Synthetic Standing Rigging

[HEINZIR]

I wonder if anyone has replaced any part of the standing rigging on a small (26' or under) trailerable boat with high tech HMDPE line?

Amsteel Blue, for example, is advertised as being just as strong or stronger than stainless wire of equal diameter at 1/7 the weight. 5/32 Amsteel Blue has a tensile strength of 4000 lb compared to 3300 lb for 5/32 stainless wire. 3/16 Amsteel has a tensile strength of 5400 lb and sells for only $.48/ft. It is very easy to splice, and a couple of thimbles are much cheaper than mechanical fittings for wire rope. On the surface, at least, high tech line seems to be a cost effective alternative to wire, especially for runners and backstays. I don't think I would use it as a forestay with a hanked on jib, though.

I'm not saying that Amsteel or other Dyneema lines are necessarily the best choice; Spectra may be better, or PBO, although that seems outrageously expensive for a small boat. What I am asking about is the idea of using high tech fiber instead of wire itself. I know that it has been done on larger boats. One real advantage on a trailerable boat that I have not seen mentioned is the ease of handling when the mast is down. Line would be much easier to handle and secure to the mast for trailering than steel cable that has a mind of its own. No worries about scratching the gel coat with errant stays or kinking the wire trying to get it bundled up.



Comments?

 

[woodster]

hummmmmm......... seems to me before there was ss that may have been what they use on the old wooden masters .....i think it was called Hemp.....oh wait a min that would work now days they would steal it and smoke it

 

[HEINZIR]

hummmmmm......... seems to me before there was ss that may have been what they use on the old wooden masters .....i think it was called Hemp.....oh wait a min that would work now days they would steal it and smoke it

I tried looking up the strength characteristics of hemp rope just for fun. The closest I could come was Manila. You would have to go to 5/8" diameter to get a 3900 lb breaking strength. And the rope is subject to shrink or stretch 10-15%! Dyneema and Spectra, in theory at least, could be a size for size replacement for wire with similar stretch characteristics.

 

[tommays]

By the time you BUY or MAKE all the correct upper and lower termaination fittings its not so cheep

buying a singel compleat 7mm kit is 399 dollars

 

[HEINZIR]

By the time you BUY or MAKE all the correct upper and lower termaination fittings its not so cheep

buying a singel compleat 7mm kit is 399 dollars

Thanks for the reply. Where did you find a kit for $399? is that for wire or for rope?

I guess I was looking more at the convenience than the cost, although I think the cost could be significantly cheaper than wire (for me.) Your J24 has a much more sophisticated rig than my little cruiser.

My mast uses tangs rather than t-ball fittings, and the turnbuckles have double toggles. All I need is an eye at each end of each stay, which, with single braid high tech line, is easily spliced around a thimble. That means 4 shrouds plus 1 backstay X 2 = 10 thimbles @ about $3 ea = $30. Add to that 150' of 3/16" Amsteel Blue (which is overkill for my boat) @ $.48/ft = $72 or about $100 for a complete re-rig that is much stronger than the 5/32" rigging I have now! I couldn't even buy 3 Norseman fittings for that price!

I'm not actually planning on replacing my shrouds with synthetic rope (yet); I just put it out there for discussion to see what the drawbacks vs benefits are. I might go ahead and replace my backstay, though. It is largely superfluous on my boat anyway because of the swept back spreaders.

 

[sailingdog]

The kit he's talking about is probably a Dynex Dux rigging kit from Colligo Marine. You could probably rig the boat with a spectra or dyneema cored line for far less. I'd go with a double-braid, rather than a 12-strand, as the outer jacket is often mainly there for UV and abrasion protection, with most of the strength in the core.

IIRC, Dynex Dux is a heat-treated, UV stabilized form of Dyneema.

 

[tommays]

You need to BUY or Make some type of end fitting that allows the lines to be lashed and how the holes are made and the angles there at is a pretty big part of the stuff lasting

 

[Barnacle Bill]

There are some racing boats, like the Melges 32 who use cordage for the standing rigging. Samson is the source (can't buy directly). They have special ends that the line feeds into for proper attachment to mast and deck fittings. Very expensive in comparison to good old 1x19 SS wire rope. Amsteel, or similar cordage is not used for standing rigging, but it is used for running rigging, such as adjustable backstay adjusters (usually seen on racing boats rather than cruising boats). Very strong, but I have seen the line break at points where they are spliced, so must be examined regularly. Some racing boat masts have adjustable backstays in line with the backstay that supports the mast too and so, if the Amsteel breaks, the mast could fail (I know of a Tripp design which lost their mast twice because of this). So, you have to make sure you are doing a proper splice and don't let the line get too sun degraded (some splices are better and more fail proof than others).

