What are soft sails and how do they work?

The origin of such a sail system for a commercial ship use is definitely derived from the yacht wind design experience and experimentation, with first square-rigged soft sail systems appearing since the 1960s.


One of the most reputable such introductions has been made from Dykstra naval architects who are specializing in yacht design and have developed the so called ‘Dynarig’ system which is an advanced automated deployed and trimming soft sail wind propulsion system.


The Dynarig system is comprised of free-standing masts where the soft sails are deployed on the rigidly attached curved yards, in a way to have no gaps between them as seen in traditional conventional soft sail system.


Operations for unfurling are done automatically from a remote control panel, and it takes about a minute to set a sail with setting one per mast at the same time, thus requiring about six minutes for the entire sail system to be hoisted. Rotation of the rig into the wind automatically if the ship starts to heel too much, with specific limits able to be set, connected to sensors such as anemometers.


With the Dynarig the ship can sail upwind at apparent wind angles between 33 and 36 degrees and managed also with change of mast direction through 100 to 105 degrees.


Soft sails need deck space for installing the mast, the foundation, and the rotating system with bearings. It is expected however that moving parts such as soft sail furling would need replacement depending on their operational use and the soft sail cloth as well.




– Information courtesy of Konstantinos Fakiolas’ book ‘Wind Propulsion Principles’, Edition 1 –