The balast tank is a compartment in boats, boats or other floating structures that retain water, which is used in return to provide stability for ships. Using water in the tank allows for easier weight adjustment than stone or iron reply as used on older vessels. It also allows the ballast to be pumped out to reduce temporary draft of the vessel when needed to enter the shallow water. Airships use ballast tanks for similar advantages.
Video Ballast tank
History
The basic concept behind the ballast tank can be seen in various forms of aquatic life, such as blowfish or argonaut octopus, and the concept has been discovered and recreated many times by humans to serve various purposes. The first example of a submarine using a ballast tank is in the SS Turtle of David Bushnell, which was the first submarine ever used in combat. Also, in 1849 Abraham Lincoln, an Illinois lawyer, patented a ballast-tank system to allow cargo ships to pass through shoals in North American rivers.
Maps Ballast tank
Ship
To provide adequate stability for ships at sea, ballasts are used to weigh down ships and lower their center of gravity. International agreements under the Sea Life Security Agreement (SOLAS) require that cargo ships and passenger vessels be built in such a way that they can withstand certain types of damage. These criteria determine the separation of the compartments in the vessel and also the distribution of the compartment. International agreements depend on countries that have signed agreements to apply the rules in their waters and on vessels entitled to fly their flags. Ballasts are generally sea water that is pumped into tanks known as ballast tanks. Depending on the type of vessel, the tank can be double bottom (extending across the width of the ship), tank wings (located in the outboard area from keel to deck) or hopper tanks (occupying the upper corner between the hull and the main deck). The ballast tank is connected to a pump that can pump incoming or outgoing water. These tanks are filled to increase the weight of the ship when the load has run out, and increase its stability. In some extreme conditions, the ballast water may be introduced into a special cargo room to add extra weight during bad weather or over a low bridge.
Submarine
In submarines and submarines, ballast tanks are used to control the buoyancy of the ship.
Some submersibles, such as bathyscaphes, dive and re-surface solely by controlling their buoyancy. They overwhelm the return tanks to soak, then bring back either dropping ballastable ballastable weights, or using compressed air stored to blow their ballast tanks out of the water, becoming floating again.
Submarines are bigger, more sophisticated and have a strong underwater driving force. They must travel a horizontal distance submerged, requiring proper depth control, but not so deep down, and no need to dive vertically in the station. Their main tool in controlling the depth is their diving field, in combination with forward motion. On the surface of the ballast tank is emptied to provide positive buoyancy. When diving, the tanks are partially flooded to achieve a neutral buoyancy. The plane is then adjusted together to push the stomach down, while still flat. For a steeper dive, the stern plane may be reversed and used to throw the stomach down.
Immersion is done by opening the vents at the top of the ballast tank, as well as opening the valve at the bottom. This allows the water to flood the tank, and allows the air already in the tank to exit through the upper vents. when the air comes out of the tank, the buoyancy of the ship decreases, causing it to sink. In order for the submarine to surface, the hole at the top of the ballast tank is closed, and compressed air is allowed into the tank. High pressure air bags push the water out through the bottom valve and increase the buoyancy of the ship, causing it to rise. A submarine may have some type of reply tank: the main reply tank, which is the main tank used for diving and surface, and the trimming tank, which is used to adjust the submarine's ('trim') posture both on the surface and under water.
Floating structure
Ballast tanks are also an integral part of the stability and operation of offshore deepwater oil platforms and floating wind turbines. Balast facilitates "hydrodynamic stability by moving the center of mass as low as possible, placing it under a floating tank [filled with air]."
Wakeboard Boat
Most wakeboard-powered boats have some integrated ballast tanks filled with ballast pumps controlled from the steering wheel with rocker switches. Usually the configuration is based on a three tank system with a tank in the middle of the boat and two more at the rear of the boat on either side of the engine compartment. Just as larger vessels when adding water ballast to a smaller wakeboard boat the hull has a lower center of gravity, and increases the draft of the boat. Most of the wakeboard boat mill's ballast systems can be upgraded with a larger capacity by adding a soft structured ballast bag.
Environmental issues
Water retrieval taken into the tank from one body of water and disposed of in another water body can introduce aquatic life invasive species. Water retrieval from the ballast tank is responsible for the introduction of species that cause environmental and economic damage. For example, zebra mussels in the Great Lakes of Canada and the United States.
Non-indigenous macroinvertebrates can find their way to the reply tank. This can cause problems ecologically and economically. Macro-invertebrates are transported by transosania ships and beaches that arrive at ports around the world. Researchers from Switzerland sampled 67 tanks of vaccine from 62 different ships operating along geographic lines, and tested for middle or long ocean voyage shifts that have high probability of macro-invertebrates that move to different parts of the world. Assessment is made between the relationship of macro invertebrate existence, and the amount of sediment in the return tank. They found the existence of a highly invasive European green crab, mud crab, ordinary periwinkle, soft shell shells, and blue shells in the reply tank from the sample vessel. Despite the low macro invertebrate density, invasion of non-native macro invertebrates can be alarming during their mating season. The worst thing that can happen is if a female macro-invertebrate carries millions of eggs per animal.
