• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.254-261
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• 2022

Every vessel shall proceed at a safe speed to avoid collision. Additionally, every vessel shall comply with the speed limit rules in the territorial water and internal waters of Korea. The VTS operator shall properly control the compliance of the vessel with the safe speed and speed limit rules. Safe speed under the COLREG 1972 is not explicitly stipulated in knots. However, under the Domestic law for traffic safety-specific sea areas, etc., the speed limit is specified in knots and complied with. This speed limit rule is mainly based on the 'speed made good over the ground'; however, in some places, it is based on the 'speed making way through the water'. In this paper, I analyzed marine accidents that occurred in the past 5 years and the rate of violation of speed limits. Furthermore, I reviewed safe speed under the COLREG 1972, speed limit rules under domestic and foreign laws, and cases of non-compliance with safe speed in the judgment of the Korea Maritime Safety Tribunal. Resultantly, I suggested in this paper that the speed limit rules in the domestic law must be observed by vessels to prevent marine accidents, and the rules which are stipulated in terms of 'speed making way through the water' must be revised as 'speed made good over the ground' such that the vessels can easily comply with them and the VTS operator can control the vessel properly.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.303-305
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• 2014

관제구역 내 선박의 충돌을 예방할 수 있는 통항선박의 안전속력을 제시하기 위하여 선박의 충돌에 미치는 속력의 영향을 분석함으로써 속력과 충돌사고의 관련성을 통계적인 분석을 통하여 제시하였으며, 다중회귀분석법 및 정보기준의 최적화 기법을 적용하여 정량적인 측면에서 선박속력의 평균 및 분산이 잠재적 충돌사고에 미치는 영향을 검토하였다.

• Journal of Navigation and Port Research
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• v.33 no.1
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• pp.1-7
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• 2009

Navigation speed control is an important factor to improve the traffic safety, it is only researched about maximum speed control until now. Recently, there are lots of the low speed vessels including towing boats, carry heavy shipbuilding blocks in the Korean waters, so the danger degree of navigating vessels was increasing more and more. This paper analysed the effectiveness of minimum speed control with the operation burden's decrease, and it proposed the proper the minimum navigation speed of each traffic volume. Main results of this research are as follows. (1) in the case of 5 ships/hour, minimum speed control is effective if the lowest speed is fixed more than 5kts. (2) in the case of more than 10 ships/hour, speed control is some effective if the lowest speed is established 7kts. (3) But, when there are many ships in the waters, minimum speed control is not effective because distances between ships become near and ships navigate for a long time by a lot of ship having a few difference of relative speed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.2
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• pp.193-201
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• 2014

This study provided safe sailing speed and appropriate passing time to areas of known strong current water to prevent marine accident of the ships. To the interpretation of these data which target Myeongnyang waterway, AIS data of the ship was collected from $12^{th}$ July to $15^{th}$ July 2010 and site environment was investigated on $4^{th}$ September 2010. On the basis of the collected data, the 'Minimum Navigation Speed' and 'Optimum Navigation Speed' were calculated. It has also considered the 'Spare control force' or allowance and the 'Respond Rudder Angle' for each tidal current speed. Additionally, it suggested the safe passing time to strong current area by analyzing tidal level and tidal current speed. The conclusion of the research are as follows : (1) If the flow rate is greater than 4.4 kn, it is difficult for the model ship to control herself by her own steering power and to cope with tidal current pressure force and yaw moment caused by the tidal current.. (2) The minimum navigation speed should be over 2.3 times the tidal current and the optimum navigation speed should be over 4.0 times the tidal current. (3) When spring tide, the optimum passing time at Myeongnyang waterway is between 30 minutes to 1 hour before the time of high/low water, and at 5 hours after high/low water, passing of ships should be avoided because it is time when the flow rate is over 4 kn.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.6
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• pp.593-599
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• 2016

Incheon Bridge is 13.38 km long with an 800 m span, connecting Incheon International Airport and Songdo International City, Per hour 73.8 vessels navigate this space. The purpose of this study was to suggest a safe passing speed based on the displacement of a vessel based on the safety criteria of Incheon Bridge's anti-collision fence, which was designed during its initial construction. As AASHTO LRFD suggested, vessel collision energy, vessel collision velocity, and the hydrodynamic mass coefficient were considered to derive a safe vessel traffic speed. Incheon Bridge's anti-collision fence was designed so that 100,000 DWT vessels can navigate at a speed of 10 knot. This research suggests a safe speed for vessel traffic through a comparative analysis of an experimental ship's (300,000 DWT) speed and cargo conditions, regulation speed has been calculated according to the collision energy under each set of conditions. Additionally, safe traffic vessel's safe speed was analyzed with reference to tidal levels. Results from the experimental ship showed that a vessel of maximum 150,000 DWT is able to pass Incheon Bridge at a maximum of 7 knots with an above average water level, and is able to pass the bridge with a maximum of 8 knots under ballast conditions.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.5
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• pp.423-430
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• 2012

