- Hyundai Mipo Dockyard is developing the first ballast free LNG vessel in the world.
- The German company, Bernhard Schulte Ship management ordered it in 2016.
- The vessel is currently under construction at the Ulsan shipyard.
- The maintenance cost will be less as the ballast water treatment is absent.
Although ballast water treatment is essential for the safe and efficient operation of vessels, bu it also poses an ecological, economic and health threat because of the increased number of species that could be moved from one place to another. Hyundai Mipo Dockyard is trying to address this problem by manufacturing a ballast free vessel. HMD has developed world’s first ballast free LNG bunkering vessel which is scheduled for delivery this year. The 7,600m³ vessel which is currently under construction for LR class at HMD’s Ulsan shipyard, was ordered by the German company Bernhard Schulte Ship management in late 2016.
The Ballast Free Design
To apply the ballast-free concept to this vessel design, HMD gave careful consideration to the special hull form with dead-rise; forward ‘engine room and deckhouse’ and a twin propulsion system with azimuth thrusters, so that the vessel can retain its damage stability and easily control the trim and heel without ballasting.
HMD’s first obstacle was the speed management by dead-rise. In general, dead-rise is known to help improve the ship’s stability, which is critical to this ballast-free vessel, but it is also likely to deteriorate the vessel’s speed performance. To counteract this, HMD focused heavily on the hull form optimisation and successfully developed a better performing deadrise hull form, confirmed through the wet model test.
Another key feature of this vessel that enables it to be ballast-free is the twin propulsion system with two azimuth thrusters. The smaller diameter of propellers fitted in the azimuth thrusters enables the vessel to achieve full immersion in all operational conditions.
LNG Storage Section
Two independent IMO type C tanks are designed to contain the LNG with a minimum temperature of minus 165° C and maximum vapour pressure of 3.75 bar(g), and can be transferred to an LNG-fuelled vessel at the rate of about 1,250m³/hour through the cryogenic flexible hoses without ballasting and/or de-ballasting operation. The boil off gas and the natural vaporizing gas from the bunker will be compressed [ up to 220 bar(g)] and stored in two sets of 40 feet container, which will be used as a propulsion fuel and generate electric power.
Utility of the System
“The ballast-free concept will be made a reality by the technology expertise of HMD. We aim to stand out in the field of eco-friendly business practice”, said the SVP of HMD’s Initial Planning Division, Seung-Ho Jeon.
Jin-Tae Lee, Ph.D, LR’s Korea Chief Representative & Marine Manager, a great supporter of technical innovation, said: “We are delighted to work with the shipyard helping the marine industry bring innovative designs to the market. We believe that this design is another remarkable development for HMD to realise the industry’s need for safe, efficient and clean requirements in the shipping industry worldwide.”
This means that the vessel doesn’t need to install a ballast water treatment system and hence doesn’t have to comply with the Performance Standard for Protective Coatings for ballast tanks and related regulation, which will reduce ship maintenance cost. Therein lies the utility of the new system.
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Source: Lloyd’s Register
