• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2017.11a
• /
• pp.121-123
• /
• 2017

계선주는 선박이 접안 중 안전성을 확보하는 설비로서 계류안전성 평가에 필수 설비 중 하나이다. 이러한 계선주는 국내 항만 및 어항설계 기준의 견인력에 따라 규격이 구분되어 설치되나 규격별 성능 확인을 위한 평가 방법이 제시되지 않아 평가 방법 검토가 필요하다. 이 연구에서는 견인력에 따라 설치되는 계선주 규격별 제원을 분석하여 재질과 특성에 따라 견인력에 따라 작용하는 수평력과 수직력을 휨 응력과 전단 응력으로 나누어 분석하고 이에 따른 성능 적정성을 평가하고 살제 허용 견인력을 평가 하고자 하였다. 또한 계선주 설치 후 노후화로 인한 성능 변경을 평가하고 예측하고자 두께를 통한 평가 방안을 검토하고자 하였다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.7 no.2
• /
• pp.309-315
• /
• 2012

We develpoed auto winch control which will be applied when we want to fix ship or marine structure in the ocean. In this paper, an effort has been made to design and develop a control unit for Winch control purpose. Developed result shows usefulness when it is applied to Han-river floating island.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2001.05a
• /
• pp.103-107
• /
• 2001

When ship claps against the ocean structure sited at shallow water, the time simulation of motion responses of dolphin-moored ocean structure is presented. The equatien of motion based on Cummin's theory of impulse responses are employed, and solved in time domain by using the Newmark $\beta$ method. The added mass and damping coefficients involved in the equations are obtained from a three-dimensional panel method in the frequency domain. The impact forces due to ship collision are modeled as two method, and those are elastic and non-elastic collisions. The mooring forces for dolphin systems of scean structure are considered as linear spring system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2022.11a
• /
• pp.155-155
• /
• 2022

유조선 우이산호 부두시설 접촉사고는 광양항 원유 2부두에 접근 중 과도한 속력 등 도선사의 부적절한 도선으로 좌회두를 적절하게 통제하지 못해 발생한 사고이다. 광양항 원유 2부두에 접안하고자 하는 VLCC는 부두 법선을 감안하여 약 10도 이내의 경사각으로 서서히 속력을 감속하면서 부두 전면 해상으로 접근하여 부두로부터 선폭의 약 2~3배 거리에 정선시킨 다음 예선의 도움을 받아 접안 예정 선박을 횡방향으로 5~10 cm/s 속도로 평행 이동시켜 부두에 계류시키는 것이 통상적인 접안 방법이다. 하지만, 우이산호의 부두 접근 시 속력을 살펴보면, 부두 1마일 전에서 8.4노트, 부두 0.5마일 전에서 7.1노트, 그리고 부두 0.2마일 전에서 5.2노트로 정상적인 타 선박의 속력보다 2~3배 빠른 속력으로 부두에 접근하면서 예선을 사용하였음에도 속력제어에 실패하여 부두와 접촉한 사고이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2016.05a
• /
• pp.98-99
• /
• 2016

The aim of study is to develop a dual driven ship berthing/deberthing system with $360^{\circ}$ steerability. A large ship used bow thruster, side thruster and pod propulsor etc. when approaching to a pier. But as marine leisure boats become large-scaled, the number of accidents is recently increasing what caused a ship to crash into a ship and a ship to crash into mooring facilities during berthing/deberthing on a marina. To solve the problem, the control responsiveness of a joystick connected with two motors and a propeller was checked and torque was increased by the electromagnetic design of magnetic gear. A sea trial test was carried out to investigate a performance of the developed system in the real sea.

