Main Halyard Question

[Cruisin Cat]

I have a 5 year old 40 ft cruising catamaran that I live on and sail around S pacific so the boat is pretty much in full time use. Some of my sheets and halyards are starting to get a bit stiff and the covers are looking a bit "shaggy" in high wear areas.

Is there some way to assess when line failure is imminent and hence replace the line before it fails?

I have checked prices of replacement line...one chandlery says I should use spectra for the main halyard at AU$11/m but another says I don't need spectra and double braid polyester will be fine at AU$3.30/m. My question here is...what sort of line are cruising boats generally using?

I'm looking forward to hearing any advice on this

[Delancey]

Double braid polyester of the appropriate diameter is likely the type of line provided by the builder when the boat was new and is generally considered to be adequate.

The principle benefit to the using Spectra is that due to the comparatively greater strength, a significantly smaller diameter single braid line may be used which in turn reduces the amount of weight aloft. Reducing weight aloft has an impact on reducing inertia which reduces hobby-horsing as well as providing a benefit in terms of stability.

Generally speaking, the use of Spectra halyards tends to be limited to the go-fast racing crowd but I believe many cruising sailors would benefit it as well, in particular those who like to actually sail their boats. Whether or not the cost is justifiable is up to the individual to determine.

With regards to cost, I don't have a catalog in front of me but in general, owing to its superior abrasion resistance and strength, when you switch to high-tech lines you can go down in size as well as make the switch from double to single braid construction.

Typically racing boats will sew on a cover over critical areas such as where the halyard goes over the masthead shelves, sometimes the turning block at the deck, and very often at the halyard winch to provide chafe protection.

High tech line for sheets? Maybe not so much. A lot of times sheets are oversized to make them comfortable to pull on with your hands. But not always. Generally double braid polyester is the way to go. High tech line is great for things like light-air spinnaker sheets, but small diameter high tech line is tough on your hands.

The down side to high tech line is that it can be difficult to cut, but it is very easy to splice. Personally, I use it for my lifelines where I think the benefits are both in cost and performance. It can be cheaper to replace with high tech line since you don't have to buy any stainless turnbuckles or fittings.

Just splice an eye in one end and loop it around the pullpit, splice an eye in the other end and use lashing to develop some tension when attaching to the pushpit at the other end. Very simple, the lashing might seem old fashioned but it's what all the fancy expensive racing yachts do.

PS without knowing but guessing based on cost it would seem they are trying to sell you a double braid spectra - that is to say a spectra core with a polyester cover. Use single braid spectra for you halyards, it's a lot cheaper. You can make a cover by stripping one off of some old junk line. Don't use the double braid spectra for your sheets, stick with polyester for those.

[Delancey]

Back in the day there were some high tech line constructions that included a Kevlar core and with a polyester cover. I can remember trimming a jib once on a racing boat when all of the sudden BOOM!!! The Kevlar line parted. To this day I am still amazed at how loud it was. Suffice it to say no one uses Kelvar lines these days.

[colemj]

The main reason for spectra, etc on halyards is stretch, not weight. Particularly for large area, large roach catamaran mainsails. Double braid will be fine. I believe your boat has a double-purchase halyard, that will help minimize any stretch.

What is on it now? If double braid, and no problems, then go with that again. You might also consider end-for-ending the halyard and lines to move the worn and stiff parts to different areas.

Mark

[Cruisin Cat]

Thanks Delancey for your very detailed reply.
I have 12mm halyards and 14mm sheets.

Is there some "rule of thumb" about when to replace double braid polyester or spectra lines ?

[Cruisin Cat]

Originally Posted by colemj

The main reason for spectra, etc on halyards is stretch, not weight. Particularly for large area, large roach catamaran mainsails. Double braid will be fine. I believe your boat has a double-purchase halyard, that will help minimize any stretch.

What is on it now? If double braid, and no problems, then go with that again. You might also consider end-for-ending the halyard and lines to move the worn and stiff parts to different areas.

Mark

Yes I do have a double purchase main halyard and I have end-for-ended it as you said. I don't know what type of line is on the boat now. It's original from the factory so I guess it will not be expensive line.

[Delancey]

It's a fact Dyneema and Spectra stretch. The technical term is CREEP. They are used on racing boats because of HIGH STRENGTH and LOW WEIGHT.


I know what I know first hand but if you don't believe me, here's someone else's explanation -
All About Rope - Everything You Need To Know About Cordage


HMDPE (Spectra and Dyneema)
Though it starts out life as something not much more complicated than the material that your supermarket carrier bag is made from, High Molecular Density Polyethylene is a remarkable material. In fact, the carrier bag provides a good example of just why HMDPE is so strong. Try this; lightly load a piece of supermarket bag in the main body of the material by pulling it between your fingers. It stretches easily and shows little strength. Now fill the bag with heavy groceries and lift it up. By some apparent miracle the all too thin looking handles stretch a bit before stabilising and supporting what can be quite a high load (yes, I know they split when you put too many bottles in). What has happened is that the molecules in the material making up the handle aligned themselves in the direction of the load during the initial stretching process. Thus organised they are much better able to support a big load than in their original random orientation.

The manufacturers of HMDPE exploit the phenomenon of molecular alignment to produce their super strong material. In the case of HMDPE fibres the alignment process takes place by means of chemical and mechanical processes during manufacturing rather than when you, the user, apply the load for the first time.

