Subject: Re: [harryproa] Re:: Flat bottom hulls?
From: "=?UTF-8?B?QmrDtnJu?= bjornmail@gmail.com [harryproa]" <harryproa@yahoogroups.com.au>
Date: 3/14/2019, 7:39 AM
To: harryproa@yahoogroups.com.au
Reply-to:
harryproa@yahoogroups.com.au

 

>> >> |   Okay.  And that's a problem why? [Regarding reefing in less than 15 knots]
>> See, I was thinking I must be missing something. Thanks for clarifying.  

I think the point made by people claiming that: 'boats which required reefing already in less than 15 knots of wind are dangerous', is that we humans don't instinctively feel danger in that kind of wind. We don't feel any need for reefing. So if we don't use instruments to measure the windspeed, and read the manual for the boat which has a table of sailarea/reefs vs windspeed, we will go out without expecting any danger, and are shocked when the boat starts pitching and heeling and almost capsizes immediately.

But in 20 knots and above, most people feel with their senses that the wind is strong, and starts thinking something like "oh, I think it's quite windy today, I think we should consider reefing!".

In 15 knots you just feel a breeze, there is not much motion in the trees, and the sea looks fine. In 20 knots trees are moving a lot in the wind, and the waves starts getting whitecaps.  The strength of the wind has doubled, even though the ratio of the numbers doesn't indicate such a big increase.

I think the Beaufort's scale isn't a good scale, because it makes the relationship between the power in the wind and the number in the scale even more exponential than when looking at the windstrength. Like, "No worries, we only went from a Beaufort 4 to a 5'. But going from a 4 - 5, the force of the wind has doubled! and the power of the wind has tripled! So of the boat can carry full sail only to a 4, then a 5 means the sail area should be reduced to half, more or less. Or at least, the heeling moment should be halved. Taking in such a big reef isn't maybe what you would think when a number increases from 4 to 5.

I think the scale should be based on the force or power of the wind. So that one step in the scale means that the power of the wind has increased a manageable amount, maybe 50%. Not that the power has increased 300% for each step.





On Thu, Mar 14, 2019 at 9:26 AM Doug Haines doha720@yahoo.co.uk [harryproa] <harryproa@yahoogroups.com.au> wrote:
 

I was thinking towards a 15m lw hull for next boat. With accom etc still camp cruising minimal type.
But I think that is just me being overly cautious in having such a long lw hull.
I had in mind the avoid burying the bows stability.
But trailering and mooring, navigating tights passages will be easier if lw hull is restricted to 12 or 13m length.
But with only single bunk, minimal accomod. then it will be light and won't need much sail area, so keep the masts short and reduce any instability issues.
Rarely calm winds around these parts anyway.


On ‎Thursday‎, ‎14‎ ‎March‎ ‎2019‎ ‎04‎:‎10‎:‎48‎ ‎AM‎ ‎AWST, StoneTool owly@ttc-cmc.net [harryproa] <harryproa@yahoogroups.com.au> wrote:


 

    Mast height, and rig size is a big part of why I want to keep to a smaller boat....  the absurd and unreasonable limitation on boat size.   It drove me here to the HP group, because infused sandwich means a lighter boat, so I can carry the payload I want on a smaller boat.  Unless money is no object, everything mitigates toward smaller and lighter.   A 30' cat built of infused sandwich can meet both my space and payload requirements.  The pressure to build larger is intense, but I'm a stubborn man.   I'm willing to build using a more expensive system (sandwich versus ply), because it can meet my criteria, and the payout will continue for the life of the boat.

                                                                                                                                                                                                            H.W.


On 3/13/19 1:40 PM, '.' eruttan@yahoo.com [harryproa] wrote:
 



|   I don't know if the masts can extend over the tow vehicle or not. That could depend upon how each state defines what "trailer" means.

Attached are the permit rules for Maine. Pdf attached.
Movememaine.com
The oversized permit has a max length of 80', without a pilot car.

Also, side point about 5th wheels making the length shorter

| Can I have a 45' trailer/boat with 48' masts that extend over the truck bed? 

As far as i know. I mean, I have seen such overhangs, and have been told its fine. I figured that's how it had to be done for masts.

But, hold up. How much bury are we thinking these masts have? Cause 48' is not much mast in the air, right?

| Can I extend them 3' over the truck bed to 48'?  Or can we go crazy with 65' masts that are even with the front bumper long as we're under 13' high?

I wanna say, crazy!?

|   I originally wanted a supermaxi trailer, extending those masts as far as they could go. Now that I've had to squeeze 42' house trusses down our road, with inches to spare on either side when turning the corner, I'm thinking that Rob's fancy origami with the fold-up bows, along with two-part masts, makes a lot of sense.  I could always leave the masts fully-assembled if I were in an area where their length wouldn't get in the way.

When you said 48', I was thinking the same thing. But then I thought trucks haul 53' trailers all the time. I might not be comfortable doing it, but it must be done all the time.

So, we are planing to jump through hoops to make the road profile shorter?

|   As for reefing, it's an odd thing.
|
|   For lots of guys, it's like admitting failure.  They put off reefing until long after they should have and then regret it.
| The best case is that you have less fun and the boat slows down (having up too much sail, and trying to manage it, is less efficient than a well-shaped reefed sail).  Then the scale dips down towards being miserable and wet, then beating up the boat, and then equipment failures and/or capsizing.
|
|   I think I remember Wharram writing about mast height on a Tiki 38, saying something like "sure, you could have higher masts and more sail area, but then you'd have to reef under 15 knots".

Over, not under, 15kts, right? Because gust overloading the oversized sails? Or do I misunderstand whats happening?

|   Okay.  And that's a problem why?

See, I was thinking I must be missing something. Thanks for clarifying.

|   If I wanted to be conservative while cruising in variable winds, I'd keep a reef in all the time.  But if you have one of those 2-knot days where another 200 sf of sail high up will be the difference between moving and bobbing, the taller masts would be wonderful.

I was wondering why one would not have all the safe sail one could get, for use in this scenario.

|   And since it's a harryproa, you can always completely dump your sails, go to neutral, and calmly reef without running into anything. 
|
| That makes it a lot safer to be carrying too much sail.
|
|   The standard method of flying a lot of extra sail area for those light-wind days is to put up a code zero or asymmetrical spinnaker.
| But that makes tacking a production, can flip the boat in a gust, and at some points of sail you can't just dump the sheets.
|
|   I'd /much/ rather have a schooner harryrpoa.
|
|   Plus, shunting a schooner has got to be easier than threading a screecher on a bowsprit in front of the forestay.  Particularly in very light winds, or if the wind picks up to the point where you need to bring that sail in, but have to tack first in order to avoid the shore, a shoal, or another boat.
|
|   So, for the most part, reefing is a silly ego issue.  Just get over your manly self, reef, and have a better day.  Particularly if you're on a bidirectional proa with an unstayed rig.
|
|   But with a stayed mast, there are extra reasons to consider not
| going
| to tall.
|
|         - Mike

Thank you for the above and beyond answer. I appreciate the patient detailing of why, as I am new to alot of this.


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