Journal of the Korean Society of Marine Environment & Safety (해양환경안전학회지)

The Korean Society of Marine Environment and safety (해양환경안전학회)
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Development of the Large-Capacity Mooring Fittings according to MEG4(Mooring Equipment Guideline 4)

MEG4(Mooring Equipment Guideline 4) 적용에 따른 대용량 무어링 피팅 개발

  • Myung-Su Yi (Department of Naval Architecture and Ocean Engineering, Chosun University) ;
  • Kwang-Cheol Seo (Dept. of Naval Architecture and Ocean Engineering, Mokpo National Maritime University) ;
  • Joo-Shin Park (Ship and Offshore Research Institutes, Samsung Heavy Industries)
  • 이명수 (조선대학교 선박해양공학과) ;
  • 서광철 (목포해양대학교 조선해양공학과) ;
  • 박주신 (삼성중공업 조선해양연구소)
  • Received : 2023.10.10
  • Accepted : 2023.12.29
  • Published : 2023.12.31
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Abstract

For safe mooring and towing between the ship and port, the equipment must be designed in accordance with the relevant international regulations. However, some small shipyards and engineering companies often do not fully comprehend the core contents. Therefore, the international regulations regarding towing and mooring equipment are reviewed and the bollard and chock are newly developed based on the Mooring Equipment Guideline 4 (MEG4) standards. A bollard is a mooring equipment used to fix a mooring rope to the hull. It has two columns and is mostly used in a figure eight pattern knots under the mooring condition. The chock, which is used to change the mooring rope direction coming into the ship from outside, is manufactured using a casting with curvature. The two mooring equipment are widely used in the stern, bow, and mid-side. Owing to the increase in the size of container vessels and LNG ships, the mooring rope load has increased and the safe working load of the mooring equipment must be revised. This study summarizes and examines the results of the allowable stress method obtained using finite element analysis modelling. To consider the mesh size effect, a reasonable criteria was suggested by referring the existing class guidance. Additionally, the safe working load was verified through nonlinear collapse analysis, and the elastic region against load increments was confirmed. Furthermore, the proposed evaluation method can be used to develop similar equipment in the near future.

선박이 부두에 안전하게 계류 및 예인하기 위해서는 관련 국제규정에 부합하는 설계를 해야 한다. 그러나 현재까지도 일부 소형 조선소 및 설계 회사에서는 그 내용을 정확히 숙지하지 못하고 있는 경우가 많다. 따라서 본 논문에서는 예인 및 계류설비에 관한 국제규정을 살펴보고, 최신 발효된 MEG4(Mooring equipment guideline 4) 기준에 만족하는 대표적인 계류 의장품인 볼라드(Bollard)와 쵸크(Chock)를 개발하고자 한다. 볼라드는 계류 밧줄을 선체에 고박하기 위한 의장품이며, 일반적으로 2개의 기둥으로, 대부분은 8자 매듭 형태로 사용하고 있다. 쵸크는 선외에서 선내로 들어오는 계류 밧줄의 방향을 전환하고, 밧줄의 손상을 방지하기 위하여 곡률을 갖는 주물방식으로 제작한다. 이 두 가지 계류 의장품은 선박의 선수와 선미, 중앙부 측면에서 많이 사용되고 있다. 최근 컨테이너선 및 LNG 운반선의 크기 증가로 인하여, 계류 밧줄 하중이 증가하고 있으며, 계류 의장품도 안전사용하중(Safe working load)이 변경되어야 한다. 본 연구에서는 유한요소해석 모델링을 통한 허용응력 평가법 결과를 정리하고, 분석하였다. 추가적으로 비선형 붕괴 거동 평가를 통하여, 안전사용하중 결정에 대한 검증을 수행하였고, 탄성영역 내 설계가 되었음을 확인하였다. 연구에서 제안하는 평가법 및 기준, 그리고 해석절차는 향후 유사 의장품 개발 시 참조가 가능하다.

Keywords

Acknowledgement

This research was supported by "Regional Innovation Strategy (RIS)" through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(MOE) (2021RIS-002).

References

  1. API(2014), Recommended Practice 2A-WSD : Planning, Designing and Constructing Fixed Offshore Platforms-Working Stress Design, 21th edition.
  2. Cho, S. R., J. M. Choung, C. M. Oh, K. S. Lee, and J. Y. Kim(2010), Ultimate load capacities of mooring bollards and hull foundation structures, Ocean Engineering, Vol. 37, pp. 770-776. https://doi.org/10.1016/j.oceaneng.2010.02.011
  3. IACS(International Association of Classification Societies) (2017), Shipboard fittings and supporting hull structures associated with towing and mooring on conventional ships, pp. 3-11.
  4. Jung, J. W. and B. H. Lee(2012), Strength analysis and standardization for closed chocks by using the finite elements method, Journal of the Society of Naval Architects of Korea, Vol. 49, No. 2, pp. 132-145. https://doi.org/10.3744/SNAK.2012.49.2.132
  5. MSC Software(2012), Patran 2012 User's Guide, Chapter 6, Material modeling, pp. 125-136.
  6. OCIMF(2008), Mooring Equipment Guidelines (MEG3), Oil Companies International Marine Forum, Book ISBN 978 1 90533132 1, United Kingdom.
  7. OCIMF(2018), Mooring Equipment Guidelines (MEG4), Oil Companies International Marine Forum, Book ISBN 978 1 85609771 0, United Kingdom.
  8. Oh, C. M., J. M. Choung, and S. R. Cho(2006), Ultimate strength assessment of bollard and its foundation considering production costs, Journal of the Society of Naval Architects of Korea, Vol. 43, No. 5, pp. 604-610. https://doi.org/10.3744/SNAK.2006.43.5.604
  9. Tran, P., S. Linforth, T. D. Ngo, R. Lurnantarna, and T. Q. Nguyen(2018), Design analysis of hybrid composite anti-ram bollard subjected to implusive loadings, Composite Structures, Vol. 189, pp. 598-613. https://doi.org/10.1016/j.compstruct.2018.01.093