Go Back   Cruiser Log World Cruising & Sailing Forums > Cruising Forums > The Bosun's Locker > Rigging & Sails
Cruiser Wiki Click Here to Login

Join Cruiser Log Today

Reply
 
Thread Tools Search this Thread Display Modes
 
Old 11-12-2010, 04:16 AM   #21
Admiral
 
MMNETSEA's Avatar
 
Join Date: Oct 2004
Posts: 3,067
Default

Petr,

It is becoming apparent that the search for information that meets your objectives is not available in these forums.

Could I suggest that you take some time to read the many articles and scientific papers pertaining to Nautical Aerodynamics in the AYRS,

A research society that has been active for 55 years - many of its members have contributed to the progress in yacht design in every format, particularly the development of modern day sails. Their Web Site C L I C K

There is only one thing that might condense my thoughts regarding your Hallberg-Rassy 31 Momson and that is:- what is the best SOG that the boat has achieved in cruising mode, in ideal sailing conditions.
__________________

__________________
MMNETSEA is offline   Reply With Quote
Old 11-12-2010, 04:19 AM   #22
Lieutenant
 
Join Date: Aug 2007
Posts: 54
Default

Yes and thanks for the link. From the top of my head, SOG sustained for longer period typically 6kn, 6,5kn if the seas are very nice.
__________________

__________________
Petr and Jana

s/y Janna, https://www.klubko.net
klubko is offline   Reply With Quote
Old 11-12-2010, 05:02 AM   #23
Admiral
 
MMNETSEA's Avatar
 
Join Date: Oct 2004
Posts: 3,067
Default

Quote:
Originally Posted by klubko View Post

Yes and thanks for the link. From the top of my head, SOG sustained for longer period typically 6kn, 6,5kn if the seas are very nice.
Well, if that is from the top of your head - then when you eventually go cruising with a full cruising payload - 144>>156 nm/day will not be bettered by the addition of any new sails. The Froude number is the determinater.
__________________
MMNETSEA is offline   Reply With Quote
Old 11-12-2010, 05:10 AM   #24
Lieutenant
 
Join Date: Aug 2007
Posts: 54
Default

Thank you. Sorry, I just don't get the tone. Is anything wrong when I told you our fastest SOG only "from the top of my head"? That's what I remember and I don't have the log at hand. But perhaps that's only my non-native speaker impression. Apologies if that is the case.

Petr
__________________
Petr and Jana

s/y Janna, https://www.klubko.net
klubko is offline   Reply With Quote
Old 11-12-2010, 05:23 AM   #25
Admiral
 
MMNETSEA's Avatar
 
Join Date: Oct 2004
Posts: 3,067
Default

Nothing wrong - no reason to apologise
__________________
MMNETSEA is offline   Reply With Quote
Old 11-12-2010, 05:26 AM   #26
Lieutenant
 
Join Date: Aug 2007
Posts: 54
Default

OK, sorry then. The repetition of my statement confused me. Pace.
__________________
Petr and Jana

s/y Janna, https://www.klubko.net
klubko is offline   Reply With Quote
Old 01-14-2011, 11:59 AM   #27
Rear Admiral
 
Silver Raven's Avatar
 
Join Date: Aug 2010
Posts: 218
Default

[QUOTE=klubko;1289543212]

OK, sorry then. The repetition of my statement confused me. Pace.

G'day to both Petr & Jana - SV Janna. I sure do hope this subject if still open for a more balanced & rational further discussion. Please let me know. I was away from computers when the subject was first started. I've been sailing boats of many kinds for some time now. I've cruised, raced & done some long & short distance yachting no many types of hulls & rigs. I would like to offer some fundamental observations about your fine & very sound idea of looking for an improvement for the rather antiquated rig that your boat was originally designed with. I would also like the other contributors to do two things. Re-read several times all that all of you have said - then sit down - have a drink of your choice & then re-read what you all have said yet again. Please. Some of what has been said has merit, then some of it leaves very much to be desired. I've now read this whole matter 4 times over 5 days & I'm still disturbed by what I see as a - very limited attitude towards progress. There are also some matters raised that have been redundant for many years & yes some of us in the yachting world have moved-on with the times.