• Journal of Wind Energy
• /
• v.15 no.1
• /
• pp.91-102
• /
• 2024

Rapid progress is being made in foundational technology research and engineering for the construction of floating offshore wind farms. There is active development of technology for detachable mooring systems, which have strengths in addressing maintenance issues that arise in floating offshore wind farms and enhance their economic viability. Conventional detachable mooring systems use Kenter links inserted into the middle of mooring chains, which require excessive time for retrieval by Anchor Handling Tug Supply (AHTS) vessels during detachment operations. Moreover, these operations pose risks of link damage and accidents. Therefore, there is a demand for the development of a new concept of detachable mooring systems. The proposed detachable mooring system in this study simultaneously integrates a fairlead chain stoppers (FCS) and submersible mooring pulleys (SMP), which enables all operations to be conducted on the AHTS vessel without underwater tasks. This study detailed the design and safety evaluation of the SMP, a core component of the detachable mooring system, based on the minimum breaking load (MBL) of selected mooring lines according to the capacity of the floating platform. It referenced international codes (AISC Specification for Structural Steel Buildings D5, Pin-Connected Members) for design verification and performed finite element analysis to evaluate the strength of major components in installation and operation scenarios. Additionally, procedures and techniques for evaluating the structural strength of components under uncertain boundary conditions were proposed.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.15 no.1
• /
• pp.49-55
• /
• 2009

Typhoons are usually influencing at least 3 or 4 times per year in Korean peninsula and they accompanied with strong winds and heavy rains and then brought tremendous loss of properties and lives. Especially typhoon "MAEMI" resulted in a lot of marine accidents of vessels such as sinking, stranding, collision etc. at anchoring or on berthing in pier. If the typhoon comes up to expected area influencing the incidents, the vessel tries to escape from the route of typhoon or anchor in sheltering anchorage. However, consideration of the anchoring or judgement of ship's safety against strong winds is decided only by the experience of operators without detail evaluation of the safety. Therefore, this paper evaluated the safety of T.S. HANBADA by comparing the external forces with the holding powers. Furthermore, based on this evaluation, the anchoring manual was produced for the maximum endurable wind velocity, the general precautions and the actions taken on the ship with steps.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2003.10a
• /
• pp.232-236
• /
• 2003

The anchor is laid on seabed and the main engine is worked to against incident environmental loads in typoon. As the main engine is broken down in the storm, the anchor chain is cutted and the vessel is drifted. Although a ship is moored by two point mooring lines to keep the her position, a ship is crashed into a rock because of typoon and the accident of oil spilling may be occured. In this paper, we studied the position-keeping of a ship which is analyized based on the slow motion maneuvering equations considering wave, current and wind. The direct integration method is employed to estimate wave loads. The current forces are calculated by using mathematical of MMG. The two point mooring forces are quasisatatically evaluated by using the catenary equation. The coefficeints of wind forces are modeled from Isherwood’s emperical data and the variation of wind speed is estimated by wind spectrum. The nonlinear motions of a two point moored ship are simulated considering wave, current, wind load in time domain.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2003.10a
• /
• pp.237-242
• /
• 2003

The influence of wave forces on the moored ship beside quay was investigated based on in-house ship mooring analysis and ship motion program in this paper. The wind and current are the general environmental factors for the mooring analysis beside quay in the mild weather. However, the weather is becoming rough, the wave phenomenon should be included in the mooring analysis. In this paper, as preliminary stages, each moored rope tension was evaluated based on wind and current environmental condition. The results were compared with those from MOSES, commercial program. In addition to this, wave forces of the ship were calculated in order to solve moored ship motion of equation. We will leave to solve this motion equation as future work.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2017.10a
• /
• pp.1-7
• /
• 2017

It has been developed large mooring fittings having the capacity of 160 tons and 180 tons installed on 170K LNG FSRU. The finite element analysis for the mooring fittings was carried out in order to check the structural integrity and to confirm satisfaction of the rule requirements. The 3 kinds of mooring fittings such as chock, bollard and universal fairlead are selected for FE analysis and load test. According to the FE analysis results, all the stress levels satisfied the acceptance criteria guided by the IACS UR A2, ISO standard, ship rules and OCIMF. As test results under design load, no structural defects were found.