Hello Folks,
I've noticed that I have a slight amount of deflection in my mast on a close reach. I'm wondering if that is typical? I'm wondering if I have a bit too much tension on my shrouds... or perhaps not enough? I suspect too much as I am accustomed to tensioning shrouds on a much larger mast and probably over did it. Anyone out there know how much tension to look for on a Loos Gauge?
Thanks,
Steve
Most of us sail our 16 a bit on the loose side with a bit of forward rake. The lee shroud should be slack but not floppy.
What about mast deflection?
Quote from: Rick-K on July 12, 2009, 03:20:26 PM
Most of us sail our 16 a bit on the loose side with a bit of forward rake. The lee shroud should be slack but not floppy.
I haven't noticed any.
I haven't noticed any mast deflection either. Both shrouds sailing leeward is as Rick mentioned "slack but not floppy". The mast leans to leeward maybe 2 degrees off the parallel cabin top surface at most--not really deflection but just a property of aluminum being "bendy".
My foreshroud is about the same tightness as the leeward shroud (difficult to tell due to rolling furler). It has maybe 1" of deflection in the middle of the lee and fore shrouds. Sorry, no loos measurements to share or other accurate data.
Lay on the vee birth and 'site-tube' up the mast through the open deck hatch. You can actually see the standing rigging pulling a bend on the mast. Make her straight.
I will say that on my C-P 19 that when sailing and stress is placed on the mast sails and rig that the two stays/shrouds/standing rigging attached to the chainplates [or what ever you wish to call it] on the lee side, [slack side], are just that. Just a hint of looseness.
While on the windward side the standing rigging is taught. Be mindful that each port or starboard standing rigging coming off the chain plates need their own pin. Do Not use one pin for both standing rigging shrouds. One shroud anchors at the junction of the mast and spreader while the other shroud anchors at the mast head. Two different angles. Additionally assure that the spreaders are horizontal, perpendicular to the mast.
Now fore and aft. With my furler tight and my mast straight up and down, I close up the turnbuckle on the stern till it's kind of tight. Not real tight 'cause there is no reason to try to pull the mast down onto the compression post that the two lag screws holding the post into PLYWOOD need to be bent downward.
What must be avoided at all costs is to place way too much strain on the rig. Don't over tighten anything. Just like setting the sails, sail her loose. Sheet out till she luffs then sheet in till the luff just goes away. skip.
Steve,
With the 3 stay rig of the 16 there is no way of adjusting to bring the mast into column. However as a fractional forestay rig, tension of the mainsheet when sailing on the wind could put bend in the mast if sheeted in hard, though I wouldn't think it to be a significant amount.
Could it be that the mast is slightly bent or twisted as from driving under an obstruction with the mast up? I did that once.
Ron
Ron -I had a very minor bow to windward on either tack. I was just curious whether other's had noted the same thing. I just replaced my head stay and retensioned the shrouds. The mast currently appears to be in column on the hard, going to give it a whirl on the water tomorrow and see if I observe the same minor bow I saw before. I have eased the tension on the shrouds from the tension recommended in the Loos Gauge documentation for this shroud diameter. That may have an effect as well. I was in close hauled in 15-20mph winds with gusts to 25+ when I observed that bowing, the winds may have played a role too...
Steve
Quote from: Potcake boy on July 18, 2009, 06:12:10 PM
Steve,
With the 3 stay rig of the 16 there is no way of adjusting to bring the mast into column. However as a fractional forestay rig, tension of the mainsheet when sailing on the wind could put bend in the mast if sheeted in hard, though I wouldn't think it to be a significant amount.
Could it be that the mast is slightly bent or twisted as from driving under an obstruction with the mast up? I did that once.
Ron
The loose measurements on my 1985 cp16 are 35, side, 30, forward. I works well for me. I did the same thing. Tightened the hell out of the stays based on loose recommendation. You just dont need it for these boats. I have just a bit of forward rake to help with the weather helm. I dont get much, if any noticeable, slack in the lee shroud even when its pretty windy (10-15mph).
I backed mine off considerably too. The shrouds on the C-16 are the same diameter as the shrouds were on my Hunter 23. Much stouter than they probably need to be. That's nice. They don't need to be anywhere near as tight as I had them on the Hunter. I was out in brisk winds today. I might have them just a tad too loose right now but it was too windy to let go of the tiller and see what they felt like on the lee side. I'm going to have to rig a tiller tamer.
Thanks for your input...
Quote from: adschmid on July 28, 2009, 08:52:57 PM
The loose measurements on my 1985 cp16 are 35, side, 30, forward. I works well for me. I did the same thing. Tightened the hell out of the stays based on loose recommendation. You just dont need it for these boats. I have just a bit of forward rake to help with the weather helm. I dont get much, if any noticeable, slack in the lee shroud even when its pretty windy (10-15mph).
Steve,
Is it possible that a slight hook to windward could simply be the result of the CE being lower than the shroud tangs? These masts aren't very stout (don't need to be) extrusions. It doesn't seem like it would be something to have any appreciable effect on a boats sailing qualities, and it doesn't sound like your mast is in imminent danger of falling down.