Aren't there any professional practicing sail-makers, mast builders & rigging people in these forums - cause we could & would sure like to hear from you. Your factual observations are sure needed to shed some honest real light on this matter. If there aren't any of these people in here - I'll go and find them - get them to join and ask them to contribute some valid facts to this subject. for a lot of what I read hear is by no means correct unless the rules of both aero & hydro dynamics has changed in basic principles which I sincerely doubt. I don't want to start a war here, but I'm all-in for a factual discussion without all the false suppositions. With respectful regards to all, james aka Silver Raven.

Richard - I'm totally bamboozled that a catamaran owner & very experienced sailor is quoting 'the Froude number' as being THE biblical number of all time. Please explain, thank you. Might you just take a moment to explain how said # is applicable to 'Nokia', 'Gitana', 'Sopra' & other ORMA 60's or even 'Sodeb'o or then USA 17 @ 28kts boat speed to windward in 8 kts of breeze. 'Froude who?

Now for 'Monsun 31' designed in the early 70's & 904 built between '74 & '82 - why would someone not want to put a better rigged main on it. WHY has no one mentioned to Petr & Jana to look into having a mast-head crane manufactured of somewhere between 300 & 500 mm @ 90% to the back-stay to allow for a fully battened - full roach main that with the mast raked back a tad would balance the helm & give a faster boat speed that stood-up well & didn't have to cart lead around the oceans of the world in order to ware-out boat, sails, gear & people just to prove that we can't think out-side the square. Again - beats me - I just don't understand. Back to all of you, james

__________________
Silver Raven is offline   Reply With Quote
Old 01-14-2011, 12:45 PM   #28
Lieutenant
 
Join Date: Aug 2007
Posts: 54
Default

james,

many thanks for moral support. We had better luck on sailnet.com and sailinganarchy.com with our question, where first hand experience was shared, the good and the bad. We are still pondering and weighting the options before we have the new main made (later this year). Any relevant opinions regarding this choice of mainsail are still hole heartedly welcome!

Fair winds

Petr
__________________
Petr and Jana

s/y Janna, https://www.klubko.net
klubko is offline   Reply With Quote
Old 01-14-2011, 03:50 PM   #29
Moderator
 
redbopeep's Avatar
 
Join Date: Jun 2007
Home Port: Washington DC
Vessel Name: SV Mahdee
Posts: 3,236
Default

Hi, James, Thanks for thoughtfully reading through this thread. As you note, there are numerous things that Petr & Jana could do the "change" their boat's performance. I don't know their boat, but was quite keen to know exactly what was driving them to changing the roach--their particular experience/complaint. Your idea of crane to move the backstay aft--that is a solution! and I must admit I do not know how many people employ such a solution. I immediately think about the torque/motion introduced in terms of loading up the crane--but it may be insignificant in the overall scheme of things. My preference would be to running back stays (as I mentioned)

If you re-read this thread (as you have!), you'll find it's not speed that they wanted but rather Petr stated his interest in having less heel. That's an interesting aspect of having more roach and I introduced the topic of twist to this discussion because that's something that would seem to be valuable in understanding how/why the high roach allows for less heel. While I remain quite interested in twist and a discussion of its utility, that aspect of the discussion was not of interest to Petr and didn't assist him.

It often seems that we sailors "want what we want" and get an idea in our heads that "xyz" is what we want--and we cast about for experiences where people have done whatever "xyz" is. In such case, we don't want theory nor opinion of experienced sailors, we don't want to explain ourselves, we're just seeking out the particulars and practicalities of doing exactly what we propose to do. Therein comes the difference in definition that different ones among us have of the term "relevant" to various information provided by experienced sailors. That is the nature of this thread--Petr really wanted the opinions of people who had done exactly the thing he wants to do. I'm glad that he found such people elsewhere on the web since we didn't have anyone here who responded to him with direct experience.

