• Journal of Navigation and Port Research
• /
• v.35 no.6
• /
• pp.483-488
• /
• 2011

When a tug-barge navigates in the water, maneuvering ability of a tug is affected by the slewing motion of barge. Therefore it is necessary to decrease the slewing motion of a barge for safe towing work. We chose two different types of barge model and investigated their motion depending on the existence of bridle, towing speed and length of towline. The experiments are performed in the still water using the wire rope for the towline. A longer towline makes the heading angle smaller. The towing speed does not largely affect the turning of barge. Finally, it is noted that the bridle of a towing line decrease the slewing motion of barge more effectively.

• Journal of Navigation and Port Research
• /
• v.36 no.8
• /
• pp.607-612
• /
• 2012

In this paper, calculation methods of resistance of the ship to be towed and towline tension are discussed. When the vessel is fallen into dead ship condition then appropriate towing force have to be estimated to move the vessel from accident place to safe area. In this research, resistance of the ship to be towed and the tow hawser were considered to estimate total towline tension. Polynomial interpolation method is also applied to estimate additional hydrodynamic resistance of towline. Finally, UI program to calculate the resistance and total towline tension is developed. The developed program based on the research results is effective and convenient to use.

• Journal of Korea Ship Safrty Technology Authority
• /
• s.36
• /
• pp.28-42
• /
• 2014

본 연구는 예인선 해양사고로 인한 사망사건 중 예인삭 절단사건이 큰 비중을 차지하고 있어 인명사고 예방이 시급한 가운데 예인 로프의 아이스플라이스에 대한 기준이 현재 국내에 마련되어 있지 않아 본선의 임의대로 제작?사용하는 실정이다. 이에 우리 공단에서 수검 중인 예인선을 대상으로 예인선에서 주로 사용하는 예인삭의 종류와 구조, 재질 등에 대한 국내 사용실태를 조사하고, 조사를 바탕으로 선정된 로프의 인장강도 시험을 통하여 스플라이스 횟수에 따른 유의성 평가를 시행하며, 국내 외 유사 기준 및 표준을 조사 분석하여 최종적으로 국내에서 적용할 수 있는 예인삭 아이스플라이스 기준을 제시하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2013.06a
• /
• pp.180-181
• /
• 2013

해상에서 사고 선박을 신속하게 예인하는 것은 현장에서 일어날 수 있는 2차적인 피해를 사전에 예방할 수 있는 중요한 조치이다. 이를 위해서는 예인선을 이용하여 사고선박을 이동시켜야 하고 예인선과 피 예인 선박은 예인삭에 의해 연결되게 된다. 자력운항이 불가능한 상태에서 피 예인 선박은 예인선의 예인력에 의해 거동이 좌우되고 예인력은 해상환경 및 피예인 선박의 저항력을 고려하여 결정되어야 한다. 본 연구에서는 피 예인 선박 예인 시 예인저항과 이로 인해 예인삭에 걸리는 장력해석법에 대해 검토한다. 본 연구를 통해 얻어진 결과는 사고선박 예인지원시스템에 효율적으로 활용 가능할 것이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2011.06a
• /
• pp.346-348
• /
• 2011

해상에서 예부선이 항행시 부선의 선회운동으로 인하여 예부선의 안전운항에 많은 어려움을 겪고 있다. 본 연구에서는 안전한 예항업무를 위하여 실무에서 많이 사용되고 있는 2가지 부선 모델을 대상으로 skeg의 설치 유무 및 skeg의 설치 위치에 의한 부선의 선회운동과 이에 따른 예인장력을 알아보기 위해 정수중에서의 수조실험을 실행하였다. 실험결과 예인삭의 선회각도는 skeg을 설치하지 않았을 때 가장 크게 나타났고, center skeg을 설치했을 때부터 작아지기 시작하여 side skeg을 설치했을 때 예인삭의 선회각도가 급격히 작아지는 것으로 파악되었으며, 이러한 특성은 선수형상에 따라 조금씩 다르게 나타나고 있음을 확인하였다. 또한 예인삭의 선회각도가 커질수록 예인장력이 커지는 것을 알 수 있었다. 따라서 부선에 skeg을 설치하여 운항하는 것이 부선의 선회 운동을 감소시켜 최종적으로 예인장력이 작아지게 하여 안전예항업무에 도움이 될 것으로 판단된다.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.22 no.7
• /
• pp.800-806
• /
• 2016

