THE latest, towering additions to Southampton’s skyline, two enormous cranes, rising more than 278 feet over the port, are so huge they had to be delivered to the docks by ship.

Designed to handle the new generation of ultra-large container ships, the additional cranes will be a major boost to Southampton’s role as a vital, maritime hub in international, global trade.

It will take another three months to construct and test the two, super-post panamax cranes at DP World Southampton’s container terminal in the Western Docks.

A “post-panamax’’ crane is able to fully load, and unload containers from a ship too wide to pass through the Panama Canal, while “superpost panamax’’, is the most modern container crane able to handle even larger vessels.

Sections of the new cranes were brought from Ireland, where they were manufactured by Liebherr Container Cranes, using the highly specialised, heavy-lift vessel, MV Beluga Formation.

Over the coming weeks a team of engineers will build the cranes, each capable of reaching out over 22 containers, on site at DP World Southampton, before they are moved into position on the quayside. When the new cranes come into operation in May, they will join the existing fleet of ten gantry cranes and a mobile harbour crane.

This will bring the total number of “22 container wide capable cranes’’ to six, and together with the remaining crane fleet it will enable the terminal to service three ultra large container vessels at the same time.

The arrival of the cranes is all part of a continuing expansion scheme at the terminal, which has also recently completed a wide-ranging dredging programme.

Southampton’s super postpanamax cranes are capable of lifting containers almost 150 feet above the quay, which enables the handling of 14,000 container unit vessels with nine tiers of containers on deck and 11 under deck.

CMA CGM Cristophe Colomb and CMA CGM Magella which called at the terminal during 2010, and CMA CGM Alaska due to dock at Southampton later this month, are examples of this new generation of vessels.

The industry trend towards these ultra large vessels is reflected in the number of shipping lines, which have already taken delivery of similar sized ships or have placed orders for the giant, container carriers.

Chris Lewis, managing director, DP World Southampton, said: “The arrival of these two new cranes demonstrates our determination to meet the requirements of our customers, potential new customers as well as industry trends.

“Taking into account the dredging of the berths, we are now able to provide better facilities and services to our customers and give them more flexibility.’’