Reasonable rig tension gage

[SvenG]

I'd really like to have a way to measure and record the tension in our rig. For one thing I'd like to be able to re-measure it maybe once or twice a year to see if it is changing unexpectedly or if it needs periodic tightening.

I'd also like to be able to detach and re-attach shrouds and stays, knowing that I put it back together as it was. I'll pay our rigger to tune us up so we have a baseline to compare with, but after that I'd like to be self-sufficient for a few years.

As an example, right now I have a slightly leaky chainplate ... bad news and I'm trying to keep it from causing any permanent damage. I think I have the leak under control but to do it right I'd need to remove a plate covering the bedding and I can't really do that unless I detach the shrouds.

So, without wasting money on too good equipment but at the same time avoiding Harbor Freight (which has its place too), what are some good but not too expensive options ? As noted in the Sig we have a 39 footer, not an ultralight and not a 60 foot schooner.

Thanks,


PS With an adjustable backstay the tension in the stays is probably not that relevant to measure.



-Sven

[Jim Cate]

G'Day Sven,

Can't help you with the tension gage, but the chainplate cover plate issue is one that I've faced myself. My solution was to simply split the plates into two halves, thus allowing them to be removed without bothering the shrouds. Saved lots of time over the years.

Cheers,

Jim

[FrankZ]

I have a Loos. It wasn't expensive.

[boatman61]

And I'm no help whatsoever as I tension by touch and sight....

[daddle]

If you simply want to service a shroud, measure the distance between the turnbuckle screw ends with calipers before loosening. After servicing reset to that same distance. Better and more accurate than tension.

[cal40john]

You can tell rig tension based on the stretch of the wire. Tape one end of a 2 meter stick onto the wire. The other end is at an easily found point, the swage. Apply tension, measure the gap.

This book has the details.

Amazon.com: Sail and Rig Tuning (9781898660675): Ivar Dedekam: Books

Mine is on my boat and I don't remember the numbers.

John

[READY2GO]

Get a Loos & Co. gauge from Defender.com for about $75, and know exactly what tension you have. No guessing.

[boatman61]

Originally Posted by READY2GO

Get a Loos & Co. gauge from Defender.com for about $75, and know exactly what tension you have. No guessing.

Oiii.... Shush... I'm trying to blag a free ride to So Cal....

[SvenG]

Originally Posted by boatman61

Oiii.... Shush... I'm trying to blag a free ride to So Cal....

Your references said something about having trouble keeping your hands where they belong.

Please give specifics if you want to appeal.



-Sven

[boatman61]

Originally Posted by SvenG

Your references said something about having trouble keeping your hands where they belong.

Please give specifics if you want to appeal.



-Sven

Leave my love life out of it....

[cal40john]

No need to buy the book, Seldon masts also describes how to do this method.

Seldén Mast AB

select rigging hints in your favorite language. Folding rule method page 28

(I do like the book by Ivar for other reasons.)



I'm curious, you think this is a guessing method?

Originally Posted by READY2GO

Get a Loos & Co. gauge from Defender.com for about $75, and know exactly what tension you have. No guessing.

[GordMay]

See ➥ How to use PT Series Tension Gauges

And ➥ How To Use Tension Gauges (1 of 2) - Cruisers & Sailing Photo Gallery

[boatman61]

Originally Posted by SvenG

Your references said something about having trouble keeping your hands where they belong.

Please give specifics if you want to appeal.
-Sven

Oh... by the way Sven...
I think you should either word things much better... or more directly...
Someone has enquired if you were inferring that one of my former customers was saying I was a crook...
Which got me wondering if I Was being slandered...

[Mark Johnson]

Hi Sven,
I use a Loos gauge, as with my boat's tall skinny stick, I need a good bit of pretension to keep it straight, and I have to be careful not to over do it.. If I need to remove a wire to re caulk a chainplate or something, and the rig seems to otherwise be in tune, this is how I do it... (Now, this assumes that the "lowers", "uppers", or another set of wires will hold the mast up).

I take 5 turns off of the turnbuckle, then 5 off of the opposite wire's turnbuckle. Then 5 more turns off of the original, and 5 more off of it's opposite. KEEP TRACK ON PAPER!

After about 10 turns it should be slack. since they are both at the same # of turns, this is an even starting point, and you haven't bent the mast to one side by loosening one side only. Now you can pull the pin on the turnbuckle and do what you need to do.

Afterward, replace the pin, and re-tension to the same # of turns, port, starboard, port, starboard, like in the loosing process.

There ya go. unless your chainplate moved, it should be identical to where it was. If it did move, you may see it as a bend in the mast, eyeballing up from above the boom. Since the opposite side is exactly like it was, you can adjust the turnbuckle on the side that you changed, until the mast is straight again.

I have done this a number of times.

Good luck with it... M

[beetle]

What's the rigging material? Rod, 1x19, dyform/compact strand, fiber - something else perhaps (though unlikely)...

If you're racing a boat with small diameter wire rigging where you constantly raise and lower the rig for trailering (which I suspect you're not) then a tension gauge is handy for speeding up the time to get the rig back to a known setup.

If, on the other hand, you have a relatively large boat where the mast stays up for years a rig tension gauge isn't that necessary - you don't need to know the rigging wire tension as much as you need to know whether or not the mast is remaining on centerline and in column as the boat heels. In other words, what you really want to measure is the location and condition of the mast - which you can do by eyeball sighting up the rear of the spar for column-check and measuring the distance from masthead to toe rail for checking the masthead location.

Adjust tension in the rigging to maintain the mast's location, and depending upon standing rigging material you will have more or less stretch to contend with.

It's a lot simpler than it sounds. And you should not be worrying about somehow over-tensioning the rigging and breaking something, provided you start with light tension and build up over time while sailing. The loads on the mast are supplied by the righting moment of the hull and keel, and you can't put more load on the rigging than the righting moment will supply. The rigging wire itself should have been specified by the builder to be strong enough to handle the loads plus a safety factor, and really what you're fighting is stretch as wire ages - not breakage.

As regards removing a wire and resetting to the original tension - the above folks have it right. If you're going to remove a cap shroud or diagonal, undo to the tension by backing off an equal number of turns on the same wire on each side of the boat (and write down exactly what you do as you do it!), then disconnect the rigging you want to work on. When reconnecting the wire, put back on exactly the same number of turns as you took off (that's why you wrote down what you did, right?!). This works if both wires have set equally - this doesn't work if you're replacing one old wire with a new one. If you swap in a new piece of standing rigging, taking it up to the old setting will not work, nor will measuring the tension in the wire, as the wire will set and stretch with age - that's where you go back to observing the mast while sailing in moderate air.

- rob/beetle