Clutch Testing, engagement and load slip for 10mm line

Sails and cordage keep evolving with every new fiber, construction and treatment.  With each generation sailors get a stronger lower stretch product that performs better than the last version.  For riggers, we’ve got ultra low stretch rope cores, and incredibly touch and sticky covers that can handle the increased loads. This is key to handling new sails that have high carbon contents and other low stretch adaptations.  With low stretch sails, the dynamic loads of sailing get transferred into the lines. If your core is stretching, the lowest stretch sail in the world won’t hold it’s shape. If your core is low stretch but your covers can’t handle the increased load, the results are either cover failure or slip.  We’ve got some great solutions for problems like that, but one of the hardest areas to get good performance out of is the rope holding clutch.  To see what the best solution would be for the typical Chicago Yacht Rigging customer, I set up a simple test on the rigging bench and tried out a variety of common clutches.  To paraphrase the great Mr. Fry: I’m shocked, well, not that shocked.

The baseline for most of the testing I do is aimed at my most common type of customer’s boat; racing boat, 35-40′ long.  I wanted to use rope that represented what I’m likely to see when I visit a boat that needs clutch help, so selected 10mm V100, a fairly common vectran cored, polyester covered double braid.  After that test was done, I also tried an upgraded cover with 10mm New England Poly Tec.  The Poly Tec cover is often specified where the line sees either high abrasion or needs to be high grip, so it made a lot of sense to try here in a clutch.

The testing method was a bit tricky to decide on. In a perfect world, I’d have a large static load like a weight providing constant pressure on the rope. This would best represent tensioning a halyard, with a loaded sail on the other end.  Our test equipment instead has a winch on one end of the bench and a hydraulic cylinder on the other,  with the clutch in between.  To do our test I anchored one end of a line to the cylinder, ran it through the clutch, and then tensioned the other end on the winch.  Each line was knotted in place, so that I could move the knot and therefore move the point on the rope where each clutch was used.

What I wanted to get out of the test was how much slip there would be  when the winch side load was released (initial slip) and how much slip  it would take to then reach the target load. In any clutch there is always going to be a certain amount of slip as the cam, teeth, jaws or rope sleeve engages, but less is definitely better than more here! The process was easy: first stretch the rope and engage and disengage the clutch several times to remove the stretch and set the knots. Then load the line to 1000lbs. Following that I’d release the line from the winch to see how much of the load was lost, and how much the line would slip while that happened. Then I would tension the cylinder to simulate the load continuing to be present on a halyard.  The test would be repeated for a several cycles, and then I’d take the average number for three different values:  how much load remained when the winch was eased, how much the line moved as the winch was eased, and then how much slip through the clutch it would take to get the load back to 1000lbs.  It’s a hard test on clutches as the load behind the clutch would not be constant, as I only had about 4′ of rope between the clutch and the cylinder. This meant the load would drop considertably with the smallest amount of slip, leading to big drops in tension.  The measurement of slip to get the tension back to 1000lbs was going to be the more important number here, as it would measure the transition from near zero load to 1000lbs, so we could see how much rope had to pass through the clutch to engage to our target.

The other part of the clutch was full load releasing, to see how much the line was worn. If you’ve ever read your clutch instructions, you’ve probably noted that every line is supposed to be winch tensioned before the clutch is released.  This is ideal, however it has very little in common with how crews actually treat the clutch during racing.  In our projected 35-40′ boat racing around the buoys, you can imagine that the genoa halyard clutch would get dumped at least twice in your typical buoy race, after the spinnaker set. Lastly the top two, middle two and bottom two clutches were tested head-to-head for a video that provided a visual example of how they compared.

For products to test, I wanted to be as comprehensive as I could so had every brand and type of clutch I’d sold that would be appropriate for our imaginary mid size racer cruiser with 1000lbs on the halyard.  I started with the venerable Spinlock XTS/XCS.  This is by far the most common clutch we encounter as it’s been standard equipment for years from the J Boats, Beneteau and other factories.  All of the XTS and XCS clutches function the same: a stationary base plate, opposed by a rotating cam above. As the rope slides through the clutch, the cam rotates down to the baseplate, and the gap between the base and cam get’s smaller and tighter until the rope stops moving.  However, all XTS/XCS are not created equal. The model numbers always end with one of two numbers: 0610, or 0814.  The 0610 indicates that the clutch is sized for 6-10mm line, and the 0814 is for 8-14mm line.