I once trailed my 16 with the mast up under an overhead wire and caught it just above the forestay. Being alerted to this error in judgement by the resounding bang behind me, I assume the the boat was lifted partially off the trailer and surely the mast flexed to allow the wire to pass over. The mast appeared to be unscathed, but close inspection revealed a slight torque twist to the mast. Never the less, she sailed fine there after - a testament to how sturdy these rigs are. Ain't never heard of a Compac gettin' dismasted.
Ron
Potcake - I completely agree, but thought I'd ask the forum. I was surprised that nobody else noted a slight bow so remained a bit concerned for a little while. Maybe I'm just a little more observant? Maybe the shrouds are still a tad too tight? Easing the shroud tension from my original tune seemed to reduce the effect considerably but it is still observable on a close reach on either tack in winds of 16 knots and up. After yesterday's excursion in gusts to 20 knots and above I'm pretty confident it isn't significant. I may ease the shrouds a couple of more turns before the next outing. I don't want loose shrouds to leeward though, too much potential damage to the tabernacle and coach roof on a tack or jib as the mast slams across center. Recipe for a dismast if there ever was one...
Lucky you didn't pull down a hot wire with your mast. That would have sucked a lot. I try to watch trees and crap over the launches and rigging areas carefully but, even so, I've nicked a couple of small and flexible branches overhead. A lot of public launches weren't designed with sailboats in mind. I complained to the DNR about the public access lot and ramp at Prior Lake as it is closest to home. Maybe it will do some good, maybe it won't.
Quote from: Potcake boy on July 29, 2009, 09:26:55 AM
Steve,
Is it possible that a slight hook to windward could simply be the result of the CE being lower than the shroud tangs? These masts aren't very stout (don't need to be) extrusions. It doesn't seem like it would be something to have any appreciable effect on a boats sailing qualities, and it doesn't sound like your mast is in imminent danger of falling down.
I once trailed my 16 with the mast up under an overhead wire and caught it just above the forestay. Being alerted to this error in judgement by the resounding bang behind me, I assume the the boat was lifted partially off the trailer and surely the mast flexed to allow the wire to pass over. The mast appeared to be unscathed, but close inspection revealed a slight torque twist to the mast. Never the less, she sailed fine there after - a testament to how sturdy these rigs are. Ain't never heard of a Compac gettin' dismasted.
Ron
Are you talking about mast curve or bend forward and aft? Or are you talking about deflection side to side?
I noticed when I was sailing reefed in a strong wind that there was considerable side to side deflection as the pressure was more on the mid mast area as opposed to being spread over the entire length.
I made a set of "lowers" (side shrouds from the spreader down) and they virtually eliminated that... It also gives me the peace of mind that if a side shroud broke loose, I wouldn't be dismasted immediately before I had a chance to release the main sheet.
If the forestay ever broke, at least you have the sail and halyard to keep the mast up, but with only one side shroud...
Anyway, here is a pic of my rig... hope it helps...
Happy sails to you
Dale
http://groups.yahoo.com/group/com-pac/photos/album/712582202/pic/705800588/view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc
(//) Sorry, I haven't figured out how to insert an image here... the link is to the "other" ComPac site's gallery.
Dale,
I've noticed a slight curve in the mast when sailing in heavy air, mid mast. When I eased the shroud tension a bit the curve wasn't as pronounced but it is still there. Easing the shrounds allowed side to side deflection instead. Again, slight but I'm aware of it. My last two sailboats had lower shrouds, I might have a couple made for me just for peace of mind. I couldn't get to the picture you recommended, access denied, but thanks. I know what it should look like.
Steve
Quote from: multimedia_smith on August 13, 2009, 02:46:28 AM
Are you talking about mast curve or bend forward and aft? Or are you talking about deflection side to side?
I noticed when I was sailing reefed in a strong wind that there was considerable side to side deflection as the pressure was more on the mid mast area as opposed to being spread over the entire length.
I made a set of "lowers" (side shrouds from the spreader down) and they virtually eliminated that... It also gives me the peace of mind that if a side shroud broke loose, I wouldn't be dismasted immediately before I had a chance to release the main sheet.
If the forestay ever broke, at least you have the sail and halyard to keep the mast up, but with only one side shroud...
Anyway, here is a pic of my rig... hope it helps...
Happy sails to you
Dale
http://groups.yahoo.com/group/com-pac/photos/album/712582202/pic/705800588/view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc
(//) Sorry, I haven't figured out how to insert an image here... the link is to the "other" ComPac site's gallery.
Steve,
I'm still messing with my shroud tension too. The mast deflection is definitely due to tension on the side stays. Whether it is bad, good, or indifferent, I don't know? A few weeks ago when I was on Pepin, I had my shrouds fairly tight, and even reefed in 25-30 mph I was getting some deflection (and quite a bit before I reefed). Before my lee shroud would be visibly slack and there was no noticeable deflection in the mast. I'm going to keep messing with it, there has to be a happy medium between slack and deflection. Probably going to depend on whether it is a I or a II also.
