Shell Offshore has taken delivery of its third liquified natural gas (LNG)-powered offshore supply vessel, the Harvey Liberty.

Chartered from Harvey Gulf International Marine, the 302’ Harvey Liberty joined sister ships Harvey Energy and Harvey Power in Port Fourchon, La., earlier this week. The new vessel will support Shell’s deepwater operations in the Gulf of Mexico.

“This is an important milestone for Shell and Harvey Gulf,” said Tahir Faruqui, Shell’s general manager LNG North America. “The Harvey Liberty highlights our efforts to grow LNG as a fuel in the transport sector, and is a welcome addition to our portfolio.”

The Harvey Liberty runs on 99% LNG fuel and can operate for up to 15 days before refuelling. The LNG powered vessels provide vessel owners an alternative fuel to meet sulphur and nitrogen oxide emissions regulations in the North American Emission Control Area (ECA).

The innovative design of these OSVs landed Harvey Energy and Harvey Power atop WorkBoat’s Significant Boats list in 2015. The LNG OSVs were named 2015 Boat of the Year by WorkBoat.

All three vessels are powered by three Wärtsilä 6L34DF dual-fuel gensets providing 7,530 kW (10,100 hp) fueled by Wärtsilä’s LNGPac system — a complete fuel gas handling system for LNG vessels. It includes the bunkering station, the LNG tank and related process equipment, as well as the control and monitoring system. The 10,241-cu.-ft. vacuum-insulated LNG tank (about 100' long) is located under the cargo deck just aft of the house. It has a capacity of 73,000 gals. of LNG fuel.

R.W. Fernstrum supplied Weka boxcoolers to cool the Wärtsilä dual-fuel gensets and Wärtsilä bowthrusters.

“Harvey Gulf is excited to share these historical maritime events with Shell,” said Shane Guidry, chairman and CEO of New Orleans-based Harvey Gulf. “This represents another significant step in the path for Harvey Gulf to establish itself as a leader in utilizing LNG as a marine fuel.”