Boat Design Forums  |  Boat Design Directory  |  Boat Design Gallery  |  Boat Design Book Store  |  Thanks to Our Site Sponsors

User Name
Password
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

  Home · Search · Register  

Home » Member Galleries » brian eiland Photo Options

Previous image

Slots between Sails on Fractional, & Masthead Sloop Rigs
Click on image to view larger image

Previous image

more
124inentive.jpg
124incentive-rearview.jpg

Photo Details
brian eiland



Senior Member

Registered: June 2002
Location: Washinton DC, Annapolis MD, Thailand
Posts: 2,647
users gallery
Now imagine looking down on the sailing rigs from directly overhead and evaluating the cross-sections at various vertical levels ( I probably should draw a diagram of this view and post it on my website).

Significantly this is no-where near the case with the traditional Bermudan rig, either fractional or masthead configured. In both of these cases the throat of the slot is decreasing in size as we move vertically up the mast, while the wind velocity is increasing with this height……sort of a reverse of what we might desire. And the overlap of the necessarily hollow-leached headsail is at best really only effective at the bottom 1/3 of the sailplan. Seems there are many more questions of the compatible interactivity of the main and the headsail of the Bermudan configuration than with my twin headsail arrangement. In this comparison I think my aftmast rig configuration will prove significantly superior.

Note also that this nice uniform genoa overlap is attained while utilizing only what amounts to a 110-120% genoa rather than a radical 150-180% sail (Bermuda rig designations). And the foot areas are fully compatible, unlike the raised boom region of the Bermuda rig. Above the hounds the natural twist in apparent wind should help to make this upper portion of my genoa be a more productive sail area, certainly more productive than the thin strip of Bermudan mainsail hidden behind a mast structure on a fractional rig vessel. Just possibly the slot formed between my bare mast and the genoa sail in this upper region may create an upwash that could assist this productive task.

http://boatdesign.net/forums/showpos...p;postcount=13
· Date: May-21-2008 · Views: 1753
· Filesize: 72.4kb, 97.7kb ·
Additional Info
Keywords: Aftmast. Mast Aft, Single Masted Ketch, Ketch



All times are GMT -5. The time now is 01:00 AM.


Powered by: vBulletin Copyright ©2000 - 2012, Jelsoft Enterprises Ltd.
Web Site Design and Content Copyright ©1999 - 2012 Boat Design Net