DESIGN FEATURES FOR SHIP-ASSIST TUGS

The ship-assist tug is a highly specialized vessel. It bears little resemblance to tugs used for barge towing or for salvage, and performs a critical and dangerous job. The author draws on 20 years of experience in designing ship-assist tugs to discuss the design features of the tug type. He takes up, in turn: operational efficiency; safety; stability and hull form; propulsion and steering systems; deck layout and machinery; and control station design. Drawings show the force diagram for ship turning operations; towing equipment and positions; and wheelhouse arrangements for the two-man "Z-30" tug.