Web XTS_1

 

What this means in practice is that best rope holding for the smaller cam is going to be with 10mm line, and for the larger cam with 14mm line. It’s incredibly common both for OEM and customer purchases to get the 8-14mm model, with the thought that the bigger range will be more versatile. This is a mistake, as the typical 10mm halyard on our fictional boat will be quite small relative to the cam on the 8-14mm clutch, and so we’d expect a lot of slip. To that end, we tested the 0610 cams, the 0814 cams, and the 0610 ceramic cams. Wait, the what? Spinlock has also started making a ceramic coated cam for these clutches, with the goal of improving initial slip, ultimate slip and rope wear, optimized for blended cover lines like our 10mm Poly Tec sample. We tested the Spinlock XTS with the 6-10mm cams, and the XCS with 8-14mm cams, and then the XCS with the 6-10mm ceramic cams. The XTS and XCS use the same cams, baseplates, handles, just with different fasteners and metal side plates (XCS) vs plastic (XTS). For the purposes of our test they’re the same, but it did save me some time swapping cams out! The XTS0610 usually sells for around $130, with the ceramic version usually being around $175 (although you can purchase the bases and ceramic cams separately to upgrade your existing XTS or XCS) and the XCS is around $215. In terms of load capacity, the metal sided XCS has a higher working load, 2640 vs 2200lbs for the plastic sides on the XTS.

Also from Spinlock was their XX clutch. This was an unfair test in some ways, as the XX is a far higher specced clutch for this test, with a load capacity significantly higher (3970lbs vs the 2000~lbs for the others) and a much higher cost (usually around $450 although there are other variants like side mount, lock-open, ceramic and carbon versions that are all higher priced) so it’s a bit overkill for our pretend boat (which needs a name… Clutchy McClutchtest?) as this clutch is found on lots of 40-50′ boats. However, this clutch is really designed for larger lines than our target 10mm line, so would it actually be at as disadvantage? To find out, we took it to our test track..er, bench. The XX uses textured jaws that slide on roller bearings to hold the rope, so there are two gripping surfaces in motion, with a larger contact surface.

 

Becoming more common on production boats are the clutches from Antal. Their V Cam clutches are a cam style clutch, but instead of the flat grooved cam as found on the Spinlock cams, the V Cam is-surprise!-V shaped. They’re also stainless steel instead of aluminum.  Loads of newer J Boats have these from the factory, so we wanted to see how it would handle our lines. The working load was lower than the others at 1874lbs,  as was the cost at around $115 each.

 

 

Less common on race boats, but often specced on cruisers are the Lewmar D2 clutches. Instead of a moving cam as on the Spinlock and Antal clutches, these use a series of hinged plates, that tilt forward with the line and apply tension over many different points.  The advantage here is that the multiple points of contact reduces the point load on the rope cover. The cost on these is around $120, and the working load is the lowest of the test at 1102lbs. The typcial assumption is that the Lewmars are kinder to line, but slip a bit more than the Spinlocks.  The other differentiating feature on the Lewmars is that the handle is hinged at the aft end of the clutch, not the front as all of the others.  This can lead to hilarious installation mistakes, so do be advised that the clutches have an embossed picture of a winch, with an arrow, so there really is no excuse!

Finally from the “now for something completely different” department, we have the Constrictor. This has no cams, plates or jaws, but instead uses a long sleeve of hollow rope which constricts-ha-on the rope and holds it in place by the same principle as a single braid splice. The clutch is also unusual in that it takes quite a bit more space than the others; the spec sheet says 25”, but I found better results with the bungee stretched out so that the whole clutch took up closer to 30”  The bungee  cord tension is key: if the tension is too low, the clutch will slip more before engaging. Too high, and the clutch won’t release. I have some concerns over how the sleeves will hold up over time, but haven’t modeled that.  We also had a bungee hog ring fail during testing, which in the real world would make the clutch unable to re-engage.  What’s really slick about these is the forward mounting hole is actually a slot, so you could use these with fastener spacings from 70-90mm. The cost on these is usually around $175. They don’t list a working load, but do list a break load at 4920lbs.   These have been used on many offshore boats as the rope sleeve puts less wear on rope covers, but how would it hold?

