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Old 28-11-2008, 18:16   #1
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Appropiate rope sizes for various applications.

We need to rig the ropes for on our Adams 35 cutter (dual spreaders, roller furler). Before we lash out and buy drums of rope we need to bounce the ideas around to make sure we have it correct.

We have a drum of 8mm poly DB and have some 16mm Poly DB headsail sheets in good condition. Apart from that the rest is rotten or non existant. I was thinking 10 or 12mm Poly braid for most applications, but certainly am open to any suggestions. Would love to use spectra, etc and will in certain applications but we are on a tight budget. If we go for say 12mm then we will buy a drum and put up with all the ropes being the same colour (or two). Unless we can swap some colours with someone.

the list of gear to rope up is:

SHEETS - Main, Headsail, Staysail - all poly double braid, what size.
HALYARDS - Main, Headsail (furling), Staysail - poly DB, but also consider spectra, etc.
MISC - Reefing lines, Vang, Topping lift, Furling cord, Lazy Jacks (spectra or VB cord ?).

We wont worry too much about the Spinnaker at the moment, as we do not know how to use one anyway, yet.

Currently our halyards were rope with wire spliced for the last several meters.

There will be some trial and error in the process as we sort out the deck gear and get things sailing on the vessel for casual coastal cruising. Before we think of heading off shore we would revise many of the systems and upgrads some of the running rig and sails (mostly old). But that could be in 1 year or several, so no point spending a lot of $ on gear not utilized.
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Old 28-11-2008, 18:19   #2
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I think you will find your blocks and shivs to be the determining factor..I dont have that kind of leeway with but a couple of mine
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Old 28-11-2008, 18:32   #3
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Sheaves on top of the mast must be V shaped & versatile as they run both fuzzy old rope and wire through each one. The rope is about 14-15mm but some of that must be form old age spread (Im sure some will know about that).

Most of the clutches and blocks below will cope with 8 to 12mm ropes in their specifications.
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Old 28-11-2008, 18:40   #4
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IMHO..Then I would go with as large as you can for cruising..easier on the hands and takes more abrasion...I dont care about weight aloft so much on a cruiser
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Old 28-11-2008, 18:54   #5
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Hi I recently replaced all the running rigging on my Vancouver 27' cutter, here in the UK we have available Marlowbraid which is a 3 ply core with a braid exterior, this is 40% stronger than braid on braid, I used 8mm throughout and was pleased as this spec was over what was specified for the boat, however 8mm is quite thin to handle and I went to the local boat jumble hoping to find 31m of 10mm in solid red for my Yankee sheets, I found 32m of 12mm for 20quid (about 30 us dollars), what a result and it looks so good and is great to handle I have quite often non-sailors on my boat so I have designated the ropes/sheets on the boat to our national flag which everyone can remember.. red white and blue.. so the haliard and sheets for the foresail are red. the staysail halliards and sheets are white and the main are blue, the lines for the first,second and third reefs are the same, it makes life easier because you can say "pull on the red rope"
Spectra... why go for the extra expense this stuff is for out & out racers I see no need in the cruiser.
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Old 28-11-2008, 19:48   #6
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Sheets, spinnaker halyards and all those go polyester double braid.
Halyards, headsail and main at least, I'd seriously look at dyneema/spectra core. Way stronger and a lot less stretch meaning better more stable sail shapes hence performance.

Spectra is very very common place and the extra cost isn't really that much considering the performance and longevity gains. It is unusual to replace main or headsail halyards with anything but Spectra/Dyneema or vectran these days even on the cruisers. Covers chafed are not uncommon and if you have a polyster over polyester halyard and it happens you'll get an damn near instant 50% lose of strength. With a Spectra you won't, the cover is only UV protection and to help ease of handling.

You would be seriously advised to check existing sheeves and so on for wear and sharp bits first, no matter what you put back in, this includes using a rope to wire halyard.

Most sizes would want to be 12mm, maybe bigger on the mainsheet and headsail sheets just for handling purposes. 14 or 16mm max. too big and they don't run well sometimes.

Cacique - Not too sure about the claimed 40% stronger bit. A 12mm (example) polyester rope uses X amount of 'ends' no matter what the construction is so to get a 40% increase in strength the rope has to be either seriously packed (more ends in it) to the point of being wire like or 40% bigger. There are some small differances between constructions but 40% is well outside of that. I think you may find it's one of those ones where some manufacturers use the largest load seen in testing against those who use minimums. There is a standard way of testing ropes but some wildly differing ways of reporting those loads. Some even use a load numbers which includes a termination, a splice not a knot.

We have the same thing here. 2 top end manufacturers using exactly the same machinery and raw product. One will give a load of, say, 6000kg on a rope and the other will say 4500kg for their version. One uses maximum ever achieved and the other uses the minimum. Both ropes will generally break within a 100kg odd of each other.

A bit like the US Hi-Test chain verses the rest of the worlds Grade 40. Both will break at the same time but each is sold using a differing method of publishing load numbers, which makes the US look a big pile stronger.
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Old 28-11-2008, 20:37   #7
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If we went for spectra in lieu of Poly, then is it simply a matter finding a spectra breaking strain equlivent to the poly that we would have used or is size going to matter for the halyards. Sheets we will go for poly and something thicker.

