A Bigger Ship For More Efficiency: Maersk Line orders larger, more efficient shipping vessels for Asia to Europe routes,
by bo svensson
Maersk Line has signed a contract with Korea’s Daewoo Shipbuilding & Marine Engineering Co. Ltd. to build 10 larger and more efficient vessels, along with an option for an additional 20 vessels. The Triple-E vessels are scheduled for delivery between 2013 and 2015. At a cost of US$190 million per vessel and therefore a contract value of US$5.7 billion should the option for a further 20 be exercised Maersk Line is buying the ships to position itself to profit from the 5 to 8% growth in trade from Asia to Europe that the company expects, the company said.
At 400 m long, 59 m wide and 73 m high, the Triple-E is Maersk’s largest vessel of any type on the water today. Its 18 000 twenty-foot equivalent unit (TEU) container capacity is 1% greater (2500 containers) than the company’s current largest container vessel, Emma Mærsk. The Triple-E is designed for a top speed of 23 knots, compared to Emma Mærsk’s top speed of 25 knots. That tiny difference in maximum speed lowers the power output needed from the engine by 19%, which allows for slower revolutions in its engines and far greater fuel economy. And the Triple-E is projected to produce 20% less CO2 per container moved compared to Emma Mærsk and 50% less than the industry average on the Asia-Europe trade lane. Seen per container, Triple-E will consume approximately 35% less fuel than the 13 100 TEU vessels being delivered to other container shipping lines in the next few years for Asia-Europe service, said the company.
“For the health of the planet, we must continue to reduce our CO2 emissions. It is not only a top priority for us, but also for our customers, who depend on us in their supply chain, and also for a growing number of consumers who base their purchasing decisions on this type of information,” said Eivind Kolding, CEO of Maersk Line. Two “ultra-long stroke” engines turn two propellers, and specially optimized hull and bow forms guide the vessel through the water at the speeds typical in the industry today. The manufacturer of the engines has not yet become published. An advanced
waste heat recovery (WHR) system captures and reuses energy from the engines’ exhaust gas for extra propulsion with less fuel consumption.
The Triple-E is the latest in a lon succession of Maersk Line vessels, including the Emma Mærsk class of vessels, to be equipped with an energy saving, advanced WHR system. The purpose of the system is simply that it reduces the vessel’s need for fuel and therefore its CO2 footprint. Instead of wasting approximately 25% of the energy through the stack, the WHRproduced steam generates electricity.
For the Triple-E, the effect of the waste heat recovery system is an approximate 9% reduction of the CO2 emissions. At 75 tonnes, the WHR unit is a large piece of complicated mechanical machinery. And for a cost of approximately US$10 million per unit, it isn’t cheap. But the long-term benefits of installing these systems on vessels outweigh the initial cost. Depending on the price of oil, Maersk Line estimates a return on investment for the waste heat recovery system in the range of five to 10 years.
“The waste heat recovery system is an integral part of the Triple-E’s industry best efficiency, and we’re committed to installing it in many more of our vessels. There will be costs associated with any steps we take to reduce our fuel consumption and emissions, but they don’t compare to the long-term benefits to us, our customers and the environment,” said Kolding.
The Triple-E has two ultra-long stroke, slow-running engines and two large propellers, a combination called “twin skeg.” The reason for using this combination is that Maersk Line studies found that using two of these slower-running engines to turn two propellers results in further energy savings of 4% compared to a one engine/one propeller design. The Triple-E’s two propellers are 9.8 m in diameter with four blades each, while Emma Mærsk’s single propeller is 9.6 m in diameter with six blades. The combined diameter of the propellers provides greater pushing power in the water and the fewer number of blades creates less resistance. Triple-E’s “twin skeg” propulsion system is central to the vessel’s efficiency.
Unlike Emma’s more typical Vshaped hull, which limits container capacity toward the bottom of the “V” in the cargo holds, the hull of the Triple-E is more like a U-shape. An additional row of containers was added to the Triple-E as well, giving it 23 rows across its width, compared to Emma’s 22. The more spacious hull and extra row provides additional capacity for 1500 containers.
Additional container space has been created in the vessel by moving the navigation bridge and accommodation five bays forward and the engine room and chimney six bays back in what is called a “two-island” design. With the more forward navigation bridge, containers can be stacked higher in front of the bridge (approximately 250 more) without losing visibility. And approximately 750 more containers fill the space behind the bridge above deck and below deck using the space created by the engine room’s position further to the back of the vessel. The company said if the 18 000 TEU containers, carried by the vessel, were to be put on a train — it would need to be 110 km long.
Source: Diesel & Gas Turbine Worldwide