Shaver's Samantha S Redefines the Multi-Purpose Tug
Shaver builds a tug for all seasons
March 1, 2019
The Columbia River has presented a challenge to towing companies like Shaver Transportation since the pioneer days in the late 1800's when steam-powered sternwheelers had to handle all types of work, from towing and docking sailing ships to moving wooden barges loaded with wheat and lumber. By the 1960's, the Snake/Columbia Navigation System had opened a new barge route 450 miles upstream to Lewiston, Idaho, adding another challenge for Shaver's crews and boats. Today, Shaver is still equipping many of its new tugs for the dual roles of ship-assist and barge work.
In 2017, after extensive discussions about a new boat with his customers, crewmembers, managers and the Columbia River Bar Pilots and Columbia River Pilots, company president Steve Shaver had a clear idea of what a new boat should look like. "We wanted to design a versatile tug that could meet the needs of the Columbia River today and well into the future," he said. "After more input from naval architects Jensen Maritime, we came up with the Samantha S. She is designed to do every conceivable task relating to ship assist on the Columbia River and offshore. She is the future," he added.
Jensen drew a 112-foot-long hull with a broad beam of 44 feet and a maximum draft of 20 feet that gives the tug the extra deck space and displacement to accommodate the added weight of all the equipment required to fulfill multiple roles. This includes six Wintech wire winches on the aft deck and two on the foredeck, and a pair of heavy GE V-12 Tier 4 diesels each weighing 30 short tons and producing 4,224 hp. The bollard pull of 115 tons puts the Samantha S in a class of its own well above typical ship-handling tugs.
The tug was built at Diversified Marine in Portland, which had previously constructed the 78-foot ASD tug Sommer S (5,360 hp), launched in 2012, and numerous tugs for Harley and Brusco since then. The hull design of the new tug is notable for having a flat rectangular bow protected with seven lines of Schuyler laminated rubber, topped with a Shibata cylindrical fender, all extending along the topsides.
"The bow shape provides a molded contact contour for ship assist assignments on vessels both loaded and in ballast," said Rob Rich, Shaver's vice president of marine services. "This should allow making up to the stern for escort or dead ship assignments along the coast and across the Columbia Bar if the need arises," he noted.
The tug is classed under the general heading ABS Classification Maltese Cross A1. This encompasses a large group of certification options, from which Shaver selected the following: Towing Vessel, Escort vessel, FiFi Class 1, and Loadline. This high-performance classification involves ABS visually inspecting the vessel's major components like engines, drives, generators, firefighting system, winches, etc. before launch. Between the GE mains is a Caterpillar C 32 pump engine on the center line powering the hydraulics and the Swedish FFS fire pump supplied by Inmar Systems. "As with other FIFI class tugs we have fire-fighter outfits and SCBA's along with a breathing-air compressor to refill bottles for extra-long operations. A Jason's cradle is available for man-overboard recovery," Port Captain Fred Harding reported.
The pair of GE 12V 250 diesels produce 8,448 hp at 900 rpm to turn a pair of Rolls Royce 305-4100 azimuthing stern drives with four-bladed 118-inch-diameter propellers. These medium-speed engines meet Tier 4 and IMO Tier 3 emissions standards without after-treatment by using advanced exhaust gas recirculation (EGR). High-pressure common rail fuel injection, two-stage turbocharger, electronic fuel injection, and efficient combustion management all combine to reduce key emissions by more than 70 percent while maintaining fuel efficiency and providing about 15 percent more power than the earlier engines. On a typical marine duty cycle, most GE components are durable enough to run for up to 40,000 hours before overhaul. The total fuel capacity is 108,000 gallons.
A pair of Tier 3 John Deere Magnaplus 6090A 200 kW generators meet the vessel's demands from the electric winches, electronics and hotel, with a single hydraulic PTO as a back-up to the 1,333-hp Caterpillar C32 on the centerline with a Veljan multiple pump drive with four PTO's on the aft end. This powers the two Rapp hydraulic winches. The FiFi 1 water pump on the forward end supplies the twin 6,000 GPM monitors with remote-control monitors on both sides of the wheel house.
The hawser winch on the foredeck is a Rapp HA-149H-250 for ship assist and escort duty. It is capable of fully paying out and retrieving with a pull of 100 tons. On the aft deck is a new design from Rapp – a double drum AHTW-75H-165 model with a bollard pull of more than 100 metric tons. Each drum is under-wound and independently driven by a separate four-motor hydraulic gearbox driven by the C32, which provides the speed and torque of 74.5 metric tons on the first layer, necessary for the active payout and retrieval operation.
The band brakes are designed to hold up to 250 metric tons of tension, with both level-winds independently driven by VFD electric motors that will allow for on-the-fly adjustment of the fairlead during operations. The main winch control stations will be situated in the wheelhouse – one facing the bow and the other the stern – with secondary controls located on the winch. They will also use Rapp Marine's advanced Pentagon Tug PLC Control System. "This is the biggest set of winches that Rapp Marine has delivered for an American tugboat," says Johann Sigurjonsson, CEO of Rapp Marine US.
The winch is equipped to handle multiple demands, including emergency and long-haul towing. The two drums will hold 3,000 feet of 2.5-inch wire and a Samson hawser for emergency ship-towing. This is backed up by an EVATS system from Glosten. (EVATS stands for "Emergency Vessel Attachment & Towing System.") It allows for faster deployments, safer retrieval of the towing hawser, and a more secure connection to the disabled vessel. This overcomes some of the most dangerous aspects of emergency towing. The tow pins were supplied by Smith Berger Marine.
For barge work between the Pacific Ocean and Portland, the Samantha S is fitted with a total of eight electric Wintech wire winches – six on the aft deck with a capacity of 120 tons (SWL) and two on the foredeck. All eight will be used for rigging to barges on the river, as well as with deep draft vessels.
"As far as the additional horsepower and bollard pull, ships are getting bigger all the time and we wanted to pioneer the next class of tug to meet that demand," Steve Shaver commented. "It's really hard to argue against having more horsepower. in our industry – it's all about safety and we want to make our region a safe place for ships to visit," he emphasized.
To ensure reliable navigation, the bridge is equipped with electronics from three manufacturers – Furuno, Simrad and Sailor – and Rose Point software for charting. A satellite phone is fitted for offshore communications. Shaver Transportation's double-crewed Harbor and upriver tugs routinely spend a week on board as they deliver the Columbia-Snake River System assignments.
The Samantha S can accommodate four to six crew members, with total accommodations for 10. The cabins are well insulated from noise and vibration: the floors were laid down with an acoustic underlay followed by 1 inch of poured cement with special aggregate fill. Appliances include a Whirlpool reefer/range, washer/dryer and dishwasher.
"The size and special features of Samantha S demonstrate our ability to provide agile, efficient vessels for a variety of requirements," said Bryan Nichols, director, business development, Jensen. "This tug is the latest multi-purpose escort, ocean towing and assist tugboat to hit the water from our diverse design portfolio, which includes all types of workboats from 55-foot push boats to 225-foot anchor-handling tugs."