Dutch invention prevents towline failure on tugboats

MAY 30, 2012 — Rotterdam based tugboat operator Rotortug and ASD Ship Design have invented a revolutionary tugboat technology to prevent towline failures resulting from chafing against a tugboat’s fixed towing point.

The invention of Mr. Ton Kooren (Rotortug) and Mr. Arie Aalbers (ASD Ship Design), the azimuth friction-free towing point, was unveiled today at the 22nd International Tug, Salvage and OSV (ITS) convention in Barcelona, Spain.

Conventional towing point designs are usually fixed bitts fitted with polished and stainless steel cladding in line contact areas guiding a towline to a towing winch. Using state of the art towing winches, towlines are winched in and out automatically by using a pre-set line force to prevent both dynamic overloads and slack wires. Synthetic towlines can easily fail due to chafing and friction with increased risks for safety.

Fast ingoing and outgoing movements of a towline with these winches cause high temperatures, especially in the inner core of synthetic towlines. The issue is particularly acute when ambient temperatures are high. The friction and the resulting high temperature cause considerable wear and, eventually, failure of the towline connection.
        
Rotortug and ASD Ship Design, in cooperation with Hasselt-based winch specialist Ridderinkhof,  have developed a rotating wheel construction to guide the towline without friction.

“Our azimuth friction-free towing point will be of great influence to towing methods,’’ says Rotortug’s Ton Kooren. ‘’Especially when synthetic towlines are used our invention holds many advantages.”

The patent on this invention is currently pending.