The new Princess Cruises’ ships will each have a 52 MW powerplant, consisting of two 12-cylinder and two 14-cylinder Wartsila F series engines. The engines will feature dual pumps to optimize fuel consumption, according to John Gunner, senior vice president of technical operations.

With a hydro-dynamically improved hull form, the required propulsion power to run the 147,000-ton ships at 22 to 24 knots will be the in same range as for the previous generation of 116,000-ton ships. That is a significant efficiency gain, especially on a per passenger basis.

Propulsion will be via two shaft lines with water lubricated stern tubes.

Gunner said: “In principle, the pods are more fuel efficient. But there are trade-offs both inside the ship in terms of configuration and outside on the hull form. We believe that the shaft lines provide the best solution for us and in terms of longevity.

“The seawater lubricated shaft requires much less maintenance than pods. It is a question of optimizing what you want to accomplish with the ship.”

The cruise line is also testing a sophisticated monitoring system to get a detailed understanding of the different power consumers onboard.

Princess pioneered shorepower and today has 10 ships equipped to plug into so-called alternative marine power.

“When we consider new technology, we take energy conservation and fuel savings into account,” Gunner said. “We prepare a mathematical model before we do any practical testing. If the numbers add up, we may test new equipment on one engine, for example, or on one ship. Pending the outcome, we may later decide to roll it out to the entire fleet. We are always looking for new solutions. Small innovations can have significant effects when applied to a fleet of 20 ships.”

Excerpt from Cruise Industry News Quarterly Magazine: Fall 2011