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Washington State Ferries switch to LNG fuel

LNG Industry,

Washington State Ferries (WSF) has taken another step towards reducing fuel costs and transportation emissions by switching from diesel fuel to liquefied natural gas (LNG) for a class of vessels.

WSF intends to convert six Issaquah Class vessels to use cleaner LNG fuel. The proposal was officially submitted by the company to the US Coast Guard on 18th November in a letter of intent, accompanied by a waterways suitability assessment. The submissions mark the official starting point of the Coast Guard’s review process. WSF hopes the Coast Guard will issue a response to the LNG conversion proposal in 2014.

“Fuel is WSF’s fastest growing operating expense,” commented David Moseley, assistant secretary for the Washington State Department of Transportation, Ferries Division. “Replacing diesel with LNG on the Issaquah Class ferries could result in very substantial savings on fuel over the remaining 30 years of their service life. This will also mean a cleaner, more efficient future for our fleet by significantly decreasing emissions.”

Lower emissions

The average Issaquah Class vessel carries up to 124 cars and 1200 passengers, serving on some of Washington’s busiest ferry routes. Converting the fuel systems to LNG would significantly reduce emissions including:

  • 89% reduction in particulate matter
  • 61% reduction in nitrous oxide
  • 28% reduction in carbon dioxide
  • 59% reduction in sulfur dioxide

For the proposed conversion vessels, WSF plans to install main propulsion engines to use natural gas and retrofit LNG fuel tanks on the top decks of the six vessels.

Evaluation process

WSF has been studying the benefits of alternative fuels for a number of years, and has been evaluating the possibility and safety of using LNG to fuel its ferries. The process included the US Coast Guard, state and local agencies, private organisations, the Washington State Joint Transportation Committee and consultants including Cedar River Group and Det Norske Veritas, the world’s leading authority on LNG fuelled passenger ferries.

WSF concluded its study process by issuing the final waterways suitability assessment, which includes a safety and security assessment and a risk-management plan.

Adapted from press release by Katie Woodward

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