 

 

 

So here are the numbers for the 10mm V100 tests:

Clutch Remain after release (kg) Release Loss    (mm) Return to 1000lb in mm
XX 31.3 7.6 11.3
XCS0610C 72 8.6 14.3
XTS0610 33.6 12 16.3
Constrictor 10mm 39 18.3 18.3
Antal VCam-0814 (10mm) 23.3 34 20
Lewmar D2 10mm 22.3 17 21.3
XCS0814 5 50 33.6

 

And here with 10mm Poly Tec

 

 

Clutch Remain after release (kg) Release Loss (mm) Return to 500kg in mm
XX 102 5.33 8
XTS0610C 76 6 12
Constrictor 66.33 8 14.66
XTS0610 36.33 7.33 15
Lewmar D2 10mm 44.33 16 17.33
Antal V Cam 0814 37 22 18.66

 

 

Phew, lots of numbers, which one matters?  Good question.  The release loss number was surprising at first; this number was what load remained on our load cell when the line-at 1000lbs-was released from the winch. The numbers are all in the double digits except for the Poly Tec in the XX which frankly seems like a huge loss. However when you consider that the loaded portion of the line was only several feet, and there was nothing keeping constant tension on it, it makes sense. The “release loss” column is how much line slipped through the clutch as the winch was unloaded. Given how little load remained, this number should be considered in context, and I don’t think it’s very useful. The most useful number was how much slip it took to bring the load back to 1000lbs on the cylinder. This number was corroborated when we did the head-to-head videos, as the slip numbers were similar.

 

So, what are our conclusions? Let’s start with the obvious: the wrong size clutch did the wrong thing. The 8-14mm cams slipped the most, which is not a surprise. The 0814 cams simply have to move more to catch 10mm rope than they would for 14mm. The rope when removed looked flattened out.

The next up was the Lewmar D2, which slid the 6th best with V100, and 5th best with Poly Tec, although it did better than it’s slippy reputation would suggest. The impression left on the rope was wavy, as opposed to flattened like the Spinlock. What was really shocking was the wear from the D2.  I saw the most wear of any clutch with the D2, which could have been because we were using it quite close to it’s working load.

The Antal’s were next up, coming up in the middle of the test. The triangular profile of the grippy surfaces did not seem to make much difference here, although it was neat to pull the line out and see it be triangular. This was 5th best with the V100, and 6th best with the Poly Tec.

 

The Constrictor performed next best (4th best with V100, 3rd best with Poly Tec), although there are some asterisks present on this test. The Constrictor’s rope holding is all done with the rope sleeve, which is tensioned forward by way of a bungee. I tried quite a few bungee tensions to see which was best; the higher the tension on the bungee cord, the lower the slip, but the harder it was to release the clutch.  The testing was done with the bungee as taught as it could be while still being releasable.  Incidentally, one of the frequent questions on this piece of gear is “will it release under load” the answer is yes, as at 1000lbs, this was actually easier to release than the other clutches excepting the XX. The other asterisk, was that this number was obtained without a “cheat code”, Say what? You can cheat the Constrictor tighter if you manually “milk” the rope sleeve forward until it’s tight on the rope.  In our tests, this reduced the slip-to number down to 14mm average.  As a sidenote, you can also cheat the Spinlock XTS/XCS as well, by partially opening the clutch after closing it, and manually pushing the cam down onto the rope (doing this netted the following numbers in slip-to: XTS0610C 13.6mm, XTS0610 12.3mm)

 

Then cam in the standard Spinlock 0610 cam at 16.3mm, then the ceramic 0610 at 14.3mm for V100, and 0610/15mm and 0610C/12mm.  Since these are pretty much the default for rope holding, it wasn’t too surprising.  These were quite hard to release at 1000lbs, as was the Antal and the Lewmar. The release felt harder to me than doing it on an actual boat like a 36.7 does, although it’s clearly not a back to back test. This does make me think that the typical genoa halyard load is probably less than 1000lbs, especially after a mark rounding where the rig is being pushed forward, the apparent wind is lower and the sheet is (better be!) eased.

 

The double-edged sword of the XX performed best, with the least slip to at 11.3mm with V100, and 8mm with Poly Tec, and an easy release.  One one hand, it’s clearly the most expensive clutch so perhaps should be best, but on the other, it really should hold best with 12mm line, not the 10mm used here.  To see how it would do, I also tried only this clutch with a 12mm chunk of line, and got averages of 150lb remaining load, 4.3mm initial slip, and 7.6mm slip to, which was pretty impressive.  I can’t say this is the most cost effective solution for our imagined boat, but it certainly would be the best in terms of slip, especially if you were to bulk the line to 12mm at the clutch.

