25 replies to this topic

[tiz]

I'm splicing 1/4" amsteel to a tball ring terminal and the other end to a shackle on a block for a babystay.

Can someone recommend thimbles to use or let me know what to use to terminate this line properly? Can the bare line go on the hardware?

This is on a club cruiser - racer to just stabilize the mast when it's rough. Replacing the 1/4" wire one.

--Kevin

[MSA]

Seem to work fairly well...
http://www.colligoma...nd-Fittings.htm

[THOR]

give John a shout and he will help
he is a good guy

thanks thor

[Occams Razor]

if you like cheaper ones ( and the Colligo ones are really nice) you can use a sailmakers thimble, but it's not quite the gucci solution. The Colligo ones are great if you're replacing a turnbuckle as well and need adjustability.

[tiz]

Thanks all.

One of the colligo 5-7mm thimbles would work at the bottom for the shackled block. Not sure how I could use one at the top for the t-ball ring, which is a welded loop.

Ideas for that end?

--Kevin

[allen]

I always ask myself a question before deciding on making something: What will happen if it breaks? In your case sounds like not much. The next question is how much load is there on the line. You are using something that is rated at 7,400 pounds. Next thing to consider is the rating at the terminal, which is twice the rating of the line or about 15,000 pounds because there are two strands involved in the splice. To that you need to derate it for whatever radius you go around. I have tested Amsteel going around a soft shackle as the termination, which is to say around something that starts out 1.4x the diameter of the line. This is likely a worst case than going around a some steel hardware. In the case of this test there were eye splices on each end of the length of Amsteel, one stitched and one a brummel. The line broke in the middle, away from either end. That says to me the derating for this rather tight turning radius is less than the 50% that would make it as strong as the line. Bottom line is that I always just go around the bare hardware and would especially in the case where nothing breaks and nobody gets hurt if the line fails (question number one). You can see my testing on this page. You, however, need to evaluate your application and make your decision. Samson recommends a 3:1 diameter ratio which in your case would be a 3/4 inch.

[tiz]

I always ask myself a question before deciding on making something: What will happen if it breaks? In your case sounds like not much. The next question is how much load is there on the line. You are using something that is rated at 7,400 pounds. Next thing to consider is the rating at the terminal, which is twice the rating of the line or about 15,000 pounds because there are two strands involved in the splice. To that you need to derate it for whatever radius you go around. I have tested Amsteel going around a soft shackle as the termination, which is to say around something that starts out 1.4x the diameter of the line. This is likely a worst case than going around a some steel hardware. In the case of this test there were eye splices on each end of the length of Amsteel, one stitched and one a brummel. The line broke in the middle, away from either end. That says to me the derating for this rather tight turning radius is less than the 50% that would make it as strong as the line. Bottom line is that I always just go around the bare hardware and would especially in the case where nothing breaks and nobody gets hurt if the line fails (question number one). You can see my testing on this page. You, however, need to evaluate your application and make your decision. Samson recommends a 3:1 diameter ratio which in your case would be a 3/4 inch.

Thanks much. Interesting specs.

I expect this line will have a static load of 500-700lbs on it, if that. We're just stabilizing the middle of the mast and trying to bend it forward a touch. What that load becomes while bouncing in a seaway I don't know. But the mast won't come down (we've sailed for years without it) and nothing heavy will fall on passengers.

--Kevin

[Occams Razor]

Thanks all.

One of the colligo 5-7mm thimbles would work at the bottom for the shackled block. Not sure how I could use one at the top for the t-ball ring, which is a welded loop.

Ideas for that end?

--Kevin

Luggage tag directly to the loop

[xyzzy]

I've used Ronstan sailmakers thimbles. Here's a picture of one in action, http://forums.sailin...5

The thimble size and the amsteel size don't seem to be exactly comparable. It's better to fit the line in the thimbles and see what fits best. Make sure the block attaches to the thimble ok too. You can see in the above post I had to change out the shackle that came with the block with one that fit in the thimble better.

[Pokey uh da LBC]

Interesting you should ask. Just yesterday I put this question to Rod Favela at Vela Sailing. He put forth a really cool solution.

