A frame on a five metre wide Kat?

[fred278]

1 Height of A frame to width of Kat
2 Is there a mathematical formula
3 What tension is required for the steel rope
I am sorry if this is not the right term for the A frame, but it is the
Only way to describe it.
I would be grateful for any information.
Fred

[Sailmonkey]

I’m not even sure what it is you’re asking about?

This is posted in anchoring and mooring so I’m even less sure of what you’re looking for.

[Sailmonkey]

I’ve just had a thought....are you asking about the pelican striker on the forward crossbeam? The strut that supports the loads from the forestay?

[B-Baysailer]

Maybe he is asking about the load on a cross beam on a cataram ?

[fred278]

Thank you for trying to help.I'll try to explain it better. 1. If you stand in front of the cat in the middle of the cross member at the front there is a triangle of steel piping, what is the name of this? 2. From the apex of the triangle is a steel wire running to each hull. Is there a mathematical formula regarding height and tension of triangle and wire.
Again thank you for your help and patience. Fred

[B-Baysailer]

I think it's called resolving force do a Google search for that

[zstine]

Just simple balance of forces with the forestay pulling up on the cross beam, the tension in the wire pushes down on the vertical tubing attached to the cross beam. I haven't done a free body diagram, but I think the balance is:
2 * (Cos angle)*(wire tension) = Vertical forestay tension



2 because the wire is on both port and stbd so it acts twice on the vertical tube.

the "angle" is between the cross wire and vertical.



use similar trig to solve for vertical tension in forestay load, which for this you could assume 15-20% breaking strength I'd guess... but i'm not a rigger.

[Jamme]

FWIW... I think the "A frame" is called "seagull striker". The "V frame" (if any) is called "dolphin striker."

I was looking at this video: an original (don't know if / how safe) way of rigging the striker:

https://www.youtube.com/watch?v=2xJK4LJQYw0

[fred278]

Originally Posted by B-Baysailer

I think it's called resolving force do a Google search for that

Thank you very much for the information
Fred

[fred278]

Originally Posted by zstine

Just simple balance of forces with the forestay pulling up on the cross beam, the tension in the wire pushes down on the vertical tubing attached to the cross beam. I haven't done a free body diagram, but I think the balance is:
2 * (Cos angle)*(wire tension) = Vertical forestay tension



2 because the wire is on both port and stbd so it acts twice on the vertical tube.

the "angle" is between the cross wire and vertical.



use similar trig to solve for vertical tension in forestay load, which for this you could assume 15-20% breaking strength I'd guess... but i'm not a rigger.

Thanks that's great
Fred

[fred278]

Originally Posted by zstine

Just simple balance of forces with the forestay pulling up on the cross beam, the tension in the wire pushes down on the vertical tubing attached to the cross beam. I haven't done a free body diagram, but I think the balance is:
2 * (Cos angle)*(wire tension) = Vertical forestay tension



2 because the wire is on both port and stbd so it acts twice on the vertical tube.

the "angle" is between the cross wire and vertical.



use similar trig to solve for vertical tension in forestay load, which for this you could assume 15-20% breaking strength I'd guess... but i'm not a rigger.

That is very informative. Thank you.
Fred