 

 

Suggested Retail Fasteners and hole spacing Max Working load lbs Slip to 1000lbs V100 Slip to 1000lbs Poly Tec 10mm
Spinlock XX0812 $523.49 140mm 3970 11.3 8
Spinlock XCS0610C $157.04 70mm 2640 14.3 12
Spinlock XTS0610C $206.36 70mm 2200 14.3(projected) 12(projected)
Ronstan Constrictor 10mm $189.54 70-90mm 4920(break) 18.3 14.6
Spinlock XTS0610 $262.34 70mm 2200 16.2 15
Lewmar D2 10mm $130.71 70mm or 107mm 1102 21.3 17.33
Antal VCam814 8-10mm $119 105mm 1874 20 18.6
Spinlock XCS0814 $262.34 70mm 2640 33.7 27

 

 

For those of you that prefer a visual comparison, here are some head to head clutch testing videos

 

 

Here was our top performing clutch, up against our best performing cam in an XCS clutch. As you can see the differences weren’t great, but there was a little more movement with the XCS0610C than the XX0812.

 

Here were the middle ground clutches, with the Constrictor vs the XTS0610 with the standard cam. The different angle from the other videos is due to the ginormous length of the Constrictor existing right where I had shot the previous videos.

Here are the stragglers in the test, as you can see it’s really very close between the Lewmar and the Antal.

 

For a comparison on what the clutches did to the rope, here are the Poly Tec samples, immediately after the head-to-head videos.

Top is the Spinlock XTS0610. It’s clearly flattened out the line, which makes sense as the cam is flat/toothed, pressing on a flat toothed baseplate.  The Constrictor shows no deformation or wear, which is one of the reasons I would think this unit is going to do very very well if rope longevity is your concern.

Top in the above image is the line after the XCS0610C was done with it, as you can see  the line gets flattened quite a bit. One of the treatments we do to improve rope holding, is to bulk the line internally, which adds both size and stiffness to the rope. The stiffness keeps the rope rounded under load. The XX flattened the rope as well, but not as extremely, likely do to the increased area.

Wow. The Lewmar really did a number on the Poly Tec, which is an extremely tough rope.  This is probably because we were using it at the upper end of it’s working range but it’s still surprising as this clutch is commonly regarded as being gentle on line.  The photos don’t show it well, but the Antal compressed the rope into a triangle shape which was kinda neat.

 

Here are some other pics of the rope wear, shown next to the clutch.  This is after several cycles to stretch the rope and set the knots, then 3 tests of taking the clutch to 1000lbs with the winch, easing the winch, then using the hydro to bring the load back to 1000lbs, then dumping the clutch. Generally, the XX and the Constrictor showed no wear that I could detect, the Spinlock 0610 regular showed some, then the

 

The Spinlock XX was easy to release, and didn’t show any wear on the line with the standard jaws.

The Ronstan Constrictor is really kind to line, and CAN be released under load which may surprise some

The Spinlock XTS0610 showed some wear, a lot more than I was expecting but I believe that the load and releasing were probably a little more extreme than the usual boat experiences in 3 cycles.

The Antal V Cam wore on the line pretty similarly to the Spinlock 0610, but was very very hard to release so I only did it once instead of 3 cycles.

The Spinlock 0610 ceramic cams did wear the line a lot more on the V100 than it did on the Poly Tec. The ceramic cams are explicitly designed for blended covers like Poly Tec, so this is not surprising.

The Lewmar was surprising in how much wear it did to the rope. It was the only one to do significant damage to the Poly Tec.  If I were to do the test at lower loads, say 500lbs, I would imagine this would not be the case. 

Inhaulers

We first used these on J/109s last year when the class allowed the addition of an inhauler system, and since then I’ve gotten tons of questions, most of which are about whether they’re plastic or not, so here is some information and answers to popular questions.

Are they plastic?

I’m glad you asked, NO, these are not plastic. They’re aluminum with a very very nice hardcote anodizing so they look plastic.

But they look plastic, are you sure they’re not plastic? Can you check?

I checked, they’re really not plastic.

How big are they?

I’m glad you asked, I was worried you were going to ask if they were plastic again!

