Inland Towboats: The Next Generation -Paper

By Ed Shearer, P.E. and Greg Beers, P.E . 
The Shearer Group, Inc. 

Inland towboats on all the inland waterways and Gulf Coast have traditionally been built using main engines connected to reduction gearboxes connected to long drive shafts passing through the towboat hull to a propeller held in place by a large support strut and large rudders in front and behind the propeller. This paper explores the possibility and recent applications of azimuthing stern drives (ASD’s, commonly known as z-drives). 

The advantages of using z-drives on inland towboats are decreased installation time, increased fuel efficiency, increased trip time efficiency, decreased major maintenance downtime, and higher customer satisfaction. Savings in fuel and trip time from ten to thirty percent will be shown in both theory and actual towboat operation in the body of this paper.

Results included herein show an average of 28% fuel savings and 11% trip time savings for a set of controlled experiments with unit tows. 

Read the full paper HERE.