Client: Leading Container Shipping Company
Engine: 2-Stroke, 64,000 kW Main Propulsion Engine
Challenge: Undetected Engine Inefficiency Leads to higher Fuel Consumption

Context

A major player in the shipping industry, operating a Post-Panamax container vessel with a 64,000 kW 2-stroke main engine, approached us to implemen our VIB360 Smart Efficiency Monitoring and Analytics System. Initially, the client reported no performance issues, assuming that their vessel was operating efficiently. However, through our efforts, they were convinced to try the VIB360 system to monitor the engine’s health and optimize performance.

Fault Diagnosis

The engine typically operates between 30 and 95 RPM, with a rated maximum RPM of 102. During the trial period, the VIB360 system detected unusual engine behaviour when the RPM was crossing above 70 RPM. This anomaly resulted in a significant increase in fuel consumption by over 1.2%, a deviation that had previously gone unnoticed by the operator.

Investigation

Upon further analysis, our team discovered that the vibration damper, which as designed, was being excited whenever the engine RPM exceeded 70. This excitation created torsional vibrations that led to slight twisting of the 18-meter-long crankshaft, disrupting the synchronization of piston travel in certain cylinders. This disturbance altered the fuel injection timing, leading to a 1.2% increase in fuel consumption at higher RPMs.

While this increase might seem negligible on paper, the real-world impact was significant: an additional 30 tons of fuel consumed annually for the same power output.

Impact

The financial implications of this issue were considerable. At an average cost of $600 per ton of marine fuel, the 30 additional tons of fuel consumed each year amounted to an extra $18,000 in annual fuel expenses. Beyond the financial burden, there were notable environmental impacts, as higher fuel consumption inevitably leads to increased emissions, further emphasizing the inefficiency.

After presenting our findings to the shipowner, we recommended they closely monitor fuel consumption between 30 to 70 RPM and compare it to consumption at 75 RPM and above. Their independent investigations corroborated our findings, and the client recognized the importance of addressing this inefficiency.

Conclusion

The VIB360 system’s early detection of this inherent design flaw in the engine’s vibration damper enabled the client to take proactive steps to mitigate the issue. By consciously managing engine RPM and monitoring fuel consumption more carefully, the shipowner was able to significantly reduce unnecessary fuel usage and avoid further financial losses.