• Announcements

    • Zapata

      Abbreviated rules   07/28/2017

      Underdawg did an excellent job of explaining the rules.  Here's the simplified version: Don't insinuate Pedo.  Warning and or timeout for a first offense.  PermaFlick for any subsequent offenses Don't out members.  See above for penalties.  Caveat:  if you have ever used your own real name or personal information here on the forums since, like, ever - it doesn't count and you are fair game. If you see spam posts, report it to the mods.  We do not hang out in every thread 24/7 If you see any of the above, report it to the mods by hitting the Report button in the offending post.   We do not take action for foul language, off-subject content, or abusive behavior unless it escalates to persistent stalking.  There may be times that we might warn someone or flick someone for something particularly egregious.  There is no standard, we will know it when we see it.  If you continually report things that do not fall into rules #1 or 2 above, you may very well get a timeout yourself for annoying the Mods with repeated whining.  Use your best judgement. Warnings, timeouts, suspensions and flicks are arbitrary and capricious.  Deal with it.  Welcome to anarchy.   If you are a newbie, there are unwritten rules to adhere to.  They will be explained to you soon enough.  

Archived

This topic is now archived and is closed to further replies.

sietchells

2:1 main halyard setup

Recommended Posts

J111's are now allowed to have a 2:1 main halyard. I'm preparing to set one up by increasing the current halyard length by the P dimension plus a little, drilling a hole in the mast crane to accept a pin for an eye on the end of the halyard and running it on a tylaska 2:1 halyard shackle. Now I have a couple of questions: should the halyard be stripped? Should the halyard still be led to a rope clutch on deck or should it be on the mast? Is endura braid low stretch enough or should I use something more exotic. Any and all suggestions are welcome and thanks for your time!

Share this post


Link to post
Share on other sites

Good move on the class rules, in my opinion. Yes, stripping the halyard will reduce weight and friction, both important elements. Endura Braid (Dyneema core) as well as any other DSK-78 double braid lines in the market will last longer that most of the other fibers, however, I reckon Vectran works better on the static loads but is more UV sensitive than Dyneema. That been said, probably the best shot is to get a hybrid, such as the Samson Validator SKB which carries a Vectran/Dyneema blend core.

The SKB 3/8" has a tensile strength of 12,900 lbs, vs. 11,000 of Endura Braid in 10mm and 12,600 lbs of V-100 in 3/8", therefore is the strongest and more UV stable option.

I would add an anti-chafe sleeve to the eye that will go pinned on the mast crane, just make sure the line is well protected up there.

In regards to where to lead the line to, I think is best to run the halyard aft for strength and also for the bunch of rope that you'll have once the mainsail is fully hoisted. It is easier to toss the line down than keep it on the mast area,

Let me know if we can help on any way.

Share this post


Link to post
Share on other sites

If you go the Vectran route (which is not a bad idea - I have that on my boat) it is a very good idea to add a 2-3 foot pigtail of Dyneema at the masthead end as it is much better in terms of both abrasion and UV resistance. you can even just replace the pigtail when it gets tired and not the entire halyard. Not sure that I would bother with a chafe guard but make sure the turning radius around the pin is not too tight - a thimble could be a good thing to add to the splice if there is room and it doesn't impact your hoist.

Another way to skin the cat is to use Dynex Dux for the halyard - marginally more creep than Vectran but without the (small) downsides of Vectran.

Good move on the class rules, in my opinion. Yes, stripping the halyard will reduce weight and friction, both important elements. Endura Braid (Dyneema core) as well as any other DSK-78 double braid lines in the market will last longer that most of the other fibers, however, I reckon Vectran works better on the static loads but is more UV sensitive than Dyneema. That been said, probably the best shot is to get a hybrid, such as the Samson Validator SKB which carries a Vectran/Dyneema blend core.

The SKB 3/8" has a tensile strength of 12,900 lbs, vs. 11,000 of Endura Braid in 10mm and 12,600 lbs of V-100 in 3/8", therefore is the strongest and more UV stable option.

I would add an anti-chafe sleeve to the eye that will go pinned on the mast crane, just make sure the line is well protected up there.

