Question about rigging tension gauge

[bsangs]

Anyone have a suggestion for a rigging tension gauge? Would like to fine tune my shrouds and stays, and have been looking at Loos gauges. Unfortunately, the different wire diameters I have are on the very end and beginning of the Loos' gauge specs, which would necessitate two different gauges. That just the cost of doing business, or is there a single gauge out there that could handle a wider range of diameters? Loos used to offer one that did, but seems to be in short supply and the ones I found have a ridiculous mark up, even for the boat world.

 

[Pete the Cat]

A professional rigger (who is in demand for international yacht competitions here in San Francisco) does use any tension guage. He tunes by feel initially and then fine tunes underway going to weather in 12 or so knots. The actual tensions that are most effective vary by vessel. Those with bendy masts are most complicated.

 

[Dave G.]

I use the PT-2 loos gauge which works on everything except the headstay and aft lowers. You can force it on the larger cable but it's only good for a known reference point as there isn't a scale for 9/32 wire. I just tune the lowers by feel, which is tight enough that they don't slack in 12-14 knots. Not sure what your shroud sizes are though, the remainder of mine are 3/16 & 1/4.

 

[Frank Langer]

Brion Toss, pro rigger, suggested a method in his book The Riggers Apprentice, using a tape measure on the shrouds which you can probably find on line somewhere. Failing that, doing it by feel to ensure that the lee shrouds just feel slightly slack in about 15 knot wind, but don't actually look slack, will usually be good, ensuring that the mast is straight with no S bends.
Frank

 

[Pete the Cat]

I can go into the tuning taught by my rigger friend if you like, but that was not your question. It all involves doing the final adjustments when under sail going to weather in relatively flat seas and in 10 12kts of wind. I have been using this process on boats without bendy masts (most older production boats). Fairly simple and he claims is much better than using a gauge. FWIW.

 

[Christian Williams]

Look up the luff track of the mast frequently and in all conditions. It should always be straight as an arrow. If it isn't, adjust the shrouds so it is.

Added, after walking away from the computer and then walking back to it scratching my head:

Frank's comment from Toss (above) causes me to realize that a mast might be permanently canted by shrouds of unequal length, by turnbuckle turns or even by wire length. You couldn't notice that from eyeballing, since with a keel-mounted mast the fulcrum of the bend would be the deck. I think I will hoist my 100-foot tape on the main halyard, hold it to the chainplates, and see how different the measurement is port and starboard. Never have done that but it will only take a minute.

 

[Alan Gomes]

Brion Toss, pro rigger, suggested a method in his book The Riggers Apprentice, using a tape measure on the shrouds which you can probably find on line somewhere. Failing that, doing it by feel to ensure that the lee shrouds just feel slightly slack in about 15 knot wind, but don't actually look slack, will usually be good, ensuring that the mast is straight with no S bends.
Frank

I believe you may be referring to a Rigstick. This is a gizmo that Brion referred to in an older video I own. (I'm not sure of the date, but it was on VHS, so that tells you something.) I could not find them online, and so I am guessing that they are no longer being sold. (A Google search for "rigstick" turned up a bunch of Ham Radio antenna references.)

This older article from Practical Sailor does make a passing reference to it, though.

 

[Dave G.]

I think I will hoist my 100-foot tape on the main halyard, hold it to the chainplates, and see how different the measurement is port and starboard.

I do the same to get the mast centered athwartships before tightening rigging. Check and recheck through the process, although in theory if you tighten opposing shrouds equally it should stay centered. For reasons I do not know the theory seems to fail in practice so generally need to make adjustments along the way to keep it centered. I found keeping the mast centered is a particularly tedious process if I did the full tune under sail. While it took me some time to know my static(dock) tune numbers/percentages on a Loos gauge. I now can get the rig 98% tuned before leaving the dock and turning mother nature loose on it. Sure a shake out sail will move things around a bit but back at the dock a couple more double check measurements a half a turn here and there, 100% done I think it's a great tool to be able to establish and repeat a known set of specs but each & every boat is different so there is some work to do to get there. "Before Loos" I used to take a standard open end wrench and tighten the shrouds until the wrench started to hurt my hand a little for my "known" static tune. Not real scientific but it was a good starting point, using a gauge is much better IMHO.

 

[bsangs]

I can go into the tuning taught by my rigger friend if you like, but that was not your question. It all involves doing the final adjustments when under sail going to weather in relatively flat seas and in 10 12kts of wind. I have been using this process on boats without bendy masts (most older production boats). Fairly simple and he claims is much better than using a gauge. FWIW.

By all means, please do share. If I don't have to plunk down more boat dollars for gauges, I'm all for it.

 

[Alan Gomes]

I believe you may be referring to a Rigstick. This is a gizmo that Brion referred to in an older video I own. (I'm not sure of the date, but it was on VHS, so that tells you something.) I could not find them online, and so I am guessing that they are no longer being sold. (A Google search for "rigstick" turned up a bunch of Ham Radio antenna references.)

This older article from Practical Sailor does make a passing reference to it, though.

By the way: If the device Brion was talking about was the Rigstick, it has nothing to do with centering the mast athwartships. It is a sort of measuring tape that indicates stretch in the wire.