Just like the motor in your car, marine engines need regular maintenance to keep them running in tip-top condition. When two of the Wärtsilä 46F main engines onboard one of Finnlines’ vessels were due for their 48,000-hour turbocharger overhaul, Wärtsilä seized the opportunity to help their long-term customer turn this scheduled maintenance break into a golden opportunity to reduce costs, improve reliability and cut fuel consumption and emissions.
Improve main engine performance and reduce emissions for two ro-ro cargo vessels.
Turbocharger performance upgrade package incorporating the latest technology, with all work completed during standard 48,000 hour turbocharger overhaul.
Extended turbocharger component lifetime and reduced fuel consumption and emissions.
Finnlines – part of the Grimaldi Group and a leading provider of cargo and passenger transport services as well as port services in the Baltic and North Sea areas – operates over 170 weekly departures carrying passengers and cargo safely and efficiently to their destinations around Europe.
Over the last decade the company has backed its commitments to reducing its carbon emissions and improving its sustainability performance to the tune of hundreds of millions of euros. These investments have included newbuild vessels featuring Wärtsilä engines and hybrid technologies and retrofits of existing vessels including emission abatement systems and energy-saving technologies such as rudder and propeller modifications to cut fuel consumption.
In 2018, Finnlines completed a 70-million-euro investment programme to lengthen six of its ro-ro vessels, increasing their capacity by 30% and reducing the energy consumption and emissions per transported cargo unit.
One of these vessels, the M/S Finnsun, a 14,467 DWT ro-ro vessel built in 2012, plies a route between Finland and Germany transporting products for Finnish industrial customers. As the OEM for the main engines, Wärtsilä was aware that the clock was ticking down towards the 48,000-hour turbocharger maintenance interval and so stepped in with a proactive and compelling proposal.
“Wärtsilä had initiated a W46F performance upgrade development together with the turbocharger supplier Accelleron, formerly ABB Turbocharging, who developed a new turbocharger specification that incorporates new compressor and turbine design upgrade for Wärtsilä 46F engines equipped with TPL76 turbochargers,” explains Eero Laine, Senior Product Manager, Wärtsilä 46F engines, Wärtsilä Marine Power. “It extends the exchange interval of the turbocharger’s rotating components from 48,000 to 75,000 running hours. It also boosts engine performance and fuel economy, which has a direct link to decarbonisation, by replacing the existing turbocharger cartridge with the latest C8X design technology,” he continues.
“The 48,000-hour scheduled overhaul is a fantastic opportunity to enhance performance for a comparatively small additional cost and without extending the time needed to complete the overhaul,” highlights Gino Rizzetto, Senior Technical Expert, Turbocharging and Performance, Wärtsilä.
“This type of upgrade was of particular interest to Finnlines because its customers are actively seeking ways to reduce the indirect emissions from their supply chain as part of their efforts to cut their overall carbon footprint,” Laine explains.
The upgrade involves replacing the rotating parts of turbocharger – the compressor, compressor wheel and compressor diffuser – with new parts incorporating the latest technology.
It is typical to see engine exhaust gas temperatures increase gradually over time, as this is an indication of engine and turbocharger aging and wear. This is why, when measuring engine performance, exhaust gas temperature is used as a good indication of the overall health of the engine. “Higher-than-normal temperatures are usually a sign that the engine may not be running optimally or perhaps that something more serious is going on,” Rizzetto explains. “With this upgrade we can see a reduction of perhaps 15 to 20 degrees Celsius in the exhaust temperature before the turbo and the exhaust temperature after the cylinders, which extends the lifetime of both the engine and turbocharger components.”
As well as extending component lifetime this temperature reduction also translates into fuel savings. “From experience we can say that fuel savings are in the region of 1 to 1.5 g/kWh, which of course means a reduction in CO2 emissions as well,” explains Laine. “Using a tool from the US Environmental Protection Agency we were able to demonstrate that for the Finnsun the reduction would be equivalent to the emissions generated by 64 passenger vehicles driving for one year, or a single vehicle driving for around 740,000 miles,” he continues.
“In practice we are not doing anything different than what we would do during a standard 48,000-hour scheduled overhaul because we are replacing parts that would be replaced anyway. This means the upgrade doesn’t extend the length of the overhaul, which is of course critical for vessel owners’ profitability,” says Rizzetto.
The upgrade of the two main engines onboard M/S Finnsun took place during a routine port stay in Helsinki during September and October of 2021 and therefore had no impact on its scheduling.
“We worked with the technical support team at Accelleron to define the turbocharger specification and the turbocharger matching process, then after installation we monitored the engine behaviour and made adjustments to ensure everything was aligned and working properly,” Rizzetto explains.
The process took one week in total, including gathering reference data from the engine prior to the upgrade, performing the modification work and then gathering data from the engine again to measure the results of the upgrade. Finnlines subsequently commissioned Wärtsilä to perform the same upgrade to a second ro-ro vessel – the M/S Finntide, also built in 2012.
“Our relationship with Finnlines has grown stronger year after year,” says Markus Nyström, Senior Account Manager, Sales, Finland and Baltics, Wärtsilä Marine Power. We have an excellent open working relationship with Finnlines, who trust us implicitly to help them resolve any obstacle they encounter in their daily operations with their fleet. We supply them with spare parts and services, scrubber technologies to ensure emissions compliance, and of course innovative new solutions that support their operational objectives – for example for their newbuilds which include Wärtsilä engines and hybrid technologies,” he continues. “Wärtsilä’s vast knowledge and know-how puts us in a good position to proactively suggest new innovations to enhance vessel performance, reliability and efficiency,” Nyström concludes.
“Part of our strategy is to invest in operational efficiency and, by enabling us to safely extend the exchange interval of the turbocharger’s rotating components, this upgrade is a great example of a solution that demonstrates our commitment to that strategy. The upgrade also helps us to slightly reduce our fuel consumption and emissions, which is good news for both Finnlines and our Finnish industrial customers as they seek to reduce the carbon footprint of their supply chains. We are committed to providing all our customers, from small entrepreneurial businesses to major global players, with the same high-quality, reliable service and Wärtsilä's support helps us to do that.” Sampo Salmi, Technical Manager RoRo, Finnlines.