Marine Auxiliary Engines and Generators

Background

Why ships need auxiliary engines

Ships need substantial electrical power for many operations:

• Main engine ancillaries: cooling water pumps, lube oil pumps, fuel oil pumps, fuel oil purifiers, control systems.
• Navigation and bridge: radar, GPS, ECDIS, AIS, autopilot, communication equipment.
• Accommodation services: HVAC, lighting, galley, laundry, fresh water generation.
• Cargo operations: cargo pumps on tankers, container cranes (small ships), reefer container power, ballast pumps.
• Mooring and anchoring: winches, capstans.
• Safety and life-saving: fire pumps, emergency lighting, communication.
• Specialty: propulsion (on diesel-electric ships), thrusters (on DP vessels).

The total electrical demand on a typical cargo ship at sea is 1 to 4 MW; on cruise ships up to 80 MW; on offshore service vessels with DP up to 40 MW; on very large container ships with reefer load up to 20 MW.

Configuration types

Different ship types use different auxiliary configurations:

• Conventional diesel propulsion: 3 to 4 main gensets plus emergency generator, with main engine providing propulsion separately.
• Diesel-electric: 4 to 8 large gensets providing both propulsion (through electric motors) and ship services. Common on cruise ships, offshore vessels, ice-class ships, some specialty cargo.
• Dual-fuel diesel-electric (DFDE): gensets running on LNG (with oil pilot) or oil, common on modern LNG carriers.
• Hybrid diesel-battery: generators plus battery banks for peak shaving and zero-emission operation in port.
• All-electric (battery-only): pure battery for short-route ferries.
• Shaft generator: PTO from main engine providing electrical power, supplementing or replacing one auxiliary genset.

The configuration choice reflects the ship’s electrical demand profile, operational pattern, and decarbonisation strategy.

Major manufacturers

The marine auxiliary engine industry includes major manufacturers:

• Caterpillar Marine: extensive product range from small to large auxiliary engines.
• MAN Energy Solutions: Holeby brand for medium-speed auxiliaries (32/44CR, 21/31, 18/45 series).
• Wartsila: 14, 20, 32, 46 series medium-speed engines.
• Cummins Marine: smaller auxiliaries for cargo ships and specialty vessels.
• Mitsubishi Heavy Industries: marine auxiliary engines for Japanese yards.
• Yanmar: smaller-class engines.
• MTU (Rolls-Royce): high-speed engines for specialty applications.
• Volvo Penta: smaller auxiliaries.
• Hyundai Heavy Industries: H-class auxiliary engines.
• Doosan: D-class auxiliary engines.

The Korean and Chinese yards typically specify domestic auxiliary engines (Hyundai, Doosan, Weichai, etc.) on new construction.

Engine types and characteristics

4-stroke vs 2-stroke

Marine auxiliary engines are typically 4-stroke (whereas main engines on large ships are typically 2-stroke):

• 4-stroke advantages: smaller size for given power, better fuel flexibility, suitable for varying load, easier maintenance access.
• 2-stroke advantages (used on main engines, not aux): higher efficiency, longer service life between overhauls, suitable for slow-speed direct-coupled propulsion.

For aux engines, the 4-stroke architecture is dominant.

Speed classes

Auxiliary engines are classed by speed:

• High-speed: 1000 to 1500 rpm; smaller-class engines used on smaller ships.
• Medium-speed: 500 to 1000 rpm; the dominant class for medium and large auxiliary applications.
• Low/medium-speed: below 500 rpm; less common for aux but used for some large cargo ship arrangements.

Higher speed allows smaller engine size for given power; lower speed gives longer service life and better fuel efficiency.

Cylinder configurations

Common configurations:

• In-line 6 to 9 cylinder: typical for smaller auxiliaries.
• V-12 to V-20: typical for larger auxiliaries.
• W-engines: less common but used in specific applications.

