The International Load Line Convention stipulates requirements for scuttles and windows mainly to ensure the watertight integrity and safety of ships. The rational design and installation of scuttles and windows can prevent seawater from entering the ship's interior, especially in severe sea conditions, protecting the ship's compartments and the safety of personnel.
1. Location Restrictions:
Scuttles should not be installed on the side walls of the first deckhouse below the bulkhead deck within the scope of Position 1 (on the exposed freeboard deck and the raised quarterdeck, as well as on the exposed superstructure deck forward of one - quarter of the ship's length from the forward perpendicular). This is because these locations are more vulnerable to wave impact, and scuttles at lower positions may lead to a large amount of seawater surging in.
For scuttles located in Position 2 (on the exposed superstructure deck aft of one - quarter of the ship's length from the forward perpendicular), there are also general requirements for the distance from the lower edge to the load waterline. For example, under normal circumstances, the lower edge should be at least 500mm from the load waterline, which can reduce the risk of seawater overflowing through the scuttle into the compartment.
2. Structural Strength and Watertightness:
Scuttles should have sufficient structural strength to withstand various external forces during the ship's navigation, such as wave impact and ship vibration. The frame materials of scuttles usually need to be high - strength metal materials, such as steel or aluminum alloy, and their thickness should meet the strength standards specified in the convention.
Scuttles must be watertight. The glass should be installed using reliable sealing methods, such as rubber gaskets, and there are also corresponding requirements for the thickness and quality of the glass. Generally, scuttle glass should be tempered glass or laminated glass to prevent seawater from entering after breakage. For example, the thickness of tempered glass is determined according to factors such as the size of the scuttle and the ship's navigation area, usually between 10 - 15mm, and the interlayer of laminated glass should effectively prevent water penetration.
3. Closing Devices:
Scuttles should be equipped with reliable closing devices, usually hinged metal covers. After the cover is closed, it should fit tightly to the frame to ensure watertightness. The closing device should be easily operable from inside the ship, and in the closed state, there should be sufficient locking devices to prevent the cover from accidentally opening during the ship's swaying. For example, the locking device can be a bolt with a lock - nut or a buckle with a safety device to ensure the tightness of the scuttle in severe sea conditions.
4. Location and Height Restrictions:
For windows located above the freeboard deck, their locations and heights are distinguished according to the ship's Position 1 and Position 2. The height requirement from the lower edge of the window in Position 1 to the load waterline is higher than that of the window in Position 2. Under normal circumstances, the lower edge of the window in Position 1 should be at least 600mm from the load waterline to prevent waves from splashing onto the window easily.
The location of the window also needs to consider the layout of the ship's superstructure and deckhouse. If the window is located at the end of the superstructure, the impact of side waves should also be considered, and it may be necessary to appropriately increase its height or strengthen its protective measures.
5. Watertightness and Air - tightness:
Windows also need to have good watertightness and air - tightness. Similar to scuttles, the installation of their frames and glass should adopt effective sealing measures. For some compartments with requirements for the indoor environment, such as the ship's bridge and crew accommodation cabins, the air - tightness of the window can ensure that the indoor temperature, humidity, and air quality are not overly affected by the external environment. For example, in the ship's bridge, the air - tightness of the window can reduce the generation of fog and improve the visibility.
The sealing materials of the window should be able to withstand the corrosion of seawater and the temperature changes of the ship under different climatic conditions. Usually, seawater - resistant rubber materials are used as sealing strips, and their service life should meet the requirements of the ship's operating cycle.
6. Protective Measures:
Depending on the ship's navigation area and purpose, windows may need to be equipped with additional protective measures. For example, ships navigating in ice - covered areas may need to install protective grilles on windows to prevent damage from ice impacts. In some areas that may be affected by strong winds or foreign objects, windows can adopt double - glazed or reinforced frame structures to improve their impact resistance. At the same time, the opening angle and method of the window are also regulated to prevent the window from accidentally opening in strong winds and causing potential safety hazards. For example, the maximum opening angle of the window is generally not more than 15 - 30 degrees, and there should be a reliable limit device.