Damen develops fuel-flexible ASD tug designs

“If, in the future, it becomes commercially attractive – or indeed, mandatory – to sail with hybrid propulsion, HVO or methanol, operators can switch at that moment,” said Damen product manager for tugs, Erik van Schaik.

“Tug owners can undertake a retrofit to a different energy source during the lifetime of the vessel when they are certain there is a business case for it,” he said.

“If that moment never occurs during the lifetime of the vessel no money is lost.”

Damen’s fuel-flexible tugs are prepared for an easy retrofit from diesel or HVO to diesel, or HVO, plus methanol or diesel, or HVO, plus battery electric PTI/PTO hybrid.

“A newbuild tug ordered today may still be in operation three decades from now. Who knows what the fuel picture will be five years from now, never mind 25 or 30 years?” said Mr van Schaik.

Having a vessel ready for future retrofit enables operators to switch as required with lower investment costs and faster returns on that capital outlay, he added.

The type of fuel and propulsion required would be determined by the tug’s operational profile and regulatory environment, both of which can change over the lifetime of the vessel.

“With a predictable port-based towage operation, a fully electric, zero-emissions approach makes sense,” said Mr van Schaik.

“For less predictable operations farther from shore, the way forward is more likely to be a carbon-neutral approach with HVO or green methanol.”

On the regulatory front, the European Union plans to change the range for which its emissions trading scheme will be applied, from currently vessels over 5,000 gross tonnes to covering all vessels over 400 gross tonnes in 2027.

Already in Europe, newbuild tugs delivered into IMO’s emissions control areas have aftertreatment systems for compliance with IMO Tier III emissions standards. If these regulations tighten, then HVO or green methanol fuels will be needed.