DENMARK's shipping giant, Maersk Line, has confirmed earlier news that it has signed a contract for 10 of the world's biggest containerships - each 18,000 TEU - with an option to buy another 20 from Korea's Daewoo Shipbuilding and Marine Engineering for delivery between 2013 to 2015.

The ships are in the Triple-E class based on "Economy" of scale, "Energy" efficiency and "Environmentally" improvement. Maersk Line CEO Eivind Kolding said the new ships would have all the latest environmental features.

It will have 16 per cent more capacity than the current record holder the Emma Maersk, which has been reckoned at 14,000 TEU, but now Maersk says it is 15,500 TEU indirectly by announcing that the new 18,000-TEU vessels will be 2,500 TEU larger than their largest. Subtracting 2,500 TEU from 18,000 TEU gives the true size of the Emma Maersk - 15,500 TEU - and now it's finally official.

But there's not much difference to look at between the Emma Maersk the new Triple E class. They are only about three metres larger in all directions - 400 metres long against 397 for the Emma Maersk, 59 metres abeam against 56 for the Emma Maersk and 16.5 metres draft against 16 for the Emma Maersk.

At a cost of US$190 million per ship - to total $5.7 billion if 20 are build, Maersk is buying the ships for the Asia-Europe which the company expects will grow five to eight per cent.