Seminar on Marine Diesel engines with example of diesel engine used in 120m long DSV Ship. This is pure academic related. This is from an real time experience in Shipyard on Naval Ships. Very useful and Authentic information. This also gives an idea about the engine size requirement for a particular ship size & speed.

1. MARINE DIESEL ENGINES
KAKUMANU SARATH CHANDRA
REG NO-423206939013

2. Presentation Flow
Engine parameters of DSV ship
Low speed & Medium speed engines
Scavenging & Supercharging systems
Starting system
Maintenance, Automation & Hazards in engine room
Conclusion
References

3. Engine Parameters of DSV Ship
Engine Model : c280 16, Four stroke
Engine Power : ~ 5500 kw
Engine Speed : 950 rpm max.
Engine OEM : Caterpillar
Number of Engines : Two
Speed of ship @ 85% MCR : 20 kn max.
(Ship L 120m, B 22m, T 6m approx.)

4. Low speed & Medium speed Marine Engines
• Low-Speed Engines
• Low-speed engines are typically two-stroke engines, operate at speeds < 300 RPM.
• Commonly used in large ships (bulkers, tankers & container ships), where high
power output is essential. These engines are often large and heavy.
• Low-speed engines generally burn heavy fuel oil, which is less refined but cheaper.
• Medium-Speed Engines
• These engines typically operate between 300 and 1000 RPM (used in DSV ships).
• Medium-speed engines offer a balance between size, efficiency, and cost.
• These engines are more compact and lighter compared to low-speed engines.
• More fuel efficient & run on various fuels like heavy fuel oil, marine diesel oil etc.
• These often employ four-stroke cycle designs, although some two-stroke medium-
speed engines exist as well.

5. Scavenging & Supercharging systems
• Essential processes, intricately designed components of marine engines, to
optimize combustion efficiency, power output, and overall engine performance and
efficiency.
• Scavenging is the process of removing exhaust gases from the combustion
chamber after the power stroke and replacing them with fresh air for the next cycle.
In two-stroke marine diesel engines, scavenging is particularly critical since they
lack intake and exhaust valves. Instead, ports are used for these functions. Turbo
chargers consist of a turbine wheel & Compressors wheel mounted on a common
shaft (used in DSV engines) for exhaust & compression of intake air (to have more
oxygen).
• Supercharging is the process of compressing the intake air before it enters the
combustion chamber, using inbuilt engine driven air compressor system (not used in
DSV engines). Where high duty engine performance is required, these mechanism
is used.
• In marine diesel engines, supercharging is commonly achieved using turbochargers,
which are driven by exhaust gases. Turbochargers consist of a turbine wheel and a
compressor wheel mounted on a common shaft. The exhaust gases passing
through the turbine wheel drive the compressor wheel, which compresses the intake
air.

6. Starting system of Marine Diesel Engines
• The starting system of marine diesel engines must be robust and reliable, as the
engine's ability to start promptly is crucial for the safety and efficiency of maritime
operations. Various types are
• Electric Starters: Most modern marine diesel engines are equipped with electric
starters. These starters use electric motors to crank the engine until it achieves
sufficient speed for combustion to occur. Electric starters are convenient and
reliable.
• Air Starters: Some larger marine diesel engines, particularly those in large ships,
may use compressed air starters (used in DSV ship). These systems use
compressed air to drive a pneumatic motor, which rotates the engine's crankshaft
to start the combustion process. Air starters are robust and suitable for heavy-duty
applications.
• Hydraulic Starters: Hydraulic starters are another option for starting marine diesel
engines. They use hydraulic fluid to drive a hydraulic motor, which turns the
engine's crankshaft. Hydraulic starters are often used in applications where
compressed air is not readily available.