Power range

Marine auxiliary engine power range:

• Small auxiliary: 100 to 500 kW for small cargo ships, fishing vessels, yachts.
• Medium auxiliary: 500 kW to 3 MW for typical cargo ships, smaller passenger ships.
• Large auxiliary: 3 to 12 MW for large cargo ships, cruise ships, offshore vessels.
• Very large auxiliary (used as main propulsion in diesel-electric): 12 to 25 MW.

The N-1 redundancy rule (under SOLAS II-1 Part D) typically drives 3 to 4 medium-sized gensets rather than 2 large ones.

Generator characteristics

AC synchronous generators

Marine auxiliary generators are synchronous AC machines:

• Frequency: typically 50 Hz or 60 Hz depending on flag state (60 Hz on US-flag and many Asian, 50 Hz on European and most other).
• Voltage: typically 440 V or 450 V on smaller ships; 690 V or 6.6 kV on larger ships with high-power demand.
• Phases: 3-phase wye or delta configuration.
• Excitation: brushless rotating exciter with permanent-magnet pilot exciter.
• Automatic Voltage Regulator (AVR): maintains voltage at set point under varying load.
• Speed governor: maintains frequency by adjusting fuel rack on the prime mover.

Generator parallel operation

Multiple generators operate in parallel through:

• Synchronisation: matching voltage, frequency and phase before paralleling.
• Load sharing: typically droop-based or isochronous load distribution.
• Reactive load sharing: matching reactive (kVAR) between machines.

The load sharing droop calculator and generator parallel operation calculator cover these operations.

Active vs reactive power

Generator output has active (kW) and reactive (kVAR) components:

• Active power: real power consumed by ship loads (motors, lighting, heating).
• Reactive power: power that flows back and forth in the circuit due to inductive (motor) or capacitive loads.
• Apparent power: vector sum of active and reactive (kVA).
• Power factor: cosine of phase angle between voltage and current; typically 0.8 to 0.95 lagging.

Modern automation manages active and reactive load sharing automatically. The generator active and reactive power calculator addresses this.

Power management system (PMS)

PMS functions

Modern ship electrical systems use a Power Management System (PMS) for automation:

• Automatic generator start: based on load demand or anticipated demand.
• Automatic synchronisation: when adding a generator to running bus.
• Automatic load sharing: distributing load between paralleled generators.
• Generator stop: when load drops below a threshold.
• Fault detection: protective shutdown for over-voltage, over-current, reverse power, frequency variation.
• Bus tie management: connecting/disconnecting bus sections.
• Heavy consumer prioritisation: managing loads above a threshold.
• Black start sequencing: in case of complete electrical failure.

Heavy consumer management

Heavy consumers like bow thrusters, large pumps, and air compressors require specific PMS handling:

• Pre-start sequencing: ensuring sufficient generators are online before start.
• Auto-start triggers: starting standby generator if heavy load is requested.
• Load shedding: in case of generator failure during heavy load operation.

Emergency generator

Emergency generator function

An emergency generator under SOLAS Chapter II-1 Part D is required on:

• Cargo ships of 500 GT and above: emergency power for 18 hours.
• Passenger ships: emergency power for 36 hours.

Emergency generator features:

• Located outside main machinery space and above bulkhead deck: protected from main machinery casualty.
• Self-contained: own fuel, lube, cooling, starting.
• Auto-start on main power loss: typically within 45 seconds.
• Dedicated fuel tank: typically 6 to 12 hours of operation at full load.

The emergency generator is critical safety equipment with periodic testing and surveys.

Emergency services covered

Emergency electrical services include:

• Emergency lighting at escape routes and embarkation stations.
• Navigation lights.
• Communication equipment (GMDSS).
• Fire detection and alarms.
• Steering gear (where electrical).
• Watertight door indication and remote operation.
• Bilge alarm system.
• Selected fire pumps.
• Bridge lighting.

