Senesco Marine, which for the last few years has been building nothing but barges at its North Kingstown, R.I., boatyard, recently expanded its building portfolio with the signing of a contract to build an articulated tug-barge unit that will haul both chemical and petroleum products. The contract is valued at over $40 million and includes options for three more ATBs.
“It’s a really big deal,” said Chris Cole, vice president of sales and marketing in Senesco Marine’s Metairie, La., office. The project will more than double Senesco’s workforce to over 500. The ATB will be the biggest vessel ever built by Senesco.
The ATB includes a 150’×46’ tug and a 512’×71’ barge with some innovative features. “Typically ATBs are kind of slow and clunky. They are more of a regular barge with a boat attached,” said John Smith, Senesco Marine’s vice president of sales and engineering.
The ATB to be built at Senesco for U.S. Shipping Partners LP, Edison, N.J., should be different. One of its design requirements is to travel at 13.5 knots in a sea state 4. “That’s a very high speed for an ATB. We had to do some nifty things to improve the efficiency of both units,” said Sal Guarino of Guarino and Cox, New Orleans, the project’s naval architects.
Guarino said that the barge has a unique stern configuration. “Most barges on the stern have a regular rake. Our rake is considerably different. It’s a shallow-run rake with reverse curve. It blends into the tug a little bit better.”
In addition, Guarino said the barge’s skeg configuration is different from other barges. In both cases, the purpose is to make the water flow more smoothly back to the tug.
While the tug’s design is not as radical as the barge’s, it won’t have open propeller struts. Instead, said Guarino, “a twin combination of boss and skeg will be used. We hope it helps straighten out the flow into the propellers.”
Another difference between this tug and others is that it’s a heavy-fuel boat with a pair of Wärtsilä 9L32 diesels, each putting out 6,155 hp at 750 rpm. At the other end of the propulsion system are four-bladed, 144” Lips props inside of Lips high-performance nozzles.
Hooked up to the tug with an Intercon connecting system, the double-hulled barge will have 10 cargo tanks with cofferdams between each five pairs of tanks. It will also be Coast Guard certified for Grade A petroleum products and chemicals, said Smith. The barge will carry 140,000 bbls. of product.
On the barge’s deck will be two anchor windlasses, three mooring winches, and two single-drum mooring winches on the stern.
Steel cutting for the tug and barge was scheduled to begin in December following a last round of tank tests in Germany. Construction is expected to take 14 months for the barge and a year for the tug, with delivery in early 2006.
— Michael Crowley