Poland’s Conrad Shipyard and Texas-based The Shearer Group (TSGI) have received an approval in principle from the American Bureau of Shipping (ABS) for the design of a 4,200HP LNG towboat.
The new LNG towboat is based on TSGI’s azimuth drive (z-drive) design that was delivered in 2008, and also capitalises on Wärtsilä’s dual fuel technology.
TSGI president Greg Beers, PE said: "By combining two widely accepted technologies, z-drives and Wärtsilä’s dual fuel engines and fuel system, we have mitigated most of the risks associated with being an early adopter of this novel technology.
"By incorporating proven technologies, we have minimised the risks that first movers will be taking with the switch to utilising LNG as a fuel."
The new design is expected to use a smaller version of the Wärtsilä system, which is currently using on the Harvey Gulf multi-purpose supply vessels.
However, the existing Wärtsilä dual fuel engines are medium-speed diesels and it is anticipated that future engine developments will result in smaller, lighter, high-speed units, TSGI stated.
Integrating LNG technology and z-drives on a towboat, the new design is said to offer reduced operating costs and greater environmental benefits.
Conrad Shipyard and TSGI have so far constructed eight azimuth drive (z-drive) towboats for Southern Towing Company and the vessels have been in service since 2008.
Image: The new LNG towboat design developed by Conrad Shipyard and TSGI. Photo: courtesy of The Shearer Group Inc.