Rather than use a standard thimble shackled to a block, splice a Sparcraft low friction ring to your backstay and use it for your first cascade block. He says that as long as the cascade line is your typically slippery SK75 single braid, the additional friction will be manageable. These rings are very affordable and have crazy-high safe working loads.

I plan on using these rings for the first two cascades on the backstay for my 30 foot r/c boat. The third will be a double block.

Any other opinions on this system?

[Super Delegate]

Pokey,
Friction rings are a great solution for cascading backstays, I have been building these for over a year now with all positive results. They are great for vang purchase systems also.

Tiz,
I assume by t-ball ring you mean the type of fitting that is used mainly for running backstays. Splicing dyneema directly to the ring on the fitting is certainly ideal. You can use a thimble in this case, however if you are seeing any loads that are even close to breaking strength of 1/4" line (which I doubt with the babystay, you might be deforming the thimble before you are breaking the line, thus risking chafe eventually. You have two options, the first is directly to the ring, the second is to a thimble that is able to be pulled apart and put inside the ring, i.e. Seadog SS type. You can't use an antal ring or a sailmaker's thimble unless you want to add yet another piece of hardware to the equation like a shackle.

[P2 Marine]

Interesting you should ask. Just yesterday I put this question to Rod Favela at Vela Sailing. He put forth a really cool solution.

Rather than use a standard thimble shackled to a block, splice a Sparcraft low friction ring to your backstay and use it for your first cascade block. He says that as long as the cascade line is your typically slippery SK75 single braid, the additional friction will be manageable. These rings are very affordable and have crazy-high safe working loads.

I plan on using these rings for the first two cascades on the backstay for my 30 foot r/c boat. The third will be a double block.

Any other opinions on this system?

That's a really nice looking thimble! A bit pricey though...

For an application where you're just snugging up I'd use one of these. Friction's not a big deal, and the breaking load is insane-high!

[allen]

Interesting you should ask. Just yesterday I put this question to Rod Favela at Vela Sailing. He put forth a really cool solution.

Rather than use a standard thimble shackled to a block, splice a Sparcraft low friction ring to your backstay and use it for your first cascade block. He says that as long as the cascade line is your typically slippery SK75 single braid, the additional friction will be manageable. These rings are very affordable and have crazy-high safe working loads.

I plan on using these rings for the first two cascades on the backstay for my 30 foot r/c boat. The third will be a double block.

Any other opinions on this system?

I thought I replied already but can't find it. Strange. Anyway, I have done testing on using a low friction ring, or any ring for that matter, and can share the numbers. For rings with diameters from 1/4 inch to 1 inch for the part that involves the friction for each pound pulling on the line you get from 1.6 to 1.7 pounds on the backstay in this case. Ideal of course is 2 pounds. The 1 inch ring gave 1.7 where the 1/4 inch 1.6. A half inch diameter was between so larger was better. Perhaps there is a point where a very large turning radius adds more friction that it saves but the main point is that it doesn't seem to matter very much what the turning radius is. I was using 3/16 line. StaSet gave 1.4 pounds btw.

Allen

[Olsonist]

I use those low friction rings for the first turning block on my check stays which are 12 strand spectra something.

That was bad. Turns out that spectra gets rock hard under tension and 12 strand going over a friction ring is like chewing gravel the entire beat. Every pant and puff is a gnashy grind right next to your ear.

So we put a Dyneema chafe cover on and the problem went away; but a covered line to begin with would have been better.

[MSA]

Funny.. I put low friction rings for the first 2 cascades of a 24:1 backstay that has a large range of movement on a very stiff rig. It is easier to use than the old Harken gigantic turning blocks it had!

Using 7mm Dux for Cascade 1 and 5mm Dux for cascade 2 with 20x14 Antal LFR's..

[allen]

Amsteel gets rock hard when it gets near its rated load. If the load is low, it will stay flexible. 7mm dux is rated at 15,000 pounds so it is unlikely to get stiff on a backstay where smaller line might.

[Olsonist]

This was for checkstays. They load and unload with the mast pumping in chop. I don't think it was near rated load (tensile 5400) or the mast would break. But I'll figure out some way to check the load.