The purpose of Speed limit at sea is to keep harbor calmness, to maintain efficient traffic flow and to prevent maritime accidents. The Korean Regional Maritime Affairs and Port Office(KRMAPO) specified and enforced the ship's speed limits at the 19 harbors around the Korean coasts. However, problems have been raised to the adequacy of speed limits. This paper made a research on the speed limit set standards, analyzed vessel traffic survey and the dilemma on the specified speed limits imposed by KRMAPO. The result of this study has shown an overall average of 48 % violation rate on speed limit with passenger ships and large vessels of more than 5,000 tons having higher violation rate. Average speed was higher than the limit speed in some harbors and deviation of 4.2 to 5.2 knots was investigated. Further, harbors having higher average speed also have higher deviation accident incidence. Therefore, this paper had confirmed that there is a need for institutional review and improvement of Korea's port and fairways speed traffic management.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.07a
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• pp.366-368
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• 2015

광양항은 4개의 항로가 설정되어 있다. 광양항 제1항로는 광양항 항계에서 "해사안전법" 제10조에 따른 교통안전특정해역(여수구역)과 연결되어 있고, 낙포각 사포부두(원유부두 북측) 전면 해상에서 광양항 제2항로와 광양항 제3항로 및 제4항로가 분기 합류된다. 이 글은 광양항 제1항로에서 제2항로로 진입하고 있던 선박과 광양항 제3항로에서 제1항로로 진입하고 있던 선박 사이에 발생한 충돌사건의 개요와 원인을 살펴보고, 개항내 항로가 분기 합류되는 수역에서 합의항법이 적용될 수 있는 점과 현행 광양항 항로의 재배치 필요성, 여수지방해양항만청 고시로 규정하고 있는 광양항내 안전한 속력을 광양항에 입출항하는 모든 선장 및 항해사가 알 수 있도록 해도 및 "Guide to Port Entry"에 반영할 것, 그리고 VTS관제사가 광양항에 입출항하는 선박이 안전한 속력을 준수하도록 권고 또는 지시 필요성 등의 교훈 및 개선사항을 제시하고 있다.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.53-58
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• 2006

Recently, vessel's average speed in the sea becomes fast because of the increasing of high-speeds vessel like a container ship and ferry. So, it is considered that speed control in the korean narrow waterway isn't the proper vessel traffic management, now. And, there is a rare paper studied about speed control quantitatively and numerically, especially speed control is discussing continuously, as abrogation of Incheon Port's speed control and alleviation of Kwangyang Port's speed control a according to navigating mariner's request. After this paper replayed the navigation traffic flow in the straight waterway using marine traffic flow simulation, the Environmental Stress Model is introduced to evaluate difficulty of each vessel's traffic.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.2 s.25
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• pp.139-144
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• 2006

Recently, ships' average navigation speed become faster than before because of the increasing of high-speeds vessel including container ships and passenger-ferries. So, it is considered that the speed limit in the navigation channel in Korea isn't proper for vessel management in these days. Also, there is rare paper studies about the speed limit quantitatively and numerically, especially the speed limit is discussing continuously, as abrogation of Incheon Port's speed limit and alleviation of Gwang-yang Port's speed limit according to the requests by the navigating mariners. Consequently this paper deals with the effectiveness of speed limits using the Environmental Stress Model, after replay of the navigation traffic flow in the straight waterway using marine traffic flow simulation technique.

• Journal of Navigation and Port Research
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• v.30 no.10 s.116
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• pp.779-785
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• 2006

From a point of view of suggesting the method to avoid ship's collision, the speed of ships has to be considered sufficiently according to encounter angle of ships. But the new safe-guard ring of ship's collision avoidance support model in the close quarters is established assuming that the ratio of own ship' speed to a target ship's speed is less than about 1.7. Therefore in this paper, as doing a study concerned with the establishment of safe-guard ring reflected the encounter angle and the speed of ships, we will propose the new model of ship collision avoidance for safe maneuver of ship's collision avoidance.