Upper and lower shrouds on one chain plate. How to?

[Benz]

^^ It is common to have the spinnaker halyard external to the mast, and common as well to have port and starboard spin halyards where the forestay and spin halyard are near each other, to avoid chafe.
The spinnaker halyard needs more freedom to articulate than an internal mast sheave can usually provide, so a lot of masthead units have a bail on the forward end on either side to put a block onto.

[Tupaia]

Running backstays may or may not be necessary but you need to understand why and what they do. They come into play when there is no fixed backstay (majority of cats) and the angles of the shrouds do not provide sufficient resistance to maintain forestay tension and in the case of multiple runners limit pumping of the lower mid sections and prevent mast inversion.

I do not have runners. Our original design called for 3 pairs. Since we sail as a couple we are essentially single handing most of the time. It was felt that forgetting to deal with runners was a huge risk and we therefore opted to set the shroud chain plates further aft (750mm) to provide the necessary tension on the forestay (all done in consult with the boat and rig designers). We do have a top mast jumper stay to keep that part of the mast stiff and transfer the loads exerted by the top of the main down to the forestay. The disadvantage is the limitation on the boom angles. As it turns out we are quite quick so the main rarely rests on the shrouds.

If you are a lazy sailor or sail single handed then runners are just another complication. Bear in mind they are only required under certain conditions so adjusting your sail plan or sailing style will eliminate the need providing you stay within the design limits which in your case are bit vague given the history of your mast.

[Chotu]

Originally Posted by Benz

^^ It is common to have the spinnaker halyard external to the mast, and common as well to have port and starboard spin halyards where the forestay and spin halyard are near each other, to avoid chafe.
The spinnaker halyard needs more freedom to articulate than an internal mast sheave can usually provide, so a lot of masthead units have a bail on the forward end on either side to put a block onto.

OK, this I might have. I think I have three sheaves at the mast head, and there are so many unknown attachment points on this mast. I’m going to have to take a ton of pictures as soon as this place reopens. And I will put them all up in this thread.

All of the attachment points are half inch aluminum welded to the mast. There seem to be a whole bunch of them forward and up high. They look like they could be used with blocks to hoist a spinnaker.

I’m going to take a ton of pictures to see if anyone can identify some of these attachment points.

[Chotu]

Originally Posted by Tupaia

Running backstays may or may not be necessary but you need to understand why and what they do. They come into play when there is no fixed backstay (majority of cats) and the angles of the shrouds do not provide sufficient resistance to maintain forestay tension and in the case of multiple runners limit pumping of the lower mid sections and prevent mast inversion.

I do not have runners. Our original design called for 3 pairs. Since we sail as a couple we are essentially single handing most of the time. It was felt that forgetting to deal with runners was a huge risk and we therefore opted to set the shroud chain plates further aft (750mm) to provide the necessary tension on the forestay (all done in consult with the boat and rig designers). We do have a top mast jumper stay to keep that part of the mast stiff and transfer the loads exerted by the top of the main down to the forestay. The disadvantage is the limitation on the boom angles. As it turns out we are quite quick so the main rarely rests on the shrouds.

If you are a lazy sailor or sail single handed then runners are just another complication. Bear in mind they are only required under certain conditions so adjusting your sail plan or sailing style will eliminate the need providing you stay within the design limits which in your case are bit vague given the history of your mast.

Yes. Definitely I am understanding this now.

Thank you for the guidance.

It would be a lot better if the place my boat is was open right now. I could go ahead and get measurements. All the dimensions are there on the boat. I don’t have any of my documentation with me. I just jumped off the boat and I am basically just drifting around on land right now waiting for things to get done.

So I will post the complete dimensions of the attachment points and what not once they open next week. I’ll put it all in this thread. This seems to be where the discussion is.

I’ll post how far back the shrouds are attached.

[s/v Jedi]

Every boat is different but I think my rig is very similar to Chotu’s. My spreaders are swept aft by 30 degrees and I have no backstays at all. The cap-shrouds are the backstays.

For the worst weather conditions, as well as downwind sailing with spinnakers, it is highly recommended to use our running backstays, which are attached all the way up to the masthead. I use 10mm Amsteel Blue with 2:1 tails.

The high attachment on the mast also makes these great for tuning mast bend.

In practice, we always use the runners. With gybing in heavy weather, we gybe the sails into the backstays to help dampen the slam, then retract that backstay and set the other.

[s/v Jedi]

Originally Posted by Franziska

Just ignore the bad posts (it's hard sometimes!).

The ignore function is great when someone works on your nerves, but it doesn’t work when people hunt you down and kill every thread you start. There is no solution other than quitting. I have decided to stay and post in threads but have stopped new threads in the series I posted on electric installation diagrams because of this problem.

I also hope GRIT stays, we even met them out there in the blue

[Chotu]

Originally Posted by s/v Jedi

The ignore function is great when someone works on your nerves, but it doesn’t work when people hunt you down and kill every thread you start. There is no solution other than quitting. I have decided to stay and post in threads but have stopped new threads in the series I posted on electric installation diagrams because of this problem.

I also hope GRIT stays, we even met them out there in the blue

Now THAT is a true loss to the forum. Those electrical threads were fantastic.

It truly seems like the cretins come out here if things are going well for someone, such as they were in your electrical threads. Nice work, there. Beautifully done and so original. Loved the Jedi branding too.

It’s a huge loss that you are backing away from that. It’s quality contributions like that that make the forum good to read.

And I agree, our rigs sound very similar. I’m sure I’ll meet you out there on the eastern seaboard as well. I assume your boat is pretty hard to miss. Ha ha. Well, so is mine.

As soon as this rigging is done over here, I am heading east. And then north. Hallelujah.

[OutOfControl]

Originally Posted by GRIT

Thanks "out of control".

That looks better!

Was it easy to do, or does it require in-depth knowledge of forum software?

In other words... how embarrassed should I be?

Cheers.
Paul.

Sorry about the late response. I have a separate Blogger site that I use for posting pictures.
I first had to down load your pic and reopen in a photo app. Then I can rotate and edit as needed. I then have to upload to my Vlog and then upload to the forum.
I am sure there is an easier way, but this works for me.

Here's a link to create your own Blog. I believe it's still free.
https://www.blogger.com/