Thanks again for contributing ideas in this thread--they may or may not be relevant to Petr but they will certainly be helpful to another sailor who happens along with a similar question.
__________________
"Do or do not. There is no try." - Yoda

What we're doing - The sailing life aboard and the Schooner Chandlery.

redbopeep is offline   Reply With Quote
Old 01-16-2011, 03:06 AM   #30
Rear Admiral
 
Silver Raven's Avatar
 
Join Date: Aug 2010
Posts: 218
Default

[QUOTE=redbopeep;1295023858]

Hi, James, Thanks for thoughtfully reading through this thread. As you note, there are numerous things that Petr & Jana could do the "change" their boat's performance. I don't know their boat, but was quite keen to know exactly what was driving them to changing the roach--their particular experience/complaint. Your idea of crane to move the backstay aft--that is a solution! and I must admit I do not know how many people employ such a solution. I immediately think about the torque/motion introduced in terms of loading up the crane--but it may be insignificant in the overall scheme of things. My preference would be to running back stays (as I mentioned)

If you re-read this thread (as you have!), you'll find it's not speed that they wanted but rather Petr stated his interest in having less heel. That's an interesting aspect of having more roach and I introduced the topic of twist to this discussion because that's something that would seem to be valuable in understanding how/why the high roach allows for less heel. While I remain quite interested in twist and a discussion of its utility, that aspect of the discussion was not of interest to Petr and didn't assist him.

It often seems that we sailors "want what we want" and get an idea in our heads that "xyz" is what we want--and we cast about for experiences where people have done whatever "xyz" is. In such case, we don't want theory nor opinion of experienced sailors, we don't want to explain ourselves, we're just seeking out the particulars and practicalities of doing exactly what we propose to do. Therein comes the difference in definition that different ones among us have of the term "relevant" to various information provided by experienced sailors. That is the nature of this thread--Petr really wanted the opinions of people who had done exactly the thing he wants to do. I'm glad that he found such people elsewhere on the web since we didn't have anyone here who responded to him with direct experience.

Thanks again for contributing ideas in this thread--they may or may not be relevant to Petr but they will certainly be helpful to another sailor who happens along with a similar question.

Hello there to you both. I & I'm sure many others - would be hard pressed to adequately express our thanks & acknowledgment of your very valuable contributions to this subject & the 100's of others that you & David advise us on. Thanks muchly & especially from me. Now - being double handicapped (male & over 70) - I'll start from the bottom up.

I'm sure you are correct in saying that - the subject will certainly be helpful to other sailors & I know that it is helping Jana & Petr. So I do hope we all will continue this through to a knowledgeable conclusion of sorts.