Nate
Multimedia_smith - IMHO you would be better off not adding lowers to your rig for a couple of reasons.
1. Extra maintenance - and adjustment - if it was necessary ComPac would have done it
2. If you have the lowers too tight the uppers will stretch more from the static position and bring the mast out of column increasing the risk of breaking the mast at the lowers. If the single shroud breaks, damage may well be limited to the tabernacle instead of a broken mast. In fact if you replace the bolt at the mast base with some sort of breakaway pin you may only have a slightly bent tabernacle to repair.
3. You will encounter the same sheeting issues as 19 owners have. Although this isn't a big deal - you sheet the jib in between the shrouds and a genoa outside.
Remember the KISS principle - that's an important part of the ComPac success story.
Wishing you wind in your hair - or is that hair in the wind.
Ron
Hi Nate,
I've noticed the posts you have been making. Good to see you are getting out on the water a lot this summer, more than I have for sure.
I think we are on the right track with shroud tension. For sure they don't need to be anywhere near as tight as they needed to be on my Hunter 23. I backed off the tension a little bit more when I was out on Monday afternoon. Light air so not a real test but the slight bow we both noticed when out on Mille Lacs was almost impossible to see. Heavy air is going to be the test. Breezy today, might get out yet this afternoon on Prior Lake. I'm recovering a bit from too much brew at the Buffalo Wild Wings last night so I might lay around and watch a movie instead.
Quote from: NateD on August 13, 2009, 11:20:43 PM
Steve,
I'm still messing with my shroud tension too. The mast deflection is definitely due to tension on the side stays. Whether it is bad, good, or indifferent, I don't know? A few weeks ago when I was on Pepin, I had my shrouds fairly tight, and even reefed in 25-30 mph I was getting some deflection (and quite a bit before I reefed). Before my lee shroud would be visibly slack and there was no noticeable deflection in the mast. I'm going to keep messing with it, there has to be a happy medium between slack and deflection. Probably going to depend on whether it is a I or a II also.
Nate
I think you must be talking about Mast "bend" or "curve"... that would be deflection fore and aft. In the RC sailboats and some racing sailboats there is an angled piece at the masthead that the backstay attaches to called a Crane. When tension is increased on the backstay, it pulls Down as well as back allowing you to increase the amount of (fore and aft) curve in the mast. Several sets of my expensive carbon fiber sails for the RC boats were actually cut with a curved luff. This would only shape correctly when the exact matching curve was introduced into the mast.
Since we don't have a backstay on the 16s, we can only cause or remedy the fore and aft deflection by the amount of tension in the leech of the sail (how flat we make it or how tightly we sheet it) or through the amount of tension in the headstay. The headstay tension can be affected by it's own turnbuckle OR by how much tension is applied to the shrouds.
The deflection I was correcting for with my "lowers) was sideways deflection caused by more force being applied to the center of the mast when running reefed in a strong wind. Real lowers are set on chainplates that are further aft than the uppers and pull back on the middle of the mast correcting for the amount of curve (straightening it out). The uppers are set on chainplates that are paralell with the mast. Since we only have one set they are already set aft of the mast foot... we really wouldn't want anything further aft as the boom already hits them on a full downwind run. The three form a triangle and thus we don't bother with a backstay... the sail leech essentially becomes our backstay.
As far as the tension on the shrouds, they should be tight enough not to slack on the leward side when sailing... if they are allowed to be slack... they will snap tight with a bang when you tack and that's not a good thing. The rule of thumb when tensioning shrouds or headstay is that they should be sort of like a bass guitar string... not a high note, but still a note.
Just my 2c
Dale
Hi Dale,
Thanks for the post. Actually, I am also talking about a slight bend port and starboard. Caused, most likely, by heavy winds, a baggy main and too much shroud tension. I understood your post and am still considering adding lower shrouds. As reducing shroud tension seems to have corrected the bend almost completely since my original post I may not have lowers made. I have a new main on order from National Sails that should help too as there is absolutely no way to flatten my current main. The original main is just blown out and needs to go. I'm expecting the new sail any day now, I can hardly wait... It is worse than Christmas!
Thanks,
Steve
Quote from: multimedia_smith on August 16, 2009, 05:52:07 AM
I think you must be talking about Mast "bend" or "curve"... that would be deflection fore and aft. In the RC sailboats and some racing sailboats there is an angled piece at the masthead that the backstay attaches to called a Crane. When tension is increased on the backstay, it pulls Down as well as back allowing you to increase the amount of (fore and aft) curve in the mast. Several sets of my expensive carbon fiber sails for the RC boats were actually cut with a curved luff. This would only shape correctly when the exact matching curve was introduced into the mast.
Since we don't have a backstay on the 16s, we can only cause or remedy the fore and aft deflection by the amount of tension in the leech of the sail (how flat we make it or how tightly we sheet it) or through the amount of tension in the headstay. The headstay tension can be affected by it's own turnbuckle OR by how much tension is applied to the shrouds.
