• Journal of Power System Engineering
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• v.17 no.2
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• pp.95-102
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• 2013

For vessels operating in the cold climate regions, the ballast water inside or hopper tanks above the waterline may be frozen, starting at the top of the tank and at the side walls. Therefore, countermeasures against freeze-up of the ballast tank such as air-bubbling system, hot steam injecting system, heating coil system and water circulating system are taken to prevent freeze-up phenomenon; however, there are no rigorous investigations of anti-freezing to examine the effectiveness and validity of systems against freeze-up of the ballast tank, in which the temperatures are about $-25^{\circ}C$ (ambient air temperature) and $0^{\circ}C$ (sea water), respectively. In this paper, to ensure reasonable specifications for cold regions if the measures from the above-mentioned systems against freeze-up are effective, the phenomenon of ballast tank freeze-up is simulated and discussed in low temperature conditions. With the results using the commercial CFD code, CFX 14, the most cost-effective solution is conducted to prevent being frozen along the outer surface.

• Corrosion Science and Technology
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• v.7 no.4
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• pp.219-223
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• 2008

In 2006, as a means to minimize early corrosion failure of ships, thus to enhance marine safety, International Maritime Organization (IMO), proposed a mandatory regulation for Performance Standards for the Protective Coatings (PSPC) for ballast tanks of newly built ships to satisfy 15 years of target useful life. In this regulation, several unprecedented strict rules are adopted as minimum, mandatory requirements for protective coatings of ship's water ballast tanks, and all type of ships sailing international sea are subjected to this regulation which is to be effective as early as June of 2008. The PSPC addresses many technical issues in the areas of surface pretreatment (primary and secondary), coating materials, coating application procedure and inspection as well as necessary documentation. The PSPC rules are new and unproven concepts, which calls for rigorous incorporation of reality-based evidences currently available, since there are no practical experiences in terms of the validity of the PSPC rules. There has been much controversy surrounding these regulations and considerable effort has been made by both shipyards and ship owners alike to achieve a performance standard for ballast tank coatings, which is acceptable to all. In this paper, the background and overview of the PSPC rules are given, and several issues in the PSPC are reviewed as a base to achieve robustness of the proposed PSPC, which will serve as a means to minimize early corrosion and to ensure 15 year target useful life of ships.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.2
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• pp.163-170
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• 2017

The International Convention for the Control and Management of Ships' Ballast Water and Sediments (hereafter "BWM Convention") will be enforced beginning on September 8, 2017. Even though the STCW Convention (International Convention on Standards of Training, Certification and Watchkeeping for Seafarers) and other international instruments require all ship personnel be qualified under certain competencies and standards, the International Maritime Organization (hereafter "IMO") has no unified requirements for training ship personnel on ballast water management. When the BWM Convention enters into force, all officers and crew on board ships should be intimately familiar with the guidelines and procedures outlined by the BWM Convention, regarding, among other topics, proper record keeping techniques and measures, the layout of the ballast control system, methods of ballast water exchange, and inspections by the port state control. To ensure that officers and crew members are adequately familiar, this paper proposes new competency requirements for ballast water management training and education to be added to the STCW Code. To support the introduction of these new competency requirements, this paper explores the evolution of the BWM Convention and examines how international regulations will be used to implement it.

• Ocean and Polar Research
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• v.33 no.2
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• pp.113-125
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• 2011

In order to assess the survival success of microphytoplankton species in ship ballast water, we examined microphytoplankton diversity from international commercial ships berthed at Ulsan and Pyeongtaek Ports, Korea, and also subjected them to laboratory studies. The ages of ballast water in each ship ranged from 1 to 365 days. Vessels originated from coastal China (Weihai, Lianyunsang and Shanghai), Chile, and from the Yellow and Pacific Oceans. The numbers of species and phytoplankton standing crops in uploaded ballast water were significantly related to the age of ballast water. The most diverse taxonomic group was diatoms. In the laboratory study, the value of in vivo fluorescence in M/V Spring Lyra gradually increased with increasing nutrients such as nitrate and phosphate. Phytoplankton in new (9 days), medium (31 days) and old (365 days) ballast water successfully survived under typical nutrient condition of port water and F/2 medium at $15^{\circ}C$ and $20^{\circ}C$, whereas phytoplankton in ballast water treatment did not survive, regardless of optimal temperature. Colonization process was dominated by diatoms; Skeletonema coastatum for M/V Spring Lyra, Thalassiosira pseudonana and Thalassiosira for M/V Han Yang, Thalassiosira pacifica and Odontella aurita for M/V Modern Express, and Chaetoceros pseudocurvisetus and Pseudo-nitzschia seriata for M/V Asian Legend. The successful establishment of non-native species was also related to nutrient richness. Our laboratory design can be applied as a practical tool to assess the survivability of invasive microphytoplankton introduced into local waters of Ulsan and Pyeongtaek.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.4
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• pp.284-288
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• 2009

