CHIEF ENGINEER Unit 15 Periodical Dry Docking Q3

Before a vessel enters dry dock, several precautions must be taken to ensure the safety of the operation and the vessel itself. Here are some key measures:

1. Vessel Preparation

• Stability and Trim:
  • Ensure the vessel has adequate stability and is trimmed as per the docking plan.
  • Adjust ballast and cargo distribution if necessary.
  • Carry out stability calculations to confirm the vessel’s stability during the docking process, particularly when taking the blocks.
• Hull and Underwater Appendages:
  • Thoroughly clean the hull to remove marine growth and facilitate inspection.
  • Inspect and close all sea valves, through-hull fittings, and overboard discharges to prevent water ingress.
  • Protect or retract echo sounders, logs, and other sensitive underwater equipment.
• Internal Systems and Tanks:
  • Empty, clean, and gas-free any tanks scheduled for inspection or work during dry-docking.
  • Prepare and isolate machinery and systems planned for maintenance or repairs.
• Safety Equipment and Procedures:
  • Verify all safety equipment, like fire extinguishers and lifesaving appliances, are in good working order.
  • Familiarize the crew with dry-docking procedures and emergency plans.

2. Coordination with Dry Dock Facility:

• Docking Plan Approval: Submit and get approval for the vessel’s docking plan from the dry dock authorities.
• Berthing and Mooring Arrangements: Confirm the readiness of berthing and mooring arrangements in the dry dock.
• Availability of Services: Ensure necessary services like shore power, water supply, and waste disposal are available and ready for connection.
• Communication Protocols: Establish clear communication channels between the ship’s crew and dry dock personnel.

3. Additional Safety and Security Measures:

• Securing Loose Items: Secure any loose items on deck and within the vessel to prevent them from falling or causing damage during docking.
• Fenders and Protection: Rig fenders along the ship’s sides to protect the hull from contact with the dock walls.
• Gangway and Accommodation Ladders: Stow and secure gangways and accommodation ladders.
• Anchors: Securely stow anchors and anchor chains to prevent them from hindering the docking process.
• Access Control: Implement measures to control access to the vessel and the dry dock area for security purposes.

4. Environmental Protection

• Pollution Prevention: Take precautions to prevent any spills or discharges of oil, sewage, or other pollutants during docking and undocking.
• Waste Management: Arrange for the proper collection and disposal of any waste generated during maintenance and repairs.

By meticulously following these precautions, the risks associated with the dry-docking operation can be significantly reduced, ensuring the safety of the vessel, its crew, and the environment.

Before re-flooding the dry dock, it’s imperative to conduct a series of meticulous inspections and take precautions to ensure a safe and successful undocking operation. Here are some key points to consider:

Hull and Underwater Appendages:

• Thorough Inspection: Conduct a final visual inspection of the entire underwater hull, focusing on repaired areas, welds, sea chests, and any other critical points. Look for signs of damage, leaks, or incomplete work.
• Sea Valves and Openings: Verify that all sea valves, through-hull fittings, and overboard discharges are properly reinstalled, secured, and operational.
• Propeller and Rudder: Ensure that the propeller and rudder are clear of any obstructions and that all necessary components, such as rope guards and propeller cones, are correctly fitted.
• Anodes: Confirm that sacrificial anodes have been installed or replaced as needed to maintain the cathodic protection system.

Internal Systems and Tanks:

• Tank Closure and Soundings: Ensure all tanks that were opened for inspection or repair are properly closed and tested for leaks. Verify that tank soundings match pre-docking levels.
• Bilge and Ballast Systems: Test bilge and ballast systems for proper operation and watertightness.
• Machinery and Equipment: Verify that all machinery and equipment that underwent maintenance or repairs are functioning correctly and ready for operation.

Safety and Security:

• Remove Scaffolding and Equipment: Clear the dry dock of any scaffolding, tools, or other equipment that could obstruct the flooding process or pose a hazard during undocking.
• Secure Loose Items: Ensure all loose items on deck and within the vessel are properly secured to prevent them from shifting or causing damage during undocking.
• Crew Readiness: Brief the crew on the undocking procedures and ensure they are aware of their roles and responsibilities.
• Emergency Preparedness: Review emergency plans and procedures, ensuring that all necessary equipment and communication channels are in place.

Coordination and Communication:

• Clearance from Contractors and Surveyors: Obtain clearance from all contractors and surveyors involved in the dry-docking work, confirming that all tasks are complete and the vessel is ready for undocking.
• Inform Dry Dock Authorities: Notify the dry dock master or authorities about the readiness to commence flooding and undocking procedures.
• Maintain Communication: Establish and maintain clear communication channels between the ship’s crew, dry dock personnel, and any tugs or pilots involved in the undocking operation.   1. Drydocking: Establishing Dry Dock/Vessel Communication – 6Sigma Marine www.6s.co.za

During Flooding:

• Gradual Flooding: Ensure that the dock is flooded gradually and evenly to avoid any undue stress on the hull or instability issues.
• Monitor for Leaks: Closely monitor the hull and all underwater fittings for any signs of leaks or water ingress.
• Check Stability: Continuously monitor the vessel’s stability during flooding and adjust ballast as needed to maintain a safe trim and list.

By diligently following these precautions and conducting thorough inspections, the risk of incidents or complications during re-flooding and undocking can be minimized, ensuring a safe and successful transition back to the water for the vessel.