Harmony of the Seas: World's Biggest Cruise Ship 20% More Fuel Efficient than Her Sister Ships

Harmony of the Seas is packed with the latest bunker-saving tech.

Royal Caribbean Cruises Ltd (RCL) has been making headlines this week following the delivery and maiden cruise of its newest vessel, Harmony of the Seas.

She is the third Oasis-class vessel to join RCL's fleet, and being just a fraction bigger than her sisters, the Oasis of the Seas and Allure of the Seas, the 361-metre-long Harmony of the Seas is the largest cruise ship in the world.

What mainstream media has missed is that she is packed full of the latest bunker saving technology; indeed, for Ship & Bunker readers likely one of the most striking differences between Harmony and the other two Oasis-class vessels is that she is 20 percent more fuel efficient, according to DNV GL who classed her.

The bunker savings have been achieved in several ways, including the use of three ABB Azipod propulsion units, a waste heat recovery system, and LED and fluorescent lighting systems throughout the ship to reduce both power consumption and heat radiation - the latter being important as it reduces the load for the air conditioning system.

The hull of the vessel is also said to have been optimised to reduce drag and enhance efficiency taking into account her operational and speed profiles, with particular attention paid to the bow.

She also features an anti-fouling coating, and an air lubrication system that creates tiny air bubbles that stick to the bottom of the hull and reduce resistance.

While this so-called "air carpet" technology might not have worked for all ships - Maersk last year said its trails on a box ship failed to show any savings - some cruise operators have seen savings of seven percent.

In October last year the keel was laid for a fourth mega-cruise ship, and on Thursday, the Miami-based cruise company added a fifth Oasis-class vessel to its order book for delivery in 2021.