The giant cruise ship Mardi Gras was launched at the Turku shipyard on Friday, months behind schedule. Built by the German-owned Meyer Turku, it is being prepared for delivery to the US-based firm Carnival Cruise Line. After handover next autumn, the vessel will become the largest in its fleet.
The 180,000-tonne ship has a capacity of 5,300 passengers and features a first-of-its-kind roller coaster spanning the upper part of the vessel.
The Mardi Gras was originally scheduled to start service in August. It is Meyer Turku's second delayed launch in recent months.
On 20 December, Meyer handed over the Costa Smeralda to its Italian owner Costa Cruises, a Carnival subsidiary after two delays. It was originally to have been delivered in mid-October.
Does LNG really cut emissions?
Both ships run on liquefied natural gas (LNG), which is touted as having lower emissions than standard shipping fuels.
The world's first LNG cruise ship, built at the Meyer shipyard in Germany, was also delayed before delivery in late 2018.
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The Mardi Gras "will be the first to use our now-proven LNG cruise ship propulsion system in North American markets and feature many other sophisticated technologies," Meyer Turku's CEO Jan Meyer said in a statement on Friday.
The Brussels-based NGO Transport & Environment (T&E) estimated in 2016 that LNG could in some cases cut the emissions from the direct use of a ship by 19 percent compared to heavy fuel oil (HFO) and by 12 percent compared to marine gas oil (MGO). However it points out that these numbers change significantly depending on how much unburnt methane is released during fuel combustion (known as methane slip).
However newer statistics suggest that LNG cruise ships are no better for the environment in the long run, and may even be worse.
"The engine technology used by cruise ships (4-stroke low pressure dual-fuel engines) has a very high methane slip - totally wiping out any CO2 savings.," says Eoin Bannon, Media Manager at T&E.
He notes that the 2016 report only accounts for methane emissions from 'tank to wake' but that "the full impact of methane is only accounted for by including emissions from the gas mining and production process. In a 'well to wake' scenario, LNG ships emit between just 10 and 0.6 percent less greenhouse gases (GHGs) than HFO powered ships. It also shows that LNG ships emit between five percent less and six percent more GHGs than MGO powered ones."
Bannon also cites a study published on Tuesday by the International Council on Clean Transportation which "shows that LNG ships emit 70 to 82 percent more GHGs life-cycle than MGO, when you look at the global warming potential in a 20-year time frame," he tells Yle News.
8 cruises cancelled
LNG also produces negligible amounts of nitrous oxide and sulphur dioxide, and is cheaper. The Mardi Gras will be the first LNG-powered cruise ship for the North American market.
It is to be handed over to Carnival in October ahead of its maiden voyage from Port Canaveral, Florida, scheduled for mid-November, according to Meyer.
Due to delays in its delivery, Carnival had to cancel eight cruises, refunding money to more than 40,000 customers, reports Travel Weekly.
The current Turku shipyard was originally built in the mid-1970s by Wärtsilä Marine, which went bankrupt in 1989. It was then owned by Masa-Yards, Kværner Masa-Yards, Aker and STX before Meyer bought it in 2014.
30 Jan: Updated with more data from T&E and ICCT.