The deflection I was correcting for with my "lowers) was sideways deflection caused by more force being applied to the center of the mast when running reefed in a strong wind. Real lowers are set on chainplates that are further aft than the uppers and pull back on the middle of the mast correcting for the amount of curve (straightening it out). The uppers are set on chainplates that are paralell with the mast. Since we only have one set they are already set aft of the mast foot... we really wouldn't want anything further aft as the boom already hits them on a full downwind run. The three form a triangle and thus we don't bother with a backstay... the sail leech essentially becomes our backstay.
As far as the tension on the shrouds, they should be tight enough not to slack on the leward side when sailing... if they are allowed to be slack... they will snap tight with a bang when you tack and that's not a good thing. The rule of thumb when tensioning shrouds or headstay is that they should be sort of like a bass guitar string... not a high note, but still a note.
Just my 2c
Dale
Hi Steve,
They make some really nice sails at National... for those who don't know, they are actually Rolley Tasker Sails out of New Zealand and are fabricated in Thailand I think. The ones I've gotten show terriffic workmanship.
Since 2004 I started with a full batten light air main and a 155 genoa (cut to fly high off the deck on a 10" pendant.
Next, I got a storm jib. They worked with me to come up with a custom design for the CP 16... it comes out to be about a 60%. It still gets me up to hull speed in a blow (with mannerly control of the boat). In order to save my new light air main. I was using my original Johnson main in heavy air with a boom roller reefing. Combined with the new storm jib, I experimented with different luff lengths in different wind conditions and made measurements. What we came up, National now calls their CP 16 heavy air main. It is loose footed (when you reef, you lose the foot rope anyway) and I changed the dimensions a bit to keep the forces low on the boat. I shortened the luff by 3" and lengthened the foot by 8" and removed the roach. It has two reef points... The first reef point takes out 3 1/2' of luff and the second reef takes another 3 1/2'. I have used this combination in some pretty strong conditions and the boat handles great... Hull speed plus without the fear of a knockdown.
Back to the "lowers"... although they are not really lowers because they have the same attachment point at the hull. They DO have a different place along the mast though, and here's where it helps. When we reef, we are placing most of the lateral strain on the middle of the mast. The shrouds are 7/8 to the top (almost the top). Thus, I saw an improvement in performance and less tension in the nerves of the skipper from not seeing the mast bend 6" off center each way on a beat.
I just added some pics of the new main... here's the link...
http://groups.yahoo.com/group/com-pac/photos/album/712582202/pic/826731363/view?picmode=&mode=tn&order=ordinal&start=21&count=20&dir=asc
http://groups.yahoo.com/group/com-pac/photos/album/712582202/pic/826731363/view?picmode=&mode=tn&order=ordinal&start=21&count=20&dir=asc
Also a couple of pics comparing the Storm Jib to the Genoa.
http://groups.yahoo.com/group/com-pac/photos/album/712582202/pic/236597013/view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc
http://groups.yahoo.com/group/com-pac/photos/album/712582202/pic/2138080087/view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc
Happy sailing
Dale
Hi Dale,
I wish I could see those pictures but all I get is an error message... I bought sails from National for two other boats and they were beautiful sails. Their main loft is in Thailand I think but the sails are made from dacron from the US, good material. I believe I delt with Dirk. I bought the heavy main but I asked for a rope on the foot. I probably don't need the heavy sail but the material sure lasts longer in normal winds. I'd love to have the measurements for the 60% storm jib you had made. Can you post those?
The tack pennant on the 155 is a great idea. I have enough room between the head of the sail and the mast to put a tack on mine as well so I'm going to do that before I go out the next time. That might shift the center of effort a bit forward as it raises it to a point where the main isn't as wide but it would sure make it easier to see the bone heads on the personal water craft and the clueless fathers pulling tubes across my bow.
I had the same experience you did in heavy air with a reefed main. I could see that mast bowing and my butt puckered up a bit. Easing the shroud tension reduced the bow greatly though now I can detect a slight mast deflection to leeward. Maybe I just shouldn't be out sailing when the gusts are hitting 30 but I just can't help myself. It is a hoot out there when the other boats are chickening out.
Steve
Quote from: multimedia_smith on August 17, 2009, 02:56:48 AM
Hi Steve,
They make some really nice sails at National... for those who don't know, they are actually Rolley Tasker Sails out of New Zealand and are fabricated in Thailand I think. The ones I've gotten show terriffic workmanship.
Since 2004 I started with a full batten light air main and a 155 genoa (cut to fly high off the deck on a 10" pendant.
Next, I got a storm jib. They worked with me to come up with a custom design for the CP 16... it comes out to be about a 60%. It still gets me up to hull speed in a blow (with mannerly control of the boat). In order to save my new light air main. I was using my original Johnson main in heavy air with a boom roller reefing. Combined with the new storm jib, I experimented with different luff lengths in different wind conditions and made measurements. What we came up, National now calls their CP 16 heavy air main. It is loose footed (when you reef, you lose the foot rope anyway) and I changed the dimensions a bit to keep the forces low on the boat. I shortened the luff by 3" and lengthened the foot by 8" and removed the roach. It has two reef points... The first reef point takes out 3 1/2' of luff and the second reef takes another 3 1/2'. I have used this combination in some pretty strong conditions and the boat handles great... Hull speed plus without the fear of a knockdown.
