Today’s cruise ships are extravagant to say the least. From magnificent dining halls and towering water parks to sky diving simulators and bowling alleys, the decks are brimming with a myriad of impressive facilities. Throw in hundreds, if not thousands of passengers and you’ve got a seriously heavy ship. So what powers these super vessels from A to B? The answer of course, is fuel.
Fuel capacity plots the voyage
Did you know that there’s a direct correlation between fuel capacity and the fuel consumption/fuel efficiency of the ship? This largely fluctuates depending on how much fuel the ship leaves port with, the rate at which fuel is burned and how much fuel it has left. These factors dictate how far a ship can travel between ports and what route it should take.
To give you an idea of what today’s state-of-the-art liners drink up we’ve taken a look at some of the biggest names in the business.
Queen Mary 2
Celebrated as the fastest cruise ship on the planet, Cunard’s Queen Mary 2 has a total fuel capacity of 4,381 metric tonnes. This propels the 151,400 tonne luxury liner at a rate of 41 feet for every gallon. At her average speed of 29 knots this gives her 10 days at-sea without having to refuel. On an hourly rate this translates to six tonnes. If she’s hitting her top speed of 32.5 knots she’d get to her destination faster but drink up a lot more fuel.
This 76,000 tonne, 878 foot long ship may be Norwegian’s smallest fleet member but it is still capable of carrying 1,150 metric tonnes of fuel, or the equivalent of 354,144 gallons. Her small size makes her extremely fuel efficient, with her average speed of 24 knots chewing up 1,100 gallons of fuel per hour. This gives her an average of 12 at-sea days before she needs to return to port to refuel.
Freedom of the Seas
At 160,000 tonnes and 1,112 feet Freedom of the Seas is over twice the size of Norwegian Spirit. It has an increased fuel capacity to match, with its tanks able to carry 3,533 metric tonnes at a time. At its average speed of 21.6 knots she burns around 2,800 gallons of fuel an hour. Thanks to advanced eco-friendly propulsion systems Norwegian Cruise Line is able to 10-15% on fuel usage and costs every voyage.
Size does matter
At the end of the day size has a weighty impact on how far a ship can sail. On a daily basis the average cruise ship uses around 140-150 tonnes of fuel, or 30 to 50 gallons per mile. Like vehicle travel, hitting higher speeds increases drag which results in the use of more fuel. The majority of cruise ships find that 21-24 knots is the most efficient speed.
The world is growing an increasing awareness for eco-friendly technology and solutions for minimising carbon footprints. The cruise sector is not exempt and has taken some important steps to maximise efficiency and slash CO2 emissions wherever possible. Rather than leave motors idling when in port many ships now plug into electrical power sources. Others take steps to maximise fuel efficiency by implementing construction features such as intelligent hull coatings, energy efficient lighting, twilight sensors, augmented heat recirculation and eco-friendly air cooling systems.
Images sourced via Flickr Creative Commons. Credits: Christian Lambert