The Ohio-headquartered tugboat company’s sister company, Great Lakes Shipyard, recently began construction on the sixth of a series of 10 diesel-electric hybrid tugboats being built for Great Lakes Towing Company. The Damen-designed vessels feature hybrid system components supplied by Logan Clutch Corporation.
Speaking during Tug Technology Webinar Week, organised by Riviera Maritime, Starck, Jr. said that while the decision to convert the tugs to hybrid propulsion had been influenced by emissions regulation, the key driver had been economics.
‘Our hybrid propulsion plan was really intended to save money,’ said Starck, Jr. ‘We wanted to develop the most cost-efficient system possible and that’s really why we went to the system that we selected with Logan.’
Starck, Jr. continued: ‘It’s sized specifically for our operations – the system that they proposed to us is not a one-size-fits all system. It was designed specifically for our horsepower and our propulsion and bollard pull requirements.
Since operating the hybrid tugs, Great Lakes Towing Company has reported significant emissions reductions, including a 73% reduction in particulate matter, 51% reduction in NOx and 27% in CO2.
Unlike other such hybrid tugs, the Great Lakes Towing Company tugs do not feature batteries. Explaining the reasoning for this, Starck, Jr. said that the CAPEX costs remain high compared with fuel and emissions savings which reduces the overall benefit. Additionally, losses of between 10% and 20% are incurred when charging and discharging. He also referenced ‘the high-profile incidents that have happened, particularly with fires and breakdowns’, as well as practical challenges associated with the installation of batteries.