In regards to where to lead the line to, I think is best to run the halyard aft for strength and also for the bunch of rope that you'll have once the mainsail is fully hoisted. It is easier to toss the line down than keep it on the mast area,

Let me know if we can help on any way.

Share this post


Link to post
Share on other sites

I race on a J/111 in Baltimore. A 2:1 halyard seems a bit silly. The main isn't that big or heavy. A small mast person can easily hoist the main.

 

You can spend more money here on more line and shackles, but it would be very marginal gains.

Share this post


Link to post
Share on other sites

I race on a J/111 in Baltimore. A 2:1 halyard seems a bit silly. The main isn't that big or heavy. A small mast person can easily hoist the main.

 

You can spend more money here on more line and shackles, but it would be very marginal gains.

 

Not the point... point is to reduce compression loads and to reduce the effects of halyard stretch/creep.

Share this post


Link to post
Share on other sites

no, total compression on the mast stays the same.

 

the advantage is that you can use a thinner halyard (lighter) and the aforementioned negated stretch/creep by a lower halyard load. the other advantage is that it is easier to adjust - even when highly loaded, and there is negligible slip in the clutch. We used a 2:1 on a J109 (didnt do any class racing) and it was a worthwhile change.

 

as for the OP, we used a non 2:1 (so no roller, just a smooth surface) Tylaska halyard shackle, H8 if i recall, and we did not strip the cover. The fact of the matter is that the friction when it is fully loaded doesnt matter that much since it is not moving once its fully loaded (full sheet/cunno etc). If you want to strip it, go for it, its not a hard splice to learn, and you can always slide the cover to end-end it. I moved the knot in the masthead crane up a few inches every year or so to move the wear points around. We used 1/4" warpseed. I do not recommend Vectran, but, then i do not recommend Vectran for anything but opti sail ties anyway. I've had too many breakages with line that wasnt all that old with that material.

 

edit: if the clutch is on deck leave it on deck. For inshore racing its nice to have the main lead to a cluth on the mast below deck, with the idea being that it keeps it out of the way etc. This is a little annoying offshore but i still prefer it that way. As for attaching to the mast crane, our boat just had a whole drilled in the crane and i tied a big stopper knot. Seems to be the way it is on the other boats i've gone up the rig on as well (Tripp41 and King 40). The material that we used is equivalent to Endurabraid, and endurabraid may even be preferable since i think it kinks a little less. Warpseed is a great line, though.

Share this post


Link to post
Share on other sites

Mustang,

 

The reason you can use thinner, lighter halyards is because the halyard load is smaller, right? If he halyard load is lighter, then the compression due to halyard loads is smaller, right?

 

Trust me, compression due to halyard loading falls by 50% in a 2:1 halyard solution.

Share this post


Link to post
Share on other sites

the force on the tack of the sail is the same. the total downward force on the mast is the same.

Disagree - The amount of load on the headboard, holding the main up, is the same, however, the amount of compression force from the masthead sheave to the mast base has been reduced by half.

 

Bam Miller

Share this post


Link to post
Share on other sites

A minor housekeeping consideration with a 2:1: If you leave the rig up in winter, you'll need to unfasten the main halyard from the crane at the end of the season to pull messengers. No biggie if your bowman will be at the MH anyway to pull the MHU. Of course, he cannot get up there on the main halyard...

 

P

Share this post


Link to post
Share on other sites

Mustang,

 

The reason you can use thinner, lighter halyards is because the halyard load is smaller, right? If he halyard load is lighter, then the compression due to halyard loads is smaller, right?

 

Trust me, compression due to halyard loading falls by 50% in a 2:1 halyard solution.

 

No. Cropduster, you're wrong here. Either you're talking voo-doo physics or you don't understand the different types of forces.

 

The only compression force would be on the mast. That won't change as long the forces in sailing, halyards and me schooling you follow the same laws of physics the rest of the universe follows. No forces are lost and no forces are created.

 

There would be a downward force on the shiv and a downward force on the mast crane where the static end of the 2:1 halyard is anchored. Any force would be spread equally across the shiv and anchor. The upward force on the head of the main would equal the downward forces. The force of tension on the halyard would be half and it experiences the same force as the shiv and anchor.