The dimensions are: Length 50mm, Width 35mm, Diameter big hole 19mm, Diameter little hole 9.5mm, thickness 19mm. They like inhauling and long walks on the beach.

Wait, so they’re plastic? 

I just checked again, no.

How strong are they?

Good question! No idea! However, given the materials involved I would say strong enough for boats whose jib sheets would fit.  10mm is safe. I have tried them on spliced, covered 11mm and had no issues, however a customer reported it was a tight fit on their 7/16″ Warpspeed, so check your sheets before ordering

Does it come with the rope?

This is just the inhauler part, price is for 1 inhauler. But we can do rope!

How much? 

Image result for j109 inhauler

NOT PLASTIC

 

 

PROtect Tapes

PROtect Tapes supplies chafe protection and other tape and film products for the worlds best race boats.  Their products include the wing film on the foiling AC boats, but for the rest of us there are a few good tapes to have on your boat. In addition to the in stock tapes which can be purchased online, we can also special order anything from the PROtect tapes catalog as a custom order.

The basic go to tape is their MASK product, which is often called “millionaires tape” due to relatively high cost of the tape. For preventing damage though, it is worth it.  Used to both prevent chafe and reduce friction, it gets used all over the boat. The applications are endless, but think about using on running backstays, spars, ropes, spreaders, toerails and more.

For boats with Carbo Foils or Tuff Luffs and assymetric spinnakers, spin sheets burning holes through the foil are a serious concern. Adding a layer of HEADFOIL tape on the foil or over your existing aluminum or kevlar chafe guard reduces friction and adds another sacrificial layer of protection.

To protect sails, rigging and crew from cotter pins, a self amalgating rigging tape is needed. The WRAP product is easy to apply, and sticks to itself in all weather.

The CHAFE product is a heavy duty  film, thicker than the MASK product and designed to be applied to smooth surface.  It prevents impact and chafe damage, so is great for spars, cabin tops, spreaders and any place you need more protection and don’t need to conform or stretch the tape.

Beneteau 36.7 Backstay Update

IMG_20160407_095336We have a new material for making 36.7 backstays, a heat set Dyneema double braid made with SK99 that meets the one design specs (breaks at 4727kg or 10421lbs) but comes in smaller and lighter than any other available option, at 6.1mm and weighing a mere 12oz with thimbles.

$396

There are several options for finishing the bottom end of this stay

-Eye Splice With Thimble (shown) this is for use with the stock Lewmar backstay block
-Harken Lead Ring: this is a low friction ring, that adds 1.3oz to the weight and $20 to the cost. Lightweight and strong, but does make pulling the backstay harder
-Harken Black Magic Block: A roller bearing block that gets spliced to the end of the backstay, adds 3.23 oz and $195 to the cost
-Karver High Load KBO Block: A plain bearing block that gets spliced to the end of the backstay, adds 3.2oz and $240 to the cost

Recovery Mode

If the picture above looks familiar, you’ve probably experienced the upper limit of a rope covers durability before!

This is an asymmetric spinnaker sheet made from New England Endura Braid Euro.  It’s a great line, very tough cover, but it still failed after just 2 seasons.  What gives?

Asymmetric sheets are very tough on covers.  They tend to have higher loads than a symmetrical spinnaker sheet, and are also trimmed more actively.  Things really get interesting in a gybe, when the line speed is MUCH higher.  In a gybe on a boat this size, you’re moving around 65′ of line every time you gybe, and the faster the better. On a boat like this with a pedestal grinder, you can pull the sheet around quite quickly, so it makes for snappy maneuvers.

What this means for the rope cover is lots of heat and abrasion.  Most assym  sheets start to feel a bit crispy in the middle, and that’s because the friction over the drums is generating enough heat to melt the cover.  The bigger the boat, the higher the loads and the more line to move, so the covers get abused more.

The solution is better covers,  specifically using heat and abrasion resistant fibers.  At the very top end we have PBO covers, which handle the highest head and load, but can retail for over $40/meter for the 10mm size. No, I’m serious, stop laughing! It gets better too, since they’ll break down in the sun and wear out quickly. Oh, and it leaves gold dust all over your boat and crew.  Anyway, the good news is there are lots of better-than-polyester covers that will cost less than a used car.  There are kevlar blends like Yaletail, and Runnertail (technically Twaron but who’s counting) but in the last couple years the default go-to special cover has been Technora blended with polyester. New England makes a rope called Poly Tec which is available as a cover or a built rope with Dyneema core.  I’ve been using this for the last 4 seasons and have been very happy with it, and have never heard a complaint about it from owners.  Marlow Ropes makes a full suite of specialty covers, but their version is Tech 50. The 2 covers are quite similar, so it usually comes down to which is available in what color first.  In addition to durability, you’re going to find that the grip on winches is more consistent, and they handle great!