 

[Ross]

A link to deadeyes for synthetic rigging. http://www.precourt.ca/

 

[HEINZIR]

You need to BUY or Make some type of end fitting that allows the lines to be lashed and how the holes are made and the angles there at is a pretty big part of the stuff lasting

Why? Why couldn't I use my existing turnbuckles instead of dead eyes and lanyards? A simple thimbled eye in the end of the shroud should work fine in the fork/toggle at the top of the turnbuckle. It would work fine at the tangs on the mast as well.

There is a note on the Colligo Marine website stating that they can now splice their rigging to exact lengths so that original turnbuckles can be used.


I'm not trying to be argumentative; I'm just trying to understand. (Trying to think outside the box!)

 

[tommays]

They seem to have specs on minium bend radius and most thimbles are to small to meet the spec which would stress the material

 

[HEINZIR]

There are some racing boats, like the Melges 32 who use cordage for the standing rigging. Samson is the source (can't buy directly). They have special ends that the line feeds into for proper attachment to mast and deck fittings. Very expensive in comparison to good old 1x19 SS wire rope. Amsteel, or similar cordage is not used for standing rigging, but it is used for running rigging, such as adjustable backstay adjusters (usually seen on racing boats rather than cruising boats). Very strong, but I have seen the line break at points where they are spliced, so must be examined regularly. Some racing boat masts have adjustable backstays in line with the backstay that supports the mast too and so, if the Amsteel breaks, the mast could fail (I know of a Tripp design which lost their mast twice because of this). So, you have to make sure you are doing a proper splice and don't let the line get too sun degraded (some splices are better and more fail proof than others).

Thanks for the input, Bill. You obviously have far more real world experience than I do. Remember, though that I am not talking about a racing boat, just a little old trailerable cruiser with just a fraction of the loads of a larger racing boat.

We used to trailer Chiquita up to Bayfield many times when my girls were young. It's getting to be too much trouble now; Chiquita stays in our home puddle. We'd love to charter out of Bayfield or Madeline but the prices seem higher than in the Caribbean even for smaller size boats.

 

[HEINZIR]

They seem to have specs on minium bend radius and most thimbles are to small to meet the spec which would stress the material

Good point. I'll have to look into that. The bend radius of the smaller size lines that I'm talking about (1/8", 5/32", 3/16" max) can't be THAT big. I suppose it would depend on the make/brand/construction of the line.

I think that HMDPE lines are evolving rapidly. I see from the Samson site that they are being used to replace wire rope on tug boats for vessel assist and for tows. The various rope companies are also coming out with new coatings for UV and chafe protection as well. Synthetic lines may not be the be-all end-all replacement for standard rigging now but I wouldn't be surprised if, in the near future, stainless wire is considered to be as obsolete as hemp.

 

[tommays]

Well

We use T900 halyards more becasue there really light and dont get fishhooks they still require good bit of wind-up on the winch to reach the correct Tension which is why i think most installs use the lashing as it allows a lot of travel to get a rig set up correctly

 

[HEINZIR]

T900 is a blended core with a cover; I was thinking more of a 12 strand single braid. The advertised stretch approaches that of wire.

Both T900 and Endura have a minimum turn radius of 8:1 but that is for rolling over a sheave, not terminating in an eye. Even so, 3/16" line would have a minimum turn radius of 1-1/2". A thimble that size would not be too big for my turnbuckles.

 

[RichBone]

What about losing the "cone of protection" from lightening that you would get from wire rigging- just for the sake of discussion.

Rich

 

[HEINZIR]

What about losing the "cone of protection" from lightening that you would get from wire rigging- just for the sake of discussion.

Rich

Now you're really trying to get my knickers in a twist!

Just shows how true the quote in your signature line is.

 

[sailingdog]

If your mast is grounded, the cone of protection exists without the need for metal rigging...

What about losing the "cone of protection" from lightening that you would get from wire rigging- just for the sake of discussion.

Rich

 

[Barnacle Bill]

I was merely telling you what boats are using cordage for standing rigging. The bottom line is, not very many and one reason is price. The reason racers use it is to minimize weight aloft too. My advice is stick to SS 1 x 19 cable used on most boats.

 

[Barnacle Bill]

In response to your chartering comment. The Caribbean is much nicer in the winter than Bayfield. Boat prices might be better down there (I wonder, however), but remember you have to get there and that costs money too. But, all in all, I don't think the two locations are in competition with each other because of their locations and seasons.