it is an int3eresting design/life style sort of a problem - putting your boat on a trailer and taking it home or somewhere overland. but i was browsing back this weeks posts and see Roberts 15m trailable, dennis' 60' trail-a-boat and maybe Rob's solitarry (though it could be called containable) . Why is it not 10 times easier leaving it in? Doug --- On Wed, 28/7/10, robert <cateran1949@ yahoo.co. uk> wrote: From: robert <cateran1949@ yahoo.co. uk> Subject: [harryproa] Re: 60' Trailerable Proa To: harryproa@yahoogrou ps.com.au Date: Wednesday, 28 July, 2010, 13:52   For a Harry schooner, the masts can be outside the cockpit area when collapsed. --- In harryproa@yahoogrou ps.com.au, Dennis Cox <dec720@...> wrote: > > Hey Mike, >   > I'm not sure I see your showstopper yet.  I've been very careful not to make a > design decision that precludes a HarryProa, Atlantic, sloop or schooner.  To > tuck the lee hull under the windward on the trailer does limit the size and thus > the mast bury.  However for the schooner rig, the bury doesn't need to be that > tall... because it'll transmit the moment directly into the cross beam.  If you > can make an ~8" diameter tube mast take that moment, making a joint within a > 2.5'x3.5' cross section isn't going to be a problem.  A sloop is a little more > difficult, unless you put a center beam across... in which case its moot also.  > >   > The design I've posted is my number 6.  I'm currently on number 7.  I think my > version 1 was Atlantic sloop with the mast in the center of a rotating clamshell > top.  Getting a saloon, master birth and master bath in a 16' diameter was > problematic.   The mast would drive up through the center of the domed room.  > There's lot of issues... that's why I went to version 2.  But here it is if you > want to see a belly flop. >   > http://au.groups. yahoo.com/ group/harryproa/ photos/album/ 1001384692/ pic/1512791390/ view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc > >   > For me, to make mine a HarryProa.  I have a big trouble rigging. > (1) dolly the center section of the lee hull off the trailer. > (2) have to use a mini crane (engine hoist based hopefully) to lift over the > bridge deck. > (3) Slide the beams in, fasten. > (4) dolly the lee hull to attach to beams. > (5) Problem - Raising the masts... they're now twenty feet away from the mini > crane mounted on the trailer.  Haven't figure a solution for that yet. >   > With yours... it should be easier.  Since you already have steps 1-4 inherently > on done, you just need to raise the mast with the mini crane.  It doesn't really > matter if its HarryProa or Atlantic style... the crane should reach to the lee > hull almost as easily as the windward. >   > Scissor beams - I don't want to argue or be negative either, but I could suggest > many reasons.  I tried working it into a design.  > >   > Something like this... who knows... this might be number 7, 8... > http://au.groups. yahoo.com/ group/harryproa/ photos/album/ 1001384692/ pic/188812332/ view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc  > >   > Dennis  > > > > > ____________ _________ _________ __ > From: Mike Crawford <jmichael@...> > To: harryproa@yahoogrou ps.com.au > Sent: Tue, July 27, 2010 2:05:51 PM > Subject: [harryproa] Re: 60' Trailerable Proa > >   > << I am certainly not implying any superiority of the Atlantic design>> > >   Hey, no worries even if you are.  They are both impressive ways to have one's > cake and eat it too. > >   Please note that none of this is an argument for Rob's Harryproa design.  I'm > just a fan of being as safe, simple, inexpensive, and fast as possible, and most > of Rob's design elements work for what I'd like to do. > >   At this point, arguing atlantic-vs- harryrpoa is almost like splitting hairs.  > But that's what forums are for! > >   Perhaps your ideas will infect my brain, and I'll end up pining for an > atlantic rig.  Actually, most atlantic proas don't appeal to me, so it's not the > rig that would sway my building plans.  I'm sold on the leeward rig. > >   What would cause me to consider an atlantic rig is the fact that you've solved > one issue that is close to being a showstopper for me: how to have a trailerable > multihull with an enclosed saloon, where my wife and daughter can stay warm > while I'm out enjoying a nice fall or spring sail. > >   Rig now the family debate is between an Etap 32 monohull (the next boat *must* > be unsinkable) and a Harryproa.  On July days when it's 80 degrees, my wife and > I are both for the proa.  But as soon as the temperature dips down to 70, which > means it will be cooler on the water, My wife is set on the boat with a heated > saloon. > > >   Since I'm not willing to spend $350k on a Dragonfly, and wouldn't want to deal > with a stayed rig even if I did have the extra cash, that puts us at an > impasse.  There's no real argument going on, but we're also not making any > decisions either. > > --- > >   My current ideal boat would be your design with a leeward rig, even if that > means going to a 10' or 12' trailering width.  