Scrubbers a 'good story' as cruise response to cutting harmful exhaust

'We think the economies are very sound on scrubbers even though the price of fuel is down now,' added Tom Dow, vp public affairs-North America, Carnival Corp. & plc. He said scrubbers 'put out a better result than using low sulfur fuel.'

With scrubbers, 'the disadvantages to this area [Canada/New England] are neutralized,' the Carnival executive told the symposium.

The Carnival group is installing scrubbers on more than 70 of its 101-vessel fleet at a cost of $400m. Dow said Carnival is in the early stages of commissioning the scrubbers that have been retrofitted.

Nineteen ships across the Royal Caribbean International and Celebrity Cruises fleets are currently scheduled for retrofits. 'We are well into our installations,' Pruitt said, adding there has been 'excellent cooperation with the US and Canadian governments.'

It hasn't been easy from a technical perspective, though.

The size, weight and location of the scrubber towers was a challenge—for the Oasis class, for example, a stack was added to make room for the tower. And scrubbing exhaust takes more water than all the water needs of the rest of the ship.

Royal Caribbean's Harri Kulovaara, evp maritime, has characterized a retrofit project of this size and complexity as 'unprecedented' for the company. Porsche Consulting is advising on the project and Royal Caribbean's classification societies are involved in the risk management.

The Carnival group's first venture into scrubbers in 2006, a pilot project in partnership with the Environmental Protection Agency and other entities, ultimately was abandoned due to issues with the wash water quality.

Royal Caribbean had two pilots and eventually settled on Wärtsilä and Alfa Laval scrubbers; one ship, Adventure of the Seas, will receive an inline hybrid scrubber with one main engine connected.

The 19 ship retrofits are in addition to newbuilds with scrubbers, including those of the Quantum class, TUI Cruises' Mein Schiffs and the next Oasis-class ships.

Carnival began working in 2012 with the ECO-EGC system, which it has helped develop, that not only scrubs sulfur oxide from exhaust but also filters harmful particulate matter and black carbon.

Due to the varied ships in its fleet, Carnival has had to develop a variety of solutions including eight tailored tower designs. The company also created a smaller, simpler exhaust filter, a new demister and improved standardized automated control software, Dow said.

Carnival is working with its classification societies—Lloyd's Register, RINA and DNV GL—on approvals and Dow said there's added complexity because the US and Europe don't have harmonized rules even though the Emission Control Area is an international regulation.

'We see [scrubbers] as the future,' he told the symposium in Bar Harbor. Though shore power can be beneficial—in places where electricity is produced by clean hydropower, is relatively cheap and scalable surplus power is available—'We're less bullish on this in the future.'

The cost to equip each ship for cold ironing is $1.5m to $2m and, outside of North America, of the places where Carnival ships trade, only Japan has 60 Herz frequency to match that of cruise ships. Converting for 50 Hz markets like Europe and Asia doubles the size and cost of the project, according to Dow.

The next shore power facility to be commissioned is at the Brooklyn Cruise Terminal in the fall.

Carnival also is experimenting with LNG on one ship. AIDAprima, to debut in October, has dual fuel engines.