The 6013 dwt Viking Energy, built by Kleven Verft AS in Norway, is the world's first LNG-powered supply vessel. Its owner, Eidesvik Shipping AS, is a Norwegian consolidated group of companies managing a worldwide fleet of purpose-built vessels and providing services for, among other things, the offshore market. The vessel was delivered in April 2003 and is chartered to Statoil where it is employed delivering supplies to oil and gas platforms in the North Sea.

Wärtsilä solution
Viking Energy has a diesel-electric propulsion plant with four Wärtsilä 6L32DF dual-fuel engines, each of 2010 kW output at 720 rpm driving the main generating sets. The engines run on liquefied natural gas (LNG) to reduce NOx emissions but they can also run on diesel oil. Should the gas supply be interrupted while the engines continue to deliver full power, they can be switched over from gas to liquid fuel automatically.