These supply vessels will be the first ever U.S. flagged platform supply vessels (PSV) to be powered by clean, safe and efficient LNG. The contract includes options for supplying propulsion equipment for additional follow-on vessels.
Wärtsilä will deliver an integrated system that includes the dual-fuel machinery, electrical and automation package, complete propulsion, and also the LNG fuel storage and handling components. The STX Marine Inc SV310DF Offshore Support Vessels will be powered by Wärtsilä 6-cylinder 34DF dual-fuel engines. The LNG storage capacity of 290 cubic meters (m3), enables more than a week of vessel operational time. In addition, the vessels will carry 5520 tons of deadweight at load line and have a transit speed of 13 knots. The vessels are scheduled for delivery in two years and will operate in the Gulf of Mexico.
Mr Shane Guidry, Harvey Gulf International Marine’s Chairman and CEO, states that the stringent governmental demands for reduced emissions, together with predictions that availability of ultra low sulphur diesel fuel will be restricted, caused the company to consider the use of gas as fuel. “We’re committed to bringing the world’s best technologies to our customers, and these vessels with Wärtsilä’s integrated system based on the use of LNG further demonstrates Harvey Gulf’s Going Green Vision,” he says.
Pete Jacobs, Business Development Manager, Offshore at Wärtsilä North America adds:, “It’s a pleasure to work with a company such as Harvey Gulf whose management is dedicated to introducing advanced, clean, natural gas supply vessels. These modern supply vessels showcase Wärtsilä’s leading position as a complete solutions provider of LNG propulsion with electric drive systems.”
“We are witnessing a transformation of the marine industry as it charts a course towards a new era for natural gas. It’s exciting for Wärtsilä to be a trusted partner in this launch with industry leader Harvey Gulf, whose natural gas supply vessel investment actions of today signal a coming paradigm shift. This is aimed at capturing operational savings while simultaneously reducing emissions,” says John Hatley, Vice President Ship Power, Wärtsilä North America.
Dual-fuel technology meets economic and environmental targets
Wärtsilä has been at the forefront in the development of highly efficient dual-fuel engine technology, allowing the same Wärtsilä 34DF engine to be operated on either gas or diesel fuel with full EPA emissions Tier 2compliance. This dual-fuel capability means that when running in gas mode, the environmental impact is minimized since nitrogen oxides (NOx) are reduced by some 85 per cent compared to diesel operation, sulphur oxide (SOx) emissions are completely eliminated as gas contains no sulphur, and emissions of CO2 are also lowered. Natural gas has no residuals, and thus the production of particulates is practically non-existent.
The shipping industry finds the operational savings that gas offers to be very compelling. Similarly, the significant environmental benefits that LNG fuel provides are of increasing importance. With fossil fuel prices, and especially the cost of low sulphur marine fuel, likely to continue to escalate, gas is an obvious economic alternative.
Drawing from decades of experience in the development and application of natural gas engines for both the power generation and marine industries, Wärtsilä is the global leader in this advanced technology. Wärtsilä recently passed the 3 million running hours milestone with its dual-fuel engine technology.