Carnival senior vice president maritime affairs Tom Strang explains the impact of LNG propulsion and bunkering on Costa Smeralda’s construction and why it is an important step forward
The smooth operational experience of Carnival Corp’s LNG-propelled AIDAnova will stand its new LNG dual-fuel ship Costa Smeralda in good stead.
Carnival senior vice president maritime affairs Tom Strang says, “Costa Smeralda’s LNG system is almost identical to AIDAnova, which was delivered at the end of last year, and whose operational experience has been excellent.”
Like AIDAnova, the intention is to run continuously on LNG, says Mr Strang. Marine gas oil is deployed as a back-up in case the LNG supply chain is disrupted and to meet safe return to port requirements. It is also deployed as the pilot fuel for the LNG, but less than 1% is used.
Again, the experience gained from AIDAnova is very positive in this regard. Mr Strang says “Our operational experience to date is the percentage of time running on LNG is in the high 90s. The engines occasionally switch to MGO, but this is very infrequent and we sometimes have to burn MGO to move it through the tank system.”
Due to be delivered this November, Costa Smeralda has three type C LNG tanks, four dual-fuel MaK/Caterpillar engines and has been designed to comply with the IGF code.
Fitting the tanks
Mr Strang comments “While it is fairly typical of LNG-fuelled vessel design, it is different as it uses three tanks.” He says three tanks were used because of the space available and the 3,600 m3 LNG capacity required.
Mr Strang says “Costa Smeralda will normally operate at 0.7 bars and the safety valves will lift on the tanks at 4.5 bars. The operational experience we have had so far is excellent. The biggest challenge you have when it comes to LNG-fuelled vessels is integrating the tank design, piping and bunkering into the ship.”
Meyer built the tanks inhouse, tailor-making them for Costa Smeralda.
Mr Strang says Carnival Corp worked closely with the shipyard to optimise the location of the tanks, the tank domes and deployed short lines to the bunker stations to minimise risk. He says, “Once we decided what we needed, the talented engineers and operational team in Carnival, Costa Cruises and the shipyard all worked together to achieve an optimised design.”
“The reason for choosing LNG is the environmental benefits. It is a phenomenal journey, but the choice of partners in this process is important”
Caterpillar/MaK put the proposal on the table and worked with Meyer Turku to develop the LNG system. Mr Strang says, “Meyer had the capability to build the tanks and these were built in the Rostock yard, where the middle section of the ship was built.” The shipyard has built tanks before for LNG carriers and so, says Mr Strang, has the “expertise and experience”.
The trio of tanks consist of two with 1,500 m3 and one at 600 m3 capacity. They have spray insulation and an external fire vapour barrier. Speaking about meeting the challenge of their large size, Mr Strang says “They are large tanks and have been designed in accordance with the IGF code to have void spaces around them. LNG takes up approximately twice the volume required for MGO, but with careful design we have integrated this into the vessel and the hull. Clearly there are optimisation challenges everyone has to overcome – it is a collaborative effort working with the shipyard.”
Bunkering infrastructure boost
The ship will be bunkered ship-to-ship. Carnival Corp entered into a strategic partnership with Shell in 2016, to develop bunkering for both AIDAnova and Costa Smeralda. Costa Smeralda will be bunkered in Barcelona every two weeks, as it will be on an itinerary in the western Mediterranean.
Speaking about operational bunkering considerations, Mr Strang says “The whole bunkering process is similar to bunkering for conventional fuels, but because it is new to the industry and ports, there is a lot more oversight provided. Together with our bunker supplier Shell, we have developed a full risk mitigation process.”
He says Carnival Corp is using a “standard bunkering system” on board, with hoses connecting the bunker vessel and cruise ship.
One challenge is the large overhanging lifeboats on the cruise ships. Mr Strang explains, “With conventional coastal LNG tankers being converted into bunkering operations, we do have some challenges with the lifeboats and need to use a pontoon between the ship and bunker vessel. But we have been working with Shell and our operational team on board to improve the bunkering on a continual basis.”
Speaking about the company’s experience of bunkering AIDAnova he says, “It has carried out very successful operations in Barcelona with no leakages, malfunctions or issues.”
Indeed, the future looks positive for LNG cruise ship bunkering. Mr Strang says “We have seen a significant increase in bunkering infrastructure. Northern Europe has always been ahead of the world in this regard. We are currently only carrying out ship-to-ship operations in Barcelona, but more bunker vessels are due to be delivered in the coming year.
“We have led the way in northern Europe. We will bunker in Southampton and Port Canaveral going forward. It is not just theoretical, and as more and more players enter the market, the opportunities for collaboration and aggregation increase.”
A major focus is on LNG training. Mr Strang says “LNG training is a big focus for us. We have developed our own competency framework, based on best practise and working together with SGMF and our flag states. We have a fantastic facility in Holland – our C Smart training centre – where we have installed our LNG system into simulators to train people on systems they will actually be using.
“We also worked with Shell to arrange for LNG officers and engineers to go on board and view operations first hand to pick up more of the ethos around the industry. Training is a major part of the development process. We have a specialist LNG engineer on board, whose job is to oversee bunkering and maintenance of the plant, but the deck officers and engineers must also be trained, so it is a significant uplift that needs to take place. But our training facility also has a bunker rig to practice bunkering operations.”
As well as using LNG, the ship is very energy efficient. Mr Strang says, “All of our ships have a significant improvement in energy efficiency in every newbuild. The lessons we have learned elsewhere in energy and HVAC optimisation means we have modern treatment systems on board.”
LNG: a significant step
Highlighting the reasons for Carnival choosing to use LNG, he says “The reason for choosing LNG is the environmental benefits. It is a phenomenal journey, but the choice of partners in this process is important. Having a yard like Meyer which has developed this in-house and has built LNG ferries, means they have the experience and capabilities.
“If you look at the Mediterranean where there are a lot of environmental sensibilities, we believe this is a major step forward in demonstrating our commitment to the environment.”
Carnival Corp has 21 ships on order, with 10 of these LNG-fuelled. LNG-fuelled vessels make up 44% of the global cruise ship orderbook.
Mr Strang sums up “We see it as a significant step forward in our journey, it almost eliminates local pollutants such as NOx, SOx and PM and reduces carbon. As we move forward on the decarbonisation journey, we see LNG and liquid bio-methane increasingly becoming part of this pathway.”
Costa Smeralda and AIDAnova are the “first step in a journey towards a zero-emissions ship”.
|Shipyard||Meyer Turku Oy (Finland)|
|Length overall||337 m|
|Maximum draft||8.95 m|
|Main engines||4 x 15440|
|Installed ME power||61,760 Kw|
|Propulsion concept||Azipod 2 x 18,500|
|Propulsion power||37 MW|
|Service speed||17 knots|
|Bow thrusters||4 x 3500|
Tom Strang (Carnival)
Carnival Corp senior vice president of maritime affairs Tom Strang leads Carnival’s LNG strategy. He was previously senior vice president of marine operations for Costa Cruises for three years. Prior to this, he was responsible for developing policy in health, environmental and safety areas of maritime operations for Carnival Corp. Before that, he worked for Carnival Corporate Shipbuilding as principal safety manager and with Lloyd’s Register as a surveyor specialising in passenger ship safety.