Rig tension experts

[Skipper]

I've had the mast out, and am now tuning the rig after restepping. This is the first time I've tuned this boat from scratch but using same Loos PT1 gauge as the last boat which had smaller diam cables. I've checked the tension on this one in the past but don't recall it showing too tight, and the boat sailed well.

I've set the shroud tension at scale 31 on the gauge which is about 350 lbs on the 5/32 shroud wires, or about 11% of breaking strength.

However, the shrouds feel idiotically loose to the touch, and sag like wayward halyards on the lee in only 8-10 knots if wind.

Am I doing something wrong? Any history of this regarding the gauge or method?

Last- The backstay is 3/16 so my gauge is not formulated for it. Maybe someone knows the mathematical conversion? The gauge physically fits on the wire.

Headstay is roller furl.

 

[Jackdaw]

Does your shroud fit into one of the sizing notches on the side of the gauge? 5/32 seems very light for a 29 footer. I would expect you would need the PT-2.

 

[RichH]

First go to:http://www.riggingandsails.com/pdf/selden-tuning.pdf and look up the 'SEQUENCE' of the adjustment of shrouds and stays, etc.

Look at the 'chart' imprinted on your loos gage for the % of load, then use the 'indicator number' (for the exact wire diameter) to set the proper tension. When all adjusted, go back and repeat check with the Loos gage to verify that the adjustment of one or more 'wires' hasnt changed the tension in adjacent 'wires'.

Usually you'll want the static tension in most 'wires' to be between 12 and 15+% for sailing in 12-15kts. of wind.
You can then reasonably increase tension on the backstay @ approaching 20% if your day's local winds are approaching 15-20+kts; returning the backstay to 12-15% (or less) when at back at the dock, etc. .... just 'mark' the rigging screw with tape, etc. so you dont always need to use the tension gage.

 

[Skipper]

Does your shroud fit into one of the sizing notches on the side of the gauge? 5/32 seems very light for a 29 footer. I would expect you would need the PT-2.

It fits halfway. -picture

 

[Scott T-Bird]

Does your shroud fit into one of the sizing notches on the side of the gauge? 5/32 seems very light for a 29 footer. I would expect you would need the PT-2.

I agree, 5/32 can't be right. 7/32 on a 27' boat ... do you mean 5/16" for a robust boat such as Bristol?

 

[Scott T-Bird]

Ah, just saw your picture ... no way that's 5/32

 

[Jackdaw]

It fits halfway. -picture

As expected. That should fit in perfectly. Your rigging is bigger, as expected as well because 5/32 is very small for a 30 footer. Time for a new gauge.

 

[RichH]

Nope, it MUST fit 'exactly' or the data and its result will be in error.

Get a caliper or micrometer, etc., measure the diameter of each 'wire' to the closest mm or 1/32"
Your wire is probably 3/8" or 9mm ..... and your gage may be 'too small'; .... not to worry, as there is another (easy) way to do this.
You can do this yourself: In that URL I previously listed --> go to that website --> go to page 29 (Folding rule method) and follow the directions using a 'meter stick'

If your tension gage turns out to be too small and that 'folding rule method' of rig tension seems confusing ... let us know
When you respond, also PM me so I'll know that youre waiting for an answer.

Hope this helps.

[ ed. correction - Your wire is probably ~3/16 or 4.5mm, NOT 3/8 or 9mm ]

 

[ALNims]

Rich,
Great information from that link.
Thank you,
Andrew Nims

 

[Skipper]

As expected. That should fit in perfectly. Your rigging is bigger, as expected as well because 5/32 is