This subtopic covers the essential skills for safely monitoring inert gas (IG) systems and pressures, and overseeing crude oil washing (COW) operations dur
Topic Synopsis
This subtopic covers the essential skills for safely monitoring inert gas (IG) systems and pressures, and overseeing crude oil washing (COW) operations during tanker loading and discharge at jetties. It emphasizes practical techniques for maintaining correct IG pressure, ensuring atmosphere control to prevent explosions, and executing COW procedures to maximize cargo discharge while adhering to strict safety and environmental regulations. Mastery of these monitoring tasks is critical for preventing incidents and ensuring compliance with organisational policies.
Key Concepts & Core Principles
- Mooring and unmooring procedures: Understanding the correct sequence and use of mooring lines, winches, and bollards to secure vessels safely, accounting for tidal variations and weather conditions.
- Cargo transfer operations: Mastery of loading and unloading protocols for different cargo types (e.g., crude oil, LNG, chemicals), including hose handling, valve operations, and inerting procedures.
- Safety management systems: Application of Permit to Work (PTW) systems, risk assessments, and emergency shutdown (ESD) procedures to prevent incidents like spills, fires, or collisions.
- Environmental compliance: Knowledge of MARPOL annexes and local regulations for ballast water management, vapour recovery, and spill containment to minimise ecological impact.
- Communication and teamwork: Effective use of VHF radio, hand signals, and intercoms to coordinate between ship crew, jetty operators, and control rooms during all phases of operation.
Exam Tips & Revision Strategies
- When answering assessment questions, use precise technical language and refer to industry guidelines such as ISGOTT to demonstrate depth of knowledge.
- For practical assessments, always verbalize your monitoring steps and safety checks, as this shows the assessor your conscious application of procedures.
Common Misconceptions & Mistakes to Avoid
- Assuming inert gas is completely oxygen-free without checking the oxygen analyser reading.
- Neglecting to verify that the inert gas pressure is sufficient before starting COW, risking tank atmosphere entry.
- Misunderstanding the difference between the inert gas system and the crude oil washing system, leading to procedural errors.
Examiner Marking Points
- Award credit for correctly identifying key components (scrubber, blower, deck seal, pressure/vacuum valve) and their role in producing and distributing inert gas.
- Award credit for explaining the importance of maintaining a positive pressure in the cargo tanks and the use of pressure alarms.
- Award credit for outlining the step-by-step COW process, including tank atmosphere checks, washing machine placement, and draining procedures.
- Award credit for describing typical issues like low IG pressure, oxygen content rise, and clogged washing machines, and suggesting appropriate immediate actions.
- Award credit for referencing specific company procedures, checklists, and communication protocols.