Knotted or Spliced Halyards?

[motorb 35]

Hi Crew, Looking to pick your collective brains a bit:

On my wee (25ft) Tracker 7.7 there is some damage on the cover of my main halyard, spin halyard is totally stuffed and the jib halyard and topping lift are at least 15 years old and looking sad. All are 8 or 10mm Dyneema and seeing as there's a sale on I'm planning to replace the lot.

All the damage and failures are from chafing or rubbing on the same spots over the years, so my thinking is if I used a knot instead of a splice, I could shorten the halyards and re-knot them every year or so to prevent damage on one spot ruining the whole length.

They are all currently spliced with a metal eye, which looks nice, but is it really necessary in my case? Looking online, for those with smaller boats like mine, a lot of people are using some version of a "halyard hitch" instead of mucking around splicing old ropes. 

Does anyone know the ins and outs of this? I'm thinking of using the above knot, possibly with the metal eyes. Given the ropes are sized for comfort well above any actual load I don't believe this would be an issue, but hey maybe you guys have some ideas.

Cheers!

[MartinRF 64]

I use a bowline knot for my jib halyard since 2+ decades.

For spi I want something with a swivel so not knotted.

If I ever convert my main halyard to 2:1 it will be knotted to the mast top.

/Martin

[eruptn 103]

I asked a rigger that just a couple of weeks an he said 'use knots'.

[CarpeDiem 512]

We put a 2m sacrificial dyneema sleeve on our halyards when we find chafe, very easy to shorten and resplice.

I've found that once the dyneema tip is on, the chafing ceases to be a problem. Infact ironically I have never needed to resplice one... 

 

[motorb 35]

14 hours ago, MartinRF said:

I use a bowline knot for my jib halyard since 2+ decades.

For spi I want something with a swivel so not knotted.

Good to know.  On my foredeck I have the quick release pin thingys with swivel built into them... not having to to cut these off and take them to be spliced onto the new halyards is one of the attractions of knotting everything.

14 hours ago, eruptn said:

I asked a rigger that just a couple of weeks an he said 'use knots'.

Well I won't argue with that!

12 hours ago, CarpeDiem said:

We put a 2m sacrificial dyneema sleeve on our halyards when we find chafe, very easy to shorten and resplice.

I've found that once the dyneema tip is on, the chafing ceases to be a problem. Infact ironically I have never needed to resplice one... 

well... my chafing issue on the spin halyard is also the "where did the masthead light go?" issue so maybe I need to think more about where the rigging lies first...

[ex Elly 229]

Be aware that dyneema rope doesn't like being knotted, and will lose a lot more strength than a polyester rope.

For example a bowline in polyester could reduce the rope strength by 30%, but in dyneema may reduce strength by 50%.

When strength is important a splice is much better, as it will only reduce strength by 20%.

This is why you should always splice your dyneema halyards.

 

[motorb 35]

50 minutes ago, ex Elly said:

For example a bowline in polyester could reduce the rope strength by 30%, but in dyneema may reduce strength by 50%.

But given the Dyneema is stronger to begin with, then end strength is about the same isn't it?

My halyards are sized for comfort in the hand well above load, so is there much advantage to using Dyneema over polyester? Doesn't it have less stretch to it?

[ex Elly 229]

1 hour ago, motorb said:

But given the Dyneema is stronger to begin with, then end strength is about the same isn't it?

My halyards are sized for comfort in the hand well above load, so is there much advantage to using Dyneema over polyester? Doesn't it have less stretch to it?

Yes, if replacing polyester with same diameter dyneema, you will have more than enough strength.

[CarpeDiem 512]

A properly done splice should take off less than 5% of the strength. A bad splice might see 10%.

But in reality you don't need to worry about breaking strength. It won't be an issue unless you're a big boat or using really small lines. 

Generally speaking, ropes get cut, (due to chafe), or they get crushed and cut (due to crappy clutches), they don't break due to excessive forces. 

Eg,

Fineline Dyneema Advantage 10mm has a breaking strain of over 5000kg.  That's a fully laden Toyota Landcruiser and Toyota Corolla hanging from the top of your mast.

10mm Fineline Classic double braid is rated to 2500kg.

Premium ropes have a formula which is:

Halyard/Sheet Load = SailArea x WindSpeedKnots² x 0.02104

So a Tp52 with 98m2 sail in 25knots needs a halyard rated for a minimum of 1300kg. 

 

 

[MartinRF 64]

59 minutes ago, CarpeDiem said:

Halyard/Sheet Load = SailArea x WindSpeedKnots² x 0.02104

 

So a Tp52 with 98m2 sail in 25knots needs a halyard rated for a minimum of 1300kg.

Seems low to me.

Anyway, halyards are about low stretch not breaking strength.

/Martin

[CarpeDiem 512]

1 hour ago, MartinRF said:

Seems low to me.

Anyway, halyards are about low stretch not breaking strength.

/Martin

Exactly. (And handling).

Look at it another way;

The clutches on our boat are High Holding Lewmar DC2 clutches they have a max working load of 1200kg and start to slip at 700kg.  They are the most powerful clutches Lewmar sell. 

Spinlock XXC, arguably the top clutch on the market, at nzd$3200 are only rated for 2350kg... 

The clutches are going to fail long before a 10mm Dyneema line with a halyard knot breaks. 

[MartinRF 64]

Clutch holding depends a lot on the line.

/Martin

[CarpeDiem 512]

36 minutes ago, MartinRF said:

Clutch holding depends a lot on the line.

/Martin

The point is the clutch will fail at or near its maximum working load long before the rope breaks.

If a manufacturer places a MWL of 2300kg on a clutch, it's totally unreasonable to expect that clutch to hold a 10mm SK78 rope at its breaking strength of 10200kg.  The clutch is going to fail or rip out of the deck long before the rope breaks.

Same as it's completely unreasonable to expect a pulley rated for 1000kg to hold a rope which sees it's maximum break force of 2500kg.

Our Lewmar winches have a MWL of 685kg, our sheets are rated to 3000kg I don't worry about the sheet with a bowline breaking, I know the winch will implode long before the rope breaks.  (in reality the sail will rip in half first...).

Generally, because of handling requirements, all the lines we use for sailing, are an order of magnitude stronger than the equipment that holds them.

So our equipment is the weak point, not the rope.  There's no benefit in having a 2500kg rope if it's held by a 1000kg equipment.

The takeaway is that one doesn't need to worry about the rope being weakened because you have used a halyard knot instead of a splice.

Not withstanding UV damage, ropes get cut, they don't break.

[ex Elly 229]

18 hours ago, CarpeDiem said:

Fineline Dyneema Advantage 10mm has a breaking strain of over 5000kg.  That's a fully laden Toyota Landcruiser and Toyota Corolla hanging from the top of your mast.

But only half of that when you tie a bowline in the end. So will only support the Corolla without a good splice! 

[Black Panther 1,717]

Anyone have a spare corolla so we can test this 

[motorb 35]

I'm not sure if my little Tracker is going to be able to lift a Toyota.... the car would weigh as much as the boat does!

[eruptn 103]

Yeah but the new halyard will....

 

[MartinRF 64]

On 24/11/2022 at 11:32 PM, CarpeDiem said:

The point is the clutch will fail at or near its maximum working load long before the rope breaks.

Not arguing against that. I just wanted to highlight that clutch performance depends on the line. More than I thought a few years ago.

/Martin