So, let’s pretend your boat has taken your nice Dyneema double braid sheets and turned them into the mess you saw in the first picture. The cores are ok, but the cover looks like a shriveled churro.  We can take the cores out of the old line, and put a Technora blend cover over the top for less money than new sheets.  The cores still have a few years of life, so this is a great way to keep them going while get a nicer hand to the line and better grip on winches.

For the above sheet, the owner opted to swap both covers for Poly Tec, and gave them distinct colors while we were at it. The sheets were end-for-ended as well so the old loaded end of the sheet is now the tail and vice versa. The sheets look new, and should perform that way for many seasons.  Win!

It was a good idea in this case for a few reasons: the sheets were relatively new, the cores were in good shape and the core material was Dyneema.  If you have a damaged cover with similar parameters we can save it!  CYR also stocks regular polyester covers for a repair at considerably lower price point, although it’s worth considering why the cover failed in the first place (*usually T10 halyard with XAS clutch) It doesn’t make sense for every line though.  If the line is particularly short, the cost of labor doesn’t usually add up to less than a new line, and if the core is damaged, or Vectran/Poly/PBO it’s not usually a good idea to recover it.  If you’re in doubt, drop by the shop and we’ll look it over.  Plenty of samples to look at, and the odds are very good I’ll have rope in for the same repair to show you!

 

1/8″ Dyneema Break Test Final: Bury Splice vs Brummel Splice

For the final it was no surprise to see the bury splice and the brummel splice.  The previous rounds saw knots, specialty splices and things done purposefully wrong, so these should be the top end.

The bury splice, again, is the tapered tail of 72x rope diameter, inserted into the rope to form an eye, and stitched to keep the splice intact under no/low loads. The brummel is the same, but with an interlocking weave instead of the stitch.

http://www.youtube.com/watch?v=R9pTA3lfdZE&feature=youtu.be

Well, as you can see it was the bury splice that walked away the winner, besting the brummel which lost at 2958lbs. This is 134% of rated strength for 1/8″ Endura 12, so pretty happy with the result. If you read the semi finals, you’ll get some explanation of why it’s so far above rated, but it’s nice to know CYR splicing is beating the numbers we use for specifying rope.

Based on the result,  you might ask why we don’t use the bury splice as standard, instead the brummel is the default for sheets and halyards.  The reason is the brummel is faster, and has a locking mechanism which can be verified and can’t possible wear out or be removed.  At the numbers seen in this and other tests, it’s always broken above rated for good quality lines, so I can use rated strength when speccing with no concerns about strength.

For the full series of tests:

1/8″ Dyneema Break Test Bracket: Quarterfinal Rd 1 Skiff Knot vs Bury Splice

1/8″ Dyneema Break Test Bracket: Quarterfinal Rd 2: Loop vs Short Bury Splice

1/8″ Dyneema Break Test Bracket: Quarterfinal Rd 3: Bowline vs Sliding Sling Splice

1/8″ Dyneema Break Test Bracket: Quarterfinal Rd 4 Soft Shackle vs Brummel Splice

1/8″ Dyneema Break Test Bracket: Semi Final 1 Full Bury Splice vs Short Bury

1/8″ Dyneema break test bracket Semi Final 2: Brummel Splice vs Sliding Splice

That concludes the break testing for now, if you have suggestions or requests for similar tests feel free to get in touch with me at kristian@chicagoyachtrigging.com

Dux all in a row

Dynex Dux was the first mainstream heat set Dyneema to arrive in the yachting world, and  had a huge effect on rope selection on racing boats.  Using heat and tension, it gave us higher strengths and lower stretch in a smaller package, and quickly stole ground from not just regular Dyneema, but has replaced Vectran and Zylon as well.

These days, there are quite a few varieties available in heat set prestretched rope. Stopping by this week is the most recent version, and likely the strongest,  from New England Ropes.  I thought it might be interesting to compare the available options, so below are some notes.

