Standing rigging lashings - how tight? - & how?! - Wharram Builders and Friends2024-03-29T14:46:14Zhttp://wharrambuilders.ning.com/forum/topics/standing-rigging-lashings-how-tight-how?commentId=2195841%3AComment%3A104378&feed=yes&xn_auth=nowhen using a winch , i use th…tag:wharrambuilders.ning.com,2013-08-08:2195841:Comment:1045602013-08-08T16:10:18.444Zalexhttp://wharrambuilders.ning.com/profile/alexvg
<p>when using a winch , i use the gaff halyard so the lashing goes as vertical as i can , then i tie a secondary small rope to the lashing bundle right next to the most convenient turning point , so i can release the lashing rope without losing tension and then tie the bitter end. Other way that works fine is by holding the lashing bundle with a wise grip (can jump into the water though) next to a turning point. it works fine but might damage the lashing rope if used without any protection (a…</p>
<p>when using a winch , i use the gaff halyard so the lashing goes as vertical as i can , then i tie a secondary small rope to the lashing bundle right next to the most convenient turning point , so i can release the lashing rope without losing tension and then tie the bitter end. Other way that works fine is by holding the lashing bundle with a wise grip (can jump into the water though) next to a turning point. it works fine but might damage the lashing rope if used without any protection (a piece o fabric). </p>
<p>but as i said in another previous comment, i am trying to find the point where the lashings are in the delicate 'balance tension' between being lose and too tight. my goal is to get the fore stay as straight as acceptable (i will never get a straight tensioned fore stay without bending the wooden mast) and a straight mast. I would really love to have JW opinion about all this topic. I guess that the correct tension for the gaff rigged boats, as per JW design , would be the point where you put the common sense. our boats are not racing boats, and avoiding material damages and stress will be always the main goal, without to compromise speed too much.</p>
<p>We should also meditate how the tension of the rigging will perform under extreme stress in the event of a storm. Will a over tensioned rigging stand the added stress of a storm? will a poor tensioned rigg compromise the mast structure?</p>
<p>In my believes so far , the bottom line would be to tension the mast till it starts to bend. a fine rope stretched from the top to the foot and against the mast will help to visualize when this tension point is reached.</p>
<p>alex</p> Hi - thanks for your replies.…tag:wharrambuilders.ning.com,2013-08-08:2195841:Comment:1047482013-08-08T15:41:37.186ZAndy Best-Dunkleyhttp://wharrambuilders.ning.com/profile/AndyBestDunkley
<p>Hi - thanks for your replies. Using spectra/dynema for frapping a polyester lashing shounds like a good solution. But I'm not sure about your last two sentences - even though the movement of the hulls/beams has effect on the rig, the two lashing "systems" are seperate - all my shrouds and stays are led to the hulls, apart from the forestay bridle on the bow beam. I totally agree that the rig should NOT flop about, that's what I am trying to solve - so thanks for the tips! As the rigging…</p>
<p>Hi - thanks for your replies. Using spectra/dynema for frapping a polyester lashing shounds like a good solution. But I'm not sure about your last two sentences - even though the movement of the hulls/beams has effect on the rig, the two lashing "systems" are seperate - all my shrouds and stays are led to the hulls, apart from the forestay bridle on the bow beam. I totally agree that the rig should NOT flop about, that's what I am trying to solve - so thanks for the tips! As the rigging lashings are narrow there is little effect from any frapping when tying off. Should I be trying to get the lashings tighter in the first place, for example using a winch to tighten them? Up til now I'm using a wooden handle at the end of the line as a good hand hold. If you use a winch (or truck!) how do you then release it to tie off without loosing the tension?</p> polyester double braid is wha…tag:wharrambuilders.ning.com,2013-08-08:2195841:Comment:1048152013-08-08T14:30:15.712Zboatsmithhttp://wharrambuilders.ning.com/profile/qe0j3ojqb10
<p>polyester double braid is what we use for the lashings. Then we frap with a mid grade of spectra. There is plenty of strech left in the lashing assembly this way even after using a truck to pull the frapping tails. <i>Imo the frappings are designed to absorb shock loads. The beam to hull connections should not allow the rig to flop around. This will highly stress your rig and is not very effective either.</i></p>
<p>polyester double braid is what we use for the lashings. Then we frap with a mid grade of spectra. There is plenty of strech left in the lashing assembly this way even after using a truck to pull the frapping tails. <i>Imo the frappings are designed to absorb shock loads. The beam to hull connections should not allow the rig to flop around. This will highly stress your rig and is not very effective either.</i></p> I use "Liros PreStretch". I t…tag:wharrambuilders.ning.com,2013-08-08:2195841:Comment:1048112013-08-08T10:08:25.654ZMichael Stephanihttp://wharrambuilders.ning.com/profile/MichaelStephani
<p>I use "Liros PreStretch". I think Dacron is also a brand for prestretched PES...</p>
<p>I use "Liros PreStretch". I think Dacron is also a brand for prestretched PES...</p> Hi Raf, yes I agree with you…tag:wharrambuilders.ning.com,2013-08-08:2195841:Comment:1048092013-08-08T08:23:55.509ZAndy Best-Dunkleyhttp://wharrambuilders.ning.com/profile/AndyBestDunkley
<p>Hi Raf, yes I agree with you regarding the hull to beam lashings. I use regular braided rope, but getting it tight, even with the frappings, is quite a job. As you say, when adding the rig onto this flexible platform, it is virtually impossible to produce a stiff setup. I can see why some stretch in the shroud lashings is a good thing - some elasticity to take up the slack when the rig is wobbling about in a big sea. It's not a problem when you're sailing constantly on one tack with the lee…</p>