Back to the "lowers"... although they are not really lowers because they have the same attachment point at the hull. They DO have a different place along the mast though, and here's where it helps. When we reef, we are placing most of the lateral strain on the middle of the mast. The shrouds are 7/8 to the top (almost the top). Thus, I saw an improvement in performance and less tension in the nerves of the skipper from not seeing the mast bend 6" off center each way on a beat.
I just added some pics of the new main... here's the link...
http://groups.yahoo.com/group/com-pac/photos/album/712582202/pic/826731363/view?picmode=&mode=tn&order=ordinal&start=21&count=20&dir=asc
http://groups.yahoo.com/group/com-pac/photos/album/712582202/pic/826731363/view?picmode=&mode=tn&order=ordinal&start=21&count=20&dir=asc
Also a couple of pics comparing the Storm Jib to the Genoa.
http://groups.yahoo.com/group/com-pac/photos/album/712582202/pic/236597013/view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc
http://groups.yahoo.com/group/com-pac/photos/album/712582202/pic/2138080087/view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc
Happy sailing
Dale
The photos are posted on the "other" ComPac site here:
http://groups.yahoo.com/group/com-pac/
go to "photos" here:
http://groups.yahoo.com/group/com-pac/photos/album/0/list
and then, my album is called "1988 Sweet Little 16 Projects"... you'll find the pics there. We used to have a gallery here, but it seems to be gone. I clicked on the links in the reply post and they work for me... it might be due to the fact that I'm registered there, but you can go to the site without doing that.
I looked up the photo that had the dimensions. Dirk Sharland at National has it on file as one of their items now... it's listed as: Inventory #3296 Compac 16 Heavy Jib. The dimensions (in meters) are: Luff 3.36m, Leech 2.44m, Foot 1.83m, Weight 6oz
(in the pic, their "1" looks like a "7", but the Europeans put a line through the 7 to avoid mistakes. You can clearly see the label in the picture of the overlay.
Since I now use that sail for anything over about 16kt winds, the boat can handle GRACEFULLY pretty high winds while other folks are hanging on... overpowered... Yes, it is fun to go out while others are heading in... What's wrong with us? Wheeee!
Happy sailing to you... Our season is about to begin in late september as yours is winding down.... can't wait 'till fall.
Dale
Well... I get an error message that states that I need to be a member to see the pictures. I needed another email address and account like I need another hole in my head but I signed up for one and requested membership in the group... I'll get in eventually.
Your sailing season is just about to begin? Where are you?
Quote from: multimedia_smith on August 18, 2009, 01:27:15 AM
The photos are posted on the "other" ComPac site here:
http://groups.yahoo.com/group/com-pac/
go to "photos" here:
http://groups.yahoo.com/group/com-pac/photos/album/0/list
and then, my album is called "1988 Sweet Little 16 Projects"... you'll find the pics there. We used to have a gallery here, but it seems to be gone. I clicked on the links in the reply post and they work for me... it might be due to the fact that I'm registered there, but you can go to the site without doing that.
I looked up the photo that had the dimensions. Dirk Sharland at National has it on file as one of their items now... it's listed as: Inventory #3296 Compac 16 Heavy Jib. The dimensions (in meters) are: Luff 3.36m, Leech 2.44m, Foot 1.83m, Weight 6oz
(in the pic, their "1" looks like a "7", but the Europeans put a line through the 7 to avoid mistakes. You can clearly see the label in the picture of the overlay.
Since I now use that sail for anything over about 16kt winds, the boat can handle GRACEFULLY pretty high winds while other folks are hanging on... overpowered... Yes, it is fun to go out while others are heading in... What's wrong with us? Wheeee!
Happy sailing to you... Our season is about to begin in late september as yours is winding down.... can't wait 'till fall.
Dale
I'm on the North side of Lake Ponchartrain... Went out this weekend for the first time since the spring... GREAT!
Post and Pics under "My Best Day Yet" topic here under the 16s posted a couple of pics there too. (7.3 on the GPS.. Whoooo!)
later
Dale
Hi All,
Have there been any updates on this topic ?
One of the things I love about the CP16 is it's heavy weather capabilities. However, after sailing several times in high winds, I also noticed the mast bending 2 inches inboard when on a close reach. After further examination, it appears that when the sidestays are under tension they push the spreaders into the mast thus bending it like a bow and arrow. My solution is to take the spreaders off and tighten the shrouds. This should reduce the sideload on the mast, keep the mast in compression, and keep the standing rigging tight. I'll let you know how it works when I get out on the water. Has anyone else done this ?
Al
1990 CP16II
Well when we use race are Star Boat we would induce a curve to our spruce spar by sliding the port and starboard rigging fore and aft for the perfect sail bend.
