Loos & Co. tension gauge

[Alberg 34]

Hi all
I have 5/16 on my Alberg 34 and run 30 lbs on the back shrouds 32 on the middle and 34 on the front . I take the time to adjust each side bit by bit ensuring the mast is straight. I find I have to put at least 5 in of mast rack in by tighting the split back stay or the mast will vibrate in higher winds at anchor (some call it pumping) Seams to work for my boat.

[leftbrainstuff]

Originally Posted by Halifax Sailor

Been looking for one, got lucky and got one for just a little money. It's a PT-2 model. NOW, i know it's important to have proper tension on the rigging. I am mostly a cruiser, 3/16 wire rigging. After reading the on-line instructions, still not sure how tight or how much tension to put on my rig. Can anyone explain exactly what i should be doing? have always just tightened to make the mast straight, then watched the rig when sailing to ensure it didn't bag too much one side or the other. not scientific but now i have the tension gauge. just looking for some advice.

The Loos gauges are a useful tool but not particularly accurate. Its consistency that is the key.

Others have advised on static tension so i wont rehash. Except to say that it depends on the lot or batch testing of the rigging supplier.

Apart from the rules of thumb for static tension, which are based on destructive testing of wire rope, you are trying to achieve two things. Firstly you want to keep the mast in column. Secondly under all loading conditions you want to avoid unloading any stay which will allow the mast to go out of column. Both of these conditions can only be checked dynamically.

The ideal static loading is the minimum needed to maintain the two dynamic loading conditions stated above. Any more tension is just compressing the mast and potentially cycling attachments.

So tension statically then check for mast alignment under load. Also check stays for loss of tension. You can check mast alignment by eye and shroud loss of tension by hand while sailing.

The top end race teams are now using load cells and real time data feeds but that approach is a little impractical for most of us.




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[Alberg 34]

Not all gauges are accurate a buddy has the same gauge as I have and there is a 3lb difference We were using both to save time setting up his tension ,one on port the other on starboard then switched them and realized they were reading the 3lb difference As he races we had to start over as the mast was not straight

[chuckr]

We have been full time cruisers for 8 years in the Carib an Atlantic crossing and now the Med. When we our Loos I hired a professional rigger to tune the rigging and wrote down the specs - I checked it myself from time to time and made small adjustments - before we crossed the Atlantic we had a pro rigger check it again and he confirmed the setting and the how well it was tuned. In the Med we checked our rigging each spring before we set out and last year had an issue with one of the shrouds and could not get the turnbuckle loose to make adjustment so had a prof turner come on to assist and he retuned the rigging and the one shroud had to have a new setting .
We have no issue of occasionally bring a pro on board to do a check - in 8 years I guess twice - -

[jag39]

Originally Posted by reed1v

That is the wrong way to do it, but if your happy with it, so be it. For deck stepped masts, that will eventually compromise the deck and possibly the compression post. For keel stepped masts, that will eventually transfer the excess compression to whatever the chainplates are attached to.

Something doesn't jive. You are saying that my tensioning is too high, though according to the breaking strength of my wire, I am still way below the recommended 15%, and I have no slack to leeward. Am i missing something here?

[jag39]

Originally Posted by Alberg 34

Hi all
I have 5/16 on my Alberg 34 and run 30 lbs on the back shrouds 32 on the middle and 34 on the front . I take the time to adjust each side bit by bit ensuring the mast is straight. I find I have to put at least 5 in of mast rack in by tighting the split back stay or the mast will vibrate in higher winds at anchor (some call it pumping) Seams to work for my boat.

Are you sure that's lbs, and not the large setting number? The lbs should be the higher number next to it, right?

[jag39]

Originally Posted by reed1v

That is the wrong way to do it, but if your happy with it, so be it. For deck stepped masts, that will eventually compromise the deck and possibly the compression post. For keel stepped masts, that will eventually transfer the excess compression to whatever the chainplates are attached to.

Just rechecked with the Loos website. Their recommendation for my rig is 1000lbs on forestay and 700lbs on shrouds. However, I will use your quote that "if your happy with it, so be it".

On that note, I have had professional riggers recommend "hand tight" and others say tension it properly, so you take your pick as to the advise you want to follow, and good luck with it.