Dux starts out rock hard. It is stronger than comparable Amsteel but not a lot: 9mm Dux is 26,527 and 9.5mm Amsteel is 19,600. It also costs more: $6.70 vs $3.73. I have a 7mm Dux genoa halyard and that seems a good investment.

I think uncovered Dux for these checks would also grind. A backstay cascade seems different. But I have Dyneema chafe covers on my Dux genoa halyard where it sits in the masthead and mast base sheaves.

[allen]

This was for checkstays. They load and unload with the mast pumping in chop. I don't think it was near rated load (tensile 5400) or the mast would break. But I'll figure out some way to check the load.

Dux starts out rock hard. It is stronger than comparable Amsteel but not a lot: 9mm Dux is 26,527 and 9.5mm Amsteel is 19,600. It also costs more: $6.70 vs $3.73. I have a 7mm Dux genoa halyard and that seems a good investment.

I think uncovered Dux for these checks would also grind. A backstay cascade seems different. But I have Dyneema chafe covers on my Dux genoa halyard where it sits in the masthead and mast base sheaves.

I think if you take Dux and work it a bit with your hands, not under load, it will get soft. Amsteel, if you pull on it really hard, will get stiff and a one foot section will stay horizontal if you hold it out.

I break Amsteel in testing my soft shackles and it is amazing how different it is after it has been stressed. This stuff is very strong. Using a 30 power winch, I cannot break 1/8 inch Amsteel. When I did my testing on 1/8 Amsteel, I had a 3:1 in front of the 30:1 winch for close to 100:1. Twice I broke the StaSet in the 3:1 before going to 1/2 inch there. I check the load by measuring how much stretch I get in 7/16 StaSet and then calibrating that with a weight on the winch handle. Ultimately Brion Toss arranged testing at New England Rope and the results were similar.

You could do something similar to test your load. Put a section of StaSet or XLS in line that will give 10% stretch or so and then calibrate that by hanging a weight on a winch handle through a block. You can probably get more than 1,000 pounds that way. In my test, I stretched a 1 foot section of 7/16 XLS by 1 inch. That was in testing 7/64 Amsteel just to give you an idea of how strong this stuff is. Made me wonder how they specify stretch but that is another story.

[jfranta]

Thanks all.

One of the colligo 5-7mm thimbles would work at the bottom for the shackled block. Not sure how I could use one at the top for the t-ball ring, which is a welded loop.

Ideas for that end?

--Kevin

Hi Kevin, this is one solution we have for T fittings to brackets. This allows you to use a line terminator for the splice which has the required bending radius for long life of you line. If you want to get the most value for your line than you need a 6/1 bending radii. There are other solutions here: http://www.colligoma...ms/Brackets.htm

John Franta, Colligo Marine.

Attached Files

•  T fitting adapter with tangs.JPG   673.05K   2 downloads

[jfranta]

Interesting you should ask. Just yesterday I put this question to Rod Favela at Vela Sailing. He put forth a really cool solution.

Rather than use a standard thimble shackled to a block, splice a Sparcraft low friction ring to your backstay and use it for your first cascade block. He says that as long as the cascade line is your typically slippery SK75 single braid, the additional friction will be manageable. These rings are very affordable and have crazy-high safe working loads.

I plan on using these rings for the first two cascades on the backstay for my 30 foot r/c boat. The third will be a double block.

Any other opinions on this system?

Try these, Put the running line thru the slot which give a larger radii, less friction, and makes the line last longer due to the larger bending radii. Oh and preserves a higher line strength.
http://www.colligomarine.com/Colligo-Synthetic-Systems/Blocks.htm

John Franta, Colligo Marine

[jfranta]

I would not splice runners or standing rigging directly to a round thimble because you then have no control over the geometry of the splice. (of course you can, lots of people do, but are they getting the most efficient use of their expensive line?) A splice at too obtuse of an angle is going to really bring down the break strength of the line, and therefore limit the life of it. If you use the correct geometry on a round thimble then you run the risk of the thimble coming off. The geometry on our line terminators is fixed and we have thoroughly tested the splice with that geometry so we know what you are going to get for life of the line.

