Sail away on the Icon of the Seas: Royal Caribbean’s latest luxury floating voyager can hold around 8 000 people 

Since 1968, Royal Caribbean has built some spectacular cruise ships. Starting with the Song of Norway in 1970, the company has created several record-breaking ocean vessels, including the world’s longest liner, the Wonder of the Seas, measuring 362.04 metres, as well as the tallest observation deck aboard the North Star, which allows passengers to view the ocean from height of 88.6 metres. Now the cruise company will break another record with the construction of the colossal Icon of the Seas cruise liner. Almost 400 metres long and weighing an incredible fifty million kilograms, the Icon of the Seas is the largest cruise liner the world has ever seen. Along with more than 20 eateries, a water park, ice rink and immersive theatres, this 20-deck vessel has enough space to welcome a maximum of 7 600 guests, along with the 2 350 crew members on board.  

But how does a ship so large stay afloat? The answer lies in a physics principle called buoyancy. Vessels that weigh millions of kilograms can float as long as they displace the same amount of water. Cruise ships have a hull – the main body of the vessel – shaped like a ‘U’. The Icon of the Seas’ wider hull shape displaces millions of kilograms of water to maximise the buoyant force holding the vessel above the water.  

However, for this level of stability at sea, there is a trade-off between buoyancy and speed. The Icon of the Seas travels at around 40 kilometers per hour.  

To assist in the Icon’s movement through the water, it will be equipped with an air lubrication system. Air bubbles are rapidly pumped beneath the bottom of the ship by compressors. The ship rides along the bubbles, moving over them like rollers and reducing the amount of friction. There’s also an autonomous cleaning robot that will periodically scrub the ship’s hull to remove sludge and slime, increasing fuel efficiency by up to four per cent.  

Liquefied natural gas is being used to power the Icon for the first time in Royal Caribbean history. To create this fuel source, natural gas, which is typically around 85 per cent methane, is transformed into a liquid state by cooling it. The liquefied natural gas is then stored in massive tanks on the ship and passed through fuel cells, where the fuel is converted into electricity and water. Construction began in 2021 and Icon began service in January 2024. 

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Removing waste 

The company is introducing a new waste-management system to the next generation of liners, including the Icon of the Seas, called microwave-assisted pyrolysis. The process will transform solid waste into synthesis gas that can be redirected into the ship’s fuel supply. Like any land-based energy-conversion plant, waste products aboard the ship, such as food and non-plastic packaging, will be subjected to high temperatures using microwaves. Oxygen is removed from the process to prevent combustion, so rather than fire and smoke, the waste is heated until it produces a synthesis gas, or syngas, which can then be fed back into the ship’s systems to be used as additional fuel. What remains after this process is a heap of by-products called biochar, which is stored and can later be used as soil nutrients. 

By: Scott Dutfield  

Photography: Royal Caribbean/Alamy

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