 

1:1 Setup

P = upward force on head

P = downward force on shiv

P = downward force on the mast crane

P = force of compression on the mast

P = force of tension in halyard

 

2:1 Setup

P = upward force on head is also equal to the force of tension on the Tylaska 2:1 H8

0.5P = downward force on anchor

0.5P = downward force on shiv which is the same as the force of tension in the halyard

0.5P + 0.5P = downward force on the mast crane

P = force of compression on the mast

0.5P = force of tension in halyard

The compression force on the mast is equal to the forces on the shiv plus the anchor as they are mounted on the mast crane.

 

The compression forces on the mast are the same in a 2:1 mounted on the mast crane as a 1:1. The benefit is that the force required to raise the sail and the force of tension on the halyard are 0.5P.

Share this post


Link to post
Share on other sites

God, we're not doing this again, are we? Please, please, please nobody mention lee bow.(*)

 

(* Bugger. Done it now). Image shamelessly nicked (via google image search) from Peaky on the Y&Y forum. And yes, it ignores friction losses. Mast compression is least with a halyard lock (1000N in this example), most with a 1:1 halyard (2000N) and 1500N with a 2:1 halyard.

 

2009-03-18_123015_mast_compression.JPG

Share this post


Link to post
Share on other sites

a 1:1 setup has a mast compression load of 2x the halyard load

a 2:1 setup reduces Mast compression loads by 25% (to 1.5x the halyard load)

a halyard lock reduces the compression loads by 50% (to 1x the halyard load)

Share this post


Link to post
Share on other sites

It is a good idea to be right when you are trying to correct someone else..........................better draw this out as you got off track on this one

 

C

 

Mustang,

 

The reason you can use thinner, lighter halyards is because the halyard load is smaller, right? If he halyard load is lighter, then the compression due to halyard loads is smaller, right?

 

Trust me, compression due to halyard loading falls by 50% in a 2:1 halyard solution.

 

No. Cropduster, you're wrong here. Either you're talking voo-doo physics or you don't understand the different types of forces.

 

The only compression force would be on the mast. That won't change as long the forces in sailing, halyards and me schooling you follow the same laws of physics the rest of the universe follows. No forces are lost and no forces are created.

 

There would be a downward force on the shiv and a downward force on the mast crane where the static end of the 2:1 halyard is anchored. Any force would be spread equally across the shiv and anchor. The upward force on the head of the main would equal the downward forces. The force of tension on the halyard would be half and it experiences the same force as the shiv and anchor.

 

1:1 Setup

P = upward force on head

P = downward force on shiv

P = downward force on the mast crane

P = force of compression on the mast

P = force of tension in halyard

 

2:1 Setup

P = upward force on head is also equal to the force of tension on the Tylaska 2:1 H8

0.5P = downward force on anchor

0.5P = downward force on shiv which is the same as the force of tension in the halyard

0.5P + 0.5P = downward force on the mast crane

P = force of compression on the mast

0.5P = force of tension in halyard

The compression force on the mast is equal to the forces on the shiv plus the anchor as they are mounted on the mast crane.

 

The compression forces on the mast are the same in a 2:1 mounted on the mast crane as a 1:1. The benefit is that the force required to raise the sail and the force of tension on the halyard are 0.5P.

Share this post


Link to post
Share on other sites

you beat me to it. By using a halyard shackle (like a Tylaska) with some friction a 2:1 setup is probably close to a 35-40% reduction in mast compression - using a sheave based halyard shackle; while making hoisting easier; the reduction is only 25%

God, we're not doing this again, are we? Please, please, please nobody mention lee bow.(*)

 

(* Bugger. Done it now). Image shamelessly nicked (via google image search) from Peaky on the Y&Y forum. And yes, it ignores friction losses. Mast compression is least with a halyard lock (1000N in this example), most with a 1:1 halyard (2000N) and 1500N with a 2:1 halyard.

 

2009-03-18_123015_mast_compression.JPG

Share this post


Link to post
Share on other sites

Well.. I'm happy to go back to school as well..