Re "want what we want" - "we don't want theory nor opinion of experienced sailors, we don't want to explain ourselves" etc. Possibly we - the rest of us - should remember that "english is not my native or first language". With that firmly in mind, I believe that Jana/Petr are doing a marvelous job at carrying on this thread. I might change "want" to - be able to adequately express - in our terms & language. I do know that they do "want" to listen, learn & carefully evaluate all of what we have to say. Both of them want to hear from all of us to learn not only from 'those who claim to have - 'been-there done-that' but also from people like yourselves & others that have done many, many cruising miles & hours. I did make an effort to check-out the 2 web sites Petr mentioned & I couldn't find the thread at all. Jana/Petr - where is it? I am positive that they both & all the rest of us will learn as well & with an open mind, of course. My reason for joining in this subject - is that - both as a hobby, chosen way of life & as my profession I have been involved in this very activity over many years going back to a - Sydney to Hobart yacht (S&S 34) in 1972 - in which we did as much as we could do, within the racing rules at that time, to think outside the square. Our experiments started several years before that with 24', 26' & 28' yachts in fleets of 15 to 30 yachts all 1-design & with the added benefit of being incorporated within a much larger 'mixed fleet', which made it easy to compare the 'actual results' in a fair & unbiased manner. Some of those yachts were 'Thunderbird, some Dragons & Primates & several others. After many years - I got frustrated with the then 'status-quo' & went sailing 'Little America's Cup' winning 'C' class cats & then back into ocean-going multihulls such as 'Sundancer', 'Stratosphere' & 'Sundreamer', 'Assassin' & others. Oh & someone in these 'forums' did reply to him that has/had experience & that dates back to 1966 with at least 10 such monohulls sporting - 'extended roach main sails c/w mast-head cranes. I also suggested that the way to - not interfere with a 'single back-stay' was the fitting of a mast-head crane - which works & was design-organized with the help of Graham Shields - back then one of the leading 'yacht mast designer/builders' world wide(Alspar - Australia. As you correctly stated, none of this is knew - it's just a new slant on a very old subject.

Jana/Petr can & should explore each & every opportunity to improve an - older concept rig & sails. IMHO Back then few knew of 'Mast-head cranes' incorporated into the building of the original mast. Weight aloft can be reduced further (thus drastically reducing 'healing-moment') by additionally - tapering the mast back down as far as the spreaders (the Monsun 31' is only a small single spreader rig - after-all) & changing the - very heavy SS (1x19) rigging with any of the new synthetic ropes designed for that purpose. I sure as all heck know I would be going down that path with the likes of Neil Pryde Sails or one of the other world-leaders in this field. Then with the added benefit of a stiffer, lighter boat c/w the 'somewhat self-feathering effect of a 'larger roach', semi flexible/controlled bend mast coupled with reduced lead ballast (compensated for by the extra weight in long-distance water & food supplies) I could have 'my cake (in the dry bilge) & eat it to'. I can see the benefit in; sailing more up-right, sailing quicker ** in yacht performance/speed is directly linked inexorably with value/enjoyment ** drier, with bigger 'smile on my dial', getting out of the way of that storm that wants to spoil my fun AND to top it all off I could then easily afford the added weight of 'a pair of Kenwoods' to keep in touch with the weather bureau & of course Richard - when cruising in the area that they are both in. How about that for a - win-win positive part resolution to the beginning of the anticipated improvement of the sailing abilities of a 'H-R 31'. To Jana/Petr ; the 'Kenwoods' are radios & it's a bit of an in joke. That said MMNETSEA - Richard - is THE man behind that - marine radio network that keeps everyone who wishes - very well informed. G'day Richard. Well that's more than enough from me but there is much more to this subject - for sure. Thanks Brenda & David, & if I haven't got 'kicked out of here - for talking to damn much, we'll talk again. Ciao from a very muddy, wet & soggy Queensland, Australia. james

__________________
Silver Raven is offline   Reply With Quote
Old 01-18-2011, 06:12 PM   #31
Ensign
 
Join Date: Jan 2011
Posts: 13
Default

Hi Petr,

I'm late to this discussion but have read several of the replies, many of which are well thought out. I'd like to add my 2cents worth to the discussion on the big roach mains for cruising sails...and I'll just speak from the practical experience I've had with these types of sails.

Re: Dashews. I actually built the first of the big roach sails for Steve when I worked at my brothers place in California back in the day. The first set had so much drag across the backstay that we sourced 4 or 5 inch wide rolls of thin teflon plastic and sewed this to both sides of the batten pockets to help lessen the friction. This kind of innovationss including the first round BATTSLIDE prototype luff adjusters made these projects a lot of fun back in the 80's.

