Ballasting/ De-Ballasting Operation

Types of Ballast Tanks in Oil Tanker Segregated ballast tanks (SBT): Ballast water is taken on board to maintain stability when a vessel is sailing empty to pickup cargo or after unloading the cargo.
Regulations The SBTs are special tanks which are constructed only to carry ballast water. Ballast water contained in segregated ballast tanks never come into contact with either cargo oil or fuel oil. Clean ballast tanks (CBT): A cargo tank can also be called as CBT in an oil tanker if it is dedicated for carrying ballast water (once the tank is free from the cargo. Regulations related to oil tankers As per MARPOL Annex 1, Regulation 18 - Every crude oil tanker of 20000 tonnes deadweight and above and every product carrier of 30000 tonnes deadweight and above delivered after 1
st
June 1982, as defined in regulation 1.28.4, shall be provided with segregated ballast tanks.
97. l Marine Insight Cargo Operations for Tanker I 98. Segregated Ballast Tanks- SBT

The capacity of segregated ballast tanks shall be so determined that the ship may operate safely on ballast voyages without any need of cargo tank as clean ballast tank for water ballast except when in need. In no case shall ballast water be carried in cargo tanks (Clean Ballast tanks, except On those rare voyages when weather conditions are so severe that in the opinion of the master, it is necessary to carry additional ballast water in cargo tanks for the safety of the ship and In exceptional cases where the particular characteristic of the oil tanker operation renders it necessary to carry more ballast water than the quantity required, provided such action of the oil tanker falls under the category of exceptional cases as established by the Authority Ballasting or de-ballasting operation to be carried out as needed. Before carrying out the operation, berth Loading) Masters permission must betaken by the chief officer or master.
99. l Marine Insight Cargo Operations for Tanker I 100. Tank Level Gauges in CCR

Before starting de-ballasting, the sighting ports of all ballast tanks must be opened, and water surface must be checked for any oil sheen. Once the ballast tanks are sighted and checked, deballasting can be commenced using one or more ballast pumps. The pump should be primed with seawater by opening the tank valve. As the pump starts, the discharge valve should be opened slowly. The rate of deballasting depends on the loading rate if loading rate is faster, the vessel should deballast using both the pumps. During initial stages of loading, deballasting can be used to keep vessel upright. The final stage of deballasting includes stripping of ballast tanks. Ballast pump drives ballast eductor and the discharge goes overboard. The suction created in eductor is led to ballast tanks via a thin line known as stripping line. The ballast stripping line is entirely separate and independent from the cargo stripping line.
101. l Marine Insight Cargo Operations for Tanker I 102. Oil Tanker Conducting Ballast Operation

The drive pressure for this line is usually up to 4 -5 bars. On some ships instead of ballast pump, fire pump is also used. For ballasting cargo tanks initially by gravity, sea chest valve is opened, and water is led into the ballast tanks by opening the tank valve. Later on, when the rate of gravity decreases, pumps can be lined up to take suction from the sea chest and discharge it into the ballast tanks. Records Valid Certificate All vessels of the party states are required to have a certificate, indicating that they are the undersigned party of the International Water Convention and are required to apply to all the terms in due diligence. Ballast Water Management Plan The copy of the
BWM plan to be carried on board, containing information regarding the requirements of ballast water such as :
103. l Marine Insight Cargo Operations for Tanker I 104. Pump Parameter

• Procedure for reporting to different port authorities
• Assistance to the master in exchanging the ballast water in a safe manner
• Safety procedures for ship and crew
• Circumstances in which ballast water exchange should not be undertaken Ballast Water Record Book It is mandatory to keep a ballast water record book onboard, which will indicate the place, time and the amount of ballast water operations of the vessel.
105. l Marine Insight Cargo Operations for Tanker I 106.

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