THE SOLUTION FOR 21 ST CENTURY MEGAPORTS

Today, ports are gearing up to meet the challenge of 10,000 TEU to 12,000 TEU container vessels. The key question is how to handle this huge number of containers efficiently to and from the ship's side.

Virtually all of the major ocean carriers today are building post-Panamax container ships of 5,000 to 6,000 TEU, and some have taken things even further with ships of 6,000 to 7,000 TEU. Drawing board designs show ships of 8,000 TEU to 12,000 TEU and, based on information supplied by the major carriers, many ports are already equipping themselves with high-speed gantry cranes capable of working ships carrying containers 22-across on deck.

This new trend has raised the question of crane productivity and, in particular, the question of how to move large numbers of containers quickly to and from the ship's side. After all, there is no point in building giant ships designed to be serviced by four or more fast ship-to-shorecranes if the container flows between the import/export stacks and the ship are not going to match the ship-to-shore capabilities.

To meet this challenge, Kalmar has a revolutionary solution: a low- height shuttle carrier. Designed primarily to convey containers between the ship's side and container stacks served by rubber-tyred gantry cranes (RTGs) or rail-mounted gantry cranes (RMGs), this machine is also able to stack containers two high and therefore can also be used for loading and unloading road trucks.

The shuttle carrier is a tempting alternative for terminals that are looking for more efficient ways to handle container transport between the stacks and the quay cranes, and still maintain high density stacking by RTG or RMG yard cranes.

Combining the best features:

Most medium-sized and large ports today operate using RMG/RTG or straddle carriersystems. Now there is demand for a system that combines the best features of these two dominant systems: the large storage capacity of yard cranes with the flexibility and speed of the straddle carrier system.

While RTG and RMG cranes take care of the storage area, fast container transport between the stacks, quay and interchange area is handled by shuttle carriers.

Superior alternative

With its ability to lift, carry and transport containers, it is a far superior alternative to other methods of transporting boxes between the quay and high density stacking areas.

Using the shuttle carrier, there are natural buffer zones both at the end or alongside the stacks and under the ship-to-shore cranes. Since it never needs to wait for the cranes, either on the quay or at the stacks, the shuttle carrier is able to provide the required operational speed and complete a high number of cycles per hour between ship and stack.

The Shuttle Carrier, which has been developed in close co-operation with the leading Belgian stevedoring company, Hessenatie, is now being actively marketed by Kalmar to other ports and terminal operators that are looking to build or upgrade their facilities.

The pioneering development of this revolutionary shuttle carrier concept has been carried out in close cooperation with Hessenatie NV, the Antwerp stevedoring company.

Hessenatie is pioneering the development of a completely new container handling system for use at its planned MSC-Hessenatie automated terminal on the left bank of the River Scheldt in Antwerp. The system is based on a new concept, the centrepiece of which is the Shuttle Carrier. The aim is to achieve extremely high levels of productivity by making ship-to-shore crane cycle times independent of the availability of transfer vehicles.

Hessenatie has selected the new concept of OBCs (overhead bridge cranes) for its import and export stacks and needed a fast method of transferring containers between the ship and the stacks. The traditional solution would have been terminal tractors but Hessenatie felt that these were inefficient for the style of operation it envisaged. In trying to achieve the required handling rates, it anticipated considerable quayside congestion or crane delays. The new Shuttle Carrier developed by Kalmar offers the perfect solution for Hessenatie's problem.

Double-buffering

The key to the concept is double buffering. The ship-to-shore cranes are able to place boxes directly onto the quay and do not have to wait for the Shuttle Carriers to arrive. Consequently the crane drivers can concentrate on trying to achieve maximum cycle times, maintaining a buffer of containers on the quayside.

Similarly, the stacking cranes work to and from buffer stacks and in theory, there should be no crane waiting time.

Successful testing

Hessenatie has been testing the concept at its terminal in the Delwaide Dock. During the test period, the Shuttle Carrier has been transporting and stacking containers with excellent reliability and has achieved impressive cycle times.

The Kalmar Shuttle Carrier can be described as a smaller, simpler version of Kalmar's proven straddle carrier design.Since it is only able to stack two-high, its construction is lightweight, resulting in higher acceleration, braking and running speeds.A lower centre of gravity also enables it to achieve higher cornering speeds safely, making it easy for the operator to manoeuvre. RMGs and RTGs Although the Hessenatie application involves overhead bridge cranes, Kalmar pointsoutthatthe Shuttle Carrier is also able to work between the quay and stack areas served by either RMGs or RTGs (rubber-tyred gantry cranes).