Section 10.7 Protecting Ship and Environment During Discharge

The completion of a bulk carrier’s voyage culminates in the discharge operation, a phase that, while focused on efficiently delivering the cargo, carries inherent risks to both the vessel itself and the marine environment. The Master’s responsibility extends beyond simply ensuring the cargo is removed; it encompasses a proactive duty to safeguard the ship from damage by discharge equipment and processes, and to ensure that all operations are conducted in strict compliance with environmental regulations, preventing pollution of any kind. This dual protective role requires constant vigilance, clear communication with shore personnel, and diligent oversight by the ship’s crew.

1. Protecting the Ship During Discharge Operations:

The heavy-duty equipment and rapid pace often associated with bulk cargo discharge can inadvertently cause significant damage to the vessel if not properly managed and supervised.

• A. Preventing Structural Damage:
  • Adherence to Discharge Sequence: As detailed in Section 10.3, strict adherence to the pre-planned discharge sequence, coordinated with ballasting, is paramount to prevent overstressing the hull girder (excessive shear forces or bending moments). The Chief Officer must continuously monitor this using the loading instrument.
  • Vigilance Against Grab Damage: This is one of the most common forms of damage.
    • Tank Tops and Hopper Plates: Heavy grabs dropped from height or dragged aggressively can severely dent, puncture, or buckle tank top plating and hopper slopes. Stevedore grab operators should be instructed to lower grabs gently and lift them vertically.
    • Frames, Brackets, and Side Shells (especially in single-hull vessels): Grabs can strike and damage side frames, end brackets, stringers, and ladders. Particular care is needed when grabs are working near the sides or ends of the hold.
    • Hatch Coamings and Undersides of Hatch Covers: Swinging grabs or spillage from overfilled grabs can strike and damage coamings, hatch trackways, or the undersides of adjacent closed or partially open hatch covers.
  • Damage by In-Hold Machinery (Bulldozers, Bobcats): If used by stevedores for final clean-up:
    • Operators must be skilled and briefed on sensitive areas within the hold (ladders, pipe guards, manhole covers, sounding pipes, bilge wells).
    • Monitor for reckless operation that could lead to impacts against bulkheads or frames.
    • Ensure the weight and type of machinery are suitable for the vessel’s tank top strength.
  • Maintaining Secure Moorings: As the vessel lightens and its freeboard increases, its windage area also increases. Mooring lines must be diligently tended to keep the vessel securely alongside, preventing ranging or excessive movement that could lead to contact with the berth, fenders, or discharge equipment.
  • Monitoring Drafts, List, and Trim: Ensure that uneven discharge or improper ballasting does not lead to excessive list (causing strain on moorings and potential contact with low quay structures) or trim that could compromise stability or grounding risk, especially in tidal berths with limited UKC.
• B. Preventing Damage to Ship’s Equipment:
  • Hatch Covers: Protect opened hatch covers from swinging grabs or spillage. Ensure they are properly secured in their stowed positions.
  • Deck Fittings: Protect air pipes, sounding pipes, deck lighting, and other fittings from spillage of abrasive or corrosive cargoes, and from accidental impact by shore equipment or vehicles on the quay.
  • Mooring Equipment: Avoid over-tensioning mooring lines. Ensure fairleads and rollers are free and lubricated to prevent chafe.
  • Gangway/Accommodation Ladder: Must be constantly monitored and adjusted as the vessel’s freeboard changes significantly during discharge. Failure to do so can damage the ladder, its securing points, or create an unsafe means of access.
  • Ship’s Cranes (if geared): If ship’s cranes are used for any part of the operation (e.g., handling stores while alongside), ensure they are operated safely and do not interfere with shore discharge equipment.

2. Protecting the Marine Environment During Discharge Operations:

All discharge operations must be conducted with a strict adherence to MARPOL regulations and any applicable local environmental rules.