[Mikado]

Originally Posted by chuckr

We have been full time cruisers for 8 years in the Carib an Atlantic crossing and now the Med. When we our Loos I hired a professional rigger to tune the rigging and wrote down the specs - I checked it myself from time to time and made small adjustments - before we crossed the Atlantic we had a pro rigger check it again and he confirmed the setting and the how well it was tuned. In the Med we checked our rigging each spring before we set out and last year had an issue with one of the shrouds and could not get the turnbuckle loose to make adjustment so had a prof turner come on to assist and he retuned the rigging and the one shroud had to have a new setting .
We have no issue of occasionally bring a pro on board to do a check - in 8 years I guess twice - -

Chuck,

For this conversation it would be very helpful if you could provide your Loos settings -vs- cable size as a reference point. Since you are using a Loos and have professional rigger feedback your settings might be excellent information. As you have read, the recommendations on this forum range from 25-50 lbs to hundreds of lbs.

Thanks,

Jeff

[Mikado]

Originally Posted by jag39

Just rechecked with the Loos website. Their recommendation for my rig is 1000lbs on forestay and 700lbs on shrouds. However, I will use your quote that "if your happy with it, so be it".

On that note, I have had professional riggers recommend "hand tight" and others say tension it properly, so you take your pick as to the advise you want to follow, and good luck with it.

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

[thomm225]

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

Someone is misreading something.

A Loos Gauge will not even go that LOW. 50 lbs

AD below for Loos Gauge PT-2 says the tension range is 180-2000 lbs

http://www.zoro.com/locoloc-tension-...Q&gclsrc=aw.ds

Example from the Loos Site:

The gauges measure tension over a range of approximately 5% to 25% of the breaking strength of the cable and provide an accuracy of + or - 5%.

Now here are the breaking strengths:

The same principles apply for other wire sizes:
WIRE SPECIFICATIONS for 1 x 19 Stainless Steel Rigging Wire:
Diameter - Approximate Breaking Strength
1/8" - 2,100 #
3/16" - 4,700 #
1/4" - 8,200 #
5/16" - 12,500 #
3/8" - 17,500 #
7/16" - 23,400 #
½" - 29,700 #

now select your size wire and you can do the math. Even the low 5% of the 3/16 wire is 235 lbs

A sample chart from Loos Gauge Company attached.

[Alberg 34]

I think people are getting confused the gauge readings are in lbs then look at he the conversion chart to get the actual poundage in hundreds of pounds or vise versa if you know what poundage % breaking you want ,then use chart to give gauge lb you need
The conversion chart should come with the gauge if not maybe you can google it

[alaskaflyfish]

For accurate measurements be sure to reference the temp conversion charts for the type of cable employed. Cable tension changes with temp. It will tighten in summer and loosen in winter. The greater the seasonal variance the greater the change.

[Mikado]

Originally Posted by Alberg 34

I think people are getting confused the gauge readings are in lbs then look at he the conversion chart to get the actual poundage in hundreds of pounds or vise versa if you know what poundage % breaking you want ,then use chart to give gauge lb you need
The conversion chart should come with the gauge if not maybe you can google it

Definitely a lot of confusion here.

The OP said he purchased a Loos tension gauge and wanted some feedback on what a good baseline would be to set his 3/16" wire rigging using his Loos PT-2.

The PT-2 readout ranges from 0-40. There are a lot of other tools to measure tension but he specifically wants to measure using his Loos gauge so telling him 200 lbs does him no good at all.

Also, here is a link to another excellent tutorial on adjusting sailboat rigging.

Thanks,

Jeff

http://www.petticrows.co.uk/download...ide%202011.pdf

[thomm225]

Originally Posted by Mikado

Definitely a lot of confusion here.

The OP said he purchased a Loos tension gauge and wanted some feedback on what a good baseline would be to set his 3/16" wire rigging using his Loos PT-2.

The PT-2 readout ranges from 0-40. There are a lot of other tools to measure tension but he specifically wants to measure using his Loos gauge so telling him 200 lbs does him no good at all.

Also, here is a link to another excellent tutorial on adjusting sailboat rigging.

Thanks,

Jeff

http://www.petticrows.co.uk/download...ide%202011.pdf

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.

[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