<p>Hi Raf, yes I agree with you regarding the hull to beam lashings. I use regular braided rope, but getting it tight, even with the frappings, is quite a job. As you say, when adding the rig onto this flexible platform, it is virtually impossible to produce a stiff setup. I can see why some stretch in the shroud lashings is a good thing - some elasticity to take up the slack when the rig is wobbling about in a big sea. It's not a problem when you're sailing constantly on one tack with the lee shrouds slack, but when we then hit some ferry wash it is like the whole boat is thrown around for some minutes, twisting this way and that! All the stress points get highly tested...! So maybe instead of dynema etc for the rig lashings, something equally strong but with some elasticity would be better? Is that then the prestretched polyester as per plans, and if so, does anyone have a brand name for me?</p>
<p>Thanks, Andy</p> Yes Andy, given one hull perf…tag:wharrambuilders.ning.com,2013-08-07:2195841:Comment:1045542013-08-07T22:56:22.487ZRafhttp://wharrambuilders.ning.com/profile/RaffaelePagliarini
<p>Yes Andy, given one hull perfectly horizontal, the bow and stern of the other hull, should be free of moving up and down about 1'. For this very reason, personally I do not consider Dynema, Spectra, and other non stretch cordage, suitable for lashing the beams to the hulls, as the all purpose of lashing, instead of bolting, is that of having a flexible join in order to absorb stresses caused by the opposing pitching of the 2 hulls. This degree of independent pitching is what makes Wharram…</p>
<p>Yes Andy, given one hull perfectly horizontal, the bow and stern of the other hull, should be free of moving up and down about 1'. For this very reason, personally I do not consider Dynema, Spectra, and other non stretch cordage, suitable for lashing the beams to the hulls, as the all purpose of lashing, instead of bolting, is that of having a flexible join in order to absorb stresses caused by the opposing pitching of the 2 hulls. This degree of independent pitching is what makes Wharram catamarans so brilliant and unique, however, this property, as desirable as it might be, poses a big challenge with the rigging. So much so that most cat designers give up the system in favor of rigid heavier structures. </p> Hi Raf - do you mean a twist…tag:wharrambuilders.ning.com,2013-08-06:2195841:Comment:1046222013-08-06T08:40:06.236ZAndy Best-Dunkleyhttp://wharrambuilders.ning.com/profile/AndyBestDunkley
<p>Hi Raf - do you mean a twist around a horizontal axis going through the central mast support beam (in my Pahi 42's case, ie the short beam)? So for example if port hull was perfectly horizontal, starboard bow would be able to flex to 1 foot above or below port bow? Difficult to judge, but we currently have flexibility in the hulls & beams. We often face very confused seas when passing high speed ferries which make huge wash (more like surf!) and of course as this is not a consistent sea…</p>
<p>Hi Raf - do you mean a twist around a horizontal axis going through the central mast support beam (in my Pahi 42's case, ie the short beam)? So for example if port hull was perfectly horizontal, starboard bow would be able to flex to 1 foot above or below port bow? Difficult to judge, but we currently have flexibility in the hulls & beams. We often face very confused seas when passing high speed ferries which make huge wash (more like surf!) and of course as this is not a consistent sea state or swell, it suddenly puts a lot of strain on the rig and hulls when the boat is bouncing around in that soup! I am wondering if the dynema lashings are too unforgiving - as they don't stretch (supposedly). Dynema acts like wire, and certainly THAT is not recommended for the standing rigging lashings. If anyone can recommend a brand of prestretched polyester that they are using that would be helpful. It's difficult to purchase "old fashioned" ropes here now, so I might have to order some online...</p> Andy, keep in mind that James…tag:wharrambuilders.ning.com,2013-08-05:2195841:Comment:1045282013-08-05T22:03:13.449ZRafhttp://wharrambuilders.ning.com/profile/RaffaelePagliarini
<p>Andy, keep in mind that James Wharram is recommending a degree of pitching freedom. He suggests that the bows move one foot to the other in the horizontal plane. Lesser than that, will substantially increase stresses to the all structure. </p>
<p>Andy, keep in mind that James Wharram is recommending a degree of pitching freedom. He suggests that the bows move one foot to the other in the horizontal plane. Lesser than that, will substantially increase stresses to the all structure. </p> Hi all - thanks for your comm…tag:wharrambuilders.ning.com,2013-08-05:2195841:Comment:1044662013-08-05T08:20:34.475ZAndy Best-Dunkleyhttp://wharrambuilders.ning.com/profile/AndyBestDunkley
<p>Hi all - thanks for your comments! Just been out for a few days sail over to Tallinn so was offline. I like Dave's suggestion to tighten the lee shrouds "a bit" while sailing - I can certainly see that the possibility for over-compensation is there. I have also been thinking that of course with Wharrams the whole boat, hull & rig, are one living system, and of course the tightness of the hull lashings will affect the rig as well, so before I do more rig ajustments I'm going to try…</p>
<p>Hi all - thanks for your comments! Just been out for a few days sail over to Tallinn so was offline. I like Dave's suggestion to tighten the lee shrouds "a bit" while sailing - I can certainly see that the possibility for over-compensation is there. I have also been thinking that of course with Wharrams the whole boat, hull & rig, are one living system, and of course the tightness of the hull lashings will affect the rig as well, so before I do more rig ajustments I'm going to try tightening the lashings!</p>
<p>cheers, Andy</p> Thanks Dave and Alex for your…tag:wharrambuilders.ning.com,2013-08-04:2195841:Comment:1047032013-08-04T21:55:49.341ZDon Brazierhttp://wharrambuilders.ning.com/profile/DonBrazier
Thanks Dave and Alex for your comments, I will give that method a try.<br />
Don
Thanks Dave and Alex for your comments, I will give that method a try.<br />
Don