the first transfer point and the twistlock station. The holding station may be positioned underneath the grid structure so as to be accessible by the container transport vehicle and the robotic load handling devices. The container transport vehicle may comprise a straddle carrier or flat bed truck. The container transport vehicle could be driven manually or alternatively as an automatic guided vehicle (AGV) and, in the alternative, the twistlock and holding stations each comprise a lifting means for moving containers from or to the container transport vehicle.

In a second aspect, the present invention provides a shipping container terminal comprising two quays defining a channel therebetween for mooring a container vessel, wherein each quay comprises a container handling system according to the first aspect.

In a third aspect, the present invention provides a method of transferring containers from a container ship moored at a container terminal utilising a container handling system of the first aspect, the method comprising the steps of lifting a container from the container vessel and depositing the container at the first transfer point using the container load handling device; transferring the container from the first transfer point to the second transfer using the container transport vehicle; and, lifting the container from the second transfer point and storing the container in the storage and sortation structure using a robotic handling device of the plurality of robotic handling devices.

These and other aspects of the invention will now be described, by way of example only, and with reference to the accompanying drawings, in which:

Figure 1 is a schematic representation of a container handling system in accordance with an embodiment of the invention showing a container ship docked at a shipping container terminal;

Figure 2 is a schematic plan representation of the container handling system of Figure 1 further comprising a twistlock station;

Figure 3 is a schematic plan representation of the container handling system of Figure 2 wherein the twistlock station is located in a designated container transfer area;

Figure 4 is a schematic plan representation of the container handling system of Figure 3 further comprising a holding station;

Figure 5 is a schematic representation of a shipping container terminal comprising a further embodiment of a container handling system according to the invention; and, Figure 6 is a schematic representation of another shipping container terminal comprising a further example of a container handling system.

In the figures, like features are denoted by like reference signs.

FIG. 1 shows a schematic view of an embodiment of a container handling system, generally designated by 2, according to the present invention. In this embodiment, a container vessel or container ship 4, carrying a plurality of shipping containers 6, is situated in a body of water 8 and moored to a container terminal 10. The container handling system 2 comprises a container load handling device 12, in the form of a ship-to-shore crane (STS) 14, for transferring the containers 6 between the container ship 4 and the container terminal 10. The STS 14 comprises a crane load handler 16 operable to transport the containers 6 to a first transfer point of one or more first transfer points, generally designated by 18. The first transfer points 18 are located in a first container transfer area of the container terminal 10 from which a container transport vehicle 20 collects containers 6 delivered by the STS 14. In the embodiment shown, the container transport vehicle 20 resides on the first transfer point 18, within the first container transfer area, and the STS 14 is lowering a shorebound container 6 directly onto it. In an alternative embodiment, the container 6 is directly lowered onto the dock of the container terminal 10 at the first transfer point 18, within the first container transfer area, for subsequent collection by the container transport vehicle 20. In this alternative embodiment, the container transport vehicle 20 is fitted with a suitable lifting mechanism for carrying the container 6 from the first transfer point 18. Once collected by the container transport vehicle 20, the shorebound container 6 is transferred from the first transfer point 18 to a second transfer point of one or more second transfer points, generally denoted by 22, located in a second container transfer area. The second container transfer area is located below one or more grid spacings 23 of a plurality of grid spacings 23 defined by a substantially horizontal grid structure 24. The grid structure 24 is part of a container storage and sortation structure 26, which, together with the container transport vehicle 20, forms part of the container handling system 2. The container storage and sortation structure 26 is similar to that described in WO2016/166308A1 , the contents of which are incorporated herein by reference, in that it comprises a plurality of upright members 28 supporting a plurality of horizontal members 30 forming the grid structure 24. Containers 6 are stacked on top of one another to form stacks 32, located beneath a respective grid spacing 23, within a workspace 34 defined below the grid structure 24. The top surface of the grid structure 24 comprises a plurality of rails (not shown) upon which a plurality of robotic load handling devices 36 are operative. A first set of substantially parallel rails guide movement of the robotic load handling devices 36 in a first direction (x) across the top of the grid structure 24, and a second set of substantially parallel rails, arranged substantially perpendicular to the first set, guide movement of the robotic load handling devices 36 in a second direction (y), substantially perpendicular to the first direction. In this way, the rails allow movement of the robotic load handling devices 36 in two dimensions in a horizontal plane, such that any one of the robotic load handling devices 36 can be moved into position above any one of the stack 32.

Each robotic load handling device 36 comprises a body 38 mounted on wheels arranged to travel in the first and second directions on the rails above the stacks 32. A first set of wheels, comprising a pair of wheels on the front of the body 38 and a pair of wheels on the back of the body 38, are arranged to engage two adjacent rails of the first set of rails. Similarly, a second set of wheels on each side of the body 38 are arranged to engage two adjacent rails of the second set of rails. Each set of wheels can be lifted and lowered relative to each other, so that either the first or second set of wheels engages with the respective set of rails at any one time.

