“We look at ways we can improve energy efficiency and reduce emissions across the fleet. We see drydocks as opportunities,” said Chris Millman, vice president of corporate marine technology at Carnival Corporation.

“That may be installing equipment, blasting and painting, thruster grids, or making hydrodynamic improvements,” Millman said, in an interview with Cruise Industry News.

While the company’s brands run their own drydocks and focus on hotel and guest upgrades, the corporation works to provide support on major upgrades, including air lubrication systems (ALS).

“We have another six of those on order,” Millman said. “We have a large program involving thruster grids. We’re paying special attention to the underwater hull, and doing a lot of blasting, painting and coating with the latest technologies.”

The ALS project started with two installations, one on a newbuild, and one retrofitted, and gathered data for Carnival over two years before more installations followed.

“We needed to get a real feel for how it was working and the savings genuinely coming from it,” Millman explained. “We had to understand the interaction of the system with the propellers and sea chests, and how it worked with the fouling system. It came out positive and that is why we went forward with a corporate-wide program.”

Waste Heat

Additional improvements are coming from HVAC tweaks, as the company has designed its service-power-pack program to provide a list of recommended upgrades that drive efficiency.

“We’re also looking at waste heat recovery and better ways to use that.

“We’re fresh off a retrofit of an absorption chiller on a Carnival Cruise Line ship. We’ve had them on a newbuild, but this is the first retrofit of this system, which uses waste heat to produce chilled water,” Millman continued.

Ship Updates

“We’re pushing forward with our next iteration of improvements,” said Millman. “We’re looking at the next service-power package and that will be much more ship-specific. We’re doing some modeling to understand where and how we invest in energy efficiency.

“Once you’ve done that first level of work, the next level is a bit harder,” he continued.

Thus, the company is taking advantage of digital twins, with a virtual ship testing various improvements.

“We are in a typical drydock cycle, looking five years in advance,” Millman said. “For bigger projects, we are planning two to three years out and for the smaller ones, about a year ahead.

“We are testing and evaluating, running prototype trials and doing quite a bit of work in the background.”

Millman said he expected more advancements to be made in ways the company can use waste heat.

“How do we best capture and utilize waste heat? That is an area that has considerable opportunity that hasn’t been fully exploited yet.”

Excerpted from the 2025-2026 Winter Cruise Industry News Quarterly Magazine.