But on Com-Pac's forget it. Up and down is fine. You'll never induce anymore speed. And curving an aluminum mast with an extruded backbone internally is like peeing into the ocean to make it overflow. Hardly gonna happen with any beneficial results. But you guys go ahead and bend them up.
skip.
Hi Skip,
I agree with you. The mast is designed to take load in compression not bending. That's why I took the spreaders off.
Al
Al:
You'll have to ask yourself: If the spreaders were a bad idea, why did Compac add them to the 16? If I'm correct, 16/1 did not have spreaders but your's does. I believe your problem is an incorrectly tuned rig. Be careful of over tightening the shrouds...you could cause some damage as you put too much downward pressure (compression) on the mast and thus the deck it sits on. Except for the additional set of lowers, my 23's rig is just like yours, only a bit bigger. When tuned correctly, my leeward shrouds are a tad loose while sailing. I'd call Hutchins about this...
Bob23
Hi all, I have read this thread 3 times trying to figure out what you all are seeing. Here is what I think you are describing on the compac 16 only.
1 on a nonspreader rig in heavy air, the top of the mast can fall off due to pressure above and no support, the windward shroud will stretch some and the bottom load on the sail may fall off in the lower part of the mast (athwartship bend). (We see this in a headstay, the luff of the sail will originally have a bit of an "s" cut into it to give the optimal shape with the optimal tension and wind strength). Shroud tension might effect how much fall off you would see. Mainsheet tension can put some fore and aft bend into the mast due to the fractional rig. By doing so you are taking some belly out of the mainsail and depowering the main some. Note also that the mast column falling off to leeward is also taking draft out of the main but also moving the leading edge of the luff leeward.
2 on a spreader rig, no lowers, shroud tension increases would put a prebend into the mast (fore and aft) taking draft out of the main, the top of the mast can fall off as described above. With the mast at rest I believe that the spreader is in compression from the force of the bend resistance on the mast, but when sailing in really heavy air could be in tension, helping to hold the mast in column depending on the amount of prebend put in and the amount of stretch in the shroud. (I have never sailed a rig like this just visualizing the forces there to the extreme).
3 on a spreader rig with lowers added, everything applies however, the lowers take the tension for mast column and the spreader are in compression helping to reduce the top of the mast from falling off. Sail shape is built in accordingly.
In summary regarding our cp16's,
1 I would think hand tight on the turnbuckles is about right, I can't imagine the need for pliers and crewdriver for leverage.
2 If you think there is too much force on the mast reduce sail.
3 Lowers seem unnecessary however I don't see them as not helping-and although I would not add them to my 16 if they were there I wouldn't get rid of them.
Although the nonspreader boats do not allow for prebend in the mast, prebend is a way of getting closer to a hyperbola shaped foil which is the shape that is most efficient for drag giving a more efficient sailplan. ( I read that somewhere years ago, a discussion on foil shape and compromises therein would require more coffee this morning and not be relevant to this thread :))
4 To really get and idea of shroud and spreader interplay, spend an hour looking at some of the mid 80's Hunter B@R rigs. You could spend all day chasing loads on one of those, but they do hold a relatively light spar in place with the proper shape, and makes a standard 8 stay rig child's play.
Thanks so much for this forum, I really enjoy you guys.
Happy Sailing.
Hi All,
Unfortunately I didn't make it to the lake this weekend to see if the mast bent less without the spreaders. For those of you without spreaders, does your mast bend side to side when sailing in high wind ?
Al
Clarification: My mast does not bend like a fishing pole, it bends like a bow and arrow with the spreader being the arrow. Mast fixed on top and bottom, bent at spreader.
Note: The spreader appears to be in compression at all times except when dangling on the leeward side.
Al, So there is no prebend, the wind picks up, loads the headstay and windward shroud, the shroud is brought into higher tension pushing the spreader into the mast and creating a bend. I have the picture, but not sure of the fix other than a set of lowers. Btw how much did you have to take up on the turnbuckles when you pulled the spreaders off, just curious. The other question, how much breeze are you talking about before you see this and get worried? I am not sure what the design parameters are of a 16, but I would think given they are out of the Tampa bay area, that they envisioned the boat to be used by young family and older sailors moving down in size (citation-Practical Sailor), that they were looking at those local conditions. I sailed the Tampa gulf coast area for 4 years, the water is pretty skinny, and wind conditions are generally pretty light until winter when a north northeasterly fills in at about 10-15 kts. Seas usually are fairly round unless beating up the bay where the waves seem to have less of a back, and a pretty crappy pounding when against the tide. Given this I would expect some rig strain in conditions above 15 although I haven't noticed any on my standard rig. Although I believe the boat would be fine, for me the fun starts to drop and the work sets in above 15, meaning it is fun for an hour or two but not for a 10 hour day. Btw I got knocked down in the 16 a couple of weeks ago by a 21 kt gust( wasn't paying attention) shipped about 15 gallons on board and about 2 went right down the companion way, interesting to watch it run right in there as the boat righted! Also I was surprised how much came in through the aft lazarette. That was reefed main and 110% closehauled and sailing by myself with 195 lbs on the windward side,( beer cooler centered below offering no particular assistance ;D). Sorry to digress, I haven't felt the rig was not suited for these conditions, but do think that 15 is probably the upper edge of when the boat was intended to be used.
