The Baltic Container Terminal (BCT), a facility at Latvia’s port authority, Freeport of Riga, has deployed an automated solution for managing the movements of containers onto and off of vessels that includes radio frequency identification. The system employs multiple identification technologies to identify containers and terminal tractors, and thereby better manage vessel loading and unloading processes. Based, in part, on cameras and optical character recognition (OCR) software, the solution utilizes passive ultrahigh-frequency (UHF) RFID technology to identify a particular terminal tractor and determine if that vehicle is in the proper position under the gantry crane for loading or unloading containers. The solution is provided by Autepra.
BCT has three gantry cranes to service up to three vessels simultaneously, and can accommodate a total of 12 tractors (four per crane) that transport containers to and from the vessel loading and unloading area. As a vessel is unloaded, a BCT crane moves a 20- or 40-foot container onto a waiting terminal tractor. Prior to installing the automated system earlier this year, BCT required a tallyman to read the ID number painted on each container and record that data on his or her mobile computer, along with the tractor’s ID. He or she then visually inspected the container and made note of any visible damage. Following that procedure, the tallyman radioed the tractor operator to begin container transportation.
The tractor delivered the container to a nearby storage area to await shipment by truck or train to destinations within Latvia, as well as to Russia or other countries within the Commonwealth of Independent States (CIS). The system is designed to move as many as 40 containers onto or off of a vessel per hour. The process worked in reverse for export containers. Tractors delivered a container to the assigned crane, and then waited under that crane for a tallyman to inspect it, thus ensuring that the appropriate container was loaded according to the bill of lading’s requirements. That worker then visually inspected the container again and, in the event that any problems were discovered, recorded them using a handheld computer (Honeywell‘s LXE MX3 Plus model).
The company required three tallymen working 24 hours daily to complete these tasks, and thus sought an automated solution that would reduce the expense of those employees’ salaries. The system also had another shortcoming, says Tomas Girdzevicius, Autepra’s director—visual inspection by an individual standing within the loading area could not detect any problems on top of the container. Moreover, he reports, the movement of heavy machinery created a risk of worker injury.
The automated system, provided by Autepra, includes cameras and OCR software to ensure that the correct container is being loaded or unloaded. Those cameras also automatically take pictures of each side of every container, thereby creating a record of any damage found.
RFID’s role relates to the tractors, the firm explains. Each tractor comes with two Omni-ID Dura 3000 UHF RFID tags affixed to the cabin roof, with a unique ID number linked to that tractor in the software residing on the terminal’s server, and integrated with the terminal operating system (TOS).
Each crane contains two fixed CAEN RFID R4300P-ION readers, one installed on each side, on the interior surface of each of two legs supporting the crane’s hoist used to lift containers. The crane’s legs are located 15 meters (49 feet) apart, and are mounted on rails so that the entire crane can move between the ship and the truck-loading area. Three truck lanes pass between them to accommodate tractors, with the center lane dedicated to tractors loading or unloading vessels, while the outside lanes are used for other passing tractors.
Now, with the automated system installed, as a tractor arrives in the center lane for loading or unloading, RFID interrogators capture every tag’s ID via four antennas attached to each reader. By employing four antennas, the solution can detect if a tractor is in the proper position to be loaded or unloaded, as well as the direction in which a particular tractor is moving. The software stores a link between the tractor and the container being carried. Thus, when a reader captures the tractor’s ID number, it then determines whether that vehicle is at the appropriate location for loading or unloading that specific container. If the tractor is in the correct position, the crane will begin loading a container onto a vessel, or removing a container from it for placement on the tractor.
In some cases, tractors pass one crane to reach another. As they do so, they can potentially interfere with the photographs being taken of other containers. As such, the system is designed to recognize the presence of another tractor in a picture, based on an RFID read, and delay any photo-taking until that tractor has passed.
The system is able to determine that the tractor is simply passing through, since only one tag (not both) would be read. This is due to the passing lane being on the side, rather than in the center, and thus within read range of only a single interrogator.
During the coming months, the tractors will be equipped with onboard computers that will display data regarding each container being transported, as well as when an error is occurring. If a driver, for example, stops at the wrong crane, the system will recognize that the tractor’s RFID number does not match the location where it is parked, and an alert would be displayed. The driver could then move the vehicle to the appropriate area.
Once the onboard computers are in use, Girdzevicius says, the tallymen will no longer manage the loading areas. But until then, they will remain at the port, radioing tractor operators to indicate when they can safely drive, and visually ensuring that the new automated system is working as expected.
The installation proved to be challenging in several ways related to the use of RFID technology, Girdzevicius reports. For example, upon entering the Freeport of Riga, vessels sometimes blocked the tags’ transmissions to some readers. This, he says, was the result of radio transmissions at similar bandwidths from devices onboard the vessels themselves, which interfered with the port’s loading-automation system. The firm was able to resolve the issue, he notes, by configuring reader modulation, which enabled accurate data reads.
The cranes’ OCR-based damage-inspection functionality is managed by Visy software that identifies each container’s receipt and delivery. That software can be integrated with Navis‘ SPARCS terminal operating system.
According to the Baltic Container Terminal, the system has made damage inspection automatic, thereby providing evidence of any container damage. The company expects that the technology will enable a reduction in the number of quay clerks required for operations.