Loos & Co. tension gauge

[Mikado]

Originally Posted by thomm225

The 0-40 is simply the scale on the gauge not the tension. You have to look to the right of the scale number for the tension.

As far as tension, he has to make that decision. Slack rig or tight rig.

I was just showing that 5 % the low number the loos example gives of 3/16 wire was 235 lbs


As I said before, I have all my stays at 440 except the forward lowers which are at 550 because I wanted a bit of mast prebend. I haven't touch mine since which was 3 years ago I believe.

I did a quick check with my halyard last week and the mast was still straight side to side.

On our racing beachcat diamond wires, we set them anywhere from 450-1000 depending on wind strength on that particular day.

I found that 750 tension with a 2" spreader rake gave me around 1 1/2 " of prebend on a Nacra F-17 carbon fiber mast.

You sort of need to know what you want for your tension then do your measurements and adjustments.

Thomm,

Thanks for the great explanation. Even my addled brain can figure this out now.

[thomm225]

Originally Posted by Mikado

I re-read the instructions that came with my Loos gauge to see if it notes that the readout is a conversion, and if so, what it is. Nothing was noted. All it says it that it measures pounds of tension.

Could it be that if the gauge reads 30 that is really 300 lbs? That would explain why there is such a huge range in recommendations.

Thanks,

Jeff

Example, on this gauge a 30 on the scale is 350 lb for 3/32 wire

https://www.google.com/search?q=loos...acyOjqedYfM%3A

On a PT-2

http://www.amazon.com/Loos-Cableware.../dp/B007CNC06U

16 on the scale is 420 lbs for 3/16 wire. (9% breaking strength)

[chris95040]

Originally Posted by Mikado

Jag39,

What device are you using that measures hundreds of pounds? The largest Loos model only goes up to 50 lbs. That alone should make it obvious that hundreds of pounds of tension is not correct.

Thanks,

Jeff

Everyone claiming numbers in the tens of pounds are misreading their gauge.

The number on the gauge is use to reference a table (usually also on the gauge) to determine pounds of tension.

Assuming you want in the neighborhood of 10% breaking tension, this will mean you'll want several hundred (for small diameter wire) to several thousand (for larger diameter wire) pounds of tension.

And always take a step back and make sure you gut-check what you are doing. Folks cranking on a turnbuckle and thinking its resulting in 20 pounds of tension are dangerously out of touch with the forces they are toying with.

[jag39]

Originally Posted by Mikado

Jag39,

What device are you using that measures hundreds of pounds? The largest Loos model only goes up to 50 lbs. That alone should make it obvious that hundreds of pounds of tension is not correct.

Thanks,

Jeff

The small numbers down the left side are just the scale. The number next to it is the lbs. For instance, don't have my gauge with me but 30 on the scale for 7/32 wire should be about 660 lbs. if my memory is correct. It isn't 30lbs.

[Mikado]

Originally Posted by jag39

The small numbers down the left side are just the scale. The number next to it is the lbs. For instance, don't have my gauge with me but 30 on the scale for 7/32 wire should be about 660 lbs. if my memory is correct. It isn't 30lbs.

This all makes sense now. I purchased my Loos gauge used and there is no sticker on the right, only the readout on top from 0-50. I contacted Loos a few minutes ago and they are sending me new stickers at no charge.

Thanks for the explaination!! I'm going to update my rigging layout records to include not only the Loos readout per wire size but the equivalent pounds of tension.

Thanks again Jag39.

Jeff

[Halifax Sailor]

I am so impressed with all the info posted and i thank all those that have taken the time to do so. I am slowly working my way through all the posts and i believe i should be able to make some good choices. Please keep sending them as i want to get it right. To repeat, i am cruising, just the "admiral" and myself. she gets real nervous when we get to 20 degrees heel so not racing when she's on board. I am however going to try some club racing and everything i've read so far says i was way out of tune last summer and quite possibly a little dangerous in the rig being so loose (not that we were out any time when big winds were expected). This is why i stay tuned to this forum, what a great bunch!!

[Mikado]

Originally Posted by Halifax Sailor

I am so impressed with all the info posted and i thank all those that have taken the time to do so. I am slowly working my way through all the posts and i believe i should be able to make some good choices. Please keep sending them as i want to get it right. To repeat, i am cruising, just the "admiral" and myself. she gets real nervous when we get to 20 degrees heel so not racing when she's on board. I am however going to try some club racing and everything i've read so far says i was way out of tune last summer and quite possibly a little dangerous in the rig being so loose (not that we were out any time when big winds were expected). This is why i stay tuned to this forum, what a great bunch!!