Unfortunately, the process is not quite perfect and this leads to a phenomenon known as 'creep'. Though the initial stretch of HMDPE is very low, if one leaves a HMDPE rope loaded for a long time it slowly but inexorably stretches, never to return to its original length. While this is not a problem in lines that are adjusted regularly it can be irritating in applications where stability is important (eg the main halyard).

In the early days, the very slippery surface of HMDPE gave rise to some problems with keeping the various parts of the rope stable. Highly loaded the core would slip inside the cover, leaving the highly loaded outer part well and truly shredded when used on winches or in clutches. More sophisticated manufacturing processes have largely alleviated the problem, though in winching and rope stopper applications the cover will likely as not still fail before the core.

These small problems aside, HMDPE is an excellent material for ropes as it is light enough to float, takes up no water and offers a very high degree of UV light and chemical resistance.

[Delancey]

Originally Posted by Cruisin Cat

Thanks Delancey for your very detailed reply.
I have 12mm halyards and 14mm sheets.

Is there some "rule of thumb" about when to replace double braid polyester or spectra lines ?

Not that this will answer your question directly, but, I have a friend who manages a very well funded racing program.

As a part of their routine preventative maintenance and risk management program, they annually replace their Dynex Dux halyards. For them the risk of losing a yacht race is enough for them to want to replace their halyards with enough frequency to ensure this doesn't happen.

I will be cutting a set of these halyards down and relocating the covers and installing them on my not very well funded cruising boat and I expect they will probably last me for ten years.

Ulitmately, it's about managing your risks but something tells me if you have already end-for-ended once, and you are asking the question, it's probably time to switch them out.

[Suijin]

Your lines are probably stiff from being full of salt. It's a good idea to take them off and wash them when they get to this point...I know people who do it every year as a matter of simple maintenance.

Salt and dirt embedded in lines will dramatically reduce their life. All those salt crystals are like having millions of tiny little knives in your line.

If you're lines are frayed you should consider replacing them if they are critical and if failure would be a Bad Thing. Cored lines get most of their strength from the core and the braided cover is largely protective, so those can go a bit longer but you should still replace them if the core gets exposed.

[smj]

Colemj is correct, the main reason for using tech line for the main halyard is the lack of stretch.

[colemj]

Originally Posted by Delancey

It's a fact Dyneema and Spectra stretch. The technical term is CREEP. They are used on racing boats because of HIGH STRENGTH and LOW WEIGHT.

Yes, those do creep - never to return to their original length. They do not, however, stretch (relatively). Those are two different properties. Stretch is dynamic, while creep is static. Once the creep is set in them, they are low-stretch lines and their use in multihull mainsail halyards in cruising boats are for that reason alone. Weight has very little to do with anything here.

For racing boats, they are used both for low stretch and low weight. Those extra few lbs do mean a lot in this application, but the main reason for their usage as halyards, even in racing boats, is lack of stretch. If the choice was between a low-stretch but heavy halyard and a high stretch but light halyard, the racing boats would be choosing the higher weight line. Luckily for them, this choice is not necessary.

Mark

[sandy stone]

I don't think it's an either-or choice anymore between expensive high-tech line or (comparatively) cheap polyester double-braid. Manufacturers have been coming out with reasonable compromises for non-grand-prix sailors who would still like low-stretch halyards. New England Rope has VPC, and Samson has XLS extra-T, for example. Prices are not too bad for a significant performance upgrade.

[Delancey]

Originally Posted by Delancey

Though the initial stretch of HMDPE is very low, if one leaves a HMDPE rope loaded for a long time it slowly but inexorably stretches, never to return to its original length. While this is not a problem in lines that are adjusted regularly it can be irritating in applications where stability is important (eg the main halyard).

Did you read this? Have you ever sailed on a boat with Dyneema halyards?

I have. Big racing boats with tall rigs. It's hard to discern, because you are constantly adjusting halyard tension anyway with changes in points of sail or changes in wind strength, but I am sure I can recall an occasion or two when I have been asked to repeatedly add main halyard tension on long beats to windward with consistent wind and seas.

Additionally, I have had to adjust the lashings twice on my Dyneema lifelines to maintain proper tension and yet my boat has not gotten any shorter.

If this is does not functionally or practically constitute "stretch" than I don't know what does. If racing boats were only concerned with low stretch they would use 7 x 7 stainless steel wire rope halyards, but they don't do they?

Racing boats want to go fast, because of this their preference is to limit weight aloft. The fact that Dyneema does stretch or creep or deform or elongate or whatever you want to call it is immaterial to racing boats because they are constantly adjusting halyards anyway.

Depending on the size of the boat there is a crew position known as "the pit" and besides being rail meat, all you do all day long is raise, lower, or adjust tension on the halyards. Yes, I have been a pit guy before.

[Suijin]

Originally Posted by Delancey

Did you read this? Have you ever sailed on a boat with Dyneema halyards?

You're missing Mark's point and getting worked up over an issue that is irrelevant to the OP. Cruisers use low stretch line like Stay-set for halyards because they don't stretch as much as "conventional" less expensive lines. You raise your sails and generally don't futz with trimming through the halyards unless conditions change dramatically. You want a halyard that you can generally speaking "set and forget". Weight is immaterial with all the other crap you have bolted to your mast like radomes and whatnot.

[Cheechako]

You just need low stretch halyard line. XLS is fine. Spectra not necessary. Easy on the hands is nice and not slippery.
BTW: you can wash lines in a bucket and soften them up as well as get all the salt and debris out of them. Wont solve worn covers though! have you end for ended them?