I'd trail the boat so little, > mostly just once in the spring and once in the fall, that I wouldn't mind > getting the wide load permit. > > >   I would probably go with scissors beams like cat2fold, which would keep the > boat together and vertical while expanding or contracting on the water.  Rafe > Francke quoted me $2,500 for a license to his patent to build a boat, and that's > something I'd be willing to pay in this case.  With the scissors beams and a > wider collapsed width, the leeward hull can stay upright and "structural" .  In > this case, putting the rig into the leeward hull versus the windward hull > probably wouldn't make much difference in terms of setting it up or breaking it > down.  It would also be nice to be able to collapse the boat on the water to fit > into a slip, if needed. > >   Most people seem to be planning on telescoping beams, saying they'll cost > less, and that they will be more than stiff enough.  I can't imagine them being > as stiff as the scissors beams (though they will be lighter), while also being > easy to expand and collapse, but I'm not going to argue with anyone.  I'm sure > they'll both work, and I'd always welcome the chance to be proven wrong by > Robert's upcoming build. > >   The 8.5' design limit would probably preclude leaving the leeward hull > attached, though.  You could still use the scissors beams, but you'd have to > demount the leeward hull to trail the boat. > >   In any case, it's a beautiful boat.  I must confess that the low, skinny > leeward hull is particularly appealing. >   >         - Mike > > > > On 7/26/2010 7:17 PM, Dennis Cox wrote: >   > >Hey Mike, et al. > > > >I have the greatest respect for Robert's HarryProa.  I am certainly not implying > >any superiority of the Atlantic design.  In fact, most of the reasons are not > >performance related.  Also, its interrelated with the steering leeway resistance > >issue.  I am hoping someone here might take pitty on my fence riding and give me > >something definitive that tips the scale either way for good... but hear me out, > >because these are the things that am pushing me toward the Atlantic. > > > >Non Performance Reasons > >These are reasons that have to do with the trailerable aspect or for me > >personally.  They have nothing to do with one design being superior to the > >other. > > * When on the trailer, the first thing, I'd step the masts on the windward > >hull.  As you suggested, I was thinking of a relatively small "crane" based on > >the cheap car engine hoists.  Once up, these can be used in conjunction with the > >boats winches to lift the windward hull up and over and down.  > > > > * I've been watching a lot of Rick Willoughby's comments.  If I keep the > >leeward hull simple (without) mast and leeway prevention structure, I can make > >it quite cheap.  The one I'm making now should come in complete for less than > >$2000 and somewhere around 800 pounds if I don't get sloppy.  The point being, I > >could very easily make a second one using the squared off sheet hulls that > >Rick's research suggests may have a superior performance edge.  It may go for > >less than a $1000.  IOWs, I can play Mr. Potato Man.  > > > > * The lee hull is lighter - for getting off the trailer and moving it around.  > >Structural > >IMO and for a schooner rig, one design has no significant advantage over the > >other.    > > * In a HarryProa or an Atlantic Sloop the mast loads have to be transferred > >from the mast base to the cross beams by torquing the hull.  In an Atlantic this > >would make things far more difficult.  It fully justifies Robert's statment > >about being able to make the unstressed HarryProa windward hull far lighter than > >the Atlantic.  It would be clearly lighter.  However, in a HarryProa or > >Atlantic Schooner there is no torque in the hulls.  If the masts are mated to > >the cross beams all moments from the masts can be directly transferred into > >cross beams.  My contention is that both hulls could be made lighter in a > >schooner rig and frankly there would be no advantage of one over the other (that > >I can imagine yet).  > > > > * The largest moment in the beams of a HarryProa (and thus largest cross > >section of the beam) is at the base of the leeward hull.  In an Atlantic, the > >largest moment in the beams is at the base of the windward hull.  It is helped > >out by a significant structure... the bridge deck.  The beam (in an Atlantic) as > >it goes into the lee hulls has nearly no moment... just shear.  It can be much > >smaller and thus offer less resistance to waves and submerging. > > * I hear what has been said about leaning the mast out and keep the boat from > >going past 70 degrees.  I can easily see that in Robert's smaller designs.  I'm > >having a little trouble with it for a 10,000 lb boat.  Mast tend to come away in > >roll overs.  It is said any mast that doesn't... is way over built and way too > >heavy.  In my minds eye, a boat traveling 20+ knots and has flipped at a rate > >that the helm couldn't save must have significant angular velocity.  When the > >mast and sail slaps the water, IT will come to a dead stop while the linear and > >angular inertia of the rest of the boat (27 feet up in the air) is certainly > >going to continue... result (I believe) is a snapped mast and flipping of the > >hulls.  