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벌크선(BULK SHIP) 1

      

   

현장에서는 Bulk와 PC 선을 이른바 "똥배"라고도 많이들 이야기했죠~

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요즘은 우리나라에서는 많이 건조하고 있지는 않지만 Bulk 선은 LPG 선박의 기본 구조 양식으로 건조됩니다.~ 또한 Loading condition 조건도 다양해서, 해석적으로도 결코 다른 선종 대비 쉽다곤 할 수 없습니다.~

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오늘부터 하나씩 살펴보도록 하겠습니다.

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BULK CARRIER : 일반적으로 곡물류, 석탄, 광석 등의 화물을 포장하지 않고 실어 나르는 선박을 의미한다.(주로 호주 쪽에서는 석탄 및 광석이 많이 운반됩니다. 호주라는 나라가 광물이 엄청나죠)

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일반적으로 Scantling(구조 개산) 상 수평 부재는 쌓여서 잘 흘러내리지 않는 화물의 특성으로 인하여 판 보강제들이 선창 내부에 돌출되지 않도록 해야 합니다. 그렇지만~ 부득이한 경우는 보강재를 수직으로 배치하거나 (외판의 hold frame), 파형(Corrugate type) 격벽의 형태로 만들어지죠~

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주된 항해 조건은 다음과 같습니다.~

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① Light ballast condition (화물이 적재되지 않은 상태)

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② Heavy ballast condition (화물을 적재하지 않고 운항 중 황천을 만났을 때 지정된 선창에 ballasting(물을 채운다는 뜻) 을 하는 상태)

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③ Homogeneous loading condition (가벼운 화물을 모든 선창에 균등하게 적재하는 상태)

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④ Alternate loading condition ( 철광석과 같이 무거운 화물을 한 선창 건너 하나씩 적재한 상태)

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④ Alternate loading condition

여기서 위에 그림과 같이 이러한 항해 조건을 바탕으로, 각각 선창 및 Ballast Tank에 해당되는 하중을 고려하여 이를 만족시키도록 강도 계산을 합니다.

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벌크화물선은 유조선이나 컨테이너선과 달리 외판이 홑 구조(Single Skin)로 되어있고, (bottom 부위는 이중 조 구조임). 그러나, 벌크화물선에 대한 최근 동향을 살펴 보면 심각한 손상 사례(외판의 대형 손상 및 침몰) 들이 보고됨에 다라 국제해사기구(IMO)에서 벌크화물선의 안정성 확보를 위한 강도 증가를 요구하고 있어요.

외판 (Side Shell)의 보강 부재인 hold frame에 대한 강도 증가 요구가 이미 IACS의 공통 Rule로 채택되어 적용되고 있으며 이에 더하여 신조선에 대해서 아래 두가지 방안을 제안하고 있어요 :

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①외판 구조 자체를 겸 구조(double skin)로 하는 방안

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②홑 구조(single skin)인 경우 cargo hold에 대한 침수(flooding)를 고려하여 선박의 안정성 및 종강도, 횡격 벼, 이중 조 구조 등에 보강을 요구하는 안이 검토되었고 기존 선박의 경우에도 이에 대한 적절한 보강을 요구

하고 있으며 이를 지키지 못할 경우 벌크화물선의 주 손상 원인이 되는 적재 condition이라 생각되는 alternate loading을 하지 못하게 하는 등의 loading 제한을 두고 있습니다.

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I am trying to learn about the structural characteristics of different types of ships. In the field, bulk and PC ships are often referred to as "dung boats." Bulk ships are not built in Korea much these days, but they are built in the same basic structural style as LPG ships. The loading conditions are also diverse, so it is not always easy to analyze compared to other ship types. Today, we will take a look at each one. BULK CARRIER: This refers to a ship that carries cargoes such as grains, coal, and ores without packaging. (Coal and ores are transported a lot in Australia. Australia is a country with a lot of minerals.) In general, according to the scantling (structural analysis), horizontal members should not protrude into the cargo hold due to the characteristics of cargo that piles up and does not flow down easily. However, in unavoidable cases, the reinforcement is placed vertically (hold frame of the outer plate) or in the form of a corrugated bulkhead. The main navigation conditions are as follows. Light ballast condition (unloaded state) Heavy ballast condition (state of ballasting (filling with water) in designated cargo holds when encountering yellow sky while not loading cargo) Homogeneous loading condition (state of loading light cargo evenly in all cargo holds) Alternate loading condition (state of loading heavy cargo one by one across one cargo hold, such as iron ore) Alternate loading condition 이미지새 창에서 열기 www.researchgate.net Alternate loading condition Based on these navigation conditions, as shown in the figure above, the strength is calculated to satisfy the loads corresponding to each cargo hold and ballast tank. Bulk carriers, unlike tankers or container ships, have a single skin (single skin) on the outer plate (bottom part is a double skin structure). However, as you can see from the recent trends in bulk carriers, serious damage cases (large damage to the outer plate and sinking) have been reported. As a result, the International Maritime Organization (IMO) is demanding an increase in strength to ensure the stability of bulk carriers. The requirement for an increase in strength of the hold frame, which is the reinforcement member of the outer plate (Side Shell), has already been adopted and applied as a common Rule of IACS. In addition, for new ships, the following two options are proposed: A plan to make the outer plate structure itself a double skin structure. In the case of a single skin (single skin), it was reviewed to require reinforcement of the ship's stability, longitudinal strength, transverse frame, and double skin structure, considering flooding of the cargo hold. In the case of existing ships, it is also required to reinforce it appropriately. If you do not keep it, loading restrictions are imposed, such as not being able to do alternate loading, which is thought to be the main cause of damage to bulk carriers.

Location: 대한민국

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