Mast Extension Rope Failure

I bought a brand new Severne Cyclops mast extension and was using it for the second time yesterday when the mast extension rope just gave way on me during my session (sailing a 5.3 wave sail). On closer inspection of the rope I'm not sure if the knot holding the rope in place inside the extension gave way (i.e. the knot undid itself from the pressure by being tied too close to the end) or if the rope itself just sheered off above the knot.

Just wondering what sort of experiences and frequency people have had with this sort of gear failure (with Cyclops or other extensions). I was lucky this happened near to shore and could easily get back in. I hate not being able to trust my gear so just wondering if this is a one off or something I need to anticipate happening on a regular basis.

I love the Cyclops extensions for the quick and easy loop and go rigging but wondering if there's more pressure exerted on the rope compared to a regular extension like a grenade where one loops the rope through an additional pulley.

See 1m30 of video below if interested to see how these work.

Formuline is notorious for slipping, and that looks like what's happened. Like imax said, they tie the knot precariously close to the end, and not tight enough, it slips to undone. It happened to me twice before I learned to check it before the first sail.


unfortunate when it does it to you and you're off the beach already. But easy fixed by re-tying the knot with a figure 8 and a little bit more of a tail to account for slippage while it tightens under tension.

Poca cima poco marinaio (little rope little sailor) ... leave a good 2-3 cm of rope at the end of the knot.

Fig 8 can still slip, just not as easily. Drop of superglue is a good idea. Climbers and fishermen always need to be careful with knots in spectra ropes.

Should be using a Duotone PowerXT anyway .. so buy one and move on.

The end of the rope should of been heat sealed, and that is not, so wondering if knot come undone or rope broke. Can always replace with Amsteel line.

I have been using formuline since it first came out (about 15 years ago). It was the only line you could trust to do the job with super high tension Sailworks race sails that you had to downhaul with a crank. I never had a figure-8 stopper knot slip or come undone. Some good ideas here about using superglue.

Amsteel is good, too. Sailboats use it a lot. I use it for adjustable outhauls.

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duzzi said..

segler said..
I have been using formuline since it first came out (about 15 years ago). It was the only line you could trust to do the job with super high tension Sailworks race sails that you had to downhaul with a crank. I never had a figure-8 stopper knot slip or come undone. Some good ideas here about using superglue.

Amsteel is good, too. Sailboats use it a lot. I use it for adjustable outhauls.

I have been using Formuline 4.5 mm for the last five years, because it is the diameter that goes with my AL360 extension. I cannot really imagine this braking, but I never broke a 3.8 either. And yep, use a figure 8 knot, what else really at the end of a line ...

Re. the amsteel: can you actually use amsteel for a downhaul? I thought it was not good with the v-cleat style stoppers found on an extension.

You are correct. The standard Amsteel is good for winch line(offroad) or halyards but not great for cleats, knots, handling. Formuline is much better but you have to careful with the knots. Chinooks Spectra line is double braid & holds well in cleats but a bit higher friction than the Formuline. Any Spectra/Dyneema line is going to be plenty strong...

I find Formuline slips in my boom clamp .Even with a new cleat . Formuline squashes after cleating in the same area then slips .I use the boom on 3 masts which need slight adjustment . So I use normal rope there but it makes me nervous .I replace it often .

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Obelix said..
With a risk of being attacked by the Formuline faithfuls...
One downhaul rope broke for me, and even more worrying, one outhaul rope too
Both reasonably new Formuline.
Both snapped just above the knot.

Maybe there is a way to test the rope strength?

Unless you watched it come of the reel i would hazard a guess that it might have been cheaper imitation stuff. I had a new extension once that came with "formuline" after two sails it looked to be on the verge of snapping. Replaced it with the genuine stuff and no problem since.

If i'd known about formuline earlier theres heaps of places i couldve used it on my boat. I would've had to rob a bank first, but still.

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Grantmac said..
I wouldn't touch anything with vectran or a loose weave like amsteel for an extension or boom clamp.
Genuine formuline with the rough external casing is what you want. I get probably 300 uses minimum before I think about shortening it slightly. Then flip it and do the same. That's years of use.

I thought the outer layer of the Amsteel rope would fray over time since it is a looser weave with no outer shell, but it has not frayed, and the smaller diameter you go in Amsteel rope the tighter the weave is to where it feels like a tight waxed rope that does not stretch significantly.

In contrast, the rope on my Streamlined extension has a tough white outer shell that is fraying, been using it for over two years, maybe it is formula line?, it does not stretch significantly.

Had a formluline fail reciently on a long NP carbon extension, I had noticed it was fraying where it left the stainless tube and had been meaning to replace it but procrastination got me, upshot the line snapped rigging up, the stainless base ring withe pulled twisted along the axes of the carbon tube destroying the extension, expensive mistake. $700 extension destroyed for the want of $18 worth of line. Lesson if your lines are worn.. replace them now.

Quite often you can simply turn the line around and you have doubled the lifetime of the line. ;)

Been trying to get more of the stuff that comes with the Severne extensions as that seems great but can't seem to find it anywhere.
I ordered some from a shop that said they had the same stuff but when it came it wasn't.
the rope of the left is what I like, smooth to touch, lasted 4years so far, flexiable. The one one on the right is what they sent me, much stiffer and rough to the touch, they called it formuline bits it's definitely different so the formuline that comes on the Severne.

I had the boom clamp line break on me with just the front foot in... Thought the boom would lower to the bottom of the sail boom window, nope, went all the way down and hit the board!

Heard a noise during the previous session but forgot to check... Simply shortened the line (although I also carry a spare in my pocket) and went on my session.