Look at using something like this: http://www.colligoma...ack-CSS71-O.htm

Or for a very lightweight solution this:http://www.colligomarine.com/Colligo-Synthetic-Systems/Line-Terminator-End-Fittings/Lightweight-Aluminum-Thimble-CSS71-OLT.htm

John Franta, Colligo Marine.

[allen]

I would not splice runners or standing rigging directly to a round thimble because you then have no control over the geometry of the splice. (of course you can, lots of people do, but are they getting the most efficient use of their expensive line?) A splice at too obtuse of an angle is going to really bring down the break strength of the line, and therefore limit the life of it. If you use the correct geometry on a round thimble then you run the risk of the thimble coming off. The geometry on our line terminators is fixed and we have thoroughly tested the splice with that geometry so we know what you are going to get for life of the line.

Look at using something like this: http://www.colligoma...ack-CSS71-O.htm

Or for a very lightweight solution this:http://www.colligomarine.com/Colligo-Synthetic-Systems/Line-Terminator-End-Fittings/Lightweight-Aluminum-Thimble-CSS71-OLT.htm

John Franta, Colligo Marine.

John,

With all due respect, you make wonderful products and great terminations, but in these stretch limited applications there is just so much excess strength in the eye of a splice where you have 2x line strength to start with does it really make a difference? I tested a section of line with two eye splices where the eyes were terminated with soft shackles of the same line diameter so the radius was at best 1.4x the line under test. The line broke in the middle, away from either splice. Here we have a case where the guy is using 7,500 pound line and loading it with 700 pounds. Does it really matter how he terminates it?

That said, I would agree that splicing small diameter line onto a round thimble might generate high loads due to the sharp exit angle at the base of the ring and is not a good idea. But even with that it is hard to think that someone could splice it with more than a 2:1 stress multiplier.



Allen
http://l-36.com/

[jfranta]

I would not splice runners or standing rigging directly to a round thimble because you then have no control over the geometry of the splice. (of course you can, lots of people do, but are they getting the most efficient use of their expensive line?) A splice at too obtuse of an angle is going to really bring down the break strength of the line, and therefore limit the life of it. If you use the correct geometry on a round thimble then you run the risk of the thimble coming off. The geometry on our line terminators is fixed and we have thoroughly tested the splice with that geometry so we know what you are going to get for life of the line.

Look at using something like this: http://www.colligoma...ack-CSS71-O.htm

Or for a very lightweight solution this:http://www.colligomarine.com/Colligo-Synthetic-Systems/Line-Terminator-End-Fittings/Lightweight-Aluminum-Thimble-CSS71-OLT.htm

John Franta, Colligo Marine.

John,

With all due respect, you make wonderful products and great terminations, but in these stretch limited applications there is just so much excess strength in the eye of a splice where you have 2x line strength to start with does it really make a difference? I tested a section of line with two eye splices where the eyes were terminated with soft shackles of the same line diameter so the radius was at best 1.4x the line under test. The line broke in the middle, away from either splice. Here we have a case where the guy is using 7,500 pound line and loading it with 700 pounds. Does it really matter how he terminates it?

That said, I would agree that splicing small diameter line onto a round thimble might generate high loads due to the sharp exit angle at the base of the ring and is not a good idea. But even with that it is hard to think that someone could splice it with more than a 2:1 stress multiplier.



Allen
http://l-36.com/

Hi Allen, We have a good statistical sample of pull testing of dyneema and, with a proper splice, the line always breaks at the bend around the line terminator or thimble. This is consistent with Hampidjan's data and DSM's data. Brion Toss was in on some of our initial testing also. Not sure what you are doing but do you have a statistical sample?

In addition, you are testing new material. Any idea what happen's over time with Dyneema in use on a boat? Have you tested used or older material? We have and continue to do so. UV damage causes a decrease in strength, with all variables the same it will break in the same place, at the bend, at a lower load. Smaller bend radii means failure at a lower load. Again, this is consistent with other statistical data sources. We have made it our business to understand dyneema and get the most use (value) out of it. Our sizing methods and hardware make it very economical to use when compared to steel or other synthetic options. You can use it, or abuse it, however you want, just remember to change it often. How often? If you use our hardware and sizing methods we can tell you when to change it out. If you use any other method you will probably not know when to change it, and probably change it more often than you need to.