Auxiliary engine fuel and emissions

Fuel options

Auxiliary engine fuel options:

• Heavy fuel oil (HFO): traditional high-viscosity fuel; requires heating, purification, viscosity control.
• Marine gas oil (MGO): distillate fuel with lower sulphur and viscosity; complies with SECA requirements.
• Marine diesel oil (MDO): intermediate distillate.
• VLSFO (Very Low Sulphur Fuel Oil): 0.5 percent sulphur fuel for global IMO 2020 compliance.
• LNG: in dual-fuel configurations.
• Methanol: in dual-fuel configurations.
• Biofuels: HVO, FAME blends.

The fuel choice depends on emissions strategy, route requirements, and economics.

MARPOL Annex VI Tier compliance

Auxiliary engines must meet MARPOL Annex VI NOx Tier requirements:

• Tier I: applies to engines installed on ships built between 1990 and 2010; NOx limit ~17 g/kWh at speeds below 130 rpm and progressively lower at higher speeds.
• Tier II: applies to engines installed on ships built 2011 onward; NOx limit ~14.4 g/kWh.
• Tier III: applies to engines on ships built 2016 onward (in NOx Emission Control Areas, NECA); NOx limit ~3.4 g/kWh, requiring after-treatment (SCR) or alternative technology.

NOx control technology

NOx control technology for Tier III compliance:

• Selective Catalytic Reduction (SCR): post-combustion treatment using urea-based catalyst to convert NOx to N2 and water. Most common Tier III technology.
• Exhaust Gas Recirculation (EGR): recirculating exhaust to combustion chamber to reduce peak temperatures.
• Combined approaches: SCR + EGR for some applications.

SO2 control

SO2 control under MARPOL Annex VI:

• Low-sulphur fuel: 0.5 percent global limit since 2020; 0.1 percent in SECA areas.
• Exhaust gas scrubber: closed-loop or open-loop SO2 scrubbing for high-sulphur fuel use.

The exhaust gas cleaning system article covers scrubber technology.

Decarbonisation pathway

Auxiliary engines on the decarbonisation pathway:

• Energy efficiency: reducing fuel consumption per kWh.
• Alternative fuels: progressive transition to LNG, methanol, ammonia, hydrogen.
• Battery hybrid: peak shaving and zero-emission port operation.
• Heat recovery: from exhaust gas via the waste heat recovery system.

The CII rating and FuelEU Maritime regulations drive auxiliary engine decisions.

Maintenance and surveys

Routine maintenance

Auxiliary engine routine maintenance:

• Daily: visual inspection, leak check, sound monitoring, vibration check.
• Weekly: fuel oil purifier inspection, lube oil sampling.
• Monthly: oil filter change, valve clearance check.
• Quarterly: more detailed inspection of accessible parts.
• Annual: comprehensive inspection, key component replacement.

Major overhaul intervals

Major overhaul intervals:

• Top-end overhaul: every 6,000 to 12,000 hours (cylinder heads, valves, injectors).
• Bottom-end overhaul: every 12,000 to 24,000 hours (pistons, rings, bearings).
• Major overhaul: every 24,000 to 60,000 hours (crankshaft, all bearings, complete inspection).

The intervals depend on engine type, operating profile, and operator policy.

Class society surveys

Class society surveys:

• Annual survey: visual examination.
• Renewal survey: every 5 years with internal inspection.
• Damage survey: after any incident affecting the auxiliary system.
• PMS surveys: continuous monitoring of selected parameters.

Operational considerations

Load profile and engine selection

Engine selection based on load profile:

• Cruising load: typically 1 generator running at 50 to 75 percent load.
• In-port load: typically 1 to 2 generators (more if cargo ops or reefer).
• Manoeuvring load: 2 to 3 generators (with bow thrusters online).
• Black-start scenario: 1 generator in standby + emergency generator ready.

The engine arrangement balances efficiency at typical load with redundancy for failure scenarios.

Specific Fuel Oil Consumption (SFOC)

Auxiliary engine SFOC characteristics:

• Modern medium-speed 4-stroke: 175 to 195 g/kWh at optimal load (typically 75 to 90 percent rated).
• Variation with load: higher SFOC at low load (under 50 percent), gradually decreasing toward optimal load, slight increase past optimal.
• Variation with fuel: slight differences between HFO, MGO, dual-fuel modes.

