Analysis of Boiler Water and Lubricating Oil on Board Vessels

Regular analysis of boiler water and lubricating oil is essential for the safe, efficient, and cost-effective operation of marine machinery. These analyses help detect contamination, monitor chemical balance, and prevent corrosion, scaling, and equipment failure—ultimately extending machinery lifespan and ensuring compliance with OEM and classification society requirements.

Boiler Water Analysis

Boiler water must be maintained within strict chemical limits to prevent internal corrosion, scale formation, foaming, and carryover, which can severely damage the boiler and associated systems.

• Purpose of Analysis
• Ensure chemical conditioning is effective
• Maintain pH, alkalinity, and hardness within operational limits
• Detect contamination (e.g., seawater ingress or oil)
• Prevent corrosion of boiler tubes and steam lines
• Parameters Commonly Tested
• Parameter Purpose
• pH Controls acidity/alkalinity
• Alkalinity (P & M) Indicates buffering capacity and treatment dosage
• Chloride (Cl⁻) Detects seawater contamination
• Phosphate (PO₄³⁻) Prevents scale; dosing control
• Hardness (Ca²⁺/Mg²⁺) Measures residual hardness; risk of scaling
• Conductivity Indicates total dissolved solids
• TDS (Total Dissolved Solids) Monitors blowdown efficiency
• Oxygen (O₂) (if applicable) Assesses risk of oxygen corrosion
• Testing Methods
• On-board test kits using colorimetric titration, test strips, or digital meters
• Sample points from boiler water drum, condensate return, and make-up water system
• Log results in boiler water treatment log for trend analysis
• Standards and Guidelines
• IMO Resolution A.351(X) – Guidelines for the operation of boilers
• OEM specifications (e.g., Aalborg, Mitsubishi)
• Classification Society Rules (DNV, ABS, Lloyd's)

Lubricating Oil Analysis

Lubricating oil analysis monitors oil condition, wear particles, and contamination. It is crucial for predictive maintenance and helps to optimize machinery performance, reduce breakdown risk, and extend overhaul intervals.

• Purpose of Analysis
• Assess lubricant degradation (oxidation, nitration, viscosity loss)
• Detect contamination (fuel, water, soot, coolant)
• Identify wear metals (Fe, Cu, Al, Pb, Cr) indicating component wear
• Ensure oil still meets performance specifications (TBN, viscosity, cleanliness)
• Parameters Commonly Tested
• Parameter Purpose
• Viscosity (at 40°C/100°C) Lubrication efficiency and degradation check
• Total Base Number (TBN) Reserve alkalinity; neutralizing ability
• Water Content (%) Indicates leaks or condensation
• Insolubles (soot/sludge) Detects incomplete combustion or oil oxidation
• Wear Metals (Fe, Cu, Al) Detects abnormal engine/component wear
• Flash Point Safety; detection of fuel dilution
• Oxidation/Nitration Levels Indicates oil aging and thermal stress
• Additive Depletion Indicates reduction in protection effectiveness
• Testing Methods
• On-board analysis kits for quick checks (e.g., TBN, water-in-oil, viscosity)
• Laboratory analysis via spectrometric and infrared (IR) analysis, ASTM methods such as:
• ASTM D445 (Viscosity)
• ASTM D2896 (TBN)
• ASTM D6304 (Water by Karl Fischer)
• ASTM D5185 (Wear metal analysis by ICP)
• Sampling and Handling
• Take samples from the designated sampling point while the engine is warm and circulating
• Use clean, labeled, sealed bottles
• Avoid cross-contamination and ensure representative sampling (not from stagnant oil)
• Complete a sample submission form with equipment details, oil hours, and operating conditions
• Standards and Guidelines
• OEM recommendations (e.g., MAN, Wärtsilä, Caterpillar)
• ISO 8217 (fuel contamination thresholds)
• DNV/ABS Class Notations for condition-based maintenance
• Reporting and Monitoring
• Trend analysis through regular sampling (weekly/monthly depending on system criticality)
• Comparison against OEM operating limits and alarm levels
• Maintenance decisions (e.g., oil change, component inspection) should be based on:
• Repeated abnormal trends
• Cross-analysis of multiple parameters
• Correlation with operational events (e.g., high load, port stays)
• Proper monitoring of boiler water and lubricating oil ensures safe, efficient, and uninterrupted vessel operations. Early detection of anomalies enables proactive maintenance, avoids costly downtime, and ensures full compliance with regulatory and classification standards.

