The Maersk Triple E class container ships comprise a family of the largest ships ever built by cargo volume, including their above deck containers, and the largest currently in service by length - 400 m (1,312 ft). They were exceeded in length, displacement, and cargo mass by the former Seawise Giant, and they are currently exceeded in displacement, and cargo mass by the TI class supertankers. They are even more fuel-efficient successors to the Maersk E-class. In February and June 2011, Maersk awarded Daewoo Shipbuilding two US$1.9 billion contracts ($3.8bn total) to build twenty of the ships. The name "Triple E" is derived from the class's three design principles: "Economy of scale, Energy efficient and Environmentally improved". These ships are expected to be not only the world's longest ships in service, but also the most efficient container ships per twenty-foot equivalent unit (TEU) of cargo. The ships are 400 metres (1,312 ft) long and 59 metres (194 ft) wide. While only 3 metres (9.8 ft) longer and 4 metres (13 ft) wider than E-class ships, the Triple E ships are able to carry 2,500 more containers. With a draft of 14.5 metres (48 ft), they are too deep to cross the Panama Canal, but can transit the Suez Canal when sailing between Europe and Asia. One of the class's main design features is its dual 32-megawatt (43,000 hp) ultra-long stroke two-stroke diesel engines, driving two propellers at a design speed of 19 knots (35 km/h; 22 mph). Slower than its predecessors, this class uses a strategy known as slow steaming, which is expected to lower fuel consumption by 37% and carbon dioxide emissions per container by 50%. The Triple E design helped Maersk win a "Sustainable Ship Operator of the Year" award in July 2011. Maersk plans to use the ships to service routes between Europe and Asia, projecting that Chinese exports will continue to grow. The Europe-Asia trade represents the company's largest market; it already has 100 ships serving this route. Maersk hopes to consolidate its share of the Europe-Asia trade with the addition of the Triple-E class ships. In February 2011, Maersk announced orders for a new "Triple E" family of containerships with a capacity of 18,000 TEU, with an emphasis on lower fuel consumption. They will be built by Daewoo Shipbuilding in South Korea; the initial order, for ten ships, was valued at US$1.9 billion (2 trillion Korean Won); Maersk had options to buy a further twenty ships. In June 2011, Maersk announced that 10 more ships had been ordered for $1.9bn, but an option for a third group of ten ships would not be exercised. Payment of the ship is "tail-heavy": 40% while the ship is being built, and the remaining 60% paid on delivery. Deliveries are scheduled to begin in 2013. Maersk negotiated a two-year warranty, where the standard is one year. Prior to 2010 many Maersk containerships had been built at Maersk's Odense Steel Shipyard in Denmark, but Asian builders are now considered more competitively priced. Maersk had approached several different builders in Asia, having ruled out European shipbuilders (for cost reasons) and Chinese (for technology reasons). DSME builds three Triple-Es at a time, and it takes little more than a year to produce a ship. Investment in more-efficient ships helped Maersk win the "Sustainable Ship Operator of the Year" award from Petromedia Group's on-line publication sustainableshipping.com in July 2011. Unlike conventional single-engined container ships, the new class of ships has a twin-skeg design: It has twin diesel engines, each driving a separate propeller. Usually, a single engine is more efficient; but using two propellers allows a better distribution of pressure, increasing propeller efficiency more than the disadvantage of using two engines. The engines have waste heat recovery (WHR) systems; these are also used in 20 other Mærsk vessels including the eight E-class ships. The name "Triple E class" highlights three design principles: "Economy of scale, energy efficient and environmentally improved". The twin-skeg principle also means that the engines can be lower and further back, allowing more room for cargo. Maersk requires ultra-long stroke two-stroke engines running at 80 rpm (versus 90 rpm in the E class); but this requires more propeller area for the same effect, and such a combination is only possible with two propellers due to the shallow water depth of the desired route. A slower speed of 19 knots is targeted as the optimum, compared to the 23–26 knots of similar ships. The top speed would be 25 knots, but steaming at 20 knots would reduce fuel consumption by 37%, and at 17.5 knots fuel consumption would be halved. These slower speeds would add 2–6 days to journey times. The various environmental features are expected to cost $30 million per ship, of which the WHR is to cost $10 million.

• published: 18 May 2015
• views: 0