Best of luck and keep us posted please.
Happy Sailing
My understanding of the design philosophy of the 16 is to squeeze as much stability and seaworthiness into a package that will fit in a certain type of shipping crate which explains the dimensions/draft. I could be mistaken. If it is true, this may of been misguided. Afterall, who doesn't want a trailer for their 16? Few for this size boat anyway.
Matt-Your knockdown shipped quite a bit of water! Gusts are rarely fun especially when it involves a bucket and sponge :)
Al- I agree with Bob23. Sounds like you need to re-tension things with the mast slightly forward of vertical. Make sure the spreaders are the correct length as well (who knows, a prior owner may of changed them?).
15 the upper end? We get 15 knots of wind around here all the time and that's when I put the first reef in my 23's main. I'd be willing to bet the 16 was designed for and could handle a great deal more. It's us humans who are the weak link.
Certainly glad you didn't invite more water aboard...can't say I've had the pleasure of water entering my cabin. I'm a firm believer that the waterline should stay on the outside of the boat!
Bob23
Hi All,
Just for heavy weather experience, I routinely sail with a reefed main in 15-25 knot winds on local lakes and have sailed in Corpus Christy Bay in 15-20 knots with 3 foot rolling waves. The boat was rock solid crashing thru the waves with spray over the bow. On those occasions I did notice the mast bending but thought it was the high wind. However, last week I was cruising in 10-15 knots and noticed the mast bend and thought "what's wrong with this picture?" Apparently, with a full main, there is enough force to straighten the windward sidestay and push the spreader into the mast. Loading a bent mast in compression can't be good, so I took the spreaders off and tightened the sidestay turnbuckles by less than an inch. Has anyone noticed that the new CP Legacy and the M15 do not have spreaders.
Al
Hi Bob, I indicated "intended use". I don't consider 15kts a lot of air for your 23 or any of my other boats, however at 15 the cp16 is getting a little overpowered, harder to keep on her feet and beginning to stall somewhat in a 3 foot chop. I was surprised that she didn't stand up a little better, but as I look at her, she is pretty round on the bottom without a stiff turn as she enters the freeboard. Keeping her on her feet to minimize leeway on a beat starts to get a little tougher. By the end of the day all you see is yarn! A lot one designs are designed in term of wind and water conditions and recommended or limited crew weights. I believe the Flying Scott recommends 6-12kts (though we don't plane a lot in 12, Y-flyer about the same and planes well in 12, Lightning maybe a little more (3 man crew), E-scow now that would be a ride in 20!! An A-cat lost a rig this weekend in 18kts. I am not saying one shouldn't or can't sail a 16 in over 15, I am just saying that I believe her performance begins to suffer at that point, as does it's performance suffer under 5kts of wind.
Salty, I have heard that about MacGregor 26, the quote: "dimensions of the Macgregor26 were not determined by what would be seaworthy, or even what would be legally trailered: rather, the boat was laid out so that four of them would fit on the truck at a time." (Practical boat buying Belvoir Publications 1992). But somewhere I remember something akin to your statement-maybe this forum?? And yes I bought the 16 to trailer around, see new water, eat sandwiches and drink a few beers with other friendly sailors. So far so good!
Al, I find that in over 15 kts just the jib on the 16 sailed better that just the main alone. Couldn't beat to windward well at all on just a main,same thing sailing up to the dock. On the jib, she sails pretty well. I put the reef in at 10-12, drop the main at around 15 and sail happily under jib after that. But it is a wet ride, amazing how much water collects on the leeward seat pooling nicely around my gps...
Happy sailing.
Mattman, I concur with your observation of sailing with the jib only with 15kts of wind! Actually, I was pleasantly surprised at how comfortable and relaxed the sailing became after dropping the reefed main...hull speed dropped about 1 knot. I had a second reef put in the main this fall and looking forward to trying this option, with the jib, under similar conditions?
j
My 78 CP16 sails under jib alone with great ease in heavy winds, so much so I purchased a storm jib but the standard jib worked just as well........only the storm jib is smaller and made with heavier cloth/stitching.....................Steve I am still using the cockpit grate you designed and sent me the spec's on, thanks again........................nies
not meaning to disagree but i have sailed my 16 many times in 15 knot plus winds. my main has no reef points and i have never felt overpowered. maybe the ida rudder does make a difference. as suprano says "all due respect---just sayin"
One thing I don't think has entered into this discussion is the condition of the sails. When I first bought my 1985 23/2 about 8 years ago, she had her original suit of sails and to my untrained eye, looked ok. But during any kind of gusts, she would heel over quickly so early reefing was a must. Since I had never owned a 23 before, I didn't know that this was not normal.
