Ballast System • Marine Engineering Knowledge •

Summary

The ballast system involves the use of a ballast pump to manage seawater levels in tanks, allowing for the transfer, addition, or removal of seawater. The pump can draw water from any tank and discharge it to another tank or overboard, depending on the situation. Different ballasting methods include taking seawater into specific tanks, discharging it overboard, and transferring water between tanks. The gravity method relies on natural flow to de-ballast tanks or transfer water when there's a level difference. Understanding these processes is crucial for managing a ship's stability and ballast efficiently.

Takeaways

• 😀 Ballast pump is responsible for pumping seawater into or removing seawater from the tanks.
• 😀 The pump takes suction from any of the tanks through the valve chest and can discharge to any tank or overboard.
• 😀 When pumping from a particular tank, all other tank valves must be shut except for the one involved.
• 😀 The ballasting process involves pumping seawater into a tank (e.g., Tank 4 starboard).
• 😀 Deep ballasting involves pumping seawater from a tank (e.g., Tank 4 starboard) and discharging it overboard.
• 😀 Tank-to-tank transfer involves the pump taking suction from one tank (e.g., Tank 7 starboard) and discharging it to another (e.g., Tank 3 port).
• 😀 Gravity method is used for de-ballasting tanks, where seawater flows out of the tank by gravity.
• 😀 The animation demonstrates Tank 4 starboard being de-ballasted using the gravity method.
• 😀 Tank-to-tank transfers can also be done by gravity if there is a level difference between the tanks.
• 😀 The ballast system operates under the principle of controlling the flow of seawater between tanks for balancing purposes.

Q & A

What is the primary function of the ballast system?

The primary function of the ballast system is to control the stability and trim of the ship by either pumping seawater into or removing seawater from the ballast tanks.

How does the ballast pump work?

The ballast pump takes suction from any of the ballast tanks through the valve chest and can discharge seawater either to a specific tank or overboard.

What must be done when pumping from a particular ballast tank?

When pumping from a particular ballast tank, all other tank valves must be shut to prevent water from entering or leaving any tank other than the one being pumped.

What is meant by 'ballasting' in the context of the ballast system?

Ballasting refers to the process of filling a specific ballast tank with seawater. In the provided example, tank 4 starboard is ballasted by the pump taking in seawater and discharging it into that tank.

How does deep ballasting work in the ballast system?

In deep ballasting, the pump takes suction from a specific ballast tank, such as tank 4 starboard, and discharges the seawater overboard, instead of adding it to another tank.

What is the process of tank-to-tank transfer in the ballast system?

Tank-to-tank transfer involves the pump taking suction from one ballast tank, such as tank 7 starboard, and discharging seawater into another tank, such as tank 3 port.

What is the gravity method of de-ballasting?

In the gravity method of de-ballasting, tanks are emptied by allowing seawater to flow out of the tank under the force of gravity, as shown in the example where tank 4 starboard is de-ballasted by gravity.

Can tank-to-tank transfers be done by gravity?

Yes, tank-to-tank transfers can also be done by gravity if there is a level difference between the two tanks, allowing seawater to flow naturally from one tank to the other.

What happens when all tank valves are shut except the one involved in ballasting?

When all other tank valves are shut, it ensures that seawater only flows into or out of the tank being worked on, preventing any interference with other ballast tanks.

Why is it important to monitor the valves during the ballast process?

It is important to monitor the valves to ensure that the ballast system functions properly and safely, preventing unwanted mixing of seawater between tanks and maintaining the ship's stability.