The Specific Fuel Oil Consumption article covers SFOC in detail.

Lubrication management

Auxiliary engine lubrication:

• Engine oil grade: typically SAE 30 or 40 trunk piston oil for medium-speed engines.
• Oil sample analysis: monthly typically, with viscosity, base number, water content, metals analysis.
• Filter change: as recommended by manufacturer or based on differential pressure.
• Oil change: typically 4,000 to 8,000 hours.

Cooling water management

Cooling water (jacket water) management:

• Coolant type: typically water with corrosion inhibitor and freeze protection.
• Temperature: typically 70 to 95 degrees Celsius outlet.
• Pressure: typically 1 to 3 bar gauge.
• Quality monitoring: pH, conductivity, inhibitor level.

Auxiliary engine on different ship types

Cargo ship auxiliary

A typical cargo ship (Capesize bulk carrier, container ship of moderate size, large product tanker) has:

• 3 to 4 main gensets of similar capacity (typically 1,200 to 2,500 kW each).
• 1 emergency generator of typically 200 to 500 kW.
• Optional shaft generator providing electrical power from main engine PTO.
• Total installed capacity: typically 4 to 10 MW.

The N-1 redundancy under SOLAS II-1 Part D is satisfied by the multi-genset arrangement.

Container ship auxiliary

Container ships have higher electrical demand due to refrigerated container (reefer) loads:

• Reefer load can reach 50 to 70 percent of total electrical demand on a fully laden reefer-heavy voyage.
• Genset count: typically 4 main gensets of 2,500 to 4,500 kW each.
• Total capacity: 10 to 20 MW.
• Variable demand: changes substantially through voyage as reefer count varies between ports.

The container ship arrangement balances genset count with sizing for typical reefer loads.

Tanker auxiliary

Tankers have specific demand patterns:

• Cargo pump operations: high demand during cargo loading and discharge.
• Inert gas system: continuous demand for IGS operation.
• Cargo heating: steam generation requires fuel for boilers; auxiliary engines drive boiler feed pumps.
• Genset count: typically 3 to 4 main gensets of 1,500 to 3,000 kW each.

Cruise ship auxiliary

Cruise ships have very high electrical demand:

• Hotel load: continuous demand for accommodation, galley, laundry, entertainment.
• HVAC load: very large for passenger comfort.
• Propulsion load: in diesel-electric configuration, propulsion is also auxiliary load.
• Genset count: typically 4 to 6 main gensets, each 8 to 14 MW.
• Total capacity: 40 to 80 MW.

Cruise ship auxiliary plants are among the largest marine electrical installations.

Offshore service vessel auxiliary

Offshore service vessels (PSV, AHTS, OSV, ROV mother ships) often use diesel-electric:

• DP requirements: dynamic positioning demands continuous high power.
• Crane and winch loads: peak transient loads.
• Genset count: typically 4 to 6 main gensets, each 1,500 to 4,000 kW.
• DP class: gensets arranged in redundancy groups for DP-2 or DP-3 classification.

The DP redundancy requirement (any single failure point cannot affect the DP function) drives the multi-genset, multi-bus architecture.

LNG carrier auxiliary

LNG carriers traditionally used steam turbines as main propulsion, with auxiliary generators for ship services. Modern LNG carriers using DFDE or ME-GI propulsion have larger auxiliary plants:

• DFDE LNG carrier: 4 dual-fuel gensets typically 8 to 14 MW each, providing both propulsion and ship services.
• Standard auxiliary: 2 to 3 smaller gensets for ship services when main engines stopped.
• Total capacity: 35 to 60 MW.

The dual-fuel capability allows operation on boil-off gas plus oil pilot.

Specific operational practices

Load following procedures

Load following procedures:

• Increasing load: PMS auto-starts standby genset when running load exceeds threshold (typically 80 percent of running capacity).
• Decreasing load: PMS auto-stops a genset when load drops below threshold (typically 50 percent of running capacity, with bias toward keeping generators online).
• Manual override: bridge or engine control room can override automatic load following.
• Time delays: hysteresis in load following to prevent excessive cycling.

