Compact Shaver z-drive long on power, versatility


Capt. Gary Setvin, at the helm of the 80-foot z-drive tug Sommer S., likes that the boat is compact. He applauds the maneuverability, the power and the comfort of the vessel, “but its greatest feature is that it is short and you can apply power in tight spaces.”

Sommer S., built at Diversified Marine in 2012, is the most powerful tug in Shaver Transportation’s fleet. Both the builder and the owner are located in Portland, Ore., but on different rivers. Diversified Marine is on the Columbia River in the shadow of the Interstate 5 bridge, and Shaver is on the south bank of the Willamette River near its confluence with the Columbia.

Sommer S. was designed by Capilano Maritime Design Ltd. of North Vancouver, British Columbia, as a ship assist and escort tug that is also capable of shifting barges. The tug operates in harbors on the Columbia River from Astoria to Portland and serves as an escort at the Columbia River Bar.

“The versatility is huge on this boat,” Setvin said.

The tug is powered by two MTU 16V 4000 M61 mains generating a total of 5,364 hp at 1,800 rpm. The z-drives are Schottel SRP 1215s with four-blade, 96-inch stainless steel propellers. The tug has a free running speed of 12.5 knots and the bollard pull is 64 tons ahead and 62 tons astern. The two 145-kW auxiliary generators are Cummins 6CTA 8.3 units.

Manning the helm of Sommer S. is Capt. Gary Setvin, who praises the tug’s ability to handle a wide range of duties.

On the foredeck, for escort and ship-assist assignments, there is a 50-hp Markey DEPCF-48 electric single-drum 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.

For barge towing, the tug has what the supplier, Schuyler Companies, calls a lower wrap fender on the model bow. There is also a custom laminated stem fender for pushing loaded low-freeboard barges. For making up the tow, there are four Wintech barge winches on the aft deck, each wound with 150 feet of 1.5-inch AmSteel-Blue line.

“We use the hydraulic deck crane for running lines to the ships,” Setvin said. “We toss a line, too, when we have to, but if you’ve got power, use power. (The tug) makes up well to ships and barges, and we can do stern jobs or tow on the hip.”

Among the many duties the tug is asked to perform is ocean towing of rock barges and wheat barges on the river. “And there are not many holes that we can’t get in to work in,” Setvin said.

Sommer S. is named in memory of Sommer Sondra Shaver, who was the sister of the company’s president, Steve Shaver.


The Sommer S. crew consists of, from left to right, Capt. Robert Dillon, deck hand Eric Cadonau, deck hand Justin Peterson and Capt. Gary Setvin.


Deck gear on the Shaver tug includes an Amco Veba crane.


Also on deck is a Markey render/recover hawser winch wound with 8-inch AmSteel-Blue line.


Peterson tends to one of the tug’s two MTU mains.

Owner/Operator: Shaver Transportation
Designer: Capilano Maritime Design Ltd., Vancouver, B.C.
Builder: Diversified Marine, Portland, Ore.
Mission: Ship assist, escort, barge handling, harbor services, ocean towing
Crew size: 4
Propulsion/Systems  Deck equipment 
  • (2) MTU 16V 4000 M61 mains generating 2,682 hp each at 1,800 rpm
  • Schottel SRP 1215 z-drives 
  • Stanley four-blade, 96-inch stainless steel propellers
  • (2) Cummins 145-kW 6CTA 8.3 auxiliary generators
  • Bollard pull: 134,000 pounds
  • Markey 50-hp DEPCF-48 electric single-drum render-recover ship-assist winch with 500 feet of Samson AmSteel-Blue 8-inch line 
  • (4) Wintech barge winches on aft deck, each wound with 150 feet of 1.5-inch AmSteel-Blue line
  • Markey capstan
  • Schuyler lower wrap fender
  • Amco Veba articulating crane
  • Icom IC-M604 VHF
  • Furuno AIS
  • Furuno electronic chart


By Professional Mariner Staff