The first giant cruise ships to be powered at sea by Liquefied Natural Gas (LNG) – claimed to be the world’s cleanest burning fossil fuel – have been ordered by Carnival Corporation.

The four new vessels – part of a previously-announced multi-billion dollar order for nine new ships between 2019 and 2022 – will also feature a revolutionary ‘green cruising’ design.

Each of the four next-generation ships will have a total capacity of 6,600 passengers, feature more than 5,000 lower berths, exceed 180,000 gross tons and incorporate an extensive number of ‘guest-friendly’ features.

A major part of the innovative design involves making much more efficient use of the ship’s spaces, creating an enhanced onboard experience.

Each new ship will be specifically designed and developed for the brand and the passengers it will serve.

Two of the ships will be built for German line AIDA Cruises at Meyer Werft’s shipyard in Papenburg, Germany.

Additional information about the ships, including which new ships will be added to each brand, will be made available at a later date, the group said.

The four new ships will be the first in the cruise industry to use LNG in dual-powered hybrid engines.

LNG will be stored onboard and used to generate 100% of power at sea. Using LNG to power the ships in port and at sea will eliminate emissions of soot particles and sulfur oxides.

Meyer Werft will build the other two ships at its yard in Turku, Finland.

Carnival Corporation chief executive, Arnold Donald (pictured), said the contract is consistent with the company’s measured capacity growth strategy to replace ships with less efficient capacity with newer, larger and more fuel efficient vessels over time.

“We are looking forward to executing on the next step in our fleet enhancement plan,” he said.

“At a cost per berth in line with our existing order book, these new ships will enhance the return profile of our fleet.

“These are exceptionally efficient ships with incredible cabins and public spaces featuring a design inspired by Micky Arison and Michael Thamm and developed by our new build teams.”

Arison is chairman of the board of directors for Carnival Corporation and Thamm is chief executive of the Costa Group, which includes AIDA Cruises and Costa Cruises.

Donald added: “It will be exciting to see our shipbuilding team bring these new ships to life. Every step of the way, our focus is on designing state-of-the-art ships that provide a vacation experience our guests will love, and we are putting all of our creative energy and resources into making sure we achieve that goal.”

Thamm said: “These ships will expand our leadership position for the Costa Group, the market leader in all the major European markets.

“These will be spectacular ships designed specifically for our guests who sail on our Costa Group brands.”

Bernard Meyer, chief executive of Meyer Werft, said: “In past years, we have built seven highly successful ships for AIDA Cruises. We are honoured that Carnival Corporation has entrusted us with the implementation of this ambitious shipbuilding program, and we look forward to building these four magnificent ships.”