The transport of goods by containers on cargo ships represents approximately two-thirds of global commerce2, transiting products worth an estimated $4.1 trillion a year. These operations employ some 4.2 million people directly as well as 13.5 million indirectly.
It’s estimated that each week3, 10,000 cargo ships call in one of the leading global ports to load and unload a substantial proportion of the world’s 17 million registered containers. Since shipping terminals operate around the clock, seven days a week, the reliability of machinery and equipment is an absolute necessity. According to Global Insight, the average annual increase in container traffic was 12% between 2001 and 2005 and 6.5% between 2006 and 2011. That’s a considerable rise in the years since that rainy Thursday morning on April 26, 1956, when American Malcolm McLean leveraged his experience in road haulage to adapt the container to maritime transport for the first time, bringing an end to the era of break bulk cargo. In recognition of his decisive contribution to maritime trade, McLean was named “Man of the Century” by the International Maritime Hall of Fame.
Once on the dock, containers are lifted by eight-wheeled machines called straddle carriers. While not certified for road use, these machines are also used in intermodal terminals.
Measuring more than ten meters long, over twelve meters high and nearly five meters wide, these impressively large machines are also ballasted to stably transport heavy containers of up to 60 tonnes. For the sake of comparison, a loaded straddle carrier weighs as much as an empty Airbus A320, i.e. the equivalent of over 100 tonnes. That gives an idea of the pressure exerted on the tyres, especially since all four axles are steering axles and have to withstand cargo-shifting. They travel at relatively low, albeit significant, speeds not exceeding 30 km/h. Resistance to heat build-up is crucially important. Unlike machines that travel long distances at the same speed – conditions in which tyres operate at constant temperature – straddle carriers make constant stops and starts, moving backward and forward, and are thus subject to considerable heat stress.
Nonetheless, solutions to improve and optimize the mode of transport can have a considerable impact on the fluidity of these operations, which, like most economic activities, are subject to time and efficiency constraints. While single spreader straddle carriers, designed to carry one container, are still in the majority, the number of double spreader carriers, designed to carry either one or two containers, is on the rise, clearly indicating that operators are looking for greater productivity. Fully assuming its role as a technology leader, Michelin was the first to provide tyres for both types of machines with the goal of optimizing each type of straddle carrier’s performance.
If all the containers carried on an 11,000 TEU4 cargo ship were to be carried by rail, the train would have to be 77 kilometers long. As is the case with many transport activities, optimizing operations in large part requires improvements in tyre performance, a key component in enhancing productivity. The challenges are equally complex, since straddle carriers operate in narrow, crowded spaces where machines must be both maneuverable and stable.
Case study: APM Terminals Rotterdam
Voted Europe’s best terminal in 2012 and 2013, APM Terminals Rotterdam illustrates the extent to which productivity is critical to port operations.
The operation includes 13 Post Panamax Cranes, 1 Barge Crane, has 74 straddle carrier in operation and has 2,250 reefer connections on 100 hectares of land and 1,600 metres of quay wall with an annual capacity of 3.25 million TEU’s.
The terminal is geared up for the hub and spoke concept, feeding the British, Irish, Scandinavian and Baltic Markets. Straight from the terminal rapid through transport is realised by barge, rail and truck. A smooth way of reaching 320 million consumers in Continental Europe.
700 dedicated team-members conduct a 24-hour shift operation and are ready to handle the future.
Straddle carriers are used to transport containers of goods between arriving and departing ships and trucks. As such, they operate in perpetual motion within the restrictive confines of the shipping yard, with the constant aim of optimizing safety for people, machines and goods, while also improving productivity. When a vessel arrives, each container must be unloaded in less than 90 seconds. In 2012, APM Terminals Rotterdam outperformed the rule by handling an average of 92 containers per hour, all vessel sizes combined. In 2013, the average came to 94.1 per hour. Future productivity gains are still possible, and the tyre is the simplest, most affordable way to achieve them. Michelin intends to prove it with the new MICHELIN XSTRADDLE 2.
The new MICHELIN X-STRADDLE 2 makes marine terminal operations safer while increasing productivity by more than 30%.
The MICHELIN X-STRADDLE 2 delivers all the benefits of radial technology – a Michelin invention – to improve marine terminal operations.
The new MICHELIN X-STRADDLE 2 is designed, in size 16.00 R25, for single spreader straddle carriers. For double spreader straddle carriers, Michelin has kept the size 480/95 R25 MICHELIN X-STRADDLE tyre in the catalogue. The new MICHELIN X-STRADDLE 2 is already available in both the original equipment and replacement markets.