Standing rigging tensioning

[Daydream believer]

No way. The rig is bar tight. With a my very large adjustable spanner, I really struggle to put any more turns on the bottlescrew. It's almost impossible.
As I said, no slack in the leeward rig going up wind
It is possible that the measurement of load is not accurate, but we used the 2m rule method and measured the stretch with a digital vernier

11% of a 12mm wire is very little stress on the rig, if you think about the max load that a 12mm wire will take.
With all due respect It suggests that your calcs are off. Obviously if it works then fair enough. One cannot dispute that.
But I cannot see that it is as low as 11%.
It would be interesting to know the opinion of others on this, if they have similar sized wires.

I use a loos guage on mine & leave my lowers slack to allow the mast to bend forward when the backstay is tensioned. This flattens the mainsail somewhat. But even then I find that 11% is a bit loose

 

[geem]

11% of a 12mm wire is very little stress on the rig, if you think about the max load that a 12mm wire will take.
With all due respect It suggests that your calcs are off. Obviously if it works then fair enough. One cannot dispute that.
But I cannot see that it is as low as 11%.
It would be interesting to know the opinion of others on this, if they have similar sized wires.

I use a loos guage on mine & leave my lowers slack to allow the mast to bend forward when the backstay is tensioned. This flattens the mainsail somewhat. But even then I find that 11% is a bit loose

There isn't really much to calculate. We use the .Selden method as described in their manual. 1mm of stretch is 5% of load. Getting 12mm to stretch beyond 13% was a serious effort. We have an 18" adjustable spanner for the task. The bottlescrews are all well lubricated.
By comparison, adjusting the mizzen mast with 6mm wire was super easy. That is set at 15%. The force to set 12mm wire to 15% would be substantial.
Since it works fine at 11% and we have no sag, I will leave it like that.
It took over 30,000nm to break a strand on wire on the babystay and 37,000nm for the same on an aft lower. It cant be too bad. Guys we met here yesterday need to replace caps as they have strand failure after only 2.5 years

 

[geem]

Thinking about the percentage rigging tension thing a bit more.
If you have 8mm rigging, the breaking load for 1x19mm wire is about 4,600kg. If you set this to 15% you should be imposing a static load of about 690kg.
If you were to upgrade let's say the babystay as I did in 2014 to 10mm you would have increased the breaking load to 7,250kg. Would you expect to tension this wire to 15% of its rating? That would impose a load of 1,087kg. An increase in tension of 57%. If you then swapped out the 10mm wire for compact strand as I did in 2021, as I had a strand failure, you would now have a wire with a breaking load of 10,250kg that has more than twice the working load of the original 8mm wire! So what are you going to tension it to?
My boat is 44ft and rigged with 12mm wire and mechanical stalok terminals. The working load of that wire is over 10t. If the rig was built like this to give is a higher safety factor, which I believe it was, why do I need to tension it to the spec of the over sized wires? Surely if the leeward rigging doesn't go slack when beating to weather under full canvas, then the rigging is sufficiently tensioned such that there is no mast sag to leeward, then the rig is tension correctly. Even if this means 13% on the lowers and 11% on the caps. The same percentages that would give a floppy rig on 8mm wire

 

[Daydream believer]

I am not criticising what suits your set up. It just prompted me to put the question for discussion

However, has it occurred to you that broken strands are sometimes caused by slack rigging?
I have heard of a cruiser who slackened his rig when on the hard & suffered a couple of snapped strands. I have read about similar reports on other media in the long distant past..
It has certainly happened on our Squibs,-- but one accepts that they are a somewhat different rig setup with different wires- but it is a result of slack rig, when left on the mooring. that being said, a 40ft boat is going to suffer from the gyro effect at the top of the mast

 

[geem]

I am not criticising what suits your set up. It just prompted me to put the question for discussion

However, has it occurred to you that broken strands are sometimes caused by slack rigging?
I have heard of a cruiser who slackened his rig when on the hard & suffered a couple of snapped strands. I have read about similar reports on other media in the long distant past..
It has certainly happened on our Squibs,-- but one accepts that they are a somewhat different rig setup with different wires- but it is a result of slack rig, when left on the mooring. that being said, a 40ft boat is going to suffer from the gyro effect at the top of the mast

Our rig is certainly not slack. It is bar tight as I keep telling you! Slack rigging will show itself when you sail hard to weather under full canvas. It's not slack.
Your 8mm rig with 15% tension will have a load of about 700kg. Our 12mm rig with a tension of 11% will have a load of about 1100kg. Why do you think it will be slack?
From the Premium Ropes website;
Shroud tension: The initial rigging tension should be high enough that the leeward shrouds do not slack when sailing up wind in some proper wind conditions. The exact tension can be found during a few trial runs under sail. If you have found the right tension then a Loos Tension Gauge can be used to measure and maintain the right value. For many boat designs a shroud tension of 10-12% of the breaking strength of the cable is adequate.
Mine are 11%. Looks like they are spot on