The Mississippi River and other inland rivers of the United States are home to several thousand towboats. They are vital carriers of goods and materials, and an important element within the country's overall transportation system. Current and future environmental restrictions on emissions are creating the need for a new 'greener' design for these vessels.

Wärtsilä and Ship Architects, Inc., USA, cooperate to develop a new environmentally sound towboat concept. Ship Architects, Inc. is a company that specializes in providing shipyards and owners with technical solutions in conceptual and detailed vessel design, project management, and other associated services. Wärtsilä is the leader in dual-fuel technology that allows its propulsion solutions to be operated on a variety of fuel types, including clean natural gas. The companies have together developed a new concept of towboat design that employs Wärtsilä 20DF and 34DF dual fuel engines for propulsion.

An industry facing stringent environmental regulations
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The riverboat industry is facing challenges as the result of progressively severe restrictions being imposed on engine emissions. Further reductions will be needed in the future when the Emissions Control Area (ECA) regulations take effect in August 2012. There is a sense of urgency to the development of more environmentally friendly vessels.

Wärtsilä's industry leading dual-fuel technology enables the towboats of US rivers to be powered by engines that comply with current and future environmental legislation, while creating operational cost savings for the operators.

"It has been clear to our company for quite a while that the river towboat industry is one whose needs match the answers that natural gas provides. With that in mind, our architects made a conceptual design to create a leading technology river towboat. It is based on the use of clean LNG as its propulsion fuel, and we are very pleased for Wärtsilä's co-operation in making this possible," commented Joe Comer, President of Ship Architects, Inc..

Wärtsilä technology eliminates need for low-sulphur fuel

The key driver to this need for change is the US Environmental Protection Agency's (EPA) lowering of sulphur content levels in the fuel used. In fact the EPA's limits are tighter than the global standards, and call for a maximum sulphur content of just one percent already this year. The bottleneck to the adoption of these new standards is the limited refining capacity for low-sulphur fuel. Not only is this creating a shortage of supply, but the demand is also leading to substantially higher fuel prices, which in turn is impacting the operational revenues of the operators. Fortunately, the USA is rich in natural gas resources. This means that natural gas is abundant, secure, available, and affordable at relatively low prices.

John Hatley, Vice President, Ship Power, Wärtsilä in North America, noted that: "This is an exciting time of change for the towboat industry, with natural gas powered engines providing a huge step forward. Wärtsilä is very pleased to be working to make this key player in America's transportation system, both 'greener' and more economically viable."

The inland river towboats of North America have been built to essentially the same design for the past 65 years or more. The accepted norms for propulsion, hull design characteristics, engine, and particularly fuel selection, have continued unchanged from one decade to the next. That is, until now.