Netherlands shipbuilding company Veka-Group has developed three new liquefied natural gas (LNG) tankers that also can serve as bunker ships. Two of the tankers will make short sea trips and provide coastal services, while the third tanker will be used for inland waterways. The LNG inland waterway bunker vessel, said by Veka to be the first of its type, operates without any emissions from load ‘boil off’.
The company already has experience with bi-fuel tankers, constructing the liquefied gas carrier Pioneer Knutsen at its Bijlsma Shipyard in 2004, which led to Veka-Group receiving a nomination for the inaugural European Union Clean Marine Award in the same year. This vessel utilised two separate engines, one for LNG and one for fuel oil.
Bijlsma Shipyard managing director Arend Bijlsma said that new technology was developed for the Pioneer Knutsen project, for the storage of LNG and for the use of LNG as fuel for the propulsion engines. “The combination of these two techniques made it possible to sail the tanker for a significant part on the ‘boil off’ (the gas that is released by keeping the load at the correct temperature),” Bijlsma said.
According to Veka, there will be a rapid increase in the use of LNG by ships for both coastal and inland shipping that will save about 25% of fuel costs, with LNG becoming increasingly attractive as fuel oil prices rise. “At this moment there are no small LNG tankers that can supply the LNG from the large terminals to smaller terminals or directly to ships,” Bijlsma added.
Also, LNG fuel provides a solution with respect to the environmental requirements becoming stricter in more and more countries. For instance in the Baltic Sea and the Gulf of Bothnia until some years ago high sulphuric heavy crude was allowed to be used; now only low sulphuric crude is allowed. In the long term the environmental requirements will be tightened worldwide. “If you want to sail really clean and cost efficient, LNG is the only answer,” says Bijlsma, unless shipowners want to employ expensive scrubbing technology.
Both coastal tankers are equipped with a dual-fuel engine that runs approximately 25% on the ‘boil off’ and the rest on the LNG cargo, making these tankers almost free of hazardous emissions.
The inland waterways tanker has a dedicated LNG engine that burns the boil-off completely, explains Veka project manager Robin Sijbrands. ‘The advantage of these engines is that with respect to the output they perform better than dual-fuel engines. Therefore only a very limited quantity of the LNG cargo is required for fuel consumption.”
The tanker design has been submitted for approval to the Central Commission for Navigation on the Rhine in Strasbourg and to the Maritime Safety Committee (AND) of the United Nations Economic Commission for Europe (UNECE).
“The results of risk assessments that have been carried out are very positive. The hull has already been completed. As soon as the plans have been approved we will immediately proceed with the construction and completion of this tanker,” planned for late 2013.
LNG inland shipping container ship
Around the same period an LNG inland shipping container ship will also be delivered. “This ship, equipped with 100 percent gas engines, will be deployed for the Rotterdam – Duisburg route,” says Sijbrands. “It will be provided with two LNG tanks each having a capacity of 40 cubic meters.” This vessel, like the LNG inland shipping bunker tanker, is also said to be the first of its type in the world.
Practically, gas engines require much less maintenance than diesel engines. ‘You can sail much longer before engine overhaul is required.’
Veko-Group has also developed a system that enables the ship, when in port, to run the on-board electrical network completely on batteries.
(This article compiled using information supplied by Veka-Group)