CHIEF ENGINEER Unit 15 Periodical Dry Docking Q1

Periodical dry-docking of a vessel refers to the mandatory practice of placing a ship in a dry dock at specific intervals to conduct inspections, maintenance, and repairs on the underwater portions of its hull and other systems that are not accessible while the ship is afloat.  

1. What is dry docking? | Clarksons

Key Points:

• Frequency: The International Maritime Organisation’s (IMO) Safety of Life at Sea (SOLAS) Convention mandates that most cargo ships undergo dry-docking twice within a five-year period, with the interval between consecutive dry-dockings not exceeding three years. Passenger ships typically have even stricter requirements, with annual or biennial dry-docking inspections.
• Purpose: The main purposes of periodical dry-docking include:
  • Inspection and Survey: Thorough inspection of the hull, underwater fittings, sea valves, propellers, rudders, and other submerged components to assess their condition and identify any damage, corrosion, or wear and tear.   1. What is dry docking? | Clarksons www.clarksons.com
  • Maintenance and Repairs: Carrying out necessary repairs, replacements, or upgrades to the hull, its coatings, and underwater equipment.   1. What is dry docking? | Clarksons www.clarksons.com
  • Cleaning and Painting: Cleaning the hull and applying new anti-fouling paint to prevent marine growth and improve the ship’s hydrodynamic efficiency.   1. What is dry docking? | Clarksons www.clarksons.com
  • Class Renewal: Dry-docking is usually required for special surveys conducted by classification societies to renew the vessel’s class certificate, confirming its compliance with safety and technical standards.   1. Vessel Dry-Docking At A Glance – Nakilat www.nakilat.com

Importance of Periodical Dry-docking:

• Ensuring Safety and Seaworthiness: Regular dry-docking helps maintain the structural integrity and watertightness of the hull, preventing potential leaks, cracks, or other damage that could compromise the ship’s safety.   1. 10 Key Benefits of Regular Dry Docking for your Commercial Vessel – Gulf Copper www.gulfcopper.com
• Preventing Corrosion: Dry-docking allows for thorough inspection and treatment of corrosion, which can significantly weaken the hull and other underwater components over time.   1. The Importance of Dry Dock: Ensuring the Safety and Efficiency of Ships – Swan Energy swan.co.in
• Improving Fuel Efficiency: Cleaning the hull and applying new anti-fouling paint reduces drag and improves the ship’s hydrodynamic performance, leading to better fuel efficiency and reduced emissions.
• Compliance with Regulations: Periodical dry-docking is mandatory under international conventions and classification society rules, ensuring that vessels adhere to safety and environmental standards.   1. What are the regulations around Dry Docking? A Guide for Ship Owners – Shipnet blog.shipnet.no

In conclusion, periodical dry-docking is a crucial aspect of ship maintenance that contributes significantly to the safety, efficiency, and longevity of vessels. By facilitating thorough inspections, maintenance, and repairs of the underwater portions, it helps prevent accidents, protect the marine environment, and ensure the continued seaworthiness of the ship.

A docking plan provides crucial information to facilitate a safe and efficient dry-docking operation. Here are some key items of information that can be obtained from a docking plan:  

1. Dry Docking Inspection Checklist (PDF Included) – Fluix

1. Ship’s Particulars:

• Vessel Name and IMO Number: Identifies the specific vessel.
• Dimensions: Overall length, breadth, draft, and other relevant dimensions for maneuvering and positioning the ship in the dry dock.
• Displacement and Deadweight: Information about the ship’s weight and cargo carrying capacity, important for calculating stability and ensuring adequate support in the dry dock.
• Center of Gravity (KG): The vertical position of the ship’s center of gravity, crucial for stability calculations and determining the proper placement of keel blocks.