The maneuverability of a tugboat is affected by the slewing motion of a barge while the tug is navigating with the barge in water. Therefore, it is necessary to reduce the slewing motion of the barge to allow for safe towing work. In this study, a water tank experiment was performed to examine the factors affecting the slewing motion of a barge and improve course stability. The characteristics of slewing motion vary according to bow shape. Three barge models, each with a different bow shape, were selected as experimental subjects. A comprehensive analysis was performed to study the effects of various factors on the slewing motion of a barge such as the presence of a skeg and bridle, towing speed, and the length of the towline. The effect of the location of the skeg varied according to bow-hull form. The slewing motion of the barge decreased as the length of the towline increased, and this decrease was even greater when a bridle was connected to the towline. In addition, the slewing motion decreased significantly as the length of the bridle increased. The slewing angles did not show significant change with respect to towing speed.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.23 no.4
• /
• pp.385-392
• /
• 2017

This research presents the results of a study on the trajectory characteristics of barges with different configurations. A towing experiment was carried out in a water tank with three types of barges in two cases: with and without skegs. The effects of towline length on trajectory were also observed. This study analyzed and compared the length and amplitude of trajectory shapes for each barge in various combinations. It revealed that the trajectory of a barge is influenced not only by skegs but also by the length of the towline. As a result of this work, it can be clearly seen that skegs significantly improve the course stability of a towed barge regardless of differences in bow shape or towline length. Water tank test results also indicated that the length of a towline plays a key role in affecting the trajectory characteristics of a barge-towing system. The length and amplitude of the slewing motion of a barge increased with an increase in the length of the towline connected to the barge. Validation of the present research results should be carried out by further experiments and computational comparisons in the near future.

• Journal of Navigation and Port Research
• /
• v.34 no.5
• /
• pp.305-309
• /
• 2010

This paper is provided to improve the discrimination of the towing line for tug-barge at the night sailing. As tugboat industry develops, marine accidents by tugboats are increasing. The main cause of accidents by tugboats is operators' negligence, and that portion is over 70 percent in total marine casualties by tugboats. The biggest cause of negligence is the passing through the towing line at night time. This paper suggests the ways to hinder operators' transit and improve discrimination of towing line(s) at night time.

• Journal of Navigation and Port Research
• /
• v.38 no.5
• /
• pp.463-470
• /
• 2014

In this paper, calculation of towing force required to tow the ship and experiments to verify its appropriacy are discussed. Friction, wind and wave-making resistance of vessel are considered to calculate towing force of specified vessel. Propeller resistance is also reflected and it is assumed that the propellers are locked. Node analysis to estimate additional resistance on towline is applied. Total towing force could be obtained by adding the ship's resistance and towline resistance. Experiments with training ship SAE YU DAL was executed to check the effectiveness of calculation methods and some comparison between experiments and calculation results was also done. From the comparative analysis, we confirmed that towing speed is primary terms in the calculation of towing force and propeller resistance is a major elements of ship's resistance with the increasing of towing speed. We can see that additional resistance induced by yawing of ship during towing have to be considered for total tow resistance.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.19 no.4
• /
• pp.259-265
• /
• 2016

The present study aims to design and utilize a model test system of a Caisson in wet towing condition, to assess towing stability of a 9,300 ton class caisson. The suggested towing system was designed to provide regular tension on the towline, whereas the previous model test system towed the model in constant speed. The new model test system was expected to reproduce the towing condition more realistically than the test system with constant speed condition, as the tugboat in actual towing condition tows the towline with constant power. Model tests were conducted in a towing tank with 1/30 scaled model. In the model tests, six-degrees-of-freedom motion of the caisson model and tension on the towline were measured and analyzed. By using the new system, fluctuation of the motion of model and tension on the towline decreased. The variation in the draft and initial trim was applied in the model tests. In the initial trim condition, the motion and towing force decreased.