What Are The 5 Different Types of Hatch Cover?

Publish Time: 2022-05-05 Origin: Site

Watertight hatch covers and matching hatch coamings are critical core marine equipment for all cargo vessels. Their core dual functions: block seawater and rainwater from flooding cargo holds, and protect hull structures from long-term saltwater corrosion, avoiding cargo wet loss during ocean transit.

Based on hydraulic drive structure, opening mode and deck stowage requirements, the global shipping industry standardizes 5 mainstream ship hatch cover types: Lifting (Lift-Away), Rolling, Folding, Sliding, Roll Stowing (Stacking). Each design matches specific vessel types including container ships, dry bulk carriers, general cargo ships and barges. This guide explains each hatch cover’s working principle, applicable ships, advantages, drawbacks and selection criteria for shipowners, shipyards and marine equipment purchasers.

The main purpose of a ship's hatch covers and hatch coamings is to prevent water from entering the cargo hold and protect the cargo from wetting and damage. The hatch cover also acts as a barrier to protect the ship's internal structure from being damaged by seawater corrosion in extreme weather. Of course, in order to meet the requirements of various types of cargo ships and the need to save costs, the hatch covers are designed into different types.

There are mainly the following 5 types of hatch covers:

Lifting type

Rolling type

Folding type

Sliding type

Roll stowing type

Lifting type is commonly used on container ships; Sliding type is usually used in dry bulk carriers (directional sliding); Rolling type is also known as rolling hatch; Folding type is usually used in general cargo ships.

However, the choice of hatch covers varies according to the stowage space of the vessel and the specific conditions of the cargo being transported.

* Sliding type, mainly used in large dry bulk carriers. The hatch cover has a simple structure and is convenient to use.

* Folding type: Folding hatch covers are usually composed of two-leaf hatch panels, which are operated by hydraulic power and are suitable for weather decks and second decks. Its main advantage is the reduction in the number of hatch panels due to its large size.

* Rolling type: Rolling type hatch cover and adding pulley to prevent vertical and horizontal movement when moving the hatch cover, mostly used for small and medium-sized general cargo ships. Due to the size and weight of the hatch, it is often hydraulically powered to reach the roll position, and opening and closing the hatch is slow.

* Lifting type: Lifting hatch covers can be divided into two types: single hatch covers and multiple hatch covers

The single hatch cover, as the name suggests, has only one hatch cover, which can be seen mainly in bulk carriers. Multiple hatch covers, that is, a cargo hold with multiple sheet hatch covers, are commonly used in grid-type container ships and multi-purpose ships to prevent cargo from shifting.

* Stacking type: This type of facility is mostly used on ships with relatively small hatch covers. It is equipped with a hydraulic power crane, which is convenient for lifting the hatch covers and stacking them at one end of the ship or in an empty space. It is relatively cheap and is often used on barges.