If you measure a rope with vernier calipers to determine the size, how much pressure do you use and do you measure the rope with a little stretech or limp ? I played around with some of the new 8mm rope and it measures 9mm no matter what way we do it. The older ropes we measure all sorts of figures until we put a little pull on them, then we get around 12mm even though when loose they seem a lot larger (14-16mm).
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Old 28-11-2008, 20:55   #8
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10 mm spectra for halyards and topping lift (the topping lift can double as a halyard if you do this. ) !2 mm double braid for all else. and by golly gingo,s that spectras dear ! Sadly from my costings there is not a lot of difference in cost with a rope to ss wire halyard. The main diference is that you can reverse a spectra halyard putting the uv exposed part in the mast a few years down the track.
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Old 28-11-2008, 21:21   #9
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We like the reversal concept to rotate the UV damage.

Looks like a drum of 12mm poly and see if we can get a bargain on some 10mm spectra.
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Old 28-11-2008, 21:24   #10
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I'd go 10mm on a 37ft coastal cruiser/racer halyards but 12mm on a offshore cruiser. Just a longevity thing. 10 will be strong enough though. Get too small and the jambers will struggle to hold it.

Rope is measured at it's widest point while under 15% of it's break load. That's the easy way of explaining it.

But then, isn't there always, it is far from uncommon to get ropes measuring a bit more than what they say they are eg, the 8mm measuring 9 mentioned above is common.

Then again, things like Nylon will swell a bit once you start using it and it gets wet. So a 12mm may measure 13mm in the shop but after a year on the boat it may go to 14mm. The overall length of the rope will be shorter than what it started as also.

Then again, dyneema/spectra/vectrans and the like will often measure spot on. This is due to cost, at US$50 per kg of raw material any over sizing can get expensive real quick.

Basically a new rope will often measure larger, sometimes even a size larger, than what it is. By that I mean a 12mm laid nylon measuring 14mm in the shop is very very common. Just pull it as tight as you can and measure away, if you get 13mm it's probably a 12mm sort of thing. Beware of older well worn ropes which may actually measure a bit under.

A good dyneema is about twice and a smidgen more than the cost of a polyester. So for example say 2 x 20mts halyards would cost $160 in polyester and $400 in Dyneema. So the difference isn't really that large considering the extra goodness of a Dyneema. That's NZ dollars for NZ made by the way. Good SS wire will be roughly in the middle.

And Cooper has a good point, end for end your ropes occasionally. It can extend the useful life a lot.
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Old 28-11-2008, 22:38   #11
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Thanks, that takes a little of the mystery out of it. So it would appear that what I initially thought to be 14-16mm ropes would actually be 12mm. As, when stretched tight (by hand) they come in at about 13mm.
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Old 30-11-2008, 13:17   #12
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AhHa - discovered yesterday that genuine 14mm rope does not work in the self tailing part of our Barlow 25's in the cockpit, it was a really stiff rope, so a softer one might work, but the one we tried would not sink into the groove. So, the sheets will have to be a good 12mm rope.
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Old 30-11-2008, 14:07   #13
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Get hold of a Harken catalog - it has a great section on calculating sail loads, based on wind speed and sail area. It also has a table of typical strengths for various types of rope and wire rope.

If you can afford it, for your halyards, go with something less stretchy than basic double braid. Vectran (with a cover) is probably the best choice, but very expensive. Next best is Spectra (with a cover), also rather expensive. Sta-set or Sta-SetX is better than plain double braid and only marginally more expensive. The size should be determined by the sail loads (i.e. sail area). I'm guessing on you 35 footer, 8mm Vectran / Spectra, or 10mm double braid will be fine, but like I say, use the formulae in the Harken Catalog to check.

If you have a separate spinnaker halyard, consider going with double braid, because a little bit of stretch in the spinnaker halyard is useful in gusts to reduce the chance of exploding spinnaker syndrome!

If your halyards have previously been wire to rope, you will be well advised to consider changing the sheaves. Firstly, wire sheaves have a different profile to rope sheaves and are not good for your halyards. Secondly, wire tends to chew up the surface of the sheave (which is typically aluminium) and if the surface of the sheave is at all chewed up it will wear away the cover on your halyard... no point buying shiny new halyards if they are going to be destroyed by your sheaves in 12 months! In the end, the expense of changing your sheaves will be more than repaid by longer life in your halyards

For your sheets, you really only need 16mm for your storm jib & trisail (and, possibly your #4 or #5 (or whatever is your "heavy weather jib before your storm jib). For the size of headsail that you carry 10mm or 12mm double braid ought to be fine for headsail sheets... in fact 10mm will probably be fine in terms of strength, but 12mm will be more comfortable to handle. 10mm d/b should also be fine for your main sheet.

If you can afford it, it can be nice to have a set of lightweight sheets for light breezes; stopping the weight of the sheet from dragging down and collapsing the headsail or spinnaker set. 8mm or even 6mm are good for this.

On our 40' (ex-racing) boat we have the following:
Main halyard 11m Vectran
Headsail halyards 10mm Spectra
Spinnaker halyards 10mm Doublebraid
Main sheet 10mm double braid
Headsail sheets 12mm double braid
Lightweight sheets 8mm double braid
Storm sheets 16mm double braid

To summarise:
Halyards - Vectran/Spectra if you can afford, Sta-Set if you can't. Check your sheaves.
Sheets - Double braid is fine
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Old 30-11-2008, 19:36   #14
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Good stuff ! We are lapping up all that info. Good points about the lighter sheets for lighter conditions and also the heavy ones for the storm sheets, had not considered those ideas before.
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Old 30-11-2008, 22:58   #15
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One other low stretch but lower cost than Spectra is to get a parallel core polyester braid. Polyester inside and out but the core construction lowers the stretch.

Suss Glienstein's Cup T, it's one. (dodgy spelling warning)
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