When the first set of wheels engages the first set of rails and the second set of wheels are lifted clear of the second set of rails, the first set of wheels can be driven, by way of a drive mechanism housed in the body 38, to move the load handling device 36 in the first direction. To move the load handling device 36 in the second direction, the first set of wheels are lifted clear of the first set of rails, and the second set of wheels are lowered into engagement with the second set of rails. The drive mechanism can then be used to drive the second set of wheels to achieve movement of the robotic handling device 36 in the second direction.

In this way, one or more robotic load handling devices 36 can move around above the top surface of the stacks 32 on the grid structure 24 under the control of a central control system (not shown). Each robotic load handling device 36 is provided with a lifting means for raising containers 6 into its body 38 from the second transfer point 22 and lowering containers 6 from its body 38 into the stacks 32 through one of the grid spacings 23 formed by the grid structure 24. In that way, containers 6 are moved from the second transfer point 22 and a storage location within the workspace 34 to await onward transport. The process works in reverse for seabound containers. That is, a robotic load handling device 36 retrieves a seabound container 6 from its storage location within the workspace 34 and transfers it to the second transfer point 22. From there, the container transport vehicle 20 transfers the container 6 from the second transfer point 22 to the first transfer point 18, where it is then collected by the STS 14 for loading on to the container ship 4. It will be understood that this is a simplified representation of the container handling system 2, and that in practice it would include multiple container load handling devices 12, or STSs 14, for loading containers 6 on or unloading containers 6 from one or more container ships 4.

FIG. 2 is a schematic plan view of another embodiment of the container handling system 2 further comprising a twistlock station 42 for mounting twistlocks to seabound containers 6 and removing twistlocks from shorebound containers 6. The twistlock station 42 may be automatic, where the mounting and removal of twistlocks are actuated by the lowering of containers in the twistlock station 42, or manual, where the removal and mounting of twistlocks is done manually while containers sit in the twistlock station 42. Conventionally, in terms of the flow of containers through a container handling system, twistlock stations are located between the container load handling device or STS in this example, and the first transfer point. That way, the STS is able to place those shorebound containers having twistlocks in the twistlock station before carrying it to the first transfer point. Similarly, for seabound containers, the STS carries those containers that require twistlocks to the twistlock station before then loading the containers onto a container ship. In both instances, the STS is required to lift containers into and out of the twistlock station, reducing the number of containers that can be processed by the STS over a period of time. In the current embodiment of the present invention, the twistlock station 42 is located between the first and second transfer point 18, 22 in terms of how containers 6 flow through the container handling system 2. That is, for shorebound containers 6, the container transport vehicle 20 collects a container 6 from the first transfer point 18 and, assuming that the container 6 comprises twistlocks, transports it to the twistlock station 42 so that the twistlocks can be removed. Following removal of the twistlocks, the container 6 is then transported, by the container transport vehicle 20, from the twistlock station 42 to the second transfer point 22 for collection by a robotic load handling device 36. Conversely, for seabound containers, a robotic load handling device 36 delivers a container 6 to the second transfer point 22 for collection by the container transport vehicle 20. Provided the container 6 requires twistlocks, the container transport vehicle 20 carries the container 6 to the twistlock station 42. Once the twistlocks have been mounted to the container 6, it is then carried by the container transport vehicle 20 from the twistlock station 42 to the first transfer point 18 where it is then collected by the STS 14.

This configuration, unlike the conventional arrangement, decouples the twistlock station 42 from the STS 14 such that the STS 14 is not required to place containers 6 into or lift containers 6 from the twistlock station 42. This frees up the STS 14, increasing the number of containers 6 that it can process over a period of time. The decoupling of the STS 14 and the twistlock station 42 also has a further benefit in that a single twistlock station 42 can be used for multiple STSs 14. Conventionally, each STS in a container terminal will be associated with its own twistlock station in a one-to-one relationship. However, since twistlocks are used only to hold stacks of containers together above the decks of container ships, typically less than half of all containers have twistlocks. Those containers held below deck are not required to use twistlocks. So this conventional arrangement sees twistlock stations generally underutilised. This issue is mitigated by having a single twistlock station 42 servicing multiple STSs 14, as in the present invention, increasing the utilisation of the twistlock stations 42 and reducing the overall number twistlock stations 42 that are required.

