• Journal of the Korean Society of Marine Environment & Safety
• /
• v.21 no.2
• /
• pp.171-178
• /
• 2015

This research is the first research on developing the speed limit select model and also it is the result of the research on the importance of each element and consideration factors when selecting the speed limit. For the consideration factor discrimination and calculation of the importance, the delphi method and AHP method was used. The delphi survey was processed through third round survey, 5 high consideration factor(Level 1) and 23 low consideration factor(Level 2) was discriminated. During the process of the third delphi survey, when the CVR cost was in the range between 0.4~1.0 it was treated as the consideration factor when selecting the speed limit and less than 0.4 cost was eliminated. In the process of the second delphi survey, 33 consideration factors were discriminated but was reordered into 23 categories through the third survey. Based on the 23 categories earned through the third delphi analysis, the AHP survey was processed. The result of the AHP survey was that out of the importance of the 5 high consideration factor(Level 1), the traffic condition was evaluated as the number one factor and the vessel condition, waterway condition, environment condition, supporting condition and etc. conditions were evaluated following the traffic condition. Out of the 23 low consideration factor(Level 2) consideration, the visibility was evaluated to be the first important and the performance of the vessel steering, objective factors within the harbor, amount of traffic and density, distance between the passing vessel, speed of the steering capacity and tidal current were the following evaluated factors.

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

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

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.1
• /
• pp.23-29
• /
• 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 with respect to the establishment of Safe-Guard Ring of Ship Collision Avoidance Support Model in Close Quarters Situation that had been newly studied to avoid ship's collision, the ratio of own ship' speed to a target ship's speed was limited to about less than 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.