Chemical Tanker Operations Part 2 - Prevention of Pollution (Edition 4)

Summary

The video script emphasizes the importance of adhering to Marpol Annex II regulations for handling noxious liquid substances (NLS) on ships. It outlines the categorization of NLS into X, Y, and Z based on their environmental impact, with category X posing the greatest threat. The script discusses emergency procedures, pollution control measures, and the necessity of proper tank cleaning and cargo handling to prevent accidental discharges. It also highlights the strict rules for discharging residues, especially for category X substances, which must be pre-washed and sent to shore facilities, and the importance of having a Shipboard Marine Pollution Emergency Plan (SMPEP) for ships carrying NLS in bulk.

Takeaways

• 📄 **Read Data Sheets**: It's crucial to read data sheets for chemicals onboard, providing necessary information for emergencies and pollution control.
• 🚨 **Emergency Preparedness**: Marpol Annex II outlines measures to control pollution from accidental discharges and operational procedures.
• 🌊 **Noxious Liquid Substances (NLS)**: Bulk liquid cargos other than petroleum are categorized as NLS, with categories X, Y, or Z based on environmental harm.
• 🔍 **Ship's Certificate of Fitness**: Lists NLS the ship is certified to carry, with specific categories indicating the degree of environmental harm.
• 🚫 **Pollution Control**: Pollution control is not limited to emergencies; it includes proper handling during tank cleaning and cargo operations.
• 🔥 **Cargo Types and Their Categories**: The script mentions toxic, corrosive, flammable, and reactive cargos, each with specific pollution categories and handling requirements.
• 🛑 **Immediate Action on Spillage**: In case of spillage, immediate action is required, including stopping pumps and notifying officers and the jetty.
• 💧 **Pre-Washing and Disposal**: Tanks carrying category X substances must be pre-washed, and residues disposed of at shore-based facilities.
• 🚧 **Tank Cleaning Regulations**: Cleaning of tanks after cargo discharge must follow an approved plan in accordance with Marpol regulations.
• ⛓ **Equipment Maintenance**: Regular inspection of hoses and connections is essential to prevent dangerous spillage due to equipment failure.
• 🌍 **Environmental Considerations**: Discharge of washings at sea is controlled, with specific requirements for speed, distance from land, and water depth.

Q & A

Why is it crucial to read the data sheets on chemicals being carried on board a ship?

Reading data sheets is crucial because they provide all the necessary information required in case of an emergency, such as when cargo escapes from its controlled containment.

What are Noxious Liquid Substances (NLS) and how are they categorized under MARPOL Annex II?

NLS are bulk liquid cargos other than petroleum that are harmful to the environment. They are categorized under MARPOL Annex II as Category X, Y, or Z, depending on the degree of harm they may represent to the environment, with Category X being the most severe.

What is the significance of the ship's Certificate of Fitness in relation to NLS?

The ship's Certificate of Fitness lists the NLS that the ship is certified to carry, ensuring that the ship can legally and safely transport these substances.

Why is it important to follow the procedures outlined in the data sheets during an emergency involving toxic cargo like dichlorobenzene?

Following procedures during an emergency is important because toxic cargoes like dichlorobenzene represent a major hazard to marine resources or human life and are considered high pollutants.

How does MARPOL categorize corrosive cargo like sulfuric acid in terms of pollution hazard?

Corrosive cargo like sulfuric acid is categorized as Category Y under MARPOL, indicating it is a lesser pollutant than Category X substances but still requires specific handling and storage procedures.

What are the stripping requirements for ships carrying Category X and Y substances, and how do they differ for older ships built before 2007?

All tanks and cargos must be stripped to the same 75 liters for newer ships. For older ships built before 2007, less stringent stripping requirements apply.

What actions should be taken immediately if a spillage or overflow involving toxic or corrosive substances occurs on board?

If a spillage involves toxic or corrosive substances, the officer of the watch must be notified immediately, and if discharging the cargo, pumps can be stopped using emergency stops located in the cargo control room and at the manifold.

What is the procedure for pre-washing tanks that have carried Category X substances?

Tanks that have carried Category X substances must be pre-washed after discharge to assure reception at a facility in accordance with the company's procedures and arrangements or P&A manual.

How should the discharge of washings at sea from tanks containing Category X, Y, or Z cargos be managed to minimize environmental impact?

The ship must proceed at an appropriate speed, at least seven knots, be at least 12 miles from land, and in at least 25 meters depth of water. The discharge must be from below the water line and ensure proper mixing in the ship's wake.

What is the role of the MARPOL Control Surveyor during the pre-washing and tank cleaning processes?

The MARPOL Control Surveyor supervises and ensures that the tank cleaning processes are done in accordance with regulations, checks that the cargo record book is up to date, and endorses the entries relating to the operations they have supervised.