Synchronisation procedures

Manual synchronisation:

• Voltage matching: adjust AVR to match running bus voltage.
• Frequency matching: adjust governor speed to match running bus frequency (slightly higher to ensure power flow on closing).
• Phase matching: align using synchroscope or synchronising lights.
• Closing breaker: at synchronoscope center or with low phase angle.
• Load uptake: gradual increase in load to avoid step disturbance.

Automatic synchronisation is faster and more reliable but manual capability is maintained for backup.

Heavy consumer management

Heavy consumer management:

• Bow thruster start: PMS confirms sufficient capacity available before allowing start.
• Cargo pump start: similar pre-start capacity verification.
• Blackout prevention: load shedding if capacity becomes insufficient during heavy consumer operation.
• Time-staggered starts: avoiding simultaneous heavy starts where possible.

Fuel changeover procedures

Fuel changeover procedures:

• HFO to MGO: gradual changeover to allow temperature equilibration; typical 30 to 60 minutes.
• MGO to HFO: similar reversal procedure.
• Crossover valves: dedicated valves for fuel switching.
• Documentation: changeover record per MARPOL Annex VI.
• Sample retention: for compliance verification.

Maintenance scheduling

Maintenance scheduling:

• Major overhauls: planned during ship’s regular dry-dock periods (every 5 years typically).
• Top-end overhauls: during voyage where practicable, with one genset out at a time.
• Filter changes: continuous rotation among gensets.
• Spare parts: maintained on board for routine maintenance.

Auxiliary engine in casualty scenarios

Engine room flooding

Engine room flooding response:

• Bilge pumping: maximum capacity activation.
• Watertight door closure: as appropriate.
• Aux engine shutdown: if water level threatens electrical equipment.
• Emergency generator transfer: if main electrical source compromised.

Engine room fire

Engine room fire response:

• Fire detection alarm: bridge notification.
• Crew evacuation: of engine room.
• Ventilation closure: stopping air supply.
• Fixed extinguishing: CO2 or water mist activation.
• Emergency generator: backup electrical supply.
• Fire main: water for boundary cooling.

Engine room blackout

Engine room blackout:

• Emergency generator auto-start: within 45 seconds.
• Bridge notification: alarm.
• Investigation: of cause.
• Recovery: starting first available aux engine using starting air.
• Documentation: in deck logbook and chief engineer’s report.

Crew training under STCW

STCW provisions

Crew training under STCW for auxiliary engines:

• STCW Section A-III/1: officer of the engineering watch on ships powered by main engines of 750 kW propulsion power or more.
• STCW Section A-III/2: chief engineer and second engineer.
• STCW Section A-III/4: ratings forming part of the engine watch.
• Specific training: on the actual auxiliary engines installed (manufacturer-specific or generic).

Hands-on training

Hands-on training elements:

• Engine start and stop procedures: in safe operating conditions.
• Load taking and load shedding: with main bus.
• Synchronisation and paralleling: manual operation.
• Maintenance procedures: routine and basic corrective.
• Emergency response: blackout, fire, flooding.

Refresher training

Refresher training:

• STCW certificate validity: 5-year cycle.
• Operator-specific training: for company procedures.
• Manufacturer training: when new engine series introduced.
• Post-incident training: following any casualty involving auxiliary system.

Insurance and class society implications

P&I cover

P&I cover for auxiliary engine incidents:

• Crew injury: from engine room operations.
• Cargo damage: from electrical failure affecting cargo systems.
• Wreck removal: in cases of total loss involving electrical fire.
• Pollution: from oil leaks during engine maintenance.

Class society oversight

Class society oversight:

• Engine certificates: for each genset at delivery.
• Continuous machinery surveys: on rotation.
• Performance monitoring: in some configurations.
• Failure reporting: to class society for investigation.

