"The primary purpose of a ship's hatch covers and hatch enclosures is to prevent water from entering the cargo hold and to protect the cargo from wetting and damage. The hatch covers also act as a barrier to protect the internal structure of the ship from damage due to corrosion by seawater in extreme meteorological conditions. Of course, in order to adapt to the requirements of various types of cargo ships and the need to save costs, hatch covers are designed into different types. There are five main types of hatch covers:
Lifting type
Rolling type
Folding type
Sliding type
Rolling stowing type
Roll stowing type covers are commonly used on container ships;
Sliding type covers are commonly used on dry bulk carriers (directional sliding);
Rolling type hatch cover is also known as rolling type hatch cover can be divided into rolling type, rolling type and rolling type three;
Folding hatch covers are commonly used on general cargo ships. However, the choice of hatch covers varies according to the cargo space and the cargo to be transported.
Side-sliding hatch covers
Side-sliding hatch cover, mainly used in large dry bulk carriers. This type of hatch cover is simple in structure and easy to use.
Folding hatch cover: Folding hatch cover usually consists of two pages of hatch cover plate, operated by hydraulic power, suitable for open deck and second deck. Its main advantage is the reduction in the number of hatch panels due to its huge size.
Rolling hatch covers: Rolling hatch covers with pulleys to prevent longitudinal and transverse movement when moving the hatch cover are mostly used on small and medium sized general cargo ships. Due to its huge size and heavy hatch cover, often by hydraulic power to achieve the rolling position, and the opening and closing of the hatch is relatively slow.
The lifting hatch cover can be divided into two types: single hatch cover and multi-hatch cover.
Single hatch cover, as the name implies, the hatch cover is only one page hatch cover, which can be seen mainly in bulk carriers. Multi-cabin cover, i.e. a cargo hold has more than one page of cover, commonly used in net-type container carriers and multi-purpose ships, to prevent cargo displacement.
Stacking hatch cover: this type of facility is mostly used in relatively small hatch cover ships, equipped with a hydraulic power crane, easy to lift the hatch cover stacked at one end of the ship or in the empty space, relatively cheap, commonly used in barges."