I was at the start of the last Route Du Rhum in France and cringed at how those racers abused the crap out of Dyneema. But, they only want to get thru the race and don't care about longevity. Change it all out after the next race. There are race boats out there now that run Dyneema sheets thru Dyneema loupes instead of blocks, works OK and saves weight, for a very limited time. Good for them but for the average guy that wants to get his money's worth it would be smart to make the line last as long as possible.

In the future it would be good to qualify your data with sample size. If your data is inconsistent with several sources I would make sure you have your I's dotted and your T's crossed before you publish it. The breakage you describe at 1.4 times the diameter does not make sense with industry data.

After looking at your website you have used our method for soft shackles and have tested them. Stating that 180% break strength for the soft shackles is optimistic. I don't know where you get 180% from but we have pull tested a statistically significant sample of our soft shackles and we stand by all of our ratings. Do you have any significant data to support your statement that these ratings are "Optimistic"? Statistical data? Keep in mind we have sold over 3,000 of our soft shackles with no failures. One question on the soft shackles: Are you using the same line,brand size, etc. as we are? Strand size and braid angle vary greatly with manufacturer. How are they actually pull tested, bending radii, etc. Are you sure you can compare your testing to ours? Honestly, if you are going to post this data on your website, and critique/compare others you should be very clear with your testing conditions. More importantly, sample size gets rid of alot of questions. I personally would make sure I am testing the same way as others if I am going to critique others posted break strength or SWL's. As you can tell, we take our SWL numbers very seriously.

John Franta, Colligo Marine

[Pokey uh da LBC]

I would not splice runners or standing rigging directly to a round thimble because you then have no control over the geometry of the splice. (of course you can, lots of people do, but are they getting the most efficient use of their expensive line?) A splice at too obtuse of an angle is going to really bring down the break strength of the line, and therefore limit the life of it. If you use the correct geometry on a round thimble then you run the risk of the thimble coming off. The geometry on our line terminators is fixed and we have thoroughly tested the splice with that geometry so we know what you are going to get for life of the line.

Look at using something like this: http://www.colligoma...ack-CSS71-O.htm

Or for a very lightweight solution this:http://www.colligomarine.com/Colligo-Synthetic-Systems/Line-Terminator-End-Fittings/Lightweight-Aluminum-Thimble-CSS71-OLT.htm

John Franta, Colligo Marine.

John,

What you're saying makes sense. Will the friction for the cascade line be similar to that of the sparcraft rings?

[allen]

I would not splice runners or standing rigging directly to a round thimble because you then have no control over the geometry of the splice. (of course you can, lots of people do, but are they getting the most efficient use of their expensive line?) A splice at too obtuse of an angle is going to really bring down the break strength of the line, and therefore limit the life of it. If you use the correct geometry on a round thimble then you run the risk of the thimble coming off. The geometry on our line terminators is fixed and we have thoroughly tested the splice with that geometry so we know what you are going to get for life of the line.

Look at using something like this: http://www.colligoma...ack-CSS71-O.htm

Or for a very lightweight solution this:http://www.colligomarine.com/Colligo-Synthetic-Systems/Line-Terminator-End-Fittings/Lightweight-Aluminum-Thimble-CSS71-OLT.htm

John Franta, Colligo Marine.

John,

With all due respect, you make wonderful products and great terminations, but in these stretch limited applications there is just so much excess strength in the eye of a splice where you have 2x line strength to start with does it really make a difference? I tested a section of line with two eye splices where the eyes were terminated with soft shackles of the same line diameter so the radius was at best 1.4x the line under test. The line broke in the middle, away from either splice. Here we have a case where the guy is using 7,500 pound line and loading it with 700 pounds. Does it really matter how he terminates it?

That said, I would agree that splicing small diameter line onto a round thimble might generate high loads due to the sharp exit angle at the base of the ring and is not a good idea. But even with that it is hard to think that someone could splice it with more than a 2:1 stress multiplier.



