Air lubrication on displacement catamaran

Yes there have obviously been many SES vessels built, but the capabilities he is discussing achieving is called a CAB (captured air bubble) vessel (which is the red headded stepchild of many SES programs), and very few successful ones were ever built.
The reason that i mentioned the HYSWAS is because i thought it had active ride control foils / fins (or some form of retractable foils ) which are really only the most practical alterations from an SES standpoint that could be added to that boat to significantly increase its capabilities. Also ... This is just my unedumacated fisherman's opinion.... but i would never try to connect the two hulls with a permenantly mounted lifting wing or foil. (for several seemingly obvious reasons).

 

Which are??

 

You know it is an old website when the front page says best viewed in Netscape, or IE4...and the latest project is dated at 1999 !!

 

You might not. But the rather large number of well-performing foil-assisted cats out there would strongly suggest that others are not so reticent.

The "CAB' by the way was a term around the time of the "GEM"..both describing the nascent developments of what later came to be commonly known as simply "hovercraft". The SES came later, though not that much later and was known and described at first as "Rigid Sidewall Hovercraft".

Straight from the horses mouth, that bit of historical trivia; I was fortunate enough to have spent many years working with the men who originally invented* both the ACV and the SES; the patent granted for the latter is in my possession - a gift from the inventor.

*Invented is used very loosely in this regard. The first known 'SES' design that I am aware of was thunk up by Thornycroft in the late1800s..and included a human-powered bellows for the air supply. Some 25 years ago, the model of it was still sitting on an office shelf in Portsmouth.

 

What about my idea of super cavitation bows. Thats basically a very small bow infront of the hulls bow. This will clear the water from the hulls bow and theoretically at some speed the water will not touch the hull at all except at the bottom of the hull or where ever you want it to.

Air will be drawn down the false bow and totaly cover the hulls bow in air.

In preliminary tests running at the side of the dock a cavitation hole of 1 foot long could be acheived.

At 20 KTs I am expecting a caviatation hole of 6 feet or more illiminating water drag form the bow and cheeks which is were the hull breaks most water.

 

Well given my screenname i think the most obvious reason for me here in New England would be the risk of entanglement with commercial fishing gear such as lobster bouys, but there are other risks or detractions associated with connecting the two hulls such as floating debris, whales, kelp areas, and the risk and mitigation or damage control in case of catostrophic failure (by whatever cause).

P.S. ... I am no pro on any subject, and i do not claim to be !!!. i am only giving opinions based upon things have read, seen, studied, or done over the years. i only offer up things if i think someone may benefit from it. Feel free to correct me when i am wrong, or mistaken, but Please do so in a manner of mutual respect. I did not come here for arguements, if i wanted that i would talk to my teenagers, or my wife, LOL.

 

You correctly listed many of the potential threats associated with all underwater appendages; vertical foils (or rudders) and horizontal foils for lift included. The full-width transverse lifting foils between cat hulls actually tend to have fewer problems than do individual foil assemblies, like "T" foils for example. And again, there are many catamarans operating today with the full-width lifting foils in place.

 

Actually...the last deliveries/installations of Hoppe's designs were just this year and the annual number of installs keeps increasing. Guess Dr. Hoppe is like our company; I don't think our web site has been updated in nearly that long either.

Here is one:http://www.marinelog.com/index.php?option=com_content&view=article&id=426%3A2011jan002703&Itemid=107

And what is apparently HYSUCAT's newer site:http://fastcc.hysucraft.com/Default.asp?Page=PhotoGallery

 

Which is the major reason I never went for the Hysucat foiled Prout Panther 64.
That,and having 2500 hp around was a waste for the jets when I'd be using a fraction of that 95% of the time.

Too many logs,whales,and seals around to be doing 43 knots,even on the occasions I wind my current boat up to 25 to 30 knots I have a couple extra sets of eyes looking out. Had a few close calls...

Hysucat full width foil