What is Underwater Hull Cleaning?
Underwater hull cleaning or ship hull cleaning is an extremely important part of maintaining the health and integrity of the vessels. The hull and structure of the ship under the surface of seawater or freshwater face various levels of fouling by marine or aquatic organisms, caused by the biofilms formed on such structures. Hull cleaning ensures that the biofilms formed, and the fouling organisms attached to all subsurface structures, including propellers, rudders, inlet and outlet ports, sonar housings, and protective grills, are removed and the health of the vessel maintained. Usually, if the vessel is very diverse or intricate in structure, it will be harder to undertake hull cleaning services.
Underwater ship hull cleaning is extremely important as hull and propeller performance may deteriorate over time, if biofouling is not cleaned routinely. This could lead to mechanical damage and the resulting poor hull conditions will reduce energy efficiency. Further, underwater hull cleaning is essential as biofilms stuck on the hull can impact the ship’s dynamics by heightening. This increases fuel consumption and CO2. emissions Studies also indicate that an idle vessel tends to gather more biofilm and, therefore, requires greater hull cleaning services to maintain its integrity.
Hull cleaning involves the use of different machines and solutions to get rid of the biofilm and the attached biofouling agents as this helps maintain the vessel’s performance and energy efficiency over years. At present, methods such as dry-docking cleaning, antifouling paint, and periodic underwater cleaning are frequently used for underwater ship hull cleaning. Studies have also indicated that use of high-pressure abrasives in dry docks can also be a good method of underwater hull cleaning.
What is the best way to clean the ship’s hull?
Let us consider the best way to clean the ship’s hull. The most common ways include manual hull cleaning, powered rotary brush cleaning systems, and noncontact cleaning technology. The first method, manual hull cleaning, is usually performed on small ships such as recreational yachts and fishing boats. Based on the amount and nature of the biofouling, including slime, biofilm, etc., and the type of antifouling coating already present on the vessel, the manual hull cleaning may be carried out using brushes, or scraping devices.
The second method is the powered rotary brush cleaning system, which uses mechatronics equipment, especially for large vessels. In such scenarios, large brush devices are preferred for quickly cleaning flat or slightly curved areas of the hull, and small brushes are utilized for better results when cleaning the propeller. Bigger vessels might even choose a combination of multiple brushes for best results. Thirdly, there is the simple cleaning tactic, where unpowered cleaning brushes are used to frequently remove deposits from the surface of ships. This is done manually and routinely to ensure that the surface remains clean and healthy. It is also simpler than the other two methods but cannot be used for larger surfaces or for harder coats of biofouling agents.
Finally, under the contactless underwater cleaning method, there are techniques like high-pressure water jet method, the cavitation water jet method, and the ultrasonic cleaning method. These methods are known to be highly effective and they cause minimal damage to the vessel, as long as they are used properly, and by experienced professionals.
What are the types of Underwater Hull Cleaners or Tools?
Given the number of methods in use for underwater hull cleaning, it is no surprise that there are a variety of underwater hull cleaners or tools created for the express purpose of keeping the hull clean and well maintained. From handheld cleaners, and large cleaning equipment, to cleaning robot systems, the marine industry has seen an array of underwater hull cleaning tools and these can be used to serve different purposes.
In addition, there are also a number of types under these categories. For instance, when looking at the humble hull cleaning brush, we realize that this brush could be of any of the following types – nylon brushes for cleaning a certain thickness of mud and sea grass, steel brushes for cleaning barnacles, heavy grass, and zebra mussels, nylon or non-metallic brushes for fiberglass, wood, aluminum, and steel surfaces and metal brushes for aluminum and steel surfaces.
Further, ship hull cleaning also involves the use of high-pressure water cleaning jets which rely on their own impact force to remove biofouling. The stronger the pressure, the better the results, but you must remember that the pressure should be dependent on the structure and surface of the vessel. Otherwise there could be some damage. As long as proper water pressure is used to safely remove the slime layer, there would be minimal damage to the hull coating.