FIG. 3 shows another embodiment of the container handling system 2 according to the present invention. This embodiment differs from the previous embodiment in that the twistlock station 42 is located underneath the grid structure 24 on one of the second transfer points 22. In this embodiment, the container transport vehicle 20, having collected a shorebound container 6 from a first transfer point 18, may place the container 6 on the twistlock station 42 regardless of whether or not the container 6 comprises twistlocks. If the container 6 comprises twistlocks, these are removed before the robotic load handling device 36 transfers it from the twistlock station 42 to a storage location within the workspace 34 of the storage and sortation structure 26. For seabound containers 6, a robotic load handling device 36 transfers a container 6 from its storage location within the workspace 34 directly to the twistlock station 42. If necessary, twistlocks are then mounted to the container 6 before the container transport vehicle 20 transfers the container 6 to the first transfer point 18. This embodiment has the advantage of reducing the number of steps in transferring those containers 6 that require twistlock handling between a container ship 4 and the storage and sortation structure 26 when compared to the previous embodiment.

FIG. 4 shows yet another embodiment of the container handling system 2 according to the present invention comprising a holding station 44 located between the first transfer point 18 and the twistlock station 42. Specifically, the embodiment shown includes two holding stations 44. The holding stations 44 provide an area for temporarily storing shorebound containers 6 that require twistlocks removed when the demand for twistlock handling exceeds that provided by the single twistlock station 42. In this embodiment, the container transport vehicle 20 would transfer a shorebound container 6 comprising twistlocks from the first transfer point 18 to one of the holding stations 44 for subsequent delivery to the twistlock station 42 in the event the twistlock station 42 is presently occupied, and then return to the first transfer point 18 to collect a second shorebound container 6. If the second container 6 includes twistlocks, the container transport vehicle 20 would transfer it to another holding station 44 to wait for the twistlock station 42 to become available or otherwise carry it to the second transfer point 22 for collection by a robotic load handling device 36. In yet another embodiment, one or more holding stations 44 may be located between the twistlock station 42 and the second transfer point 22 for temporarily holding seabound containers 6 requiring twistlocks if the twistlock station 42 is presently occupied. In yet another embodiment, one or more of the second transfer points 22 may be utilised as a holding station 44 for seabound containers 6 requiring twistlocks. The holdings stations 44 provide temporary storage for containers 6 requiring twistlock handling, avoiding delays in processing any subsequent containers 6.

FIG. 5 shows a schematic view of an embodiment of a container terminal 10 comprising opposing quays 46 defining a water channel 48 for receiving a container ship 4. The quays 46 each comprise a container handling system 2 according to any of the foregoing embodiments. The STSs 14 are arranged to extend at least halfway across the width of the water channel 48 so as to be able to access adjacent sides of the container ship 4. In practice, the container handling system 2 operates in similar ways to those embodiments described above. That is, for shorebound containers 6, one of the STSs 14 transfers a container 6 from the container ship 4 to a first transfer point 18. From there, the container transport vehicle 20 transfers the container 6 from the first transfer point 18 to a second transfer point 22, where it is then lifted by a robotic load handling device 36 for storing in a workspace 34 of a storage and sortation structure 26 to await onward transport. Similarly, for seabound containers 6, following delivery of the container 6 to the second transfer point 22 using a robotic load handling device 36, the container transport vehicle 20 transfers it to the first transfer point 18 for loading onto the container ship 4 by the STS 14. This arrangement, of two opposing quays 46 each having its own container handling system 2, reduces the time needed for loading or unloading container ships 4, reducing its idle time at the container terminal 10. This is particularly true in view of conventional arrangements for handling containers from very large container ships, which include a row of adjacent STSs arranged along only one side of the ship. In such an arrangement, the STSs are required to reach across the ship in order to access containers on the farthest side of the ship, slowing down the work of the STS and reducing the number of containers that can be handled in a given period of time.

FIG. 6 shows a schematic view of an example of another container terminal 10 comprising opposing quays 46 defining a water channel 48 therebetween. Similar to the previous embodiment, the quays 46 each include a container handling system 2 comprising a container load handling device 12, or STS 14, and a storage and sortation structure 26, together with a plurality of robotic load handling devices 36. However, instead of a container transport vehicle 20, this example uses a conveyance system 50 for transferring containers between each STS 14 and the respective storage and sortation structures 26. It will be appreciated by those skilled in the art that the present invention has been described by way of example only, and that a variety of alternative approaches may be adopted without departing from the scope of the invention as defined by the appended claims. For example, as previously mentioned, the STS 14 may lower a shorebound container 6 directly onto to the container transport vehicle 20, and may lift a seabound container 6 directly from the container transport vehicle 20. In such instances, the container transport vehicle 20 may comprise an automatic guided vehicle or “AGV”, and any associated twistlock or holding stations 42, 44 may comprise their own lifting mechanism so to be able to transfer containers 6 to and from the container transport vehicle 20. Alternatively, the container transport vehicle 20 may comprises a straddle carrier having a suitable lifting mechanism for carrying containers 6. In this instance, any associated twistlock or holding stations 42, 44 do not require their own lifting mechanism.