CHIEF ENGINEER Unit 15 Periodical Dry Docking Q2

A docking plan is a critical document that contains a wealth of information to facilitate the safe and efficient dry-docking of a vessel. It provides essential details about the ship’s structure, underwater appendages, stability requirements, and other relevant factors that need to be considered during the docking process.

Here are some key items of information that can be obtained from a docking plan:

1. Ship Particulars:

• Vessel Name and IMO Number: Identifies the specific ship.
• Dimensions: Provides the overall length, breadth, depth, draft, and other relevant dimensions of the vessel, crucial for selecting a suitable dry dock and planning the docking operation.
• Displacement and Deadweight: Specifies the ship’s weight and cargo carrying capacity, essential for calculating stability and ensuring adequate support in the dry dock.
• Center of Gravity (KG): Indicates the vertical position of the ship’s center of gravity, critical for stability calculations and determining the proper placement of keel blocks.

2. Dry Dock Details:

• Dock Dimensions: Provides the length, breadth, and depth of the dry dock to ensure it can accommodate the vessel comfortably and safely.
• Keel Block Arrangement: Shows the layout and positioning of keel blocks, side blocks, and other supports within the dry dock to ensure proper weight distribution and prevent structural damage to the hull.
• Docking and Undocking Procedures: Outlines the specific procedures and guidelines for maneuvering the vessel into and out of the dry dock, including the use of tugs, mooring lines, and other aids.

3. Critical Points and Sensitive Areas:

• Echo Sounder and Drain Plug Locations: Identifies the positions of echo sounders, drain plugs, and other sensitive equipment on the hull that require special attention or protection during docking.
• Sea Chest and Overboard Valve Locations: Marks the locations of sea chests and overboard valves to facilitate their inspection, maintenance, and closure before the vessel enters the dry dock.
• Areas Prone to Stress or Damage: Highlights any specific areas of the hull or structure that might be particularly susceptible to stress or damage during docking, allowing for extra precautions to be taken.

4. Stability Information:

• Stability Calculations: Provides stability calculations for various loading conditions to ensure that the vessel remains stable throughout the dry-docking process.
• Trim and List: Specifies the desired trim and list (if any) for the vessel in the dry dock, which helps facilitate inspections and maintenance.
• Ballast Water Management: Outlines ballast water management procedures during docking and undocking to maintain stability and prevent excessive stress on the hull.

5. Other Relevant Information:

• Access and Egress Points: Indicates the location of gangways, ladders, and other access points for personnel to enter and exit the vessel while in dry dock.
• Shore Connection Points: Shows the positions for connecting shore power, water, and other utilities to the ship during its stay in the dry dock.
• Safety Precautions: Outlines any specific safety precautions or procedures to be followed during the docking operation, such as fire prevention measures or emergency response plans.

In essence, the docking plan acts as a comprehensive guide for the entire dry-docking operation. It provides critical information to the dry dock facility, the ship’s crew, and any contractors involved, ensuring a safe, efficient, and well-coordinated process.

Before a vessel can be safely dry-docked, several critical conditions must be met to ensure the stability, safety, and successful completion of the docking operation. These conditions encompass various aspects of the vessel’s preparation, coordination with the dry dock facility, and adherence to safety protocols.

1. Vessel Preparation:

• Stability and Trim:
  • The vessel must be in a stable condition with appropriate trim and list, as specified in the docking plan.
  • This involves adjusting ballast water levels and cargo distribution to ensure the ship sits evenly on the keel blocks once the dock is dewatered.
  • Stability calculations should be performed to verify that the vessel will remain stable during the entire docking process.
• Hull and Underwater Appendages:
  • The hull should be thoroughly cleaned to remove marine growth and facilitate inspections.
  • Sea valves and other underwater openings should be inspected, tested, and closed securely to prevent water ingress.
  • Echo sounders, drain plugs, and other sensitive equipment should be protected or retracted as needed.
• Internal Systems and Tanks:
  • Tanks that will be inspected or worked on during dry-docking should be emptied, cleaned, and gas-freed as required.
  • Any machinery or systems that will be undergoing maintenance or repairs should be prepared and isolated as necessary.
• Safety Equipment and Procedures:
  • All safety equipment, such as fire extinguishers, life-saving appliances, and emergency communication systems, should be in good working order and readily accessible.
  • The crew should be familiar with the dry-docking procedures and emergency response plans.

2. Coordination with Dry Dock Facility:

• Docking Plan Approval: The ship’s docking plan, outlining the vessel’s particulars, docking procedures, and critical information, should be reviewed and approved by the dry dock authorities.
• Berthing and Mooring Arrangements: The dry dock facility should be prepared to receive the vessel, with appropriate berthing and mooring arrangements in place.
• Availability of Services: Essential services like shore power, water supply, compressed air, and waste disposal facilities should be readily available and connected to the ship once docked.
• Communication Protocols: Clear communication channels should be established between the ship’s crew and dry dock personnel to ensure smooth coordination throughout the docking process.

3. Safety and Environmental Considerations:

• Risk Assessment: A thorough risk assessment should be conducted to identify and mitigate potential hazards associated with the dry-docking operation.
• Pollution Prevention: Measures should be in place to prevent any spills or discharges of oil, sewage, or other pollutants during the docking process.
• Safety Barriers and Signage: The dry dock area should be properly secured with safety barriers and clear signage to prevent unauthorized access and mark hazardous areas.
• Personnel Protective Equipment: All personnel involved in the docking operation should be provided with and use appropriate PPE, such as hard hats, safety shoes, gloves, and eye protection.

By ensuring that these conditions are met before dry-docking, the vessel can be safely and efficiently placed in the dry dock, facilitating necessary inspections, maintenance, and repairs while minimizing risks to personnel, the ship, and the environment.