The class society relationship continues throughout the ship’s operational life.

Common engine series

MAN Energy Solutions Holeby

MAN Holeby auxiliary engine series includes:

• L23/30H: 720 to 900 kW, 720 to 900 rpm, 5 to 9 cylinder.
• L21/31: 1,000 to 2,000 kW, 720 to 900 rpm, 5 to 9 cylinder.
• L27/38: 1,000 to 3,000 kW, 720 rpm, 5 to 9 cylinder.
• L32/44CR: 3,000 to 4,500 kW, 720 to 750 rpm, 6 to 9 cylinder, with common-rail injection.
• 18/45CR: 4,000 to 6,500 kW, 500 rpm, 6 to 9 cylinder.

The MAN Holeby brand is widely used on cargo ships, ferries, tankers, and offshore vessels.

Wartsila auxiliary engines

Wartsila auxiliary engine series:

• Wartsila 14: smaller-class for yachts and smaller commercial vessels.
• Wartsila 20: medium-speed for smaller commercial.
• Wartsila 26: 2,000 to 3,500 kW, 750 to 1,000 rpm.
• Wartsila 32: 3,000 to 6,000 kW, 720 to 750 rpm, the most common Wartsila auxiliary.
• Wartsila 46: large auxiliary, also used as main propulsion in diesel-electric.
• Wartsila DF series: dual-fuel variants for LNG.

Wartsila is a market leader in aux engine technology with extensive global service network.

Other manufacturers

Other auxiliary engine manufacturers and series:

• Caterpillar: 3500, 3600 series for marine auxiliary applications.
• Cummins: K, L, M, Q series for smaller vessels.
• Mitsubishi: S6 to S16 series for Japanese yards.
• Hyundai HiMSEN: H series (H21/32, H35/40, H46/60) for Korean yards.
• Doosan: V158, V222 series.
• Yanmar: 6N, 6L series for smaller vessels.
• MTU: 4000 series, 8000 series for high-speed applications.

The choice typically depends on the shipyard’s preferred supplier, operator standardisation, and class society approval.

Subsidiary systems

Cooling water system

Auxiliary engine cooling water system:

• Closed-loop jacket water: cooling the engine cylinder block and head.
• Open-loop seawater: cooling jacket water through plate or shell-and-tube heat exchanger.
• Lube oil cooler: typically integrated with jacket water cooling.
• Charge air cooler: for turbocharged engines, cooling compressed combustion air.

The system generator jacket cooler plate cooler calculator addresses heat exchanger sizing.

Lubrication system

Lubrication system components:

• Sump and oil pan: integrated with engine block.
• Lube oil pump: gear-driven from engine.
• Lube oil cooler: heat exchange to jacket water.
• Lube oil purifier (centrifuge): removes water and contaminants.
• Lube oil filter: typically dual filters with switchover.
• Oil sampling point: for periodic analysis.

Fuel oil system

Fuel oil system per engine:

• Service tank: dedicated tank with adequate capacity (typically 4 to 8 hours of operation).
• Fuel oil pump: high-pressure injection pump.
• Filter: dual fuel filter with switchover.
• Fuel viscosity controller (HFO operation): heating to maintain viscosity.
• Fuel injection valves: on each cylinder.
• Common-rail systems: on modern CR engines.

Air system

Air system components:

• Turbocharger: exhaust-gas-driven compressor providing boost air to combustion.
• Charge air cooler (intercooler): cooling compressed air.
• Air filter: removing particulates from intake air.
• Starting air: 30 bar compressed air for engine starting.
• Crankcase breather: with oil mist separator.

Exhaust system

Exhaust system components:

• Exhaust manifold: collecting exhaust from cylinders.
• Turbocharger: extracting energy from exhaust.
• Exhaust gas economiser (where fitted): heat recovery to auxiliary boiler.
• Selective Catalytic Reduction (SCR) (Tier III): NOx reduction.
• Scrubber (where fitted): SO2 removal for HFO operation.
• Silencer: noise reduction.
• Stack: discharge to atmosphere.