Allen
http://l-36.com/

Hi Allen, We have a good statistical sample of pull testing of dyneema and, with a proper splice, the line always breaks at the bend around the line terminator or thimble. This is consistent with Hampidjan's data and DSM's data. Brion Toss was in on some of our initial testing also. Not sure what you are doing but do you have a statistical sample?

In addition, you are testing new material. Any idea what happen's over time with Dyneema in use on a boat? Have you tested used or older material? We have and continue to do so. UV damage causes a decrease in strength, with all variables the same it will break in the same place, at the bend, at a lower load. Smaller bend radii means failure at a lower load. Again, this is consistent with other statistical data sources. We have made it our business to understand dyneema and get the most use (value) out of it. Our sizing methods and hardware make it very economical to use when compared to steel or other synthetic options. You can use it, or abuse it, however you want, just remember to change it often. How often? If you use our hardware and sizing methods we can tell you when to change it out. If you use any other method you will probably not know when to change it, and probably change it more often than you need to.

I was at the start of the last Route Du Rhum in France and cringed at how those racers abused the crap out of Dyneema. But, they only want to get thru the race and don't care about longevity. Change it all out after the next race. There are race boats out there now that run Dyneema sheets thru Dyneema loupes instead of blocks, works OK and saves weight, for a very limited time. Good for them but for the average guy that wants to get his money's worth it would be smart to make the line last as long as possible.

In the future it would be good to qualify your data with sample size. If your data is inconsistent with several sources I would make sure you have your I's dotted and your T's crossed before you publish it. The breakage you describe at 1.4 times the diameter does not make sense with industry data.

After looking at your website you have used our method for soft shackles and have tested them. Stating that 180% break strength for the soft shackles is optimistic. I don't know where you get 180% from but we have pull tested a statistically significant sample of our soft shackles and we stand by all of our ratings. Do you have any significant data to support your statement that these ratings are "Optimistic"? Statistical data? Keep in mind we have sold over 3,000 of our soft shackles with no failures. One question on the soft shackles: Are you using the same line,brand size, etc. as we are? Strand size and braid angle vary greatly with manufacturer. How are they actually pull tested, bending radii, etc. Are you sure you can compare your testing to ours? Honestly, if you are going to post this data on your website, and critique/compare others you should be very clear with your testing conditions. More importantly, sample size gets rid of alot of questions. I personally would make sure I am testing the same way as others if I am going to critique others posted break strength or SWL's. As you can tell, we take our SWL numbers very seriously.

John Franta, Colligo Marine

Lots here. It looks to me that you have misunderstood what I said on my site. I am not comparing numbers from your site or critiquing your ratings which I actually don't know. You publish safe working loads but you do not publish the line they are made from that I can see so I could not possibly be critiquing your numbers, which I am no reason at all to question. I would love to know what your numbers are and to compare them to my test if can point me to the data.

The 180% number is not from your site, it was from other testing that people published mostly non marine winch lines (ATV, Jeeps, tractors, etc). My testing said that the soft shackle is stronger than the line it is made of but not twice as strong. That was all I could tell from my personal testing.

As I said on my site, Brion Toss sent me a some line and I made some of my soft shackels. They are different than yours but likely the same strength as they broke at the knot which is a common design point. The numbers I give (1.04, 1.09, and 1,10 times line strength) are from that testing which was done at New England Rope on their test beds on my improved soft shackles. It is consistent with my testing but way below what you might see from other testing -- again not your site.

Here is the writeup of the testing done with Brion Toss
http://l-36.com/soft...e_testing_3.php

Sorry for the confusion. I have nothing but respect for the great work you are doing. I was just asking if using 7,500 pounds line for a 700 pound not critical load warrants anything more than the Luggage tag directly to the loop that Mitch recommended. I would not use anything short of your terminations if I was holding up my mast but this is just a stabilizer line.

Allen
http://l-36.com/

['No.6]

Thanks all.

One of the colligo 5-7mm thimbles would work at the bottom for the shackled block. Not sure how I could use one at the top for the t-ball ring, which is a welded loop.

Ideas for that end?

--Kevin

Luggage tag directly to the loop

This.