Session 18: Ballast Water Management Flashcards
why do ships carry ballast water?
-to enhance seaworthiness and safety of the ship
-maintain stability when traveling with light or no loads
-and discharge this ballast water when laden with cargo
The amount of ballast water a ship needs depends on what factors?
-size
-type
-operational requirements of port and cargo
-length and nature of the voyage
-weather experienced or forecast
what problems do ballast water pose?
Pose..
-ecological
-economic
-health problems
Due to the great number of marine species carried in ballast water
When did BWM convention came into force?
convention came into force internationally on 8th sept 2017
Who approves the the BWM plan?
The flag state
what are the two types of BWM standards?
-D1 ballast water exchange standard (exchanging water)
-D2 Ballast water performance standard(treatment of water with equipment)
-from 2024 all new ships must have D2 standard
the BWM plan applies to who?
-Applied to all vessels regardless of size/tonnage that operate internationally more than one party to the convention( involvement of multiple countries in the agreement)
-Ships above 400GT and above should have ballast water convention certificate
What do ships have to carry from the date of entry into force?
-ballast water management plan (says who is responsible of the ballast management plan)
-ballast water record book
-international ballast water management certificate (ships of 400GT and above)
BWM doesn’t apply to whom?
-ships not constructed to carry ballast water
-ships that only operate in the waters of a single party to the convention domestically operating vessel
-ships operating in the waters of a single party and on the high seas
-warships, naval auxiliary, ship owned and operated by state and use by government in non commercial activities
-permanent ballast water in sealed tanks on ships that is not subject to discharge
which standard is this?
-ships to exchange ballast in open waters
-ships are required to conduct ballast water when
200 nm from the nearest land
And in water at least 200 m deep
ballast water management standards D1
what’s the process for “Sequential Method” for ballast water exchange
In this method, the ballast tanks are first emptied and then refilled with new water.
The process involves the complete discharge of the ballast water from a tank and then refilling it with replacement water.
This method is effective in ensuring a significant change in the water’s biological constituents, as almost all the original water is replaced.
However, it can be challenging to implement in rough sea conditions and can affect the stability of the vessel during the operation.
How does the “Flow-Through Method” work?
This method involves pumping in new ballast water into a tank, causing the existing water to overflow and be discharged.
A large volume of water, typically three times the tank’s capacity, is pumped through to ensure adequate dilution of the original water.
The flow-through method is generally safer for the ship’s stability as it avoids the need for completely emptying the tanks.
It is more feasible in rough sea conditions compared to the sequential method.
What are some drawbacks of ballast water exchange?
-difficult to remove sediments completely from the bottom of ballast tanks
-organism attached to the sides of the tank will not be completely removed
-during rough seas or stormy, it is unsafe to exchange ballast water
On what factors does a safe and efficient ballast water exchange depend on?
-weather
-ship arrangement
-distance from nearest land
-water depth
-salinity
-deviation from planned route
What does the D2 BWM standards specify about “viable organisms”?
-specifies the maximum amount of viable organisms allowed to be discharged
