Hey

I am going to replace my trapeze lines. I am thinking of using spectra line (I realise this is not class legal).

Has anybody tried this, if so what diameter line have you used and how did you terminate them. I think you would have to splice them as I have read that knots can decrease the strength of the line by as much as 50%. Have you had a problem with the line chaffing at the mast tang end (could use thimble?). If the line required is thicker than 3mm is there an issue with the trapeze handle?

In the event that it is too much hassle, buying line, buying FID. What length wire lines do you use? As the length specified seems too long. My current lines are approx 5.1 metres long, and it is nigh impossible to get back on the tramp.

All input appreciated.



Ken
Hobie 16 of unknown age (at least 15)

Ping Wouter. He uses line and had a good rundown on using it for trap lines recently.

I'm going to make a document of this topic for my class website soon, but I'll give you the run down.

I don't trust spectra, the guys I know who tried spectra broke their traplines. Everybody tell me this stuff is the same as Dyneema, but everybody that I know that hangs of dyneema has never broken a trapline in many years. Hence I trust dyneema and not spectra. I feel that dyneema appears to be alot more shock resistant. Or the friends who broke (all in anglo saxon countries) only have excess to inferiour grade lines. I know you have two choices in 3 mm dyneema. One is cheap 300 kg line and the other is slightly more expensive 500 kg line. You'll want the latter, The first WILL break and sometimes rather easily (as in by hand !) I think the cheap stuff is just, well, rubbish. No way I can pull 300 kg apart.

I have 3 mm dyneema 500 kg break strength. Others and I have dung of that for years and we leave our boats on the beach for 6 months. In full sunlight and weather. This setup is well proven. Several of use just use bowlines to tie them on to the mast shackle and it holds. I used a single line per side (two trapeze lines) that I wrapped around a plastic thimble and stitched into place. I did this to be sure that the other stays at the shackle don't wear down the trap lines at the top where I can't inspect them often.

I found that figure 8 knots don't seem to degrade the lines much so I used on up near the thimble (and stitched the loop in tight overthere. Then I made a figure 8 knot right below I wanted the plastic (RWO) handle to be. This handle rests on this figure 8 knot. Slide the handle on first of course. Then I have a loop on the bottom end (bowline or figure 8 knot loop) and I use this one to sailors hitch a shackle on or whatever. This last bit take the adjuster setup or the trapline to the dogbone or whatever.

That is it. Weight savings are at least 400 gram per couple of 4 traplines = 1 pound. (comparison 3 mm dyneema and 2 mm steel). But the best advantage is the dyneema lines don't wear down your mainsail (pockets) at all and they always hang taught even with very little bungee tension. This allows thinner bungees and other fine-tuning of the systems on board. Overall with the right modifications the new system will just work alot better and nicer.

In my class were we don't rule on details like traplines, I'm seeing D12 line being used as well and I think they are using 2 mm or 2.5 mm. This line is often of a smaller diameter under tension then the specifications; so in addition to weight they are also thinner then steel but with 500 kg break strength.

The dyneema and D12 lines will creep a little at first but after being tensioned a ffew times they are without stretch at all.


Good luck

Wouter

Spectra and Dyneema are the same stuff. "Spectra" was/is the name used in the US although "Dyneema" has come into use in the US now. Suspect the problem with the "Spectra" trap lines was the use of the the lower strength material as Wouter noted.

Believe the A Class and, possibly, F18HT and/or Tornado classes use line rather than wire for trapezes. A post in the General Forum may generate additional responses.

Dyneema and Spectra

According to Wikipedia, “Dyneema® is a registered trademark of Royal DSM NV (The Netherlands)” and “Spectra is the brand name of the chemically identical product developed independently by Allied Signal (now Honeywell) in the USA. Though the production details will undoubtedly be different, the result is comparable to Dyneema.”


In the end I rang a rigging crowd in Sydney, who advised that the product below is what they use for trap lines on the Sydney Harbour 18' skiffs. Having seen these boats I decided what was good enough for them was good enough for me.

Splicing this stuff is a cinch, and @ AU$2.73 a metre seemed like a good deal.

Check out the breaking strain below.


DYNEX 75 3MM HRL-130


* Price per Metre
Dynex ropes are impregnated with Duracoat to improve abrasion resistance and endurance. It has neutral buoyancy (ie. it floats) and low diameter to strength ratio. Dynex is made form Dyneema SK75 fibres with a polyurethane coating. These ropes combine good strength retention with good flexibility and dynamic properties. Termination is easy through splicing where up to 90% of linear strength is retained. Dynex ropes exceed the strength of steel wire ropes of the same diameter while floating on water. They have low elongation and are extremely flexible, yielding easy handling in all respects.

Breaking Load 3mm 1500kgs


Thanks for the responses



Ken

The material you refered to last is what I often refer to as D12 line. I think D12 is a brand or product name however.

Personally I don't think the breaking strength is that important, but rather its shock resistance and degradation resistance. The dyneema line we have overhere has a rugged outer mantle that seems to keep the line in good condition. I think this mantle is plain polyester. However these line have a good amount of core fibres which is dyneema/spectra. I think the lines was made by Marlow.

Wouter

Hi Ken

Having used the Dynex you refer to over the last season I can thorougly recommend it. Have it on my Mossie now & it works a treat. I sleeved the top 400mm with 4mm tubing just in case there were any abrasion issues from mast rotation/sidestays.

Cheers

Andrew

Just for reference, we have been using Dyneema D12 for the Jib halyards on the Hobie 16 for a few years. We also use other Marlow braids for sheets. Currently we use the Excel Marstron 8mm for the main sheet and 6mm for jib sheet.

These are Marlow lines. The "D12" is related to the braid or 12 strand Dyneema.

Here is a quote from the Marlow catalog:

Excel D12 is constructed from high modulus Polyethylene (SK75 Dyneema®) 12 strand single braid and is urethane coated for maximum performance. Its tolerance to abrasion is excellent and it is resistant to degradation from ultra violet. This line will also float and has zero water uptake.

Here is the catalog page I refered to:
http://www.ronstan.com/catalogue/Aus%20Supp%20p012-013.pdf