• Journal of Advanced Marine Engineering and Technology
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• v.33 no.4
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• pp.553-561
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• 2009

This paper presents development of ROV-type underwater robot capable of cleaning ship hull in automatic mode. The purpose of developing this robot is for underwater cleaning to secure the safety of divers who inspect and clean the ship hull. The robot consists of the cleaning system with rotating brush mechanism, a car-like driving mechanism, inspection system using video, and overall control system for underwater communication and operation. In this paper, we present overall design process of the cleaning system and operating system and technical contents of the overall control system for the underwater cleaning robot.

• Journal of Ocean Engineering and Technology
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• v.20 no.2 s.69
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• pp.46-51
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• 2006

Moonpool characteristics of a cleaning skip related with the performance of a skip are experimentally investigated. Resistance performances of the ship and flow patterns in the moonpool are observed, in order to determine the effect of different shaped moonpool. The ways to reduce ship pithing motion caused by force in the moonpool are examined. Experimental results, using a scale model of cleaning ship with moonpool, show that the step arranged in tier under water leads to significant improvements in performance, such us resistance and ship pithing motion. Depending upon the shape of step in the moonpool, the results indicate that the increment of resistance performance may be up to 35%, especially in the case of no step or high step.

• Journal of Marine Life Science
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• v.9 no.1
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• pp.1-8
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• 2024

Over the past decade, there has been global expansion in the advancement of underwater cleaning technology for ship hulls. This methodology ensures both diver safety and operational efficiency. However, recent attention has been drawn to the harmful effects of ship hull-cleaning wastewater on marine animals. It is anticipated that this wastewater may have various impacts on a wide range of organisms, potentially leading to populationand ecosystem-relevant alterations. This concern is especially significant when the wastewater affects functionally important species, such as aquaculture animals and habitat-forming species living in coastal regions, where underwater cleaning platforms are commonly established. Despite this, information on the ecotoxicological effects of this wastewater remains limited. In this mini review, we discuss the adverse effects of wastewater from in-water cleaning processes, as well as the current challenges and limitations in regulating and mitigating its potential toxicity. Overall, recent findings underscore the detrimental effects posed by sublethal levels of wastewater to the health status of aquatic animals under both acute and chronic exposure.

• Journal of Advanced Navigation Technology
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• v.24 no.5
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• pp.343-347
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• 2020

This paper presents the development of a software for tracking the location of objects in the water and for creating a three-dimensional hull map. The objective of this software, as a software for underwater hull cleaning robot, is to map the location of underwater hull cleaning robot and to locate the position of sensor by identifying the shaded area of acoustic communication. For the software designed for mapping the location of cleaning robot in the water, the height and intensity were applied as variables for underwater ultrasonic communication. The software for creating a three-dimensional hull was developed by OpenGL using scanned lines from a blueprint of a ship. This software can help identifying the location of underwater hull cleaning robot without actual visibility and can be used to maintain a stable communication status by locating the position of sensor by easily spotting the shaded area of acoustic communication caused by the curved area of the bottom of the ship.

• Journal of Ocean Engineering and Technology
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• v.34 no.6
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• pp.377-386
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• 2020

This paper discusses the effectiveness of onboard measurements and data extracted from weather information for speed-power analysis. Furthermore, validation results of hull and propeller cleaning and painting during dry-docking are discussed. Wind and wave information can be obtained from onboard measurements or weather information from the National Oceanic and Atmospheric Administration (NOAA). The weather information of a specified position and time is extracted from NOAA weather data and compared with onboard measurements. In addition, to validate the effects of hull cleaning and painting during dry-docking, speed-power analysis results of before and after dry-docking are compared. The results show that both onboard measurements and weather information show acceptable reliability when added resistance and speed-power analysis results are compared with each other. Moreover, the ship performance analysis (SPA) software clearly shows the effects of hull cleaning and painting, and it can provide reliable analysis results with either onboard measurements or weather information. In conclusion, it is confirmed that the analysis method and SPA software used in this study are effective in analyzing the ship's speed-power performance.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.4
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• pp.335-352
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• 2012

An underwater hull cleaning robot can be a desirable choice for the cleaning of large ships. It can make the cleaning process safe and economical. This paper presents a hydrodynamic design of an underwater cleaning robot and its evaluation for an underwater ship hull cleaning robot. The hydrodynamic design process of the robot body is described in detail. Optimal body design process with compromises among conflicting design requirements is given. Experimental results on the hydrodynamic performance of the robot are given.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.785-795
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• 2018

