Hyundai Mipo Dockyard (HMD) is scheduled to deliver the world’s first ballast free LNG bunkering vessel later this year. The 7,600m³ vessel was ordered by Germany-based Bernhard Schulte Ship management in late 2016 and is currently under construction to LR class at HMD’s Ulsan shipyard. Since the introduction of steel-hulled vessels, ballast water has been essential for the safe and efficient operation of vessels, but 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.
With the entry into force of the IMO’s Ballast Water Management Convention in September 2017, all ships constructed (keel lay date) on or after this date, to which the Convention applies, will now be required to be fitted with a ballast water treatment system at delivery. HMD is looking to address this problem through the development of this vessel without the need for a ballast water treatment system.
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. The ballast-free concept means that the vessel will not need to install a ballast water treatment system and it also removes the need to comply with the Performance Standard for Protective Coatings for ballast tanks and related regulation, enabling maintenance costs savings.
LNG will be stored in two independent IMO type C tanks which are designed to contain the LNG with a minimum temperature of minus 165° C and maximum vapor 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. Additionally, the natural vaporizing gas from the bunkering vessel and the returned boil-off gas from the LNG-fueled vessel will be compressed up to 220 bar(g), stored in two sets of 40 feet container and used for propulsion fuel and electric.