Page 40: of Marine News Magazine (January 2016)

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INLAND PROPULSION “When the industry hits a 50 percent Z-Drive adoption rate for new build projects, owners competing with old technology will have a dif? cult time winning competitive contracts. Just as the industry saw with the harbor tug market, this is when the market will meet critical mass and Z-Drives will become the preferred propulsion system for the market.” – Edward Schwarz, business development manager,

ZF Marine Propulsion Systems more important. In- ta to Texas and everywhere in between. In 2016, we project land waterway vessels that ZF Z-Drives will have accumulated over one million often operate at full operating hours, just in U.S. river applications alone.” load, following a tight schedule, and therefore

Driving Change need a robust thruster

There will always be a reason to keep the status quo, with easy maintenance especially when it comes to the maritime industry and or exchange possibili- change. On the other hand, there are dozens of reasons to ties. Towboat thrust- dip one’s toes in the waters that will soon be dominated by ers will have to answer Z-Drive technology. Here are just a few: these needs. Especially

Ef? ciency: As reported in the Shearer Group white pa- adequate for this task per, Jeffboat Shipyard and Aquamaster did a joint study are Z-Drives, which and model test of a triple screw towboat around (circa can be found on the 1997). Shearer says, “The model towboat was tested us-

U.S. inland waterways ing the traditional propulsion system and then tested us- since 2008, while they ing a Z-Drive propulsion system. Each propulsion sys- have been used in oth- tem was tested with a tow and without a tow. Thrusting er countries already for straight ahead was the same for both propulsion types; a much longer time on steering forces increased 50 percent to 70 percent using inland waterways.” the Z-Drives; stopping forces increased 50 percent using

And Wärtsilä, for the Z-Drives; and maneuverability increased 54 percent example, reports that to 390 percent using the Z-Drives. These are signi? cant owners who adopted increases in vessel ef? ciency since inland towboats do not

Image: ZF Marine the Z-Drive solution go in straight lines for long distances. These types of ef- found operational ef? ciencies that allow them to install ? ciencies translate into less fuel used to make turns and up to 20 percent less power with steerable thrusters versus bends, to enter locks, and to work around docks and ? eets; traditional FPP props. In addition, there is considerable to gain more miles per hour using the same amount or less fuel savings, as rudders provide drag when they operate. fuel; and to decrease accidents due to greater stopping and

Perhaps the most compelling argument is improvements handling ability.” in maneuverability, as there is no longer a need for com-

Reinforcing those metrics, Schwarz points to ZF’s op- plex rudder systems – steering and ? anking rudders are no erational experience and predicts it is just a matter of time longer needed.

before Z-Drives hit their stride in U.S. waters. He adds,

Separately, ZF’s Schwarz insists that the major skepti- “When the industry hits a 50 percent Z-Drive adoption cism involved the lack of references of Z-Drive vessels for rate for new build projects, owners competing with old the inland applications. Despite the proven performance technology will have a dif? cult time winning competitive bene? ts, worries about the robustness of Z-Drives in river contracts. Just as the industry saw with the harbor tug mar- applications persisted. But he says, “ZF currently has doz- ket, this is when the market will meet critical mass and ens of pushboat vessels operating everyday from Minneso-

Z-Drives will become the preferred propulsion system for

January 2016

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