Rig tension gauge

[gasdave]

I had my new to me mast unstepped for first time this winter to do the usual checks and take the opportunity to swap over to LEDs.
However I forgot to mark the rig settings prior to it coming down. Not necessarily a bad thing as I don't really know if they were appropriate or not as I hadn't changed them from what I inherited. I've not noticed any reason to suspect they were too slack or too tight while sailing.
Anyway I'm now thinking about a plan when it's re-stepped and how best to set the correct tension. Been reading about various methods on-line and am aware of the basics of setting the mast up (vertical side to side, aft pre-bend, what order to work around the various stays in, etc.). I've also been looking at rig tension gauges, which for me would be the more expensive Loos PT3 (approx. £200).

I'm curious as to how many of you (cruisers, not racers) think this is a worthwhile investment or are most of you content with the cheaper method of measuring stretch? I guess over a period of time it's cheaper than paying a rigger to check it and it makes it easy to do regular checks, which I would otherwise be unlikely to do.

 

[Appledore]

Rig tensioners very often come up for sale on Ebay (for instance), and cost much less than what you have quoted. And if you are a member of a yacht club, then almost certainly someone will have one you can borrow. After all, once you have set up your rigging tension, you probably won't use the device again for a long time.

Others here will certainly give you the sites where you can best read up on the correct methods, if you haven't already found them. Here's one such site:

https://coxengineering.sharepoint.com/Pages/Standingrigging.aspx

 

[30boat]

You could use the stretch method.It's very reliable and free.

 

[VicS]

You could use the stretch method.It's very reliable and free.

And described in the Selden Masts Hints and Advice pdf ....... download and save for future use.

http://www.seldenmast.com/files/1416926327/595-540-E.pdf

 

[rob2]

Having your own gauge has several advantages. It is quicker and easier than the stretch method and can be periodically clipped on to check that the tension has remained the same, all rigging stretches a bit in use and even if a rigger has tuned the rig to your satisfaction a bit of hard sailing may cause it to slacken off after a week or two - just bedding in really. Keep a note of the settings once you're happy with the tuning and you can maintain it during the season and hopefully repeat it when the mast is next restepped. Letting your neigbours use it wins you browny points and may help elicit help from them when you need it or the loan of a tool they have, just don't let it too far out of your sight or it may never come back!

Rob.

 

[ghostlymoron]

I've done a couple of boats using a Loos gauge (borrowed) and it makes it very, very easy compared with measuring stretch. I found the main problem was determining the tension required. The general accepted figure is 15-20% of the breaking strain. However, this is frightenly tight on an old boat so I settled for 10%.
A complication on Gwylan Làs was the ketch rig and I could decide what to do about the mizzen but eventually decided to tension it the same as the main. I don't know if that is correct as the sail loads are less but it seemed to work OK.
I would definitely try to borrow or eBay a Loos though.

 

[Javelin]

I have all the gauges and toys and yes they are fine for an initial 10% breaking strain static set up but I still want to tune on the water to get it right.
A lot depends on the rig, masthead, fractional, angled, fixed or floating spreaders, number and spread of lowers etc so not easy to give any rules of thumb.
Even then some boats with fractional rigs simply wont take the recommended rig tension or at least they will but you then can't shut the fore peak door!
Frac rigs with swept spreaders use a lot more tension as the shrouds are doing the job of a back stay as well.
That said some of the Bavs use a 7/8 frac rig which is neither one or the other and I tend to think it was a marketing ploy to make the boat look a little sportier but in fact it makes the rig less tunable.

I see you have a Bav 37, trouble is I've seen a big mix of rigs on these Bavs some of which also use linked inters to the lower spreaders which are a complete pain in the proverbial to set up correctly.

 

[Halo]

There was a PBO article by Mike Coates on how to make a rig tension device. You should be able to download it for a few quid

 

[30boat]

I've done a couple of boats using a Loos gauge (borrowed) and it makes it very, very easy compared with measuring stretch. I found the main problem was determining the tension required. The general accepted figure is 15-20% of the breaking strain. However, this is frightenly tight on an old boat so I settled for 10%.
A complication on Gwylan Làs was the ketch rig and I could decide what to do about the mizzen but eventually decided to tension it the same as the main. I don't know if that is correct as the sail loads are less but it seemed to work OK.
I would definitely try to borrow or eBay a Loos though.

