Forestay Connector/Fastener?

[mika]

Ah, good point, tkanzler. Not all rings are created equal! I wonder if anyone has ever had one without a "starter curl" fail? (Your second photo) Probably not. Thanks!

[Tomfoolery]

The downside is they're harder to start, and harder to remove (which is also a starting issue), but a small knife or thumbnail is all that's needed. Just don't use one so thick you can't get it started easily with what's readily at hand (like a thumbnail - how much more 'at hand' can you get? ).

[BOAT]

Yeah - THOSE ones! I have a hull of a time trying to get that into the pin.

[kurz]

I guess I have to conclude that most of you are entirely happy and feel perfectly secure with the pin and ring, despite reports that the cotter ring has been known to work its way out and release the pin.

The ringdings with a starter bend in them can also work themselves out, in my experience.


[/img]

Thanks - these silly orignials ringdings from MacGregor factory had alredy gone away... Down at the shroud. Good luck was that the pin still was there. I took some money and boght new ones at the local boat shop. The new ones look much better. I changed all - hope you will do also, ...

[BOAT]

Yes it's true, I have a 2013 boat and all the wing dings I got from the factory are the real hard ones to install that do not have the 'starter' bend in the wingy ding. That's why I'm having so much trouble getting the ring into the hole.

I noticed one day after sailing the the front forestay pin was all the way at the end like it was trying to work it's way out. The only thing holding it from moving further was the wingy ding. It was a windy day and the forestay had a pretty good bow in it on a close reach. (Lot's of fun) That genoa really pulls the boat along fast - I like it - but I too put up the 'secondary forestay' (spinnaker hound) on "boat" just for security. I think I would like to tape down the head of the pin to the chainplate to keep it from moving up. That's sort of bugs me (and it's creepy).

By the way, 'boat' has a name now. Should I change my avatar or wait until all the stenciling is done?

[Russ]

By the way, 'boat' has a name now. Should I change my avatar or wait until all the stenciling is done?

What's the name?
Change the AV now, why wait?

[BOAT]

Well, I just noticed that most of you guys don't use the name of your boat for your avatar. Back when i started sailing the internet did not even exist.

It seems most of you guys use parts of your name for your avatar? I don't get it.

Is highlander's boat really called "Highlander" ?

[Tomfoolery]

By the way, 'boat' has a name now. Should I change my avatar or wait until all the stenciling is done?

I hadn't noticed any way to change your own user name once it's established, other than abandoning it and starting over. I would have changed mine long ago to the name of my boat, but it doesn't seem possible.

[Judy B]

Any ring dings, no matter what style, can be pulled out by a flogging sheet unless the ring is wrapped with rigging tape. That's based on my personal expeirence. Therefore, I always put a piece of self amalgamating rigging tape around each ring. (Also around each cotter pin)

An untaped ring on a sailboat is an accident waiting to happen.

On my trailerable boats, I use a solid-core quickpin at the forestay , moused in place with a lanyard, and then protected by putting a couple of wraps of self-amalgamating rigging tape around it to hold it in place. It takes a few seconds to put the tape on the forestay pin every time I rig.

it's easy to remove self amalgamating rigging tape with a knife and it doesn't leave any sticky residue. It lasts years and years when exposed to UV. good stuff to keep on a boat.



Stay safe,
Judy B

[BOAT]

I think I would like to have a "solid-core quickpin" too! What kind? I want the tape too.

[seahouse]

If not covered, the sharp edges on the ring dings do tend to catch things like a fish hook. I had a genoa sheet catch one on the side stay adjusters and stretch it open- they are quite thin and bend easily. That was before I put tubes over them to prevent it from happening again. Now the sheets glide right over the adjusters and all.

I (unsuccessfully) tried reproducing this concept (link below) on ring dings and regular key rings, but it's difficult because you do need the flattened profile.

http://www.freekeyusa.com

A nice idea. And not made in China. Yet.

-Brian.

[Judy B]

I think I would like to have a "solid-core quickpin" too! What kind? I want the tape too.

