Weather and watertightness

On board ships, strict weather- and watertightness requirements are imposed to ensure the safety of the ship, crew and cargo. Some of the key requirements are:

• Watertightness of hull and structure: The hull of the vessel must be watertight to prevent water from entering the vessel and causing damage to the structure, machinery and cargo. This requires high-quality construction techniques and materials, as well as regular inspection and maintenance to detect and repair any leaks or damage.
• Watertight doors and hatches: Doors, hatches and other openings in the hull and structure must be watertight to prevent water from entering the vessel, especially in rough seas and bad weather. These openings must be properly sealed and equipped with locking mechanisms able to withstand high water pressure and waves.
• Watertight compartmentalisation: Ships are often divided into several compartments to limit the spread of water in case of a spill or damage. These compartments must be watertight to prevent water from spreading through the vessel and compromising its stability and buoyancy.
• Weatherproof construction: Ships have to withstand extreme weather conditions, including high winds, high waves, rain and icy conditions. This requires robust construction and materials resistant to corrosion, erosion and mechanical stresses caused by rough seas and wind forces.
• Drainage systems: Ships must be equipped with effective drainage systems to drain rainwater, slush and water washed onto the deck to prevent it from accumulating and causing damage to structure, equipment and cargo.

All these weather- and watertightness requirements are laid down in international maritime safety regulations and standards, such as those of the International Maritime Organisation (IMO) and classification societies like Lloyd’s Register, DNV and Bureau Veritas. Compliance with these regulations and standards is essential for the certification and classification of ships and to ensure safety at sea.
 

When should a door or hatch be watertight and when is weatherproofing sufficient?

Doors and hatches must be watertight when located below the main deck or if the sill height (in the case of a door) or coaming height (in the case of a hatch) required by the classification society is not met. Doors and hatches located on or above the main deck (and meeting the required sill or coaming height) and in contact with the outside air must be weathertight. The exact rules depend on the classification society selected.
 

Critical components: hinges, toggles and rubber

To create weather- or watertightness, it is important to use enough toggles and hinges. This reduces the intermediate distances, creating a good seal. During production, care must be taken to ensure that, when the door or hatch is gripped, sufficient indentation of the rubber is created so that the door or hatch is sufficiently weather- or watertight.
 

How are weather- and waterproofing tested?

The water and weather resistance of doors and hatches on board of ships is usually tested by means of specific test procedures and standards, carried out by qualified inspectors or classification societies. Here are some of the common test methods:

• Watertightness tests: These tests simulate conditions where the door or hatch is exposed to water pressure to check that it remains watertight. For watertight doors, the door is usually subjected to water pressure from the inside (the weakest side). The pressure is slowly increased to see if leakage occurs. For weathertight doors and hatches, a hose test is carried out from the outside. Water is sprayed on the closed hatch or door to see if water penetrates the seals.
• Structure stability tests: These tests evaluate the structural integrity of the door or hatch under various loads, including water pressure, wind load and waves. This often involves applying static and dynamic loads to the door or hatch to see if it can withstand the forces that may occur during normal operating conditions.
• Inspection of seals: Inspectors check the seals around the door or hatch to see if they are intact and functioning properly. This includes checking for cracks, wear, deformation or other defects that could affect waterproofing. Sometimes a visual inspection is carried out as well while the door or hatch is opened and closed to check for any leakage points.
• Operating testing: These tests evaluate the operation and functionality of the door or hatch, including its opening, closing and locking. This includes checking the operation of the locking mechanisms, hinges, latches and other components to make sure they are functioning properly and not defective.

After conducting these tests and inspections, the results are analysed and assessed to determine whether the door or hatch meets the required standards and specifications for water and weather resistance. If in compliance, it is certified as water- and weather-resistant and can be used on board the vessel. If not, any defects must be corrected before it can be approved for use.
 

Rob Snel supplies weather- and watertight doors and hatches

We are specialists in manufacturing weather- and watertight doors and hatches. We do not stock standard doors or hatches. They are always tailor-made. As a result, we can make anything you want. If you want to order a weatherproof or watertight door or hatch, remember to specify in advance whether it needs to be certified. We will invite the classification society of your choice and provide a certificate. It is not possible to have a door or hatch certified retrospectively, i.e. after delivery.

Rob Snel has its own in-house test rig for testing the watertightness of doors. We test the watertightness of your door based on the pressure you specify.

On our website, you will find numerous examples of doors and hatches we have produced. More info? Feel free to get in touch!