Let me just list a few of my thoughts for you to consider:

1. Firstly, the design. I would NOT build a large roach main in dacron of this size when I know there are other maybe better fabric alternatives. We build lots of big cat dacron mains and we must reduce the amount of roach on them significantly as the cross-cut dacron is not up to the task of handling on the loads that big roach mains have. (Dashews main had huge plies to help with the distortion and made them very heavy) As a result of this distortion they get out of shape quickly and usually have a leech that blows off to leeward..and this simply is because the dacron with threads in only two directions can't be a load bearing membrane...and without high tech (expensive) battens, the sail will not work for long as one might hope. Conversely any cloth that can be tri-radial or the new membrane style products can because of the engineering of the sails and fabric become a load bearing membrane that really will support the extra roach. (but the caveat is that in many cases for outward bound bluewater sailors, old fashioned dacron is still the better choice for cruising...in terms of durability and costs. So a bit of a conundrum there!)

2. Sail handling is complicated. One needs to reef when tacking the full sail or in cases where you will be tacking a lot, you'll need to leave the reef in for ease and safety of tacking quickly...which defeats the purpose somewhat of having the bigger main in the first place. And this is true upwind and down...and depending on the amount of overlap it might always be the case. Certainly though in passage making the big sail can stay full size and add performance.

3. Performance. The issue I think you have (as say compared to the Dashew boats) is that you are not going to go faster than hull speed...unless you are surfing...but in all other cases your top speed is your top speed. So with all thing being equal, displacement, wetted surface and the like, the big main will produce more power so that one can expect to get to hull speed sooner..so if currently you need 10 true to get the boat to hull speed upwind, maybe with a bigger roach main, you'll get to hull speed at 9.5knots true. But conversely the opposite is true to...so the wind that overpowers you comes down too, so you'll need to reef sooner than the smaller main as well....what you gain on the bottom you lose at the top. One thing to note about blue water sailing is that 70plus percent is done off the wind...so reefing comes later and hull speed is more easily improved by sail power...and the need to reduce sail is not quite so important as being close hauled and as such can be considered advantageous.

4. Full battens: For sure! Battens act as shock absorbers...effectively dampening the motion of the sail when flogged during tacking, gybing, raising/hoisting. And the two things that break down sail cloth are U.V. and use. So by damping the flogging, you reduce the wear and tear on the yarns and add both physical life and shape life to the sail for the long term. This is true regardless of fabric type.

5. 3 reefs. Hmmm. I'm in the 2 and a trysail group. Seems that third reef (like a trysail) is something you don't want to use...so if this is the case or even if you use the third reef once, you find that for the whole of the life of the sail you are carting around the weight and mass of the third reef WAY up high in the sailplan...for something you hope you don't use. Trysail on the other hand can be fitted to the mast, ready to go at anytime, preset and you know that your mainsail will not take the beating the trysail does as you heave to in 65 knots and 25 foot seas.

Attached are some interesting pictures of a 60's Coronado 25 that was modded by the owner with scoop transom and a roachy main and club jib. Same situation...it terms of reefing when tacking.

The boat was signled handed from San Francisco to Alaska with great success. This was a dacron main and at the upper limits...you'll see the amound of twist when sailing with it full size.

Bottom line is to work on the details..really know how much more area AND overlap you're dealing with, which will dictate reef heights. Consider a track system (Strong track or other) as the big roach will compress the battens more, so having a track system is a must, and if the sail has alot of roach consider something other than cross-cut dacron. And lastly, I would suggest that you go out and reef your current sail each time you plan to tack and see what you think of the practical side of this.

Best,

Bob Pattison

Technical Director

Neil Pryde Sails Int.
Attached Thumbnails
full sail cropped.jpg   first reef aft qtr.jpg   first reef cr.jpg  
__________________
BobPattison is offline   Reply With Quote
Old 01-18-2011, 08:22 PM   #32
Rear Admiral
 
Silver Raven's Avatar
 
Join Date: Aug 2010
Posts: 218
Default

Quote:
Originally Posted by BobPattison View Post

Hi Petr,

I'm late to this discussion but have read several of the replies, many of which are well thought out. I'd like to add my 2cents worth to the discussion on the big roach mains for cruising sails...and I'll just speak from the practical experience I've had with these types of sails.