15 to 20% are the figures recommended for aftswept fractional rigs.A masthead rig should start with 10% as said. My Fulmar needs more than 20% .She takes it well and all the doors (one) work perfectly but some lighter boats may not be as accomodating.
I've used the stretch method but usually resort to my gauge.

 

[Skylark]

Having your own gauge has several advantages.

I've done a couple of boats using a Loos gauge (borrowed) and it makes it very, very easy compared with measuring stretch.

The Loos PT3M, for 7 to 10mm wire rigging, is eye wateringly expensive at about £200. I simply put a search alert into everyone's favourite auction site and, after a couple of years (quite seriously), managed to get one virtually new, in box for about £85. It is a very nice piece of kit. I don't have the skills to become a rigger and, as others have said, the final checks need to be done while sailing, but it's now part of my annual check routine shortly after launch.

 

[KellysEye]

I was told by a rigger you don't need a gauge just tighten it as much as you can with a spanner, which is what I did and had no slack either side of the masts, ketch, when sailing.

 

[nigelmercier]

The Loos PT3M, for 7 to 10mm wire rigging, is eye wateringly expensive at about £200...

I've not seen them that cheap in the UK.

I bought one exactly a year ago for $211 on Amazon US, got it delivered to my hotel in Florida. Came back in the empty suitcase we always take to the US.

 

[ghostlymoron]

Ideally, the leeward shrouds should go a little slack in F4 I'm told.

I was told by a rigger you don't need a gauge just tighten it as much as you can with a spanner, which is what I did and had no slack either side of the masts, ketch, when sailing.

 

[VicS]

I was told by a rigger you don't need a gauge just tighten it as much as you can with a spanner, which is what I did and had no slack either side of the masts, ketch, when sailing.

Find a different rigger!

Ideally, the leeward shrouds should go a little slack in F4 I'm told.

Thats right, at least with a conventional mast head rig, and you will find it in the Selden pdf I mentioned in #4
Fractional rigs with aft swept spreaders are a different kettle of fish.

 

[Ceirwan]

A loos gauge is not essential to tuning your rig, just a big help.

A lot of people seem to really stress about setting up the rig themselves, once you've done it once you'll wonder why you ever worried.
I normally tighten until the rigging itself feels fairly tight, on 6mm wire I use a normal length screw driver for leverage. By fairly tight I mean you can use it as a handhold while moving around the deck and not worry about it moving to much.

Then as has been said by others, get the boat powered up to windward in a F4, the leeward shrouds should just be on the point of going slack, not flapping around but definitely not bar tight. And remember to adjust both sides evenly.

 

[Bav32]

WHEN you eventually get to mast set up to your satisfaction, using all the previous information., measure the distance between to stud ends and record this. ( not easy if you have enclosed barrel types)
I use a simple plastic vernier guage for this.
Any subsequent removals just put it back to what it was.

 

[30boat]

I was told by a rigger you don't need a gauge just tighten it as much as you can with a spanner, which is what I did and had no slack either side of the masts, ketch, when sailing.

That's really bad advice!!

 

[Vegable]

On my rig, the backstay splits just above headheight going to 2 anchor points on the deck. None of the guides I've seen show this arrangement. I've always assumed I tighten the two halves at 10% (aiming for a 20% stretch), is this assumption correct?
Mike
Apologies for slight thread drift.

 

[Halo]

On my rig, the backstay splits just above headheight going to 2 anchor points on the deck. None of the guides I've seen show this arrangement. I've always assumed I tighten the two halves at 10% (aiming for a 20% stretch), is this assumption correct?
Mike
Apologies for slight thread drift.

Assuming all the lines are the same diameter and material, and aligned in a straight line and within the elastic limit of the material you wont be far wrong.

 

[30boat]

On my rig, the backstay splits just above headheight going to 2 anchor points on the deck. None of the guides I've seen show this arrangement. I've always assumed I tighten the two halves at 10% (aiming for a 20% stretch), is this assumption correct?
Mike
Apologies for slight thread drift.

I believe that the percentage of stretch applies mainly to the caps and lowers. The backstay being set at a much higher angle needs less tension. It all depends on the forestay tension you want to achieve and the structural integrity of your boat.And,of course, the type of rig. On an aftswept fractional rig you use the backstay mainly to control the mast shape and only a little for the forestay tension depending on how fractional it is. Less for a 3/4 like mine and more for the modern 7/8s and so on.