Live animal migration and the deposition of particle-bound organisms can cause uneven distribution of biota in various locations in the world. When small organisms escape from ballast tanks, foreign organisms or animals can disrupt the balance of local habitat and potentially damage the life of the animals. The ship worker examined the ballast tank for living organisms> = 50 m in the discrete sewer segment, also representing different levels of rock or soil sediments in the tank. Throughout the sample collection, the concentrations of organisms and marine life vary in generating drain segments, patterns also varying in stratification rates in other trials. The best sampling strategy for multilevel tanks is to collect examples of integrated time that are placed evenly at each disposal.
All trans-ocean vessels coming into the Great Lakes are required to manage the ballast water and tank ballast residue with air ballast to clean and exchange the flushing tanks. Management and procedures reduce biota density and richness effectively in return waters and thereby reduce the risk of transporting organisms from other parts of the world to non-indigenous areas. Although most of the vessels performing water ballast management are not all able to clean the tank. In an emergency when the residual organism can not be cleaned, the ship worker uses salt water sodium chloride to treat the ballast tank. Ships arriving in the Great Lakes, and North Sea ports, were subjected to high concentrations of sodium chloride until a 100% mortality rate was reached. The results indicate that exposure to 115% salt water is a very effective treatment that results in a mortality rate of 99.9 live organisms in the reply tanks regardless of the type of organism. There is a 0% median. About 0.00-5.33 organisms are expected to survive from sodium chloride treatment. The Ballast Water Management Convention, adopted by the International Maritime Organization (IMO) on 13 February 2004, aims to prevent the spread of harmful aquatic organisms from one region to another by establishing standards and procedures for the management and control of ship ballast water. and sediment. This will apply worldwide on September 8, 2017. Under the Convention, all ships in international traffic are required to manage their ballast and sedimentary water to a certain standard, in accordance with the ship's special ballast water management plan. All ships should also carry a water ballet and a certificate of international ballast water management. The water management standards of reply will be phased out over a period of time. As an intermediate solution, the vessel must exchange water in the middle of the sea. However, eventually most of the vessels need to install an on-board ballast water treatment system. A number of guidelines have been developed to facilitate the implementation of the Convention. The Convention will require all vessels to implement the Ballast and Sediment Water Management Plan. All vessels must carry the Ballast Water Record Book and will be required to implement the water reply management procedures for the given standard. The existing vessels will be required to do the same, but after the in-phase phase.
One of the most common problems between ship construction and maintenance is the corrosion that occurs in the double ballast space tank in the merchant vessel. Bio-degradation occurs in ballast tank coatings in the marine environment. The ballast tank can carry more than air ballasts; most ballast tanks are filled with bacteria or other organisms. Some of these bacteria that can be taken from other parts of the world can cause the repellent tanks to be damaged. Bacteria from different regions plus natural bacteria can cause ballast tanks to break down. Natural bacterial communities have natural bio-film interactions with layers, an aspect not covered by standard procedures. Researchers have shown that biological activity does significantly affect coating properties. Micro cracks and small holes have been found in the reply tanks. Acid bacteria create holes 0.2-0.9 m long and 4-9 m wide. The natural community causes cracks with a depth of 2-8 m and a length of 1 m. The EIS technique is used to check degradation. Bacteria-exposed coatings decrease in corrosion resistance. A natural community, having a clear disadvantage in layer resistance over time. Also, the corrosion resistance of the coating decreases after 40 days of exposure to the natural community, resulting in blisters in the ballast tank. Bacteria may be associated with certain bio-film patterns that affect different types of layer attacks.
See also
References
Briski, E., Ghabooli, S., Bailey, S., & amp; MacIsaac, H. (2012). The risk of invasion generated by macroinvertebrata is transported in a ship ballast tank. Biological Invasion, 14 (9), 1843-1850.
Robbins-Wamsley, S., Riley, S., Moser, C., Smith, G., et al. (2013). Stratification of living organisms in ballast tanks: How do organisms vary as water content is removed?.Environmental Science & amp; Technology, 47 (9), 4442.
Bradie, J., Velde, G., MacIsaac, H., & amp; Bailey, S. (2010). Deaths caused brine non-native invertebrates in the remaining ballast water. Maritime Environment Research, 70 (5), 395-401.
De Baere, K., Verstraelen, H., Rigo, P., Van Passel, S., Lenaerts, S., et al. (2013). Reduce the cost of corrosion ballast tank: The approach of economic modeling. Maritime Structure, 32, 136-152.
Heyer, A., D'Souza, F., Zhang, X., Ferrari, G., Mol, J., et al. (2014). Biodegradation of ballast tank coatings was investigated by impedance spectroscopy and microscopy. Biodegradation, 25 (1), 67-83.
Source of the article : Wikipedia
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