Spreader rigging keeper tension?

[KrustyKrab]

Not quite sure what to call these things (see pic). The keeper that holds the standing rigging in the tip of the spreaders - should it be clamped down on the cable or should it be loose enough for the cable to slide through it?

While bringing my old 23.5 out of mothballs I noticed that these were clamped down on the rigging cables. I'm thinking that if these are clamped down then the force is only being transmitted from the spreader tip to the boat attachment, rather than from the top of the mast to the boat attachment. That doesn't sound right to me.

Can anyone tell me what is the proper way to adjust the cable keeper on the ends of the spreaders? Thank you.

 

[Chasemixon]

On my 22, they slide freely.

 

[justsomeguy]

They're called "spreader tips", and no, they should not be able to slide along the shroud with ease.

The "proper" way (or what worked for me, anyway) is to adjust the keeper to set it somewhat loose, so there's enough friction to prevent its moving, but loose enough to slide it to the position where you'll ultimately want it.

That position will bisect the angle that the shroud takes at the spreader tip. The angles on either side of the spreader should be as close to equal as possible. Using a boathook, you can budge the spreader up or down. When you've gotten the angles to the best that your eyes can discern, lower the mast and snug the tips up just enough to lock them in place, then maybe install some chafe-prevention on the tips.

I think...

 

[Crazy Dave Condon]

Your mast was definitely a Z Spar mast and as mentioned it is a spreader tip that was designed for the upper shrouds to be secured to. The former and last respected manager for Z Spar told me as a dealer then, to lift up on the spreader bar toward the top and when resistance was met so not to bend the spreader itself, then lock that shroud in the spreader tip as it was not designed for the shroud to slide in. Many reasons for that but one I can think of is the upper portion of the upper not getting tangled when tight.

 

[KrustyKrab]

Thanks everyone. Yes, Dave, it is a Z-Spar. Justsome and Dave are saying pretty much the same thing. Now I see that if you adjust the spreader correctly it will transmit the force vector to the top of the mast.

So Dave, I'm assuming that I do this adjustment with the mast down because I would have no way to get to the spreader tips with the mast up? Thanks as always for your expert advice!

 

[Jackdaw]

ProTip: With the mast down, pull the shroud tight downwards along the mast and mark it with a sharpie where it crosses the middle of the spreader in its base. This is the EXACT position where it needs to be tightened in the spreader tip so it correctly bisects the angle. The spreader should be angled slightly up. Check the math, no matter how long your spreaders are or how far down from the hounds, it always works. Here's a quick picture to show how it works geometrically.

Note - this is for single spreaders (or top spreaders) only.

 

[justsomeguy]

snip-

So Dave, I'm assuming that I do this adjustment with the mast down because I would have no way to get to the spreader tips with the mast up?

Mast up, using a long-ish pole that can both push and pull the spreader into position.

 

[Crazy Dave Condon]

Jackdaw, the method described came from the one who designed the mast for the 23.5

 

[Jackdaw]

Jackdaw, the method described came from the one who designed the mast for the 23.5

Dave, I'll defer to that wisdom on the 23.5; I assume the spreader base has the correct amount of angle built in.

The method I describe is used by professional riggers (and endorsed by spar designers) worldwide as it will always give the correct angle to bisect the vertical and diagonal shrouds.

I'd be willing to bet of you did my trick on the H23.5, it would end up where your guy wanted it.

 

[Crazy Dave Condon]

WE can agree to disagree but as a dealer I found that raising the spreader like the mfg. taught me, marking the wire and then tightening the spreader tip actually worked fine for me. I was taught well when many before me said to learn from the wise who knew what they were doing and apply their experience and in this case, the fellow who designed that mast and built it for Hunter.

Often I saw some masts on 260's prebend was too much and advised on how to tune. All reported sailing faster with less heel and strain to the wires which by the way were like piano wires (actually too tight)

However, your advice was good but I was going from a practical solution specifically for that boat alone.

 

[Jackdaw]

WE can agree to disagree but as a dealer I found that raising the spreader like the mfg. taught me, marking the wire and then tightening the spreader tip actually worked fine for me. I was taught well when many before me said to learn from the wise who knew what they were doing and apply their experience and in this case, the fellow who designed that mast and built it for Hunter.

Often I saw some masts on 260's prebend was too much and advised on how to tune. All reported sailing faster with less heel and strain to the wires which by the way were like piano wires (actually too tight)

However, your advice was good but I was going from a practical solution specifically for that boat alone.

Dave, not disagreeing with you. I'm sure the 'practical solution' your rep taught you was based on good engineering.

Both methods will give correct (the same) results on the H23.5

 

[Crazy Dave Condon]

I agree with both solutions. Now if I could reach out and share some rum or moonshine.,