Cargo Analysis on Tanker Vessels

Cargo analysis is a fundamental procedure carried out to verify the quality, composition, and compliance of liquid bulk cargoes such as crude oil, refined petroleum products, chemicals, and biofuels. Accurate analysis ensures conformity with contractual specifications, regulatory requirements, and safe handling practices throughout the cargo’s transportation lifecycle.

• Purpose of Cargo Analysis
• Confirm product quality and specification compliance (e.g., density, sulfur content, viscosity)
• Detect contaminants such as water, sediment, or incompatible substances
• Support commercial settlement, claims resolution, and regulatory compliance
• Ensure compatibility with vessel systems and safety during transportation and discharge
• Typical Parameters Analyzed
• Parameter Purpose
• Density / API Gravity Determines mass and volume conversions, fuel quality
• Viscosity Assesses flow characteristics and handling properties
• Sulfur Content (%) Ensures compliance with MARPOL Annex VI and fuel regulations
• Water and Sediment (BS&W) Detects contaminants that affect quality and engine performance
• Flash Point Safety indicator for flammability classification
• Pour Point Determines flow characteristics under low temperatures
• Total Acid Number (TAN) Measures acidity to detect corrosion potential
• Ash Content Indicates non-combustible residue, important in fuel oils
• Cetane Number (for distillates) Assesses ignition quality of diesel fuels
• Mercaptan Sulfur / Hydrogen Sulfide (H2S) Detects corrosive sulfur compounds
• Sampling and Sample Handling
• Samples are collected using approved sampling procedures such as MARPOL Annex I compliant drip sampling during bunkering or cargo operations.
• Multiple sample types: top, middle, bottom, and composite samples to ensure representativity.
• Samples are stored in clean, inert, and sealed containers (glass or metal) compatible with cargo type.
• Proper labeling and chain-of-custody documentation are maintained for traceability.
• Analytical Methods
• Laboratory Analysis using standardized ASTM, ISO, and EN methods, including:
• ASTM D4052 (Density)
• ASTM D86 (Distillation range)
• ASTM D4294 (Sulfur content by XRF)
• ASTM D2276 (Water and sediment)
• ASTM D93 (Flash point)
• ISO 8754 (Viscosity)
• ASTM D664 (Total Acid Number)
• On-board or portable analyzers may be used for preliminary testing (density, viscosity).
• Accredited third-party laboratories typically perform full spectrum testing for certification purposes.
• Quality Assurance and Reporting
• Analytical results are compared against contractual specifications, ISO 8217 (for marine fuels), or chemical product standards.
• Detailed Cargo Quality Certificate or Inspection Report is issued, including:
• Sampling details (location, time, method)
• Test methods used
• Quantitative results for all parameters
• Comments on compliance or deviations
• Data supports cargo acceptance/rejection, dispute resolution, and regulatory submissions.
• Compliance and Regulatory Framework
• Compliance with international regulations such as:
• MARPOL Annex VI for fuel sulfur limits and emissions
• ISO 8217 for marine fuel quality standards
• IMO IMSBC Code for chemical cargoes
• Local port state regulations and environmental legislation
• Analysis results help verify conformity with charter party terms and contractual quality clauses.
• Accurate cargo analysis is indispensable for maintaining the commercial and operational integrity of tanker operations. It ensures cargo quality, prevents engine and equipment damage, supports regulatory compliance, and reduces the risk of disputes between sellers, buyers, and charterers.