Arguably, the HarryProa having a little chance is better than no chance > >at all with an Atlantic.  > > > > * This may be a cardinal sin, but, I'm debating about putting the rudders on > >the windward hull also... see http://au.groups. yahoo.com/ group/harryproa/ > >photos/album/ 1001384692/ pic/461401281/ > >view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc  Structurally, I > >can tie all the major force producers into one structure.  See more in fluid > >dynamics section. > >Fluid Dyanmics > >Out of my comfort zone, but... > > * I guess the heeling moment does get larger with an Atlantic when flying, but > >only as a result of exposing the bottom of the hull in addition to the sail > >forces, while a HarryProa windward hull shields the sail somewhat.  But in this > >size of a boat, I don't really thing exposing my bottom is really in the game > >plan... unless I've unloaded all the soft personnel and am racing.  And even > >then, I wouldn't be flying... just kissing. > > * The main one that drove me toward a Harry Proa is the significant decrease in > >COE by lowering the base of the masts to the lee hull.  At first this was clear > >cut.  HOWEVER, strangely enough, if I go to wings or oversize wing masts (still > >debating that one also) the heeling moment is far less than a sail.  My > >calculations show I can not get the lard-ass, windward hull up so I can get to > >the 25+ knots Michlet says the lee hull could do if unburdened.  So in this > >strange case, its better to put the masts up on the windward hulls to actually > >encourage heeling.  Yes, I know, I could put larger wings/sails on the leeward > >hull, but that adds to the trailering issues.  > > > > * If I put the rudders under the mast bases (on the windward hull) all that > >splashing and spray as seen on the all the videos, is under the bridgedeck and > >we have a cleaner view from the bridgedeck overlooking the lee hull. > > * With the rudders on the windward side, flying the hull reduces leeway > >prevention and thus lets it slide. > >I think that's all, but I'll bring up more, when they hit me.  HELP!  Stop the > >voices. > >  > >Dennis > >  > >  > > > ____________ _________ _________ __ > From: Mike Crawford <jmichael@gwi. net> > >To: harryproa@yahoogrou ps.com.au > >Sent: Mon, July 26, 2010 5:07:09 PM > >Subject: [harryproa] Re: 60' atlantic proa > > > >  > >Dennis, > > > >  That is extremely cool.  Thanks for pointing out the video link.  You could > >probably do this with a purpose-built trailer and a stub mast in a separate > >socket (1/3 full mast height, used to lift the primary mast at its center of > >gravity) , no crane required.  > > > > > >  Now I *really* want to see you build it.  I've said many times that i want the > >largest trailerable boat I can get, and this would certainly qualify.  Actually, > >I'd be willing to put up with a 12' width, but fitting into 8.5' is even more > >impressive. > > > >  I had actually brought up atlantic vs. harryrproa in a post right before the > >one you responded to, but for some reason the post didn't make it.  (thus my > >comment about ignoring my question about how the boat goes on the trailer). > > > >  I'm partial to the harryproa design for the following reasons:  a) more space > >in the windward hull,  b) heeling moment decreases, or remains the same, as you > >fly a hull, while heeling moment increases with the atlantic design,  c) > >stresses are in line with the hull, while the atlantic has to translate rig > >stress through the beams to that long leeward hull, and  d) the possibility of > >popping back up after a knockdown. > > > >  As far as handling the sails, a leeward design might offer more safety in a > >schooner configuration (from the tramp), while a single mast would probably > >offer safer sail handling with the atlantic (from the cockpit). > > > >  But I'm sure you're familiar with all that.  Your design has more than enough > >space to deal with masts in the windward hull, and the taller leeward hull > >needed for a rig there might get in the way of your trailering setup.  As long > >as you don't sail on the very edge, there shouldn't be any issues. > > > >  I wouldn't put on a pod for safety as cavalier suggests.  If you're sailing an > >atlantic proa hard enough to fly a hull, in anything other than flat water, > >there's a good chance you'll be going fast enough to trip over any pod small > >enough to justify its own weight penalty. > > > >  What are you planning for steering and leeway resistance? > > > >        - Mike > > > >  > >On 7/26/2010 2:43 PM, Dennis Cox wrote: > >  > >>Hey Mike, > >> > >>Did you see the video... on post #9.  It might clear things up.  Unless you've > >>already seen it... :) > >> > >>Also, I'm still bouncing between Atlantic and HarryProa placement of the sails > >>(windward, leeward hulls).  I've got pros and cons on both sides and the tally > >>list is still balanced.  Fortunately, the hulls and internal configurations > >>don't have to be changed either way.  So... I've got PLENTY of time to decide.  > >> > >> > >>Dennis >