The International Convention for the Control and Management of Ships Ballast Water & Sediments was adopted by consensus at a diplomatic conference of IMO at 2004. To prepare the Ballast Water Management Convention, fundamental technologies such as treatment system, type approval, risk assessment and various technical informations for formulation of the regulation for national strategy shall be developed. The information item of voyage and discharge of ship's ballast water are gathered by visiting vessel and agent at port. Using the 97 results by ships type characteristic analysis on the relation between loading/unloading and discharge/uptake of ballast water, the amounts of discharge/uptake of ballast water at each port and all of country in Korea are predicted. Hence, It is apparent that the uptake of ballast water is predicted to about 70 million ton in total of Busan, Incheon, Kwangyang and Ulsan ports at 2006 which is over 3 times than discharges.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.5
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• pp.430-439
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• 2011

As the import and export cargos across the world increase with global trade environments, the ecocide caused lots of small marine organisms in the ship's ballast water is a big issue. The implementation of the BWTS (Ballast water treatment system) thus needs low-voltage high-current rectifier for electrolytic disinfection. So this paper proposes a suitable high-current inverter-type rectifier for electrolytic disinfection of seawater and analyzes its output characteristics. It also suggests the practical design guidelines for the proposed rectifier in terms of power circuit and controller designs.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.239-240
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• 2017

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.223-231
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• 2014

In order to prevent the spread of non-indigenous aquatic species through the ballast water in commercial ships, International Maritime Organization (IMO) adopted in 2004 the International Convention for Control and Management of Ship's Ballast Water and Sediments. The Convention mandates treatment of ballast water for most transoceanic voyages and its confirmation of treatment is made with plankton live/dead assay. Fluorescein diacetate assay (FDA), which produces bright green light for live phytoplankton, has been a de facto standard method to determine the survival of marine plankton, but its staining efficacy has been in dispute. In the present study, we examined the limitation of FDA, and compared its efficacy with Neutral red (NR) staining, another promising assay and widely used especially for zooplankton mortality. For all phytoplankton species studied in the present study, except Ditylum brightwellii, the staining efficiency was <50% with FDA. The green FDA fluorescence interfered with phytoplankton autofluorescence in most samples. In contrast, NR assay stained over 90% of both phytoplankton and zooplankton species tested in this study. FDA assay also showed that green FDA fluorescence rapidly faded when phytoplankton cells were exposed to microscope light. Both FDA and NR assay were negative on formalin-killed individuals of both phytoplankton and zooplankton species. Our results suggest that NR assay is more effective for determining the survival of marine plankton and can be applied to test the efficacy of ballast water treatment.

• Journal of Power System Engineering
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• v.17 no.5
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• pp.30-37
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• 2013

For vessels operating in the cold climate regions, the ballast water inside or hopper tanks above the waterline may be frozen, starting at the top of the tank and at the side walls. Therefore, countermeasures against freeze-up of the ballast tank such as air-bubbling system, hot steam injecting system, heating coil system and water circulating system are taken to prevent freeze-up phenomenon; however, there are no rigorous investigations of anti-freezing to examine the effectiveness and validity of systems against freeze-up of the ballast tank, in which the temperatures are about -$25^{\circ}C$ (ambient air temperature) and $0^{\circ}C$ (sea water), respectively. In this paper, to ensure reasonable specifications for cold regions if the measures from the above-mentioned systems against freeze-up are effective, the phenomenon of ballast tank freeze-up is simulated and discussed in low temperature conditions. With the results using the commercial CFD code, CFX 14, the most cost-effective solution is conducted to prevent being frozen along the outer surface.

• Corrosion Science and Technology
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• v.6 no.3
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• pp.90-95
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• 2007

Cathodic protection technology has been widely used on ship's outer hull and inner side of ballast water tanks as a supplementary corrosion protection measure in combination with protective organic coatings. Impressed current cathodic protection system is typically opted for the ship's hull and, sacrificial anode system, for ballast water tanks. The anticipation and interest in cathodic protection system for ships has been surprisingly low-eyed to date in comparison with protective coatings. Computational analysis for the verification of cathodic protection design has been tried sometimes for offshore marine structures, however, in commercial shipbuilding section, decades old design practice is still applied, and no systematic or analytical verification work has been done for that. In this respect, over-rotection from un-erified initial design protocol has been also concerned by several experts. Especially, it was frequently reported in sacrificial anode system that even after full design life time, anode was remaining nearly intact. Another issue for impressed current system, for example, is that the anode shield area design for ship's outer hull should be compromised with actual application situation, because the state-of-the-art design equation is quite impractical from the applicator's stand. Besides that, in this study, some other critical design issues for sacrificial anode and impressed current cathodic protection system were discussed.