Interesting New Rigid Wing..... fully pivoting

[Owly055]

      If anybody hasn't seen this yet, Google Randy Smyth rigid wingsail.    This is a fully pivoting rigid wing sail with bearings top and bottom, using stays and shrouds, on a tiny articulated trimaran about the size of a Hobie cat called scissors.   The entire boat pivots on the axis of the base of the mast, allowing one float to shift forward of the other.  The trailing edge of the rigid wing contains a sail track which allows a soft aft sail section to be hoisted.   With the aft section lifted all the way it cannot fully pivot because of standing rigging.   In strong winds only the main is up, which cannot be lowered, but it will weathercock to any direction producing less wind drag than a conventional mast.  This means that it can be depowered and parked with no more windage than a conventional sailboat with the sail dropped.  The wing will simply pivot with the wind, so unlike other rigid wing sails it doesn't need to be removed when at anchor or in a slip... or on the beach, etc.    The last photo shows the earlier rig before the wing, with the boat sailing and scissored.  Note that the floats are scissored such that the leeward float is in a more optimal location for the point of sail. 

                                                                                                                            H.W.

[Owly055]

    One interesting thing here is the fact that a round shaft has approximately 11.75 times the wind drag as a properly streamlined body of the same thickness.  That means that a symmetrical wing 8" thick and just shy of 8' length (94") has the same drag if the wing is aligned to the wind as a free standing 8" diameter mast!
     Of course Scissors has a sail track of some sort on the trailing edge, you can see the external cars in the second photo.   This, no matter how it is designed unless it is recessed inside the trailing edge which then closes up  to a sharp edge when there is no sail installed, will increase drag.   

     I'm imagining Pete Hill's catamaran Oryx with two free standing low aspect wing sails.............


                                              H.W.