Case Studies

Roll-On/Roll-Off Ferry 

Sulzer 8L ZA40S Main Engines with EGR & FSO

The Roll-On/Roll-Off ferry is powered by four Sulzer 8L ZA40S main engines, each delivering 5.7 MW at 510 rpm in a robust diesel-mechanic propulsion configuration. 

This reliable setup ensures high propulsion efficiency, excellent maneuverability, and dependable performance for demanding Ro-Ro operations on short-sea and regional routes.

Exhaust Gas Recirculation (EGR) – Emission Performance

The integration of an advanced Exhaust Gas Recirculation (EGR) system on one of the Sulzer 8L ZA40S engines enables a significant reduction in harmful exhaust emissions. By recirculating a controlled portion of the exhaust gas back into the combustion process, the engine achieves a cleaner and more environmentally friendly operation.

  • Change of emission level from IMO Tier 0+ to IMO Tier II compliance
  • NOx emissions reduced by approximately 78%
  • Improved environmental footprint in sensitive coastal and port areas
  • Enhanced compliance with current and future emission regulations

This EGR solution supports sustainable ferry operations while maintaining the proven reliability and power density of the Sulzer 8L ZA40S platform.

Fuel Saving Option (FSO) – Efficiency and Cost Reduction

The Fuel Saving Option (FSO) is designed to optimize engine performance and reduce overall fuel consumption without compromising operational safety or vessel speed. Through refined combustion control and optimized engine settings, the FSO delivers measurable savings and lower operating costs.

  • Approximate 11% fuel saving compared to standard operation
  • About 11% reduction in CO2 emissions
  • Approximate 11% reduction in particulate matter (PM)
  • Lower lifecycle operating costs and improved return on investment

By combining EGR technology with the Fuel Saving Option, the Ro-Ro ferry benefits from both reduced emissions and improved fuel efficiency, supporting greener shipping and long-term regulatory compliance.

Container Vessels

Proven Emission Reduction Solutions 

Meeting IMO Tier III emission requirements does not always require a complete engine replacement or costly LNG conversion. Vessel owners can choose from several retrofit solutions depending on operational requirements, budget, and downtime constraints.

Using a standard 1,000 TEU feeder container vessel with a 9 MW main engine as a reference, we compare the most common compliance options.

Retrofit Options Compared - Dual-Fuel LNG Conversion

The most comprehensive approach, converting the vessel to operate on natural gas.

Advantages

  • Significant emissions reduction
  • Future-ready fuel flexibility
  • Potential long-term environmental benefits

Considerations

  • Highest capital investment
  • LNG storage infrastructure required
  • Longest installation period

Estimated Investment: €10.2 million
Total Downtime: 8 weeks

SCR Catalyst Installation

Selective Catalytic Reduction (SCR) is a proven technology for reducing NOx emissions.

Advantages

  • Established and reliable solution
  • Compliance with IMO Tier III requirements
  • Suitable for a wide range of engine types

Considerations

  • Additional maintenance requirements
  • Increased space requirements onboard
  • Operational consumables needed

Estimated Investment: €1.75 million
Total Downtime: 4 weeks

EGR System Installation

Exhaust Gas Recirculation (EGR) reduces NOx emissions by recirculating a portion of exhaust gases back into the engine.

EGR with Fuel Saving Option

Estimated Investment: €1.29 million
Total Downtime: 2 weeks

EGR without Fuel Saving Option

Estimated Investment: €1.10 million
Total Downtime: 1 week

Advantages

  • Lowest retrofit cost
  • Minimal vessel downtime
  • Fast installation and commissioning
  • Attractive return on investment

Why Shipowners Choose EGR

For many feeder vessel operators, EGR provides the optimal balance between regulatory compliance, installation time, and capital expenditure.

Compared to LNG conversion, an EGR retrofit can reduce project costs by nearly 90% while minimizing off-hire periods and operational disruption.

Whether the objective is immediate compliance, cost optimization, or maintaining trading flexibility, EGR technology offers a practical pathway to IMO Tier III certification.

Quick Comparison

Solution Investment Downtime
LNG Dual-Fuel Conversion €10.2M 8 Weeks
SCR Installation €1.75M 4 Weeks
EGR with Fuel Saving €1.29M 2 Weeks
EGR without Fuel Saving €1.10M 1 Week

Disclaimer: Figures are indicative estimates based on a 1,000 TEU feeder container vessel and may vary depending on vessel design, shipyard location, engine type, and project scope.