As ships continue to get bigger and ports battle to increase throughput, the continued use of multiple conventional gantry cranes will create a bottleneck in the number of containers that can be handled. This, at least, is the central thesis of ACTA Maritime Development Corporation, a New-York-based company that has produced a concept that it envisages as the future of dockside lifting.
“Just as all other industries have moved forward with computerisation and robotics, so too must the maritime industry,” says ACTA president John Arntzen, who submitted evidence on 29 July 1998 to the US House of Representatives committee on house transportation and infrastructure’s subcommittee on coast guard and maritime transportation.
The presentation was timely as just the week before the Regina Maersk had called at the Port of New York and New Jersey but was so big that it first had to call at the deepwater port of Halifax, Canada to offload much of its cargo. The fear in the USA is that its own ports will lag behind and not be able compete.
ACTA has called its concept Speedport, which has been described as a floating garage. It is designed to speed up the loading and unloading of containers by using computer-controlled spiders that move on beams over the top of the ship.
“The design of the Speedport terminal is based on the use of the simplest structures to take advantage of natural time-movements combined with the latest in computer and control system technology,” Arntzen told the committee.
“The resultant terminal design provides for a low-tech, low maintenance facility, controlled by a high-tech computer management system, the combination of which will drastically reduce the time spent in port by even the largest ships of the future.” He explained: “Instead of employing conventional gantry cranes, Speedport relies on a fleet of independent container transfer vehicles, or spiders, that move above the ship and container yard on a network of overhead beams transferring containers from a ship directly onto a railcar, truck or even another ship. Computer programmed movements of these robotic spiders dramatically increases the speed at which a container ship can be be unloaded and loaded. A ship the size of the Regina Maersk would take a conventional terminal, operating at record speed, 70 hours to be fully unloaded and loaded. A Speedport terminal would be able to accomplish the same task in 33 hours.” Singapore is reputed to be the fastest port in the world, maintaining an average handling rate of 88 moves an hour. In July 1995 some 229 containers from a Maersk vessel were handled in one hour.
“It is estimated that while a Speedport terminal will initially cost 30% more to build than a conventional facility, it will be twice as fast and have 65% of the operating costs of a conventional terminal,” Arntzen claimed.
An added benefit claimed by Arntzen is that the Speedport could be built using stabilised, encapsulated dredge materials, saving “hundreds of millions of dollars” in the cost of disposal of dredged sediments.
The computers controlling the robot spiders would also “act as the brain and central nervous system of the terminal”. It could modify a vessel’s load plan to accommodate changes in the arrival of cargo from outside the terminal. The computer-controlled load plan would incorporate the weights and stowage locations of containers, as well as a ship’s ballast and fuelling data to maintain stability.
Arntzen says that the Speedport design allows for any of the slips to be configured as a graving dock, which can be flooded above sea level to speed operations. “By raising the water level in the dock, and thus raising the ship, lift time is minimised for each container movement. The central computer controls water level based on the ship’s load plan.
The graving dock feature also enables the ship to undergo limited repairs during cargo operations. The net time saved by not having to divert the ship to a shipyard results in significant savings to the ship owner, it is claimed.
“The graving dock feature also provides superior environmental protection during fuelling operations,” Arntzen says. “Once the graving dock’s caisson doors are closed, any oil spilled during fuelling will be contained in the dock.” He also claims that a Speedport terminal would be “inherently safer” than a conventional terminal as personnel, spiders, trucks and railcars are all physically separated.
And with a roof built over the top, like those used on large sports stadiums, the Speedport is weatherproof.
A transportable variant of the Speedport design and operating system is suggested for armed forces. A small scale Speedport could be taken on a ship and rapidly constructed at any beach or shoreline to create a fully operational container terminal to support deployed troops, says Arntzen.
It could also be adapted for inland barge terminals, or indeed any truck-to-rail intermodal transfer station.
Arntzen and his partner Richard Thorsen are both graduates of the US Merchant Marine Academy who spent many years as civilians operating ships for the US Navy before founding ACTA.
Their concept is not the only idea that has been produced to address the issues facing the docks industry.
For example, the Ceres Amsterdam terminal design makes use of a slip that provides gantry crane access to both sides of the ship. “Although an improvement over standard terminal designs, this system still relies on conventional gantry cranes that cannot match the efficiency of Speedport,” responds Arntzen.
How about the FAMAS port concept from the Netherlands’ CCT? This terminal features an elevated operations area where trains of automated ground vehicles (AGVs) move container into position under conventional gantry cranes servicing a traditionally berthed ship.
“Again, the throughput of this facility is limited by the speed of the fixed number of gantry cranes working the ship,” Arntzen says.