Section 22.2 Maintenance of Critical Equipment (Hatch Covers, Cranes, Ballast Systems)
While all shipboard equipment requires regular maintenance as per the PMS, certain systems and components on bulk carriers are particularly critical due to their direct impact on safety, cargo integrity, operational efficiency, and regulatory compliance. The Master, in conjunction with the Chief Officer and Chief Engineer, must ensure these receive priority attention.
1. Hatch Covers: Hatch covers are arguably one of the most critical structural and operational components of a bulk carrier. Their weathertight integrity is essential for protecting cargo from water damage and for the overall safety and seaworthiness of the vessel, especially in heavy weather. Failure of hatch covers has been a contributing factor in many bulk carrier losses.
Common Problems:
Loss of Weathertightness: Due to damaged or deteriorated rubber packing/seals, compression bars, or coaming surfaces.
Structural Defects: Corrosion, cracking, or deformation of panels, coamings, stiffeners, and supporting structures.
Securing Device Failures: Worn or damaged cleats, wedges, cross-joints, or hydraulic securing systems.
Operating Mechanism Malfunctions: Issues with hydraulic systems (rams, pumps, hoses, valves), drive chains, wheels, or guide rails for rolling or folding type covers.
Drainage System Blockages: Non-return valves in drain channels clogged with cargo residue or rust, leading to water accumulation.
Key Maintenance Aspects:
Regular Inspections (by ship’s staff):
Before and after each cargo operation, and at regular intervals during voyages.
Check condition of rubber seals (for elasticity, cracks, permanent set, missing sections).
Inspect compression bars for straightness and corrosion.
Examine coaming tops and vertical surfaces for damage, corrosion, and cleanliness.
Check all securing devices for proper operation, tightness, and wear.
Inspect panel structures, stiffeners, and brackets for cracks, deformation, or corrosion.
Test drainage channels and non-return valves for clear passage.
Inspect hydraulic systems for leaks, oil levels, and condition of hoses.
Weathertightness Testing:
Hose Test: Directing a jet of water at hatch cover joints and peripheries to detect leaks.
Ultrasonic Tightness Test: A more accurate method using an ultrasonic transmitter inside the hold and a receiver outside to detect sound leakage through gaps. This is often required by P&I Clubs and charterers.
Lubrication: Regular lubrication of hinges, wheels, cleats, and other moving parts as per manufacturer’s recommendations.
Steelwork Repairs: Prompt repair of any corrosion, cracks, or deformations. This may involve cropping and renewing steel sections, often requiring specialist welders.
Rubber Seal Renewal: Renewal of rubber seals when they become hardened, damaged, or lose their elasticity. This is a significant maintenance item.
Hydraulic System Maintenance: Regular checks of hydraulic oil (level, condition, analysis), filter changes, inspection of hoses and connections for leaks or damage, and servicing of pumps and valves.
Spare Parts: Maintain an adequate inventory of spare rubber seals, cleats, wedges, hydraulic components, etc.
Master’s Oversight:
Ensure a rigorous hatch cover inspection and maintenance regime is in place and followed.
Review inspection reports and ensure timely corrective actions.
Emphasize the importance of proper operation and securing of hatch covers to all deck crew.
Be particularly vigilant when carrying cargoes sensitive to water damage or when heavy weather is anticipated.
2. Deck Cranes (Cargo Gear): Many bulk carriers are “geared,” meaning they are equipped with their own cranes for loading and discharging cargo. The reliability of these cranes is crucial for efficient cargo operations and avoiding port delays.
Common Problems:
Hydraulic System Failures: Leaks, pump failures, valve malfunctions, contaminated oil.
Wire Rope Defects: Broken strands, corrosion, kinks, wear, lack of lubrication.
Structural Issues: Cracks or corrosion in crane jibs, pedestals, or slewing rings.
Electrical System Faults: Issues with motors, control systems, limit switches, or cabling.
Slewing Ring Bearing Wear: Leading to excessive play or rough operation.
Brake Malfunctions: Hoisting, luffing, or slewing brakes.
Safety Device Failures: Limit switches, emergency stops, safe load indicators (SLIs).
Key Maintenance Aspects:
Regular Inspections and Operational Tests: Daily pre-use checks by operators, and more detailed weekly/monthly inspections by ship’s staff.
Lubrication: Critical for all moving parts, including wire ropes, sheaves, bearings, slew rings, and gearboxes, as per manufacturer’s schedule.
