Spotting problems before they occur

The Aurora Spirit, launched in 2020, is the world’s first dual-fuel e-shuttle tanker and one of six new-generation tankers ordered by Altera Infrastructure, formerly Teekay Offshore, and developed in close collaboration with Wärtsilä. The vessel features four Wärtsilä 34DF dual-fuel engines alongside a unique system that recovers volatile organic compounds for use as fuel to power both the gas turbine and the main engine.

Early warning enables a rapid response

As part of the Optimised Maintenance agreement between Altera Infrastructure and Wärtsilä, the Aurora Spirit is covered by the Wärtsilä Expert Insight service – a predictive maintenance service that combines artificial intelligence (AI) techniques and advanced diagnostics with Wärtsilä’s OEM expertise to identify anomalous behaviour. The service proactively identifies and highlights potential failures and early indications of equipment deterioration and conditions that cause equipment to run less efficiently.

In early December 2020, the Aurora Spirit was on its way to collect a cargo of crude oil from an offshore platform in the North Sea. As the vessel sailed close to Stavanger, Norway, diagnostics expert Philip Westberg was alerted to a potential problem with one of its engines. “Part of my daily job is to monitor the engine operating data for this vessel, and on that day the AI-based anomaly detection system had flagged an abnormality in the lube oil pressure at the turbocharger inlet, which was slightly higher than normal. Since I am familiar with the operating profile of the vessel, I was able to conclude that this was certainly worth investigating further,“ he explains.

A little detective work goes a long way

Philip liaised with colleagues from Wärtsilä’s Technical Services and Operational Support teams to try to pin down what the problem could be. Potential causes could have been a simple sensor error, or perhaps an obstruction in the pipe leading to the sensor. Philip contacted the vessel’s chief engineer via the Expert Insight Collaboration app to request some onboard checks that would help to verify what was really going on.

“After Technical Services looked at the results of the onboard checks, they were able to confirm that there was a problem with the turbocharger and that the engine should be taken offline as a precaution,“ Philip explains. Wärtsilä then arranged an inspection which confirmed that the problem was with a bearing on the compressor side. “The bearing’s location pins had broken, meaning it was rotating inside its housing along with the shaft,“ explains Philip.

Had this problem not been identified early with the help of Expert Insight and the Wärtsilä team’s intimate knowledge of the vessel’s engines, it could have resulted in a major engine failure further down the line.

“A failed turbocharger bearing could result in damage to the compressor wheel; any metal fragments generated by this damage could then enter the charge air system, causing cylinder head damage,“ explains Marius Toldnes, Contract Manager, Wärtsilä Marine Power. “Worse still, they could cause the pistons to seize, which could cause the connection rod to break and come through the engine block.“

Man and machine in perfect harmony

For Altera Infrastructure, the cost of the Expert Insight service pales into comparison against the consequences of the potential damage the broken component could have caused to the engine and the impact a breakdown would have had on their operations.

“For this kind of issue the potential repair bill would most certainly run into six figures under normal circumstances. Thankfully we discovered this problem early with the help of Philip, our Technical Services and Operational Support teams, and of course the Expert Insight anomaly detection service,“ Toldnes highlights.

Expert Insight analyses engine data according to a set of rules based on Wärtsilä’s vast installed base, and artificial intelligence is used to model engine behaviour. Anomalies are identified by comparing the predicted value provided by the model to the actual value measured by the sensors installed in the engine. Wärtsilä’s experts then use their deep OEM engineering knowledge to confirm what is going on and provide clear recommendations on how and when to deal with the issue.

Toldnes continues: “In the end, we were able to get a service engineer on board in time to perform the repair while the vessel was in transit to the platform. The repair itself took about a day and a half, but it was critical to finish the work before the Aurora Spirit reached its destination so that it had all its engines available for the dynamic positioning required for loading. Had the engine not been back up and running again in time, the vessel would have not been able to complete its contract, which in turn could have led to financial and operational consequences for Altera.“

“This incident demonstrated not only the value of Expert Insight, but also the dedication of the Wärtsilä team in verifying the problem and coming up with a solution in a very short timeframe. The service provides our crews with invaluable support and our organisation with the peace of mind that our assets are protected by the very best in maritime engineering technologies and expertise.” – Martin Steffensen, Fleet Manager, Altera Infrastructure