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Columbia River tug designed for barge work and ship escort

Jul 1, 2012 01:13 PM

In early February the 80-foot ASD tug Sommer S, was taking shape in Diversified Marine’s dry dock, its z-drives waiting to be installed. The tug joined the Shaver Transportation fleet in May.

Both the builder and the owner are located in Portland, Ore., but on different rivers. Diversified is on the Oregon side of the Columbia River, in the shadow of the Interstate 5 bridge, and Shaver is on the south bank of the Willamette River. The naval architects at Capilano Maritime Design Ltd. in North Vancouver, British Columbia, designed Sommer S, the first of its Columbia class design and the most powerful vessel in the Shaver fleet.

The boat is named in memory of Sommer Sondra Shaver, who was the sister of the company president, Steve Shaver.

“She was vice president of ship assist marketing at the time of her passing in 2002,” said Rob Rich, Shaver’s vice president of marine services.  “As it is the first new class for ship assist we have built since her passing, we felt it fitting to name it after her.”

Sommer S will be employed primarily as an escort tug at the Columbia River Bar, and on ship assist assignments at the ports along the river: Astoria, Longview, Kalama, Vancouver and Portland. The tug will also be called upon to conduct harbor barge shifting and assisting assignments.

 “This tug was designed with significant input from the Columbia River Pilots, as well as our own crews, to ensure the Sommer S meets the goals of her mission, “ said Rich.

Shaver Transportation moves a significant amount of grain along the Columbia and Snake rivers with its fleet of 16 grain barges. The company is optimistic about the future of grain exports since the completion of a new grain elevator at the Port of Longview, the first one built on the West Coast in a quarter century. “We feel there is opportunity for this vessel to be a valued and busy addition to our fleet,” said Rich. He added that there have also been significant investments in some of the other grain exporting facilities on the river, and proposals pending for coal and other terminal expansions.

Because the company’s tug applications range from escort and assist to barge tows, Shaver is no stranger to innovative design. To address the combined demands on the tugs, the company was one of the first to employ z-drives in pushboats with traditional push knees: Deschutes in 1996 and Willamette in 1999. Both boats are 3,540 hp and both were built at J.M. Martinac Shipbuilding, in Tacoma, Wash. The design came about because the boats are pushing barge tows on the Columbia and Snake rivers roughly 60 percent of the time. The other 40 percent is spent assisting ships along the Columbia.

Sommer S is the 11th boat in the fleet and the fifth z-drive. The new tug will be an escort and assist tug more than a pushboat. “Hence the modified bow pudding configuration to handle loaded low freeboard barges,” said Rich. The model bow with a custom laminated stem fender (pudding) designed and fabricated by Schuyler of Woodinville, Wash., is fastened to the stem just below the large bore extruded rubber fender on the bulwarks, also supplied by Schuyler.

“This fender is what we call a lower wrap fender, our Model No. 140,” said Ben Beierie, a regional salesman for Schuyler. It would appear that Beierie has a knack for design, having drawn up the fender himself with input from his colleagues at Schuyler. “It was designed specifically for this vessel,” he said.

The laminated fender sits flush with the bulwarks fender above it. “The extended profile off of the stem of the Sommer S is so the fender will meet up with low-draft barges and push them further away from the stem and not have the barge rise up on a swell and rip off the large bore extruded fender on the bulwarks,” said Beierie.

Sommer S is powered by two MTU 16V4000 M61 mains generating a total of  5,364 hp at 1,800 rpm. The z-drives are Schottel SRP 1215 with four-blade 96-inch stainless steel propellers. The tug has a free running speed of 12.5 knots and the bollard pull is 67 tons ahead and 64 tons astern. The two 145-kW auxiliary generators are Cummins 6CTA 8.3 units.

On the foredeck, there is a single-drum 50-hp Markey DEPCF-48 electric powered render/recover hawser winch with 500 feet of Samson AmSteel-Blue 8-inch line. The winch has a brake capacity of 180 tons and a line pull of 10 tons.

There are four Wintech barge winches on the aft deck, each wound with 150 feet of 1.5-inch AmSteel-Blue line for facing up barge tows.

The wheelhouse is equipped with Furuno radars, electronic chart display and AIS. Icom supplied the radios. Sommer S will have a crew of four with accommodation for six. “We will be carefully evaluating the performance of this tug with an eye to a second vessel on this class as vessel assistance requirements dictate,” said Rich.
 

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