On the left is Gleistein’s Dyne One HS.  This is by far the easiest heat set product to work with, as it has a pretty wide angle, and is soft compared to Dux.  It’s also the roundest option, and tends not to flatten out over sheaves.  The downside is the high angle between braids should theoretically make it stretchier.  The other drawback is that it doesn’t seem to be much stronger than regular Dyneema, at least in the small sizes.  Last summer when doing some break testing I found that the 4mm Dyna One HS broke at ~3800lbs, where as plain old New England STS75 breaks well over 4000lbs.  The 9mm shown is supposed to be approx 18000lbs, which is again in line with regular Dyneema.

Second from left is Maffioli Ultra 75, actually the core from 11mm double braid. This is probably the least stretched product, and rated at 17000lbs it’s the weakest as well. It’s kind of an odd duck(x) here as it’s not targeted or made like the others, and I believe it’s just a quick prestretch to take out some of the constructional stretch.

Middle line, in dark gray, is Marlow’s D12 Max 78 product. Rated at ~23000lbs, this is much stronger than the first 2.  It has quite a long angle, partly from construction and partly from stretching.  This is the only SK78 product here, but they also offer an SK90 heatset, for max (ha) tensile.  Marlow has the widest range of fiber choices, and more importantly sizes, going all the way down to 3mm which is unique for a heat set dyneema.  The downside to Marlow is the stretching process makes for a rope that isn’t very round,  as it’s flattened out over whatever bobbin they use to stretch the product.  The Dyneema is a bit fuzzy when new, due to the fibers that fail during prestretching.  This is the choice of high tech dinghy and small cats, as the range of sizes makes for lots of options.

At the far right (I’m skipping the second right for the moment) is a piece of Dynex Dux in 7mm, as I was out of the 9.  The original, and still very good, it has a rated break of ~26000lbs, and is quite round and very stiff with less popped strands than the Marlow. The amount of prestretch is very high, which makes it a good choice for running rigging where stretch is key, as well as some standing rigging and slings.  I really like this material for backstays as it’s so light and strong you can be quite aggressive in downsizing.  Most people call any prestretch Dux, but that can be troublesome as some of the other heatset products aren’t exactly interchangeable as far as strength and stretch.

Second from the right is the newest arrival, an as-yet-unnamed product from New England Ropes.  Pretty excited about it, as it seems to have taken all the best attributes from the other brands and improved on them.  The construction is very similar to Dynex Dux, but lacks the flyaway/popped strands. The roundness of the rope is closest to Gleisteins product, and the smoothness is better than any of them.  NER hasn’t released final break numbers, but the initial tests had it all comparing very favorably with Dynex Dux, which is really saying something.  This particular spool is destined for the VO70 Il Mostro, replacing the Gleistein rope is arrived with.  I’ve got more spools arriving soon and am going to have more info soon!

Tylaska Dogbones

Metal or carbon dogbones are incredibly useful, strong and simple ways to terminate a line or integrate soft attachments. In the past I’ve either had them custom made from aluminum or steel, or cut lengths of steel or carbon. While this works, the custom ones are expensive, and the cut rod versions need lashing to keep them secure.

Much like spool shackles, these make all the sense in the world… once you’ve seen how they attach!  A loop of line is passed through the grommet on the sail, then the dogbone is passed through the loop.  When pulled tight, the loop cinches onto the dogbone and stays fast. 

Continuing their tradition of high quality versions of existing tech, Tylaska has introduced their line of dogbones in aluminum and stainless steel. With working loads from 650 to 15000lbs, there a dogbone for every application here. CYR is stocking select sizes, and will be using these in a number of upcoming projects. Uses for Tylaska dogbones include termination of sheets, halyards and control lines like outhauls, custom loop shackles, bobstays and more. Also in stock are CYR’s range of custom stainless/aluminum dogbones for high loads.


Free Luff Furlers (not for free though)

If you’ve ever wondered who makes those neat spinnaker furlers on the Americas Cup AC45s, or the VO70’s, well, it’s these guys KZ Race Furlers

I had the chance to look over one of their custom units aboard Il Mostro last year, and was impressed by the machining and beefiness of the furler.  The market is absolutely packed with code and spinnaker furlers, but if you’re shopping for one you have to give KZ a good look over.  See the wee and big boat sheets below:

kzbig

kzwee

 

Also in furling news, Ronstan is offering 20% off on their code and spin sail furlers, so if you’re looking for a stellar early season deal, check with us for the best price!