2. Dry Dock Details:

• Dock Dimensions: Length, breadth, and depth of the dry dock to ensure it can accommodate the vessel comfortably and safely.
• Keel Block Arrangement: 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.   1. Dry Docking Inspection Checklist (PDF Included) – Fluix fluix.io
• Docking and Undocking Procedures: Specific instructions 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: Identifying the positions of echo sounders, drain plugs, and other sensitive equipment on the hull that require special attention or protection during docking.   1. A complete guide of bringing a ship to dry dock – MySeaTime www.myseatime.com
• Sea Chest and Overboard Valve Locations: Marking 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: Highlighting any 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: Providing stability calculations for various loading conditions to ensure that the vessel remains stable throughout the dry-docking process.   1. Dry Docking Inspection Checklist (PDF Included) – Fluix fluix.io
• Trim and List: Specifying the desired trim and list (if any) for the vessel in the dry dock, which helps facilitate inspections and maintenance.
• Ballast Water Management: Outlining 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: Indicating the location of gangways, ladders, and other access points for personnel to enter and exit the vessel while in dry dock.
• Shore Connection Points: Showing the positions for connecting shore power, water, and other utilities to the ship during its stay in the dry dock.
• Safety Precautions: Outlining any specific safety precautions or procedures to be followed during the docking operation, such as fire prevention measures or emergency response plans.

By providing all this crucial information, the docking plan serves as a roadmap for the entire dry-docking operation. It helps ensure that the vessel is safely maneuvered into and out of the dry dock, properly supported, and that all necessary inspections, maintenance, and repairs are carried out efficiently and effectively.

During the periodical dry-docking of a vessel, several critical services must be made available to ensure the safety of the vessel, its crew, and the dry dock facility itself. These services can be broadly categorized into the following areas:

1. Docking and Undocking:

• Tugs and Pilot Assistance: Tugboats and experienced pilots are essential for safely maneuvering the vessel into and out of the dry dock, especially in confined waters or challenging weather conditions.
• Mooring and Berthing: Secure mooring lines and fenders must be provided to properly secure the vessel within the dry dock and prevent any movement or damage during the docking process.

2. Dry Dock Facility and Infrastructure:

• Stable and Level Blocks: The dry dock must be equipped with sturdy and level keel blocks and side blocks to support the vessel’s weight evenly and prevent structural stress or deformation.
• Adequate Lighting and Ventilation: Proper lighting and ventilation within the dry dock are necessary to ensure safe working conditions for the crew and contractors performing maintenance and repairs.   1. Dry Docking: Contractual Liability and General Best Practices – Alandia insurance alandia.com
• Fire Safety Systems: Fire detection and firefighting equipment, such as fire alarms, extinguishers, and sprinkler systems, must be readily available in the dry dock to prevent and control any fire incidents.
• Emergency Response Plans: The dry dock facility should have well-defined emergency response plans in place to handle potential accidents, injuries, or other emergencies during the docking period.

3. Shore Connections and Utilities:

• Shore Power: A reliable shore power connection is essential for powering the vessel’s essential systems and lighting during its stay in the dry dock.
• Water Supply: Access to freshwater is necessary for various onboard purposes, including sanitation, cleaning, and fire protection.
• Compressed Air: Compressed air may be required for various maintenance and repair activities, such as pneumatic tools or cleaning operations.
• Waste Management: The dry dock facility should provide appropriate waste disposal facilities for handling various types of waste generated during maintenance and repairs, including oily waste, sewage, and hazardous materials.

4. Safety and Security:

• Access Control and Security: The dry dock area should have controlled access to prevent unauthorized entry and ensure the security of the vessel and its equipment.
• Safety Barriers and Signage: Clear safety barriers and signage should be in place to mark hazardous areas, restricted zones, and emergency exits within the dry dock.
• Personnel Protective Equipment (PPE): Adequate PPE, such as hard hats, safety shoes, gloves, and eye protection, should be provided to all personnel working in the dry dock.

5. Communication and Coordination:

• Clear Communication Channels: Effective communication channels should be established between the ship’s crew, dry dock personnel, and any contractors involved in the maintenance and repair work.
• Coordination of Activities: Clear coordination is essential to ensure that various maintenance and repair activities are carried out safely and efficiently without conflicts or disruptions.

By ensuring that these critical services are available and functioning effectively, the dry-docking process can be conducted safely and efficiently, minimizing risks and ensuring the vessel’s continued seaworthiness and compliance with regulations.