How many miles to the gallon do cruise ships get?
The short answer is none - - a gallon of fuel will not move a modern cruise ship a mile.
To illustrate, Celebrity Eclipse gets 56 feet to the gallon.
Holland America's Zuiderdam gets .0129 miles per gallon or, looked at a bit differently, .34 tons of fuel per mile traveled.
At first glance, this may not seem like very good mileage. However, keep in mind that a cruise ship is moving thousands of people at once whereas a car is only moving a few people.
To look at fuel consumption more closely, it is necessary to consider how modern passenger ships are powered. Nearly all modern cruise ships and ocean liners are powered by electricity. Electricity powers the motors that turn the propellers. It also powers the air conditioning system, the lights and other appliances used aboard the ship.
Most ships produce their electricity using diesel engines. Others use gas turbine engines to generate electricity. Still others use a combination of the two.
Diesel engines use heavy fuel oil (“HFO”) while gas turbine engines use marine gas oil (“MGO”), which is similar to the fuel used in jet airplanes.
Queen Mary 2, currently the fastest passenger ship in service, consumes 261 tons of HFO and 237 tons of MGO a day when traveling at full spreed.
A ship's speed affects fuel consumption. In order to go faster, the ship must increase the flow of electricity to its motors. This requires that more of the ship's engines be employed, which in turn increases the fuel consumption.
In addition, after a certain point, there is a decreasing rate of return from adding engines. In other words, just because a ship can do 16 knots using two engines, it does not mean that employing four engines would produce 32 knots.
In order to reduce fuel consumption, the cruise lines are employing new technologies. For example, silicon coatings can be applied to the ship's hull to reduce friction as the ship goes through the water. On Celebrity Eclipse, the friction reduction is reportedly some five percent.
Ships are also experimenting with LED lighting, which uses less energy and produces less heat (and thus reduce the demand for air conditioning and for electricity).
The Celebrity Solstice class ships have a field of solar panels over the enclosed Aquaspa pool area. Not only does this provide shade for the pool area but the electricity produced by the solar panels is used to reduce the demand for electricity from the ship's engines.
Along the same lines, Queen Mary 2 has exhaust gas economizers, which use waste heat from the ship's engines to produce steam. The steam is used in heating QM2's hotel accommodations, in the ship's laundry, in the ship's galleys and to heat fuel. This in turn reduces the amount of energy that has to be produced by the ship's engines.
From top to bottom: Celebrity Eclipse; Zuiderdam; and Queen Mary 2.
Cruise ship FAQs - - How many miles per gallon does a cruise ship get?