Pioneering PSV enters dock for conversion to ammonia power

The conversion project led by Eidesvik and charterer Equinor will see a dual-fuel ammonia engine supplied by Wärtsilä Marine installed on the PSV.

“This milestone represents a decisive step forward in advancing low-emission offshore operations and demonstrates how industrial partnerships can accelerate the energy transition at sea,” said Eidesvik.

“On completion, Viking Energy will be the first offshore vessel capable of operating on ammonia as fuel, helping to demonstrate the potential of ammonia as a scalable solution for decarbonising maritime transport. 

“With the potential to significantly reduce greenhouse gas emissions, this project highlights how industrial partnerships, technology and operational experience can come together to accelerate the energy transition at sea.”

The vessel is being converted to operate on ammonia more than 20 years after it became the first LNG-fuelled OSV.

Part of the Norwegian government-backed Apollo Project, the conversion will involve the installation of a four-stroke Wärtsilä 25 dual-fuel ammonia engine, an ammonia tank, a new AmmoniaPac fuel gas supply system, an ammonia release mitigation system, an exhaust aftertreatment system, structural changes, system integration, and technical upgrades, along with testing and commissioning.

In 2025, the Norwegian owner received almost US$4M in grant funding from Enova SF for the retrofit project.

Under charter to Equinor since its launch in 2003, Viking Energy’s contract was extended by the Norwegian oil and gas major until April 2030. Equinor holds further contract options to keep the PSV working in the Norwegian continental shelf and said it will “contribute significantly to funding the conversion to ammonia operation.”

The project aims to reduce the vessel’s CO2 emissions by 70% or more compared with its current LNG and marine gasoil propulsion system.

PSVs in Norway produce about 1M tonnes of CO2 emissions annually, making them the largest emitter in the offshore logistics supply chain. As highlighted recently by OSJ, the Norwegian Government is introducing legislation that will require low- and zero-emissions technology for OSVs by 2030.

A VS 4403 design, the Norway-flagged PSV has an overall length of 95 m, beam of 20 m, deadweight of 6,013 tonnes and a clear deck area of 1,030 m3.

Naval architectural firm Breeze Ship Design has undertaken basic and detailed design work for the yard to undertake the conversion. Class society DNV has issued an approval in principle for the design of the ammonia-powered vessel.

Shipyard work began with the prefabrication of steel and piping systems in advance of the vessel’s arrival at the yard. Once conversion work is completed in Q3 2026, the vessel will be ready for testing and commissioning.