Triple E-class container ship

The Triple E class is a family of very large container ships with a capacity of more than 18,000 TEUs, which are owned and operated by Maersk Line.

With a length of 399.2 m (1,309 ft 9 in), when they were built they were the largest container ships in the world, but were subsequently surpassed by larger ones such as CSCL Globe.

In February and June 2011, Maersk Line awarded Daewoo Shipbuilding & Marine Engineering two US$1.9 billion contracts ($3.8bn total) to build twenty ships of this class.

The name "Triple E" is derived from the class's three design principles: "Economy of scale, Energy efficiency, and Environmental impact improvement".

The ships are 399.2 metres (1,309 ft 9 in) long and 59 metres (193 ft 7 in) wide. While only 3 metres (9 ft 10 in) longer and 4 metres (13 ft 1 in) wider than the Mærsk E class, the Triple E ships are able to carry 2,500 more containers. With a beam of 59 metres, they are too wide to traverse the Panama Canal, but can easily transit the Suez Canal.

One of the class's main design features is its dual 29.68-megawatt (39,800 hp), eight-cylinder, ultra-long stroke two-stroke diesel engines, driving two propellers at a design speed of 19 knots (35 km/h; 22 mph). This class is by design slower than its predecessors, using a strategy known as slow steaming expected to lower fuel consumption by 37% and carbon dioxide emissions per container by 50%. The Triple E design helped Maersk win a "Most 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. European-Asian trade represents the company's largest market; thus it already has 100 ships serving the route.

In February 2011 Maersk announced orders for a new "Triple E" family of container ships with a capacity of 18,000 TEU, with an emphasis on lower fuel consumption. They were built by Daewoo Shipbuilding & Marine Engineering (DSME) 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 were scheduled to begin in 2013. Maersk negotiated a two-year warranty, whereas the standard is one year.