Earlier this year Harvey Gulf International Marine put the first dual-fuel vessel in the U.S. into service. The 302'x64' OSV Harvey Energy has tankage for both diesel fuel and liquefied natural gas (LNG).

Now The Shearer Group and Conrad Industries are waiting for the Coast Guard to sign off on a new design for a dual-fuel towboat powered by a Wärtsilä propulsion system. (Wärtsilä provided the propulsion system for the Harvey Energy.) Conrad and The Shearer Group worked together on the design of the towboat,” Ed Shearer said at the Inland Marine Expo in St. Louis on Tuesday.

He said the design calls for dual fuel instead of LNG only because “there is a medium risk of something happening” with LNG only. But the dual-fuel boats don’t have to use diesel unless needed. “Harvey Gulf runs that boat exclusively on LNG,” Shearer said.

Currently, the U.S. inland waterways system doesn’t have the infrastructure in place to support LNG-only towboats. If a towboat doesn’t have duel fuel tanks, then it would be stuck if it breaks down due to a fuel problem until the LNG tanks could be replenished. There just aren’t many LNG “gas” stations available along the inland waterways at present. “The small boats work [financially] right now, but the linehaul boats that run all the time don’t” because of the lack of infrastructure, Shearer said.

The problem with using LNG on linehaul river towboats is that the tanks would have to be big enough to run from New Orleans to St. Louis. “One could get smaller boats and have refueling barges along the way,” Shearer said. This solution isn’t currently available, but many expect the construction of bunker barges to ramp up in the near future.

John Hatley, Wärtsilä's vice president ship power, said that there are a number of good reasons for using LNG as a fuel. These include LNG’s low cost, lower shipping rates and it will save operators 15 cents per ton over diesel-powered vessels that carry the same amount of cargo.

“It’s the cleanest fuel after [engine] combustion that we have, and we have 200-years-plus of gas that’s going to be available,” he said. “We’ve got plenty of gas here in the United States.”

Hatley said LNG is going to be used on the inland waterways system very soon. “I think we are going to see more migration to the river.” 

Ken Hocke has been the senior editor of WorkBoat since 1999. He was the associate editor of WorkBoat from 1997 to 1999. Prior to that, he was the editor of the Daily Shipping Guide, a transportation daily in New Orleans. He has written for other publications including The Times-Picayune. He graduated from Louisiana State University with an arts and sciences degree, with a concentration in English, in 1978.