When I first visited a local sail loft here in NJ, the owner looked at my sails and said politely "These sails haven't been good for a long time" and chuckled. Because of thier great reputation and their knowledge of my local conditions, I left the final sail design up to them. Btw, "Them" is John Eggers Sailmakers in South Amboy, NJ. (No commercial relationship)
The first time out, I could feel a world of difference. When the gusts hit, the power was immediately transferred into forward motion. Not only was she much more comfortable to sail, she was much faster. I also was able to point much higher and didn't need to reef quite so early.
Maybe this will help or maybe it will further confuse things!
Bob23
The Idasailor rudder definitely helps with weather helm, as does a bow sprit. New sails would really be nice. I think I'll try the jib only for high winds (especially down wind with a following sea) and approaches to boat ramps without a beach area. All good ideas.
Thanks, Al.
kickingbug1
some clarification, overpowered with wind over 15 knots was not the issue. At this stage of my life, preference, when conditions permit, is given to a more lazy type of sailing....dry, balanced and hands off the tiller is my goal. New Ida Rudder on hand for next season, looking forward to see if the positive recommendations will allow me to fall asleep while sailing (joke)!!
Bob23
point well taken, still have the original main on my 96 and it is tired but still in usable condition...just returned from Sailcare. I'll give it another year?
jb
On my first outing on my new to me CP-16 I did not like the mast visibly flexing a lot, so I installed a home made diamond, problem solved.
(http://i44.tinypic.com/ke9pc7.jpg)
(http://i41.tinypic.com/24cw5zs.jpg)
I still have my 78 sails in useable condition, replaced them 8 years ago and you can not believe the difference in the boats performance, there is a point where the sails look good but air is going right through them as the fabric is tried , just my experience and thoughts.......( new sails and the Ida rudder and you have a new boat).......................nies
jb:
Before I bought my new sails, I sent my originals to Sailcare. They were crispy and fine for about 1 1/2 seasons. Although Sailcare can extend the life of the sails, once they have lost thier shape, they really need to be replaced. I'm glad I dealt with Sailcare...saw them at the Annapolis Sailboat Show...Sam is always a pleasure to meet.
Bob23
nies & Bob23,
o.k., pretty compelling entries about the advantages of purchasing a new main sail !!
Questions, did you just order a stock mainsail for your specific year CP16 or did you make any changes other than the # of reef points.. loose footed,rope or slugs on the foot?
any recommendations as to where to make the purchase at a reasonable price?
thanks,
jb
nies, I copied your system for a down haul on the Ida Rudder. thanks for your suggestion.
Glad the down worked for you, I called Hutchins and got the name of their sail source and ordered the stock sail, they had the pattern, but had to send back as the patterns changed slightly over the years, no hassel, It would take a little research ,but if you want I will look in my records.......nies
Rope , according to the "experts" rope gives you a small fraction increase in performance of main sail, .........nies
All the 'little bits' of performance won't make her sail faster, and bending a spar with internal extruded stiffeners vs. bending a hollow wood spar or high tech carbon fiber for best sail shape goes beyond the typical Com Pac sailors ability to squeeze out every once of performance. Sailing 'this hard' is a lot of work. I'd opt for a really good set of crisp sails.
Just me. skip.
jb, I had sails built this spring by JSI, I was familiar with them from my time in Tampa. They spent a half hour on the phone with me and I described my sailing conditions and typical wind ranges etc.. Then sent them specific measurements from the boat. They use Doyle as a builder. Ended up with a main with full baton on top, slugs, and loose foot in I think 5 oz cloth (which I thought was a little heavy but they set well) leach and foot lines, with tells and 110% jib with leach and foot line and tells (did not do sail numbers) for just under a grand. I would not order stock given for just a few extra bucks you can get some really nice sails built just for your boat, sailing style and conditions. Remember it is a SAILboat. The last place I would try to save money is in sails, ground tackle or pfd's! When money is tight I drink a cheaper beverage!!
Happy Sailing.
Hi All,
I made a special trip out to the lake to test my theory. The winds were only about 7-14 with occasional gusts to 20 knots - not as high as I was expecting. However, with a full main, genoa, and no spreaders, the mast bowed about 1 inch at 10 knots and 3.5 inches at 20 knots. From earlier sails, the mast appeared to bow 2 inches at 10-15 and 4 inches at 25 knots (with shortened sails). Additional details: The spreader is about 2 inches longer than the distance from the mast to the spreaderless shroud. The leeward shroud is loose.
Based upon this information (and noting that this test was not very scientific with plenty of room for error), it appears that the spreader is causing the initial 2 inch bend. At higher loads, the spreader appears to go into tension and keep the mast from bowing as much. However, spreaders are not great in tension, especially if they're held to the shrouds with aluminum wire (like mine were).
Could it be that both port and starboard shrouds need to be tight to allow the spreaders to work properly ?
Al
Hi All,
I just found a general tuning guide for standing rigging which confirmed my suspicion that the spreader was bending the mast. Their solution was to tighten the lower shrouds to keep the mast straight. Therefore, it would probably be beneficial to add lowers for sailing in high winds, but is it really neccessary ? Has anyone ever heard of a mast breaking on a CP16 ?
Al