Re: Dashews. I actually built the first of the big roach sails for Steve when I worked at my brothers place in California back in the day. The first set had so much drag across the backstay that we sourced 4 or 5 inch wide rolls of thin teflon plastic and sewed this to both sides of the batten pockets to help lessen the friction. This kind of innovationss including the first round BATTSLIDE prototype luff adjusters made these projects a lot of fun back in the 80's.

Let me just list a few of my thoughts for you to consider:

1. Firstly, the design. I would NOT build a large roach main in dacron of this size when I know there are other maybe better fabric alternatives. We build lots of big cat dacron mains and we must reduce the amount of roach on them significantly as the cross-cut dacron is not up to the task of handling on the loads that big roach mains have. (Dashews main had huge plies to help with the distortion and made them very heavy) As a result of this distortion they get out of shape quickly and usually have a leech that blows off to leeward..and this simply is because the dacron with threads in only two directions can't be a load bearing membrane...and without high tech (expensive) battens, the sail will not work for long as one might hope. Conversely any cloth that can be tri-radial or the new membrane style products can because of the engineering of the sails and fabric become a load bearing membrane that really will support the extra roach. (but the caveat is that in many cases for outward bound bluewater sailors, old fashioned dacron is still the better choice for cruising...in terms of durability and costs. So a bit of a conundrum there!)

2. Sail handling is complicated. One needs to reef when tacking the full sail or in cases where you will be tacking a lot, you'll need to leave the reef in for ease and safety of tacking quickly...which defeats the purpose somewhat of having the bigger main in the first place. And this is true upwind and down...and depending on the amount of overlap it might always be the case. Certainly though in passage making the big sail can stay full size and add performance.

3. Performance. The issue I think you have (as say compared to the Dashew boats) is that you are not going to go faster than hull speed...unless you are surfing...but in all other cases your top speed is your top speed. So with all thing being equal, displacement, wetted surface and the like, the big main will produce more power so that one can expect to get to hull speed sooner..so if currently you need 10 true to get the boat to hull speed upwind, maybe with a bigger roach main, you'll get to hull speed at 9.5knots true. But conversely the opposite is true to...so the wind that overpowers you comes down too, so you'll need to reef sooner than the smaller main as well....what you gain on the bottom you lose at the top. One thing to note about blue water sailing is that 70plus percent is done off the wind...so reefing comes later and hull speed is more easily improved by sail power...and the need to reduce sail is not quite so important as being close hauled and as such can be considered advantageous.

4. Full battens: For sure! Battens act as shock absorbers...effectively dampening the motion of the sail when flogged during tacking, gybing, raising/hoisting. And the two things that break down sail cloth are U.V. and use. So by damping the flogging, you reduce the wear and tear on the yarns and add both physical life and shape life to the sail for the long term. This is true regardless of fabric type.

5. 3 reefs. Hmmm. I'm in the 2 and a trysail group. Seems that third reef (like a trysail) is something you don't want to use...so if this is the case or even if you use the third reef once, you find that for the whole of the life of the sail you are carting around the weight and mass of the third reef WAY up high in the sailplan...for something you hope you don't use. Trysail on the other hand can be fitted to the mast, ready to go at anytime, preset and you know that your mainsail will not take the beating the trysail does as you heave to in 65 knots and 25 foot seas.

Attached are some interesting pictures of a 60's Coronado 25 that was modded by the owner with scoop transom and a roachy main and club jib. Same situation...it terms of reefing when tacking.

The boat was signled handed from San Francisco to Alaska with great success. This was a dacron main and at the upper limits...you'll see the amound of twist when sailing with it full size.

