Table of Contents
- 1 How is the procedure of cargo preparation prior to loading?
- 2 What is D1 and D2 in ballast water management?
- 3 Why are holds inspected prior to loading?
- 4 What are the three types of ship stability?
- 5 What is d2 standard in ballast water management?
- 6 What is dirty ballast?
- 7 When do you need to carry ballast on a ship?
- 8 What happens to the ballast water during deballasting?
How is the procedure of cargo preparation prior to loading?
How to prepare cargo holds prior loading
- The compartment should be swept clean, and all traces of the previous cargo removed.
- Bilge areas should be cleaned and all ‘bilge suctions’ seen to be working satisfactorily.
- The fire/smoke detection system should be tested and seen to function correctly.
What is ballasting and de ballasting?
Ballasting or de-ballasting is a process by which sea water is taken in and out of the ship when the ship is at the port or at the sea. In ancient times, ships used to carry solid ballast for stability as the cargo was minimal or there was no cargo to be carried.
What is D1 and D2 in ballast water management?
The BWM Convention includes two performance standards for the discharge of ballast water: D1 and D2. The D1 standard concerns ballast water exchange, which must be undertaken within open ocean areas, >200nm from land and in seas >200m deep. The D2 standard covers approved ballast water treatment systems.
What are the conditions to be taken before ballast operations?
When planning and carrying out operations with ballast water the following factors must be taken into account: Shear Force and Bending Moment. Stability and Free Surface Effect. Slack Tanks.
Why are holds inspected prior to loading?
Inspection of hold helps identify for structural damage or defects in the hold. Similarly it is important to prepare holds before loading the next cargo. Preparation of holds depends upon the next cargo, if next cargo is compatible with the last, a good sweep down and removal of leftover cargo is all that is required.
What are General precautions taken prior to loading bulk cargo?
Holds inspected –in proper state for reception of cargo, paying particular attention to ; Bilge wells and lines,Sounding pipes & other service units with Protective coverings- checked & strengthened. Bilge wells & strainers plates- facilitates drainage.
What are the three types of ship stability?
There are three types of equilibrium conditions that can occur, for a floating ship, depending on the relation between the positions of the centre of gravity and centre of buoyancy….Intact Stability of Surface Ships:
- Stable Equilibrium: Study the figure below.
- Neutral Equilibrium:
- Unstable Equilibrium:
How is ballast water treated?
There are three approaches to treating ballast water; mechanical, physical or chemical. Mechanical methods would include separation and filtration; physical methods include ozone, electrical currents, or UV radiation, while chemical solutions are biocides or a form of chlorination.
What is d2 standard in ballast water management?
The D-2 standard specifies the maximum amount of viable organisms allowed to be discharged, including specified indicator microbes harmful to human health. From the date of entry into force of the BWM Convention, all ships must conform to at least the D-1 standard; and all new ships, to the D-2 standard.
Why is ballast water bad?
Ballast water is essential for safe and efficient modern shipping operations. But ballast water also impacts serious ecological problems due to the multitude of marine species carried in ships’ ballast water. The ballast water includes bacteria, microbes, small invertebrates, eggs, cysts and larvae of various species.
What is dirty ballast?
Dirty ballast is water which may contain residual fuel and other constituents as a result of sea water being stored in fuel tanks. Dirty ballast is discharged to the environment after being processed through OCMs and/or OWS systems that ensure the ballast water fuel/oil concentrations are below Federal standards.
What to know about cargo and ballast operations?
Cargo and ballast operation plans should be carefully prepared and monitored onboard all merchant ships. Such plans need to consider Seasonal Load Line Zones, Port restrictions, Shipboard limits, e.g., Draft, Cargo capacity, Stability, Stresses, etc.
When do you need to carry ballast on a ship?
When the Ship is not carrying cargo or is lightly loaded, sufficient ballast must be carried to ensure that the Ship’s stress, stability, draft, trim, and propeller immersion is within permissible limits. These can safeguard a vessel in the prevailing or expected conditions.
Which is the correct way to fill a ballast tank?
• Dilution Method: A method by which replacement ballast water is filled through the top of the ballast tank with simultaneous discharge from the bottom at the same flow rate and maintaining a constant level in the tank throughout the ballast exchange operation.
What happens to the ballast water during deballasting?
However, these pumps are not efficient in pumping out the few remaining ballast water inside the tank. This is where the ballast stripping system comes in. During the last stage of deballasting, they use an ejector to discharge the remaining ballast water in the tank.