Ballast Tank Corrosion Control
Ballast Tank Corrosion Control
V Thapar
Asst. Director Naval Architecture
Naval Headquarters, New Delhi
1.0 Introduction :
Steel, the most corrodible of all ship construction material, still remains the most economic choice of ship construction materials however, the very nature of steel, compounded by the salt laden marine ambience, makes the corrosion protection effort arduous. The marine environment is one of the harshest environments any structure could be subjected to. It is a well-established fact that the steel starts rusting/corroded before the ship is built, it continues to rust while she is being built and throughout its service life. Therefore the battle to keep the rust/corrosion at bay never ends. The marine and shipping industry is increasingly becoming more and more aware of the corrosion and its effect on steel structure leading to premature structure failure, with the loss of life and tonnage. Therefore the corrosion prevention is becoming paramount important factor for all ship builders and ship maintainers. Corrosion protection in consistently and severely corrosive marine environment often poses a challenge to ship building and ship maintenance authorities. The shipping industry expends considerably on corrosion protection measures to extend the longevity of ship and for general safety of the vessel. Though a wide variety of coatings have been developed, the poor coating practices followed often, impair the life of coatings. The most critical parts of the ship susceptible to corrosion are the boot top/ under water areas, ballast tanks and bilges. Considerable financial losses can result from premature damage to the coating system of these critical areas.
2.0 Ballast tanks
The ballast tank in a dry cargo ship constitutes around 70% of all tank spaces. As the ballast tanks are used to alternately fill in the seawater when the ships is in light condition and then to pump out the water when loaded with cargo, the
V Thapar
Asst. Director Naval Architecture
Naval Headquarters, New Delhi
1.0 Introduction :
Steel, the most corrodible of all ship construction material, still remains the most economic choice of ship construction materials however, the very nature of steel, compounded by the salt laden marine ambience, makes the corrosion protection effort arduous. The marine environment is one of the harshest environments any structure could be subjected to. It is a well-established fact that the steel starts rusting/corroded before the ship is built, it continues to rust while she is being built and throughout its service life. Therefore the battle to keep the rust/corrosion at bay never ends. The marine and shipping industry is increasingly becoming more and more aware of the corrosion and its effect on steel structure leading to premature structure failure, with the loss of life and tonnage. Therefore the corrosion prevention is becoming paramount important factor for all ship builders and ship maintainers. Corrosion protection in consistently and severely corrosive marine environment often poses a challenge to ship building and ship maintenance authorities. The shipping industry expends considerably on corrosion protection measures to extend the longevity of ship and for general safety of the vessel. Though a wide variety of coatings have been developed, the poor coating practices followed often, impair the life of coatings. The most critical parts of the ship susceptible to corrosion are the boot top/ under water areas, ballast tanks and bilges. Considerable financial losses can result from premature damage to the coating system of these critical areas.
2.0 Ballast tanks
The ballast tank in a dry cargo ship constitutes around 70% of all tank spaces. As the ballast tanks are used to alternately fill in the seawater when the ships is in light condition and then to pump out the water when loaded with cargo, the