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 Systemsmore 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 Changeneed 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 Marinethe 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 MN40MN Jan16 Layout 32-49.indd 40 1/6/2016 2:39:32 PM