I completely agree. This has been such a great learning experience for me with so many well though out, positively presented contributors. I read so many posts that turn into negative, sniping, "my way or the highway" conversations that they turn a potentially positive learning experience into a negative experience.

Because of this thread I've gone back and triple checked my last rigging adjustments and discovered that I have one size shroud adjusted to the upper limits of acceptable, so thank you all again for the lessons on proper rigging tensions.

I drew up a quick reference form that I'm going to start using for every adjustment so that I can keep track of any changes while I work towards finding the optimum tension settings.

Thanks to all who participated.

Jeff

[chuckr]

Originally Posted by Mikado

Jag39,

What device are you using that measures hundreds of pounds? The largest Loos model only goes up to 50 lbs. That alone should make it obvious that hundreds of pounds of tension is not correct.

Thanks,

Jeff

I could provide the setting but it really is not the pounds of tension but the positon of the mast. The pros spend a bit of time adjusting the tensions just a bit to get the mast straight and centered for ultimate sailing performance. We are not racers nor have any plan to race but always try to get a rigger who rigs racing boats. Reason they know how to rig for ultimate performance even though we will never get there or push the boat that hard. And all the shroud are a bit different in the Loos settings.

[mottseng]

Originally Posted by reed1v

For cruising we always kept stays and shrouds loose enough so you could pull them one inch out of true. You want all your rigging to have some play and enough toggles so the rigging can bend in all directions as the stresses change. Never start tightening leeward shrouds when under sail. they are suppose to be loose. Rule of thumb is tighten your turnbuckles hand tight and then half turn with your fid.

Where did you come up with the "Rule of Thumb"??

I believe you are way off in your advise.

[reed1v]

Originally Posted by mottseng

Where did you come up with the "Rule of Thumb"??

I believe you are way off in your advise.

Well then, tighten them so they are absolutely tight and zero flex. See how long your rig and tangs last. I was brought up with that rule of thumb by my grandfather. Worked well. No deck crazing around chainplates, no stress lines either on deck next to masts, nor any deformation in masts.

[mottseng]

Originally Posted by reed1v

Well then, tighten them so they are absolutely tight and zero flex. See how long your rig and tangs last. I was brought up with that rule of thumb by my grandfather. Worked well. No deck crazing around chainplates, no stress lines either on deck next to masts, nor any deformation in masts.

It was the first time I have heard of that particular rule of thumb. I would prefer to use calibration tools like the LOOS gauge.

Each to their own.

[reed1v]

Originally Posted by mottseng

It was the first time I have heard of that particular rule of thumb. I would prefer to use calibration tools like the LOOS gauge.

Each to their own.

Gauges are fine. We prefer slack in a long distance cruiser to reduce stress on the rigging an mast. Some folks prefer to keep bar tight as if they are racing all the time. When i was a kid(12 years old) destroyed a lighting sailboat(plywood) by way over tightening the mast. Ripped out the port chain plate. Did about the same with a 110. That is when my grand father decided to educate me in the ways of structural issues. Much like over torque on bolts. Bye bye threads. So you can use a gauge to judge torque or you can use a rule of thumb(tight, then half turn).

[chris95040]

Originally Posted by reed1v

We prefer slack in a long distance cruiser to reduce stress on the rigging an mast.

Less tension does not equal less stress.

In fact, I'd guess that in general it will mean the mast itself is being subjected to more stress as it is allowed to flex more, get more out of column, etc.

[reed1v]

Originally Posted by chris95040

Less tension does not equal less stress.

In fact, I'd guess that in general it will mean the mast itself is being subjected to more stress as it is allowed to flex more, get more out of column, etc.

If you have too much slack, then yes, every sea will cause the rigging to snap; eventually hardening the fittings and cause failure. Too tight and all the stress is immediately transferred throughout the rigging and the hull.

It's like a violin; all components have to work together at a certain tension to make the thing work well. Tight but not too tight so the wire can stretch along with everything else in a controlled manner. Ever notice how the leeward shrouds flop around? Clueless folks try to tighten them up only to find they have hocked the mast when on the other tack.

Or if you have a backstay hydraulic tensioner, see what happens if you really get that under extreme loads for a month or so.

[Halifax Sailor]

So with all the input i set my rig to 16 inner and 18 outer for this season and checked it twice during. Last two seasons i have been able to get the boat to 6.5, 6.8 knots once last year with two very experienced sailors trimming and going for it. This year after the input, i set as above and lo and behold, 7 knots on a regular basis ( and hull speed says 6.2 at best according to what i can find). So thx for all the input, i am a cruiser, the gauge is very helpful and all the advice has really helped make this past season a great one (and fast)!! and the rig doesn't bag when on opposite tack.