Wire Rope Maintenance: Regular inspection, lubrication, and end-for-ending or renewal as per condition and Class/regulatory requirements. Maintain wire rope records.
Hydraulic System: Check oil levels and condition, inspect for leaks, change filters, and service pumps/motors as per PMS.
Structural Inspections: Visually inspect crane structures for cracks, corrosion, or loose bolts.
Electrical Systems: Check motors, controllers, limit switches, and wiring for condition and proper operation.
Brake Testing and Adjustment: Regularly test and adjust brakes.
Safety Device Testing: Ensure all limit switches, emergency stops, and SLIs are functioning correctly.
Load Testing: Periodic load testing as required by Class and regulations (usually every 5 years, or after major repairs/modifications).
Spare Parts: Maintain an inventory of critical spares (e.g., hydraulic hoses, filters, contactors, wire rope grease).
Master’s Oversight:
Ensure cranes are maintained according to PMS and manufacturer’s recommendations.
Verify that operators are competent and follow safe operating procedures.
Ensure pre-use checks are diligently performed.
Review crane maintenance records and address any recurring issues.
3. Ballast Systems (Pumps, Valves, Piping, Tanks): The ballast system is essential for maintaining the ship’s stability, trim, and stress levels during loading, discharging, and voyages. It is also critical for compliance with Ballast Water Management (BWM) regulations.
Common Problems:
Pump Failures: Issues with pump motors, bearings, seals, or impellers.
Valve Malfunctions: Valves seized, passing, or inoperable (manual, hydraulic, or pneumatic). Remote valve indication systems can also fail.
Piping Corrosion and Leaks: Internal corrosion in ballast lines leading to leaks or reduced flow.
Tank Coating Breakdown: Corrosion in ballast tanks leading to structural weakening and sediment accumulation.
Clogged Suctions/Filters: Mud, sediment, or marine growth blocking suctions or strainers.
Ballast Water Treatment System (BWTS) Malfunctions: If fitted, the BWTS itself can experience various operational issues.
Sounding Pipe/Air Vent Issues: Blocked or damaged air pipes/sounding pipes affecting tank ventilation or accurate soundings.
Key Maintenance Aspects:
Pump Maintenance: Regular inspection, lubrication of bearings, checking of seals, monitoring performance (pressure, flow rate), and overhaul as per PMS.
Valve Maintenance: Regular operation of all valves (especially remote-controlled ones) to prevent seizure. Inspection for leaks, and servicing/overhaul as required. Ensure position indicators are accurate.
Piping Inspections: External inspection for leaks. Internal inspection (where possible, e.g., during dry-dock) or thickness gauging for corrosion.
Tank Inspections and Maintenance: Regular inspection of ballast tank coatings, anodes (if fitted), and structural condition. Cleaning of tanks to remove sediment.
BWTS Maintenance: Strict adherence to the manufacturer’s maintenance schedule for the BWTS, including filter cleaning/replacement, sensor calibration, and system checks.
Sounding Systems: Ensure sounding pipes are clear and tank gauging systems are accurate.
Air Pipes/Vent Heads: Check for clear passage and proper functioning of flame screens or floats.
Master’s Oversight:
Ensure ballast operations are conducted safely and in accordance with the approved Ballast Water Management Plan and stability booklet.
Verify that the ballast system is maintained effectively to ensure its availability and reliability, especially prior to cargo operations.
Monitor compliance with BWM Convention requirements, including operation and recording for the BWTS.
Review ballast tank inspection reports and ensure any structural concerns are addressed.
Other Critical Equipment for Bulk Carriers:
Mooring Equipment (Winches, Wires, Ropes): Essential for safe berthing. Regular inspection, lubrication, brake testing, and condition monitoring of wires/ropes.
Anchoring Equipment (Windlass, Anchors, Chains): Critical for emergency anchoring and routine operations. Inspection, lubrication, brake testing, and checking chain locker condition.
Steering Gear: SOLAS requirement for regular testing and drills. Comprehensive maintenance as per PMS is vital for navigational safety.
Main Engine and Auxiliary Engines/Generators: The heart of the vessel. Diligent maintenance by engineering staff as per PMS is fundamental.
Emergency Generator and Emergency Fire Pump: Must be tested regularly and maintained in a constant state of readiness.
Effective maintenance of this critical equipment, guided by a robust PMS and overseen by diligent ship’s officers under the Master’s leadership, is fundamental to the safety, environmental compliance, and commercial success of any bulk carrier.