The best rigging tape brands are West Marine and Tommy Tape. These are self-bonding, self-amalgamating tapes. Not white vinyl electrical tape.

Avibank is the manufacturer of marine quality "Avi Quick Pins". Google them. The Detente style with at least two ball bearings is preferred.


http://www.avibank.com/index.cfm?fuseac ... duct_id=92
Check out the shear strength of these pins. pretty impressive.

I got this info from a highly experienced professional rigger who worked on SF bay for decades before becoming a solo-around-the-world racer. Bruce Schwab. He recommended using only solid-core detente style quick pins because they are as strong as a regular clevis pin.

Bruce told me that the hollow core pins (delux style, push style) may deform slightly under load and be hard to remove. Bruce says you won't lose your headstay if it deforms, but you may have to cut the pin in half to lower the rig.... he recommends keeping a hack saw with a good blade handy

Additional requirments for safety:
The fitting at the bow and the bottom of the forestay must have the same diameter holes, and not be egged-out.
You must use the correct diameter pin for a precise fit.
Keep the pins clean and dry-lubed so the mechanism doesn't gum up. Inspect them each time you use them.

[Judy B]

... I do have a question though. My furler has larger holes where the pin goes through than the chainplate hole....there is a couple of non captured bushings in the furler and they are a real Booger when pinning....I'm sure I'll lose one eventually....should I just drill the chainplate hole to the larger size and use a larger pin?

JT

(BTW,The fitting at the bow for the forestay/furler attachment is called a stem fitting, not a chainplate. I want to get the terminology correct before discussion the topic)

The best practice is to match the hole and the pin size (within a few thousands of an inch.) When a pin is smaller than the hole, it causes point loading and excessive wear on both parts. When the hole (aka eye) in a fitting is larger in diameter than the pin, the loads on the eye part are not distributed evenly. It causes the loads to be concentrated on a tiny point, which can deform and wear the fitting at an accelerated rate. The eye tends to get egg-shaped over time.

But in this case, I don't know whether it's better to make the hole in the stem bigger, or make the hole on the furler smaller (by replacing it). We would need to calculate the strength of the stem fitting after drilling away some metal to know if it's strong enough after alteration.

Drilling out the hole in the stem is probably okay, but maybe not. You can't be sure unless you calculate the tensile breaking strength from measurements of how much metal there is between the hole and the edge of the fitting. So take care to keep a very close eye on it and inspect it regularly and frequently. If you see any deformation or bending (leads to fatigue), it might be headed for failure.

If you don't know how to calculate the tensile strength of the stem fitting, the safer method would be to replace the fitting at the bottom of the forestay with one that matches the hole in the stem, to avoid drilling away any of the metal that gives the stem fitting its strength.

Mis-matched rigging is a can of worms....

Fair winds,
Judy B

PS...

The question in my mind is : why does the forestay fitting (a fork?) have a bigger hole than the stem fitting?

Did you "upgrade" the forestay to a bigger diameter, which necessitated a bigger turnbuckle or fork... and now you have a size mismatch between the bottom of the forestay/furler and the stem fitting? If so, you might consider going back to the correct size forestay and fittings.

I'm going to assume that macGregor's engineers spec'd the stem so it's strong enough for the forestay loads. And that they spec'd the forestay to be strong enough for the calculated loads on it. Usually, the forestays are loaded at less than 25% of their breaking strength (reference any book on rigging design), for a 4:1 safety margin or better. The stem fittings are spec'd to have a tensile breaking strength that's 133% of wire selected. (accordiing to Skene's elements of yacht design, various references)

[Catigale]

I'm not an ME but considering the two modes of failure possible on the stem plate

1 Clevis pin forces material failure of stem plate in compression and rips out top

And

2 Clevis pin forces material failure in tension on sides of Clevis pin hole, breaking stem plate into two.

I bet there are 3-4 more things that will fail before these things, like stem plate tears out of hull, forestay failure, fitting failure at top of forestay being a couple.

[WHRoeder]

Do not use those quick pins. They will pull out sideways and you loose the rig.
Been there, tried that.
You MUST use a pin with a circular or cotter pin.