Jefffboat And Aquamaster Design Z-Drive Propelled River Towboat

Inland shipbuilders Jeffboat and Aquamaster-Rauma, Ltd. have formed a cooperative R&D program to design a state-of-the-art river towboat utilizing Z-drive propulsion. Model testing, conducted during June and July, is the latest phase in a year-long joint design program.

l b take advantage of high omnidirectional thrust available from azimuthing propulsion units, potential designs were developed, models were constructed, and quantitative data was gathered which directly compared the performance of the new Jeffboat/Aquamaster towboat hull against conventional type rudder/fixed propeller designs. The resulting towboat design was developed in conjunction with a Finnish naval architect.

The vessel is designed to be powered by three Aquamaster units of equal size, equipped with the company's patented NSMB type nozzle, with a total absorption capability of 8,000 to 12,000 hp.

Tests on the design were conducted by shallow water vessel research experts VBD of Duisburg, Germany. Steering and flanking side forces of the design were reportedly 150 to 210 percent of the conventional vessel.

The new vessel also reportedly stopped a simulated tow in one-third the distance normally achieved by a conventional vessel. The strength of this design is the redundancy of propulsion units, which increase safety and "come-home" capability. Model test results enable the Aquamaster azimuth drive units to be specifically matched to the inland river towboat. Measured model hull wake fields and propeller loadings will be used to guide selection of mechanical and hydrodynamic drive details.

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