 

Let's see if I can correct my work.

 

1:1 Setup

P = upward force on head

P = downward force on shiv

P = force of tension in halyard

2P = downward force on the mast crane

2P = force of compression on the mast

2:1 Setup w/ Anchor

P = upward force on head is also equal to the force of tension on the Tylaska 2:1 H8

0.5P = downward force on anchor

P = downward force on shiv which is the same as the force of tension in the halyard

P + 0.5P = 1.5P downward force on the mast crane

1.5P = force of compression on the mast

0.5P = force of tension in halyard

Share this post


Link to post
Share on other sites

A REALLY IMPORTANT safety consideration with 2:1 halyards is DO NOT go up the rig on the 2:1 purchase. Tie the halyard off on the harness and go up 1:1.

 

You don't know the state of the standing part ( the end secured to the crane ). I had a nasty experience many years ago on a Farr 40 OD with the crew up the rig on the 2:1 and the halyard end at the crane let go. Very fast reflex's by the crew up the rig left her wrapt around the mast above the hounds.

 

A minor housekeeping consideration with a 2:1: If you leave the rig up in winter, you'll need to unfasten the main halyard from the crane at the end of the season to pull messengers. No biggie if your bowman will be at the MH anyway to pull the MHU. Of course, he cannot get up there on the main halyard...

 

P

Share this post


Link to post
Share on other sites

 

A REALLY IMPORTANT safety consideration with 2:1 halyards is DO NOT go up the rig on the 2:1 purchase. Tie the halyard off on the harness and go up 1:1.

 

You don't know the state of the standing part ( the end secured to the crane ). I had a nasty experience many years ago on a Farr 40 OD with the crew up the rig on the 2:1 and the halyard end at the crane let go. Very fast reflex's by the crew up the rig left her wrapt around the mast above the hounds.

 

A minor housekeeping consideration with a 2:1: If you leave the rig up in winter, you'll need to unfasten the main halyard from the crane at the end of the season to pull messengers. No biggie if your bowman will be at the MH anyway to pull the MHU. Of course, he cannot get up there on the main halyard...

 

P

 

was just about to say.... standard practice, of course, to not go up on a shackle... but shit that girl was lucky and fast!

Share this post


Link to post
Share on other sites

You should always use a safety if at all possible and when you do the risk of going up on the 2:1 is backed up.

 

A REALLY IMPORTANT safety consideration with 2:1 halyards is DO NOT go up the rig on the 2:1 purchase. Tie the halyard off on the harness and go up 1:1.

 

You don't know the state of the standing part ( the end secured to the crane ). I had a nasty experience many years ago on a Farr 40 OD with the crew up the rig on the 2:1 and the halyard end at the crane let go. Very fast reflex's by the crew up the rig left her wrapt around the mast above the hounds.

 

A minor housekeeping consideration with a 2:1: If you leave the rig up in winter, you'll need to unfasten the main halyard from the crane at the end of the season to pull messengers. No biggie if your bowman will be at the MH anyway to pull the MHU. Of course, he cannot get up there on the main halyard...

 

P

Share this post


Link to post
Share on other sites

Are you still running your stock halyard and how old is it? The stock halyard is 3/8" Crystaline which is Vectran. It would be quite easy to add a light tail to make it long enough for 2:1 depending on the age. Sliding the cover creates a taper and covers a good portion of the light tail. A Dyneema pigtail highly recommended.

 

This is a good heads-up. We can easily add the hole for a 2:1 dead-end in pre-assembly so it is painted on all future rigs.

 

Mark

J111's are now allowed to have a 2:1 main halyard. I'm preparing to set one up by increasing the current halyard length by the P dimension plus a little, drilling a hole in the mast crane to accept a pin for an eye on the end of the halyard and running it on a tylaska 2:1 halyard shackle. Now I have a couple of questions: should the halyard be stripped? Should the halyard still be led to a rope clutch on deck or should it be on the mast? Is endura braid low stretch enough or should I use something more exotic. Any and all suggestions are welcome and thanks for your time!

Share this post


Link to post
Share on other sites