Starting system

Starting system options:

• Compressed air starting: most common for medium-speed engines, using 30 bar starting air injected through cylinder valves.
• Electric starting: for high-speed engines and smaller auxiliaries.
• Hydraulic starting: for some specialty applications.

The starting air receivers must have capacity for at least 12 starts under SOLAS Chapter II-1 Part C requirements.

Vibration isolation

Vibration isolation:

• Resilient mounts: between engine and ship structure.
• Flexible couplings: between engine and generator shaft.
• Vibration monitoring: with periodic measurement.
• Torsional vibration damper: for crankshaft.

Vibration management is important for engine reliability and crew comfort.

Operational scenarios

Black start

Black start scenario (complete loss of electrical power):

• Emergency generator starts automatically within 45 seconds of main power loss.
• Emergency switchboard energised providing emergency services.
• Bridge alarm and lighting restored.
• Engineers respond: investigating cause of power loss.
• Aux engine restart: starting first available auxiliary generator using starting air.
• Power restoration: paralleling restored generator with emergency board if possible, then restoring main board.

The black start procedure is documented in the safety management system and tested periodically.

Blackout investigation

Common causes of unexpected blackouts:

• Reverse power: tripping a generator due to mechanical failure.
• Excitation failure: AVR malfunction.
• Bus fault: short circuit on the main bus.
• Heavy consumer trip: unexpected motor or thruster failure tripping generators.
• Load shedding system failure: excessive load not shed in time.

Each scenario has specific recovery procedures.

Bunker fuel changeover

Bunker fuel changeover (e.g. entering SECA from open ocean):

• Changeover plan: typically 1 to 2 hours before SECA boundary.
• Auxiliary engine adjustment: viscosity, temperature, fuel rack adjustment for new fuel.
• Documentation: fuel changeover record per MARPOL Annex VI.
• Verification: fuel sample retained for compliance.

Cargo operation power demand

Cargo operations create varying electrical demand:

• Loading/discharge with cargo pumps: substantial electrical demand on tankers.
• Container reefer power: high demand on container ships with reefers.
• Bow thruster operation: peak transient demand during berthing.
• Crane operation: peak demand on smaller ships with cargo cranes.

The power management system handles these transients automatically.

Documentation

Every ship maintains:

• Auxiliary engine operating manual from manufacturer.
• Class society certificates for each genset.
• Maintenance records including overhaul history.
• Crew training records under STCW.
• MARPOL Annex VI documentation including NOx Technical File.
• Bunker Delivery Notes under MARPOL Annex VI.
• Spare parts inventory.

Related Calculators

• Auxiliary Engines - N-1 redundancy check Calculator
• Generator Paralleling, Frequency Δ Check Calculator
• Generator, P vs Q Loading Calculator
• Generator Load Sharing, Droop Calculator
• Shaft Generator, Output Capability Calculator
• System - Auxiliary Engine: Medium-speed 4-stroke Calculator
• System - Generator Jacket Cooler: Plate cooler Calculator

See also

• Marine Diesel Engine
• Specific Fuel Oil Consumption
• Marine Boilers and Steam Systems
• Heavy Fuel Oil
• Marine Gas Oil
• LNG as Marine Fuel
• Methanol as Marine Fuel
• Ammonia as Marine Fuel
• Exhaust Gas Cleaning System
• Waste Heat Recovery System
• SOLAS Chapter II-1: Construction, Subdivision, Stability, Machinery and Electrical Installations
• MARPOL Annex VI
• Battery Hybrid Propulsion

References

• IMO MARPOL Annex VI (Air pollution prevention from ships).
• IMO NOx Technical Code 2008 with amendments.
• IACS Common Structural Rules.
• IACS Unified Requirements for marine diesel engines.
• Class society marine engine rules: ABS, BV, DNV, LR, ClassNK, KR.
• Major engine manufacturer technical documentation: MAN Energy Solutions, Wartsila, Caterpillar, Cummins, Mitsubishi, Hyundai.