• A. MARPOL Annex V – Prevention of Pollution by Garbage (Including Cargo Residues):
  • Dust Control and Spillage Prevention: This is a primary environmental concern during bulk discharge.
    • Minimize Dust Generation: While largely a terminal responsibility (using shrouded grabs, water sprays on cargo/conveyors, enclosed conveyor systems), the ship should cooperate by:
      • Opening hatches only as required for the operation.
      • Closing hatches promptly during rain or strong winds if dust is becoming airborne.
      • Washing down decks regularly to prevent accumulated cargo dust from being blown or washed overboard.
    • Contain Spills: Any significant spillage of cargo on deck should be contained and cleaned up promptly. This spilled cargo is considered “cargo residue.”
  • Disposal of Cargo Residues:
    • As detailed in Section 10.6, any cargo residues collected from holds after discharge (or substantial spillage on deck) must be disposed of strictly according to MARPOL Annex V, considering whether they are HME or non-HME, the vessel’s location (Special Area or not), and distance from land. Discharge to port reception facilities is often the only compliant option for HME residues or when in port/Special Areas.
  • Management of Dunnage and Packaging: If any dunnage, separation materials, or packaging were used with the bulk cargo, these items become garbage and must be disposed of according to Annex V (plastics prohibited from sea discharge, others restricted).
  • Cleaning Agents: If any cleaning agents are used on deck or for minor hold touch-ups immediately after discharge, ensure they are not harmful to the marine environment if any washings are likely to go overboard (though such discharge is highly restricted in port).
• B. MARPOL Annex I – Prevention of Pollution by Oil:
  • Hydraulic Oil Leaks: Monitor ship’s cranes (if used) and other deck machinery (winches, hatch cover systems) for hydraulic oil leaks. Contain and clean up any spills immediately.
  • Shore Equipment Leaks: Be vigilant for oil leaks from shore-based discharge equipment (grabs, bulldozers) operating over or in the vessel. Notify the terminal immediately if such leaks are observed. Have SOPEP equipment ready for minor deck spills.
  • Bilge Discharges: Ensure no oily bilge water from machinery spaces is accidentally discharged. If bilge systems are used for pumping out hold washings (after cargo discharge and subsequent cleaning), ensure no cross-contamination with oily systems.
• C. MARPOL Annex VI – Prevention of Air Pollution:
  • Dust Emissions: As covered under Annex V, minimizing cargo dust is also an air pollution prevention measure.
  • Auxiliary Engine/Boiler Operations: Ensure any auxiliary engines or boilers operated during discharge to provide power or steam comply with SOx and NOx emission regulations, including the use of compliant fuel if in an Emission Control Area (ECA).
  • Vapour Emissions from Cargo (Rare for most bulks, but possible): If discharging a cargo that might release VOCs or other regulated vapors, ensure any specific port or MARPOL requirements are followed.
• D. Ballast Water Management Convention (BWMC):
  • Ballasting Operations: As cargo is discharged, ballast is taken on. This ballast water uptake must be managed in accordance with the ship’s approved Ballast Water Management Plan (BWMP) and the BWMC.
  • BWMS Operation: If the vessel is operating under the D-2 standard, the Ballast Water Management System (BWMS) must be operated correctly during ballast uptake. All parameters should be monitored and recorded.
  • Contingency: If the BWMS is inoperative, contingency measures as per the BWMP must be followed (e.g., notifying Port State, potentially conducting exchange later if permissible, or retaining unmanaged ballast).
  • Record Keeping: All ballast operations must be meticulously recorded in the Ballast Water Record Book.
• E. Local Environmental Regulations:
  • Be aware that individual ports or countries may have local environmental regulations that are stricter than MARPOL (e.g., regarding dust emissions, noise levels, specific discharge prohibitions). The ship’s agent should provide details of such local rules.
• F. Spill Response Readiness:
  • Ensure the Shipboard Oil Pollution Emergency Plan (SOPEP) or Shipboard Marine Pollution Emergency Plan (SMPEP) equipment is readily accessible and that the crew is familiar with spill response procedures for minor deck spills.
  • Have materials like sorbents, shovels, and containers available for dealing with small cargo spills on deck.

3. The Master’s Overall Responsibility:

The Master has the ultimate responsibility for ensuring that discharge operations are conducted in a manner that protects both the ship and the environment. This involves:

• Risk Assessment: Ensuring risks of damage and pollution associated with the specific cargo and discharge method are assessed and mitigated.
• Clear Instructions to Crew: Ensuring all officers and crew are aware of their responsibilities for preventing damage and pollution.
• Effective Communication with Shore Personnel: Establishing clear understandings with terminal operators and stevedores regarding safe working practices, discharge rates, dust control, and damage prevention. The Ship-Shore Safety Checklist is a key tool here.
• Vigilant Oversight: Ensuring that the Chief Officer and deck watch officers are diligently monitoring all aspects of the discharge operation.
• Authority to Intervene: Being prepared to slow down or stop operations if unsafe practices are observed, if damage is occurring, or if there is a risk of pollution.
• Compliance and Documentation: Ensuring full compliance with all relevant MARPOL Annexes, the BWMC, the IMSBC Code, and local regulations. All operations, incidents, and communications must be accurately documented.
• Reporting: Reporting any pollution incidents or significant damage to the relevant authorities and the company immediately.

Protecting the ship from damage and the environment from pollution during discharge operations is a fundamental tenet of good seamanship and responsible maritime practice. It requires a proactive mindset, diligent oversight from the Master and ship’s officers, and effective cooperation with shore-based personnel. By prioritizing these aspects, the operational and commercial success of the voyage can be ensured right through to its conclusion.