The International Maritime Organization (IMO) has recognized the risk of hull fouling and announced '2011 Guidelines for the control and management of ship's biofouling to minimize the transfer of invasive aquatic species'and is planning international regulations to enforce them in the future. In this study, to effectively respond to future international regulation, we introduce the case of leading countries related to management of hull fouling and also investigate environmental risk assessment techniques for in-water cleaning. Australia and New Zealand, the leading countries in hull fouling management, have established hull fouling regulations through biological and chemical risk assessment based on in-water cleaning scenarios. Most European countries without their government regulation have been found to perform in-water cleaning in accordance with the IMO's hull fouling regulations. In the Republic of Korea, there is no domestic law for hull fouling organisms, and only approximately 17 species of marine ecological disturbance organisms, are designated and managed under the Marine Ecosystem Law. Since in-water cleaning is accompanied by diffusion of alien species and release of chemical substances into aquatic environments, results from biological as well as chemical risk assessment are performed separately, and then evaluation of in-water cleaning permission is judged by combining these two results. Biological risk assessment created 40 codes of in-water cleaning scenarios, and calculated Risk Priority Number (RPN) scores based on key factors that affect intrusion of alien species during in-water cleaning. Chemical risk assessment was performed using the MAMPEC (Marine Antifoulant Model to Predict Environmental Concentrations), to determine PEC and PNEC values based on copper concentration released during in-water cleaning. Finally, if the PEC/PNEC ratio is >1, it means that chemical risk is high. Based on the assumption that the R/V EARDO ship performs in-water cleaning at Busan's Gamcheon Port, biological risk was estimated to be low due to the RPN value was <10,000, but the PEC/PNEC ratio was higher than 1, it was evaluated as impossible for in-water cleaning. Therefore, it will be necessary for the Republic of Korea to develop the in-water cleaning technology by referring to the case of leading countries and to establish domestic law of ship's hull fouling management, suitable for domestic harbors.

• Journal of Navigation and Port Research
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• v.40 no.1
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• pp.1-6
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• 2016

This study was conducted on a circulation system which can recycle waste water from EGCS(Exhaust Gas Cleaning System) using a wet scrubber that is used to treat air pollutants from ships. Though we developed a water treatment system that could remove effectively particulate matters and dispersed oil included in cleaning water for Ship Exhaust Gas Recycle System(DePM & DeSOx), we found that it is difficult to treat minutely dispersed oil only by means of centrifugal-typed purifier. Therefore, to this system, we applied a coalescer that coalesces emulsified minute oil particles in the 2nd phase of dispersion state after being filtered through the centrifugal-typed purifier. After we treated cleaning water drained out of Ship Exhaust Gas Recycle System(DePM & DeSOx) by using both purifier and coalescer, we found that particulate matters and dispersed oil were removed more than 55% and 99%, respectively, in comparison with those contained in cleaning water influent. Putting the results together, we conclude that the treated cleaning water can be recycled as normal cleaning water if this cleaning water treatment system is employed by the wet cleaning tower system for the reduction of air pollutants from ships.

• Special Issue of the Society of Naval Architects of Korea
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• 2009.09a
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• pp.35-39
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• 2009

The fouling around the surface of hull and propeller caused by marine organism and sea water occur in the vessel which is taken up mooring in a quay for a quite long time. Moreover, those are able to give rise to the loss of speed performance. The purpose of underwater cleaning is to improve the performance of vessel and customer satisfaction through management for fouling condition of propeller and hull. Therefore, systematic approach in connection with underwater cleaning is required so as to obtain the stable speed performance. As a result, we evaluate the effect of propeller polishing to speed performance from the case of 115K COT and 4,250 TEU Container Ship. In addition, we issue the importance of underwater cleaning through comparison of speed results depending on conditions of hull surface painted by silicon.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.1078-1085
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• 2022

Fouling organisms attached to a ship not only greatly increase the resistance of the ship as they grow on the hull but also cause disturbances in local marine ecosystems as they move with the ship. Accordingly, the International Maritime Organization has started discussing the removal of biofouling and evaluation of cleaning performance to prevent the migration of hull-fouling species. In this study, specimens of FRP(Fiber Reinforced Plastic), HDPE(High Density Polyethylene), and CFRP(Carbon Fiber Reinforced Plastic) materials used for small ship construction were cured in Gyeokpo Port (Jeonlakbuk-do) for about 80 days. Then, attached organism removal experiments were performed using a water jet nozzle. The results show that seaweeds, such as laver, were removed when the distance between the nozzle and the specimen was 1.8 cm and the pressure was 100 bar. Furthermore, it was confirmed that the cleaning of barnacles was possible only when the pressure was 200 bar or more.