7. Reversing Gear
• Reversing gear systems allow marine diesel engines to change the direction of
rotation, enabling the vessel to maneuver in reverse.
• Different types of reversing gear systems may be used, depending on the specific
engine and vessel design. Common types include:
• Mechanical Clutch Reversing Gear: This type of reversing gear uses a
mechanical clutch system to engage and disengage the engine's rotation
direction. When engaged, the clutch connects the engine to the propeller shaft,
allowing the vessel to move forward or backward.
• Hydraulic Reversing Gear: Hydraulic reversing gear systems use hydraulic
actuators to control the engagement of the clutch mechanism. Hydraulic
systems offer precise control and smooth operation.
• Electronic Reversing Gear: Some modern marine diesel engines may
incorporate electronic control systems for reversing. These systems use
electronic actuators to control the clutch engagement, providing precise and
responsive control.
• Reversing gear systems must be designed to handle the high torque and load
requirements associated with reversing marine diesel engines. They should also
provide smooth and reliable operation to ensure safe maneuvering of the vessel.

8. Maintenance in Engine room
• Regular maintenance of engine room equipment is essential to ensure the safe and
efficient operation of the vessel.
• Maintenance tasks typically include routine inspections, lubrication, cleaning, and
repair or replacement of components as needed.
• Maintenance schedules are established based on manufacturers'
recommendations, class society requirements, and regulatory standards.
• Common engine room equipment requiring maintenance includes engines,
generators, pumps, valves, heat exchangers, filters, and control systems.
• Proper maintenance practices help prevent equipment failures, reduce downtime,
extend the lifespan of machinery, and ensure compliance with safety and
environmental regulations.
• Diesel engines have to be maintained as per the guidance provided by the Engine
manufacturer (OEM) and maintain the recommended list of onboard spares (OBS)
for replacement of parts as necessary.

9. Automation
• Automation plays a significant role in modern engine rooms, improving efficiency,
accuracy, and safety.
• Automated systems monitor and control various engine room functions, including
propulsion, power generation, fuel management, ventilation, temperature control,
and alarm systems.
• Automation systems use sensors, actuators, controllers, and computerized
interfaces to provide real-time data, diagnostics, and automated responses to
changing operating conditions.
• Benefits of automation include reduced workload for crew members, improved fuel
efficiency, optimized performance, early detection of faults, and enhanced safety
through automatic shutdowns or alarms in case of emergencies.

10. Hazards in Engine room
• Engine rooms contain numerous hazards that pose risks to personnel, equipment,
and the environment. Effective Training to Crew would help to mitigate risk.
• Common Causes of hazards in engine rooms include:
• High temperatures/ heat-related issues in engine due to engines/ auxiliaries.
• Noise and vibration of dynamic parts inside engine room.
• Chemicals such as lubricants, fuels & cleaning agents.
• Moving machinery parts in engine room pose crush & entanglement hazards.
• Fire & Explosion risks : Flammable fuels, lubricants and electrical systems,
increasing the risk of fire and explosion. Fire detection and suppression
systems, along with proper fixed firefighting equipment and training, are
essential for mitigating these hazards.
• All diesel engines are mandatorily fitted with Automated safety measures to mitigate
possible Engine high coolant temperatures, Low lube oil pressures, over speed etc.
For better control/monitor there would be approx 30 sensors associated in Engines.

11. Conclusion
• Marine Diesel Engines are still the Robust engines In Performance, Efficiency &
Durability. Being used in onboard ships in Large Scale.
• Available vide variety of Ranges/sizes & Capacities. Could be used for different ship
propulsion systems.
• For large ships/engines, Air starters are commonly used, where compressed air is
available onboard ship.
• Turbo chargers commonly used for high efficiency (approx 45% engine efficient).
• Automated system benefits reduce workload, improve fuel efficiency, optimized
performance, early detection of faults, and enhanced safety through automatic shutdowns
or alarms in case of emergencies.
• Good Ventilation design, proper Training to crew, Maintenance as per OEM
recommended routines (Engine & associated automation system) would give continual
performance of Engines.
• Fixed fire fighting system would help to reduce the risk of fire Hazards in Engine rooms.

12. References
• Caterpillar Manual for marine diesel engine model C280 16
• Engine manual supplied by caterpillar OEM for DSV Ship.

13. THANK YOU