Bottom line is to work on the details..really know how much more area AND overlap you're dealing with, which will dictate reef heights. Consider a track system (Strong track or other) as the big roach will compress the battens more, so having a track system is a must, and if the sail has alot of roach consider something other than cross-cut dacron. And lastly, I would suggest that you go out and reef your current sail each time you plan to tack and see what you think of the practical side of this.

Best,

Bob Pattison

Technical Director

Neil Pryde Sails Int.
Well now let's start. 1st - Welcome to WC&SF's Bob. 2nd - Thanks so much for joining in - on this topic. I'm sure we will all learn from your 'highly professional' opinions. Sure look forward to more very valuable in-put in the future. I personally can't thank you enough. Might you offer your opinions with regards to a few 'related matters'? 1/ mast-head crane ( so the roach doesn't foul the backstay (which I have used for over 30 years - to great positive effect with no apparent down-side) 2/ the use of modern synthetic high modulus rigging - which would reduce the rigging weight 'by a significant amount' & 3/ the use of 'tapered - hollow light weight battens (also, which I have been successfully over many years - reducing weight by over 80% & with much better 'sail-shape' control). Look forward to the informative 'learning-curve' we will all get. Ciao for now, james. Great sailing everyone!!!!

PS - Jana/Petr (& others of course) I sure hope you learn as much out of this as I am. Good luck, jj

__________________
Silver Raven is offline   Reply With Quote
Old 01-18-2011, 11:32 PM   #33
Lieutenant
 
Join Date: Aug 2007
Posts: 54
Default

Dear Bob,

many thanks for your comments.

1. This seems like the best argument against the large roach. We've heard from a cruiser who has used laminated sails for a long time with success, but the price might be more that we are willing to pay.

3. Certainly. We've never dreamed of higher top speed. But could you please share your experience with the "less heel" effect that Dashews mention? How significant can this be? Another cruiser told us that on his boat, the effect was almost none.

5. We are actually planning to use the trysail as much as possible to safe the mainsail, but thought that the 3rd reef could be handy for short term strong winds. Will give think this through again.

Best

Petr

__________________
Petr and Jana

s/y Janna, https://www.klubko.net
klubko is offline   Reply With Quote
Old 01-19-2011, 01:42 PM   #34
Ensign
 
Join Date: Jan 2011
Posts: 13
Default

Petr,

Regarding Fabrics: There are many good laminates that do really well in cruising apps. We have some of the more basic polyster 'cruising laminates' go 55,000 nautical miles and mostly in southern lats...so the stuff does work...without question. The drawbacks to laminated goods are: 1.)mold and mildew. With one or two films inside the laminate it's really easy to trap moisture. If the sail stays furled or wrapped, it's dark and the food source can come from air pollution or sometimes adhesives. This doesn't always happen, but it does with enough frequency that cloth makers will not warranty their goods against it. 2.) cost. Generally the goods cost more per meter and it cost more to manufacturer. 3.) ease of repair. An 'old salt' told me that what he like about his dacron sails was that there was always a machine and some material that made repair easy...anywhere in the world....laminates and repairs sometime require more work than just a few stitches...

Pro's of course are improved engineering (ie able to carry more roach) better weight to strength ratio, sex appeal (they look cool and can be black for the latest go fast look)

(lastly) I'd like to say that roachy mains can and do work for certain people...that's why I included the pics of the 25' footer...and as most have read; Dashew....but there are compromises that one should really look at.

Less Heel: I would think that for a given area, a roachy main might produce less heel as they tend to twist and depower sooner than a conventional mainsail. But the fact is this: you wouldn't be comparing like sails...in other words, if you go with more roach...the area is going to be bigger than your existing sail...so even with more twist, you still fundamentally have more area / power....so in your case I really don't think this would be the case: for example if you had a main of 70m2 and then went with say a shorter rig, but a roachy sail that was of the same area...then you would see some difference.

Trysail: If you have one, then even more of an argument not to have the third reef. One of my basic philosophies of offshore sailing is that you want to have the fewest sails that cover the broadest range of conditions. The trysail is the lone exception to my rule. My preferred system is to have the trysail track lead just below the gooseneck...so that the trysail can be fitted to the track. I have the sheets attached to the clew, the adjustable tack line on the trysail premarked and the whole of it is stuffed in a round bag and left on deck ready to go. It's much easier to drop the sail completely than it is to throw in a 3rd reef I think....so the sail drops, the boom gets lashed down or in the case of a fixed kicker, pulled to one side. The halyard swapped and the trysail sheets led aft to the spinnaker blocks (or other) and hoist. With things pre-marked there is no guess work about tack height for adjusting your sheet lead position and all that is left to do is pull in or out each sheet to get the clew and angle of the sail where you want it. Very fast. I'm not saying this is the gospel, just the way I've found works best when it's dark (as it always seems to be when your in need of this sail) and blowing like stink...and the crew is fatigued and in need of some rest.

Best,

Bob P
__________________
BobPattison is offline   Reply With Quote
Old 01-19-2011, 01:53 PM   #35
Lieutenant
 
Join Date: Aug 2007
Posts: 54
Default

Bob,

Thanks for the explanation of the heel factor. I finally got it.

From what we've heard so far, from you and others, the laminate might be a bit too much for our budget (considering also the repairs and longevity), that's for sure. Your comments certainly clarified a bunch of things for us. Many thanks indeed.

Petr
__________________
Petr and Jana

s/y Janna, https://www.klubko.net
klubko is offline   Reply With Quote
Old 01-19-2011, 01:57 PM   #36
Ensign
 
Join Date: Jan 2011
Posts: 13
Default

James,

Thank you for your kind words.

Crane: They can help with clearance, but typically with a 'big roach' main, the roach is more concentrated in the up high, so the improvement in clearance is somewhat negated by the roach. But they do help.

One benefit of a bigger crane is the increased leverage via the backstay...so if you have an adjustable backstay you can either bend the rig more or apply more tension...both of which can be performance enhancing.

Weight reduction via rigging: This is all good, though I think (personally) in most cruising applications, that most folks would be hard pressed to notice a difference big enough in performance to warrant the cost of outfitting the boat in this manner. Certainly in O.D. or other high end classes...where gains are measured in meters on a 2 mile upwind leg...well then yes, everything counts.

For someone making a passage...time is often times not the most important item on the list...coming behind things like beauty of current anchorage, comfort and good weather for the next leg and the like.

Battens: Same as the rigging..they can really save weight and help in sail shape...in fact you could make an argument for dacron roachy main that is unable to maintain the shape becuse of cloth distortion, being just fine if you use a high tech carbon/glass batten....in this mode, the batten supports the roach in a way that conventional protruded glass battens do not. The are not cheap. I just priced a set of Carbon/Glass battens for a Catana 471 and they were at my cost around $3500.00 usd...and might require some special fittings at luff as well.

Best,

Bob P
__________________

__________________
BobPattison is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Large Drug Seizure On Yacht Arriving In Australia Lighthouse General Cruising Forum 1 10-14-2010 09:34 PM
What Is An Extra-tropical Cyclone? Harbor_Pilot General Weather Discussion 0 07-12-2007 06:18 PM
Large Sizes Moog The Poop Deck 0 01-07-2007 09:08 PM
Large Sizes Moog General Cruising Forum 0 01-07-2007 09:07 PM
MainSail Reefing... Bajamas General Cruising Forum 3 07-06-2006 01:02 AM

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

RV & Travel Trailer Communities

Our RV & Travel Trailer sites encompasses virtually all types of Recreational Vehicles, from brand-specific to general RV communities.

» More about our RV Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


All times are GMT. The time now is 03:35 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.0
×