• 한국기계연구소 소보
• /
• 통권14호
• /
• pp.157-168
• /
• 1985

In cargo vessels, hatch covers are used to prevent sea water from penetrating into the cargo hold and to keep the vessels buoyant. And also they can be used as cargo loading devices as in container ships. In this paper, hatch covers are classified according to their operation method and their characteristics are briefly demonstrated. Systematic description on the scantling of the hatch cover panel and how to determine the capacity of the hydraulic power system fir folding hatch cover panels are also presented. The hydraulic power system is selected from the result of dynamic analysis of the movements of the hatch cover panels when stored on the upper deck. The hatch coaming height is determined as shortly as the hydraulic cylinders can be installed. This study deals with the hatch cover system of the medium sized multi-purpose cargo vessel, but the results of this study can be applied to large-sized cargo vessels with a slight change of the input data in the calculations. Further research on the high pressure pump, hydraulic cleating system and hydraulic piping will realize domestic production of the whole hatch cover system which have been supplied from foreign makers until now

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제7권2호
• /
• pp.270-287
• /
• 2015

According to the increase of the operating cost and material cost of a ship due to the change of international oil price, a demand for the lightening of the ship weight is being made from various parties such as shipping companies, ship owners, and shipyards. To satisfy such demand, many studies for a light ship are being made. As one of them, an optimal design method of an existing hull structure, that is, a method for lightening the ship weight based on the optimization technique was proposed in this study. For this, we selected a hatch cover of a bulk carrier as an optimization target and formulated an optimization problem in order to determine optimal principal dimensions of the hatch cover for lightening the bulk carrier. Some dimensions representing the shape of the hatch cover were selected as design variables and some design considerations related to the maximum stress, maximum deflection, and geometry of the hatch cover were selected as constraints. In addition, the minimization of the weight of the hatch cover was selected as an objective function. To solve this optimization problem, we developed an optimization program based on the Sequential Quadratic Programming (SQP) using C++ programming language. To evaluate the applicability of the developed program, it was applied to a problem for finding optimal principal dimensions of the hatch cover of a deadweight 180,000 ton bulk carrier. The result shows that the developed program can decrease the hatch cover's weight by about 8.5%. Thus, this study will be able to contribute to make energy saving and environment-friendly ship in shipyard.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
• /
• pp.177-178
• /
• 2006

Post panamax급 container vessel에 hatch cover용 bearing pad type을 flexible pad로 확대 적용하여 경쟁력 확보

• 대한조선학회 특별논문집
• /
• 대한조선학회 2009년도 특별논문집
• /
• pp.1-5
• /
• 2009

Recent growth in global economic situation has led dramatic increase in new buildings of large containerships. These increased new building orders have brought keen concerns of developing and improving the quality of design and increasing the productivity of the vessel in order to satisfy the ship Owner's various requirements. For the increment of productivity and quality of containership, the plastic type bearing pad of cargo hatch cover has been investigated intensively for years with the supplier of cargo hatch cover. The result of investigation showed that there are numbers of advantages for the Owner and Builder over the existing bronze bearing pads which are better corrosion resistance long life time, low friction coefficient, easy maintenance, easy installation, better production lead time and low maintenance cost.

• Journal of Welding and Joining
• /
• 제28권4호
• /
• pp.41-48
• /
• 2010

The purpose of this study is to establish the control method of the global bending distortion caused by fabrication process of hatch-cover in a container ship. In order to do it, the transitional behavior of global bending distortion in the deck of hatch-cover during fabrication process was measured by 3-dimensional measuring instrument. From the results, the principal factor controlling the global bending distortion was identified as the bending moment associated with the longitudinal shrinkage force and transverse shrinkage caused by welding and flame heating and the change of the centroid axis of hatch-cover in each fabrication process. Therefore, in this study, with the predictive equations of the longitudinal shrinkage force and transverse shrinkage caused by welding and flame heating and the simplified thermo elastic method, the predictive method for the global bending distortion was established and verified by comparing with the measured result. Based on the results, the amount of reverse bending distortion of main stiffeners was determined to prevent the global bending distortion of hatch-cover.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 2006년도 춘계 학술대회 개요집
• /
• pp.86-88
• /
• 2006

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제9권2호
• /
• pp.185-198
• /
• 2017

The application of composites as an alternative material for marine steel hatch covers is the subject of this study. Two separate approaches are considered; weight reduction approach and strengthening approach. For both approaches Finite Element Analysis (FEA) was performed using ANSYS software. Critical design parameters of the composite hatch cover and FEA are discussed in details. Regarding the weight reduction approach; steel hatch covers of a bulk carrier were replaced by composite covers and a weight reduction of 44.32% was achieved leading to many benefits including fuel saving, Deadweight Increment and lower center of gravity of the vessel. For the strengthening approach; the foremost hatch cover was strengthened to withstand 150% of the load required by IACS for safer navigation while no change in weight was made between the steel and composite covers. Results show that both approaches are feasible and advantageous.

• 해양환경안전학회지
• /
• 제18권5호
• /
• pp.439-445
• /
• 2012

모래운반선은 호퍼도어를 갖는 경우 제한된 범위내에서 창구덮개의 설치를 면제 받을 수 있으나, 현재 국내에는 호퍼도어를 갖고 있는 선박이 단 한척도 없어 창구덮개를 면제받는 선박이 없는 실정이다. 따라서 모래운반선의 창구덮개 관련 현행 규정의 검토와 사고사례 조사 그리고 현재 운항하고 있는 모래운반선에 대한 설비현황, 복원성능 및 내항성능 평가를 통하여 모래운반선에 대한 창구덮개 면제 조건을 검토하였다. 그 결과, 모래운반선의 경우 창구덮개를 면제 받기 위해서는 화물창의 크기를 조정하여 모래를 화물창 상단부까지 가득 싣더라도 흘수가 만재흘수선을 넘지 않도록 하고, 적절한 풍우밀 조치를 취함으로써 충분한 예비 부력과 복원력 확보가 요구된다. 또한, 배수펌프의 용량은 화물창의 액상상태인 모래를 1시간 이내에 소성상태가 될 수 있도록 배수하기에 충분한 용량이어야 하며, 모든 운항상태에서 작동 가능하여야 한다. 본 연구는 모래운반선의 작업 특성상 창구덮개의 설치작업이 현실적으로 상당히 어렵고, 특히 기상악화시 인명사고로 이어질 수 있는 현실적인 문제점을 항해안전과 관련된 시설기준을 보다 강화함으로써 개선한 것이다.

• Journal of Ship and Ocean Technology
• /
• 제6권4호
• /
• pp.19-76
• /
• 2002

The author was appointed by the UK Department of Transport as a fellow Assessor with R. A. Williams during Lord Donaldson's Assessment (1995) of the loss of the OBO ship DERBYSHIRE and in 1996 as a UK Assessor for the planning and surveys of the wreck. He relinquished his appointment in October 1997 and was not thereafter Involved in the review and analysis of data gathered. This paper may be considered to be complementary to the reports of the UK and EC Assessors (Williams and Torchio, 1998a and 1998b) which followed that review and analysis. The paper deals with the history and loss of the ship, Including the concept developed in 1995 of 13 possible loss scenarios in a formal safety Risk Matrix of probability and seriousness. It analyses abnormal wave effects on hatch cover collapse, on ship bending, and on flooding of bow spaces and no. 1 hold. The implosion-explosion mechanics during sinking is outlined to explain the devastation of the wreck. The 1996 and 1997 underwater surveys are outlined as are the findings of fact. Each of the final 14 loss scenarios is analysed in the light of the firm and circumstantial survey evidence, plus many other factors of survey experience, analyses and experiments. The updated Risk Matrix speaks for itself and leads to the prime conclusions and major recommendations.

• 한국산업융합학회 논문집
• /
• 제26권6_3호
• /
• pp.1305-1314
• /
• 2023

The global ship repair and modification market is expected to grow up to approximately $ 30 billion by 2025. Korea's shipbuilding industry is leading the world grounded on its international competitiveness in design and production technology. The reality, however, is that the ship repair and modification industry is centered on Gyeongnam, and there are only two to three ship repair workplaces that can repair large ships. Therefore, domestic ship repair companies target small and medium-sized ships mainly. This is because there are few workplaces equipped with a large dock in which large ships like LNG ships can be inspected regularly or repaired, complaints are severe for environmental problems, and related environmental regulations are so strict that it is very hard to obtain government approval for the extension of ship repair and modification workplaces or the opening of new shipbuilding sites. Besides, on account of the workers' high wages, few experts related, and higher ship repair price compared to that of Southeast Asia, most of the volume of repairing large ships including domestic LNG ships is being lost to Southeast Asian or Chinese markets. In this study, the work process and pre-work preparation process for ship hull (winch, windlass, hatch cover, ramp door, cargo gear, anchor chain) repair were analyzed and presented to foster domestic ship repair experts and revitalize related industries.