Straddle carriers, used to stack containers and transport them from ship-to-shore cranes to a yard, as well as for loading and unloading of container trucks, battle it out with reachstackers, which are usually aimed at small- and medium-sized container operations, are capable of handling containers and trailers.

The choice of handling system normally depends on several criteria, such as the required storage capacity versus the space available, the shape of the terminal, required productivity and size of operation. Straddle carriers can significantly enhance productivity because a single machine can lift two 20ft containers at the same time, and stack containers one over two, and stack three or even four high. Another benefit of straddle carriers is that, where conditions allow, they can be automated, to further enhance productivity and drive down costs. Straddle carriers are widely used in Central Europe, but manufacturers report that there is also a high level of demand in the US and Asia.

Reachstackers are also widely used in intermodal operations due to their flexibility, as they can be used for all functions – loading and unloading of railcars and road trucks, transport and stacking of containers in the yard. When handling containers, reachstackers stack containers in block stacks. A typical stack is four-deep, allowing first or second row access from each side. Empty containers can be stacked deeper, if no selectivity is required. Typically, approximately 15m–18m aisles (depending on the wheelbase of the machine) are required between the stacks.

Handling containers with reachstackers provides a particularly flexible solution for a small- or medium-sized terminal, where reachstackers have a number of important advantages – including the ability to handle containers in the second and third row. They also provide freedom to manoeuvre while holding a container, which helps facilitate accurate positioning at stacking, and the absence of a mast of the type found on a forklift allows for very good forward visibility and ease of operation. Moreover, the absence of a mast and the relatively low height of the machine make for easy yard-to-yard movement and entry into warehouses.

The high level of flexibility offered by reachstackers is highlighted by applications such as that at Hirtshals in Denmark, where Linde C4230 reachstackers have made container handling both faster and easier, enabling a smaller harbour to become much more productive.

“In the stevedore department at Faroe Ship we mainly work with loading and unloading ships, approximately 200 containers per week. We mainly handle fresh and frozen fish-products and shellfish from The Faroe Islands, Norway and Canada,” explains stevedore foreman Bjarne Niebuhr. Here, reachstackers have greatly improved the efficiency and the range of container handling at Faroe Ship, because of the machine’s ability to work containers in the second and third row. This comes in particularly handy when the container handler is used to stack containers directly onboard a ship. Mr Niebuhr also emphasises another advantage with the reachstacker – due to the way it is constructed, the weight of the load is evenly distributed on the entire vehicle, thus minimising the wear on the surface of the quay.

A typical recent example of the application of reachstackers has seen Port of Portland expand its Kalmar reachstacker fleet, in order to cope with growing container volumes. Port of Portland awarded Kalmar an order for three DRF450-65S5 reachstackers with an option for eight additional units, units which were due to be delivered at the time of writing. After switching its operation from masted container handlers to reachstackers in 1999, the Port of Portland currently employs 16 Kalmar DRS4531-S5 reachstackers handling loaded containers. Lee Roundtree Jr, manager of Marine Operations at Port of Portland, describes the reachstacker as “the most flexible, versatile handling solution for our terminal, allowing us to quickly and accurately support the high volume of carriers we serve each week".

Another North American operator, Maher Terminals of Canada also recently opted for reachstackers for its new container handling operations at Fairview Terminal in Prince Rupert, British Columbia, choosing a total of 17 DRF450-60S5X reachstackers (along with 34 terminal tractors). The new units will support the container yard and intermodal on-dock double stack rail operations at Fairview terminal, and have increased load capacities of 45 tonnes in the first row, 35 tonnes in the second row and 18 tonnes in the third row.

Kalmar also continues to secure significant straddle carrier business, among the most recent orders being a further straddle carrier order from Australia’s Patrick Corporation. The order, for a total of 15 of Kalmar’s seventh generation straddle carriers for its container terminals in Melbourne and Sydney, will see 10 three-high CSC350 units for Patrick’s East Swanson Dock facility in Melbourne and five three-high EDRIVE ESC350 units for Port Botany in Sydney. All 15 of the straddle carriers will be delivered with twinlift spreaders capable of lifting 50 tons.

Patrick Corporation is a long-time user of straddle carriers, with 24 already in operation at Port Botany and 28 at East Swanson Dock. The company also operates EDRIVE straddle carriers at its Fisherman Islands automated straddle carrier (AutoStrad) terminal in Brisbane, which is the first terminal of its kind in the world, and all of the straddle carriers in this latest order will also be delivered ready for future automation.

Both East Swanson Dock and Port Botany have annual container throughputs well in excess of 1m teu, which seems to demonstrate conclusively that straddle carriers are capable of providing an optimum handling system for larger container terminals. Productivity and reliability are the keys – the new straddle carriers for Patrick will be able to undertake continuous operations – lifting anything up to 50 tonnes – around the clock, at what are relatively low operational costs. The CSC Smoothlift hoist, a feature of the straddle carriers Patrick is to acquire, is available with either three- or four-high stacking and with the ability to lift 40 tonnes in single or 50 tonnes in twinlift mode, and the ESC version is equipped with an AC drive to meet the strictest environmental standards.

For today’s terminals, however, economic considerations and enhanced productivity are not the only important considerations, and with environmental issues in mind, straddle carriers now have electrically controlled engines, which lower exhaust emissions and reduce fuel consumption – making them environmentally-friendly as well as cost-effective. For ports in built-up areas close to residential centres, noise levels are another important consideration, and noise isolation capability has become an increasingly important feature – a soft landing system minimises the noise generated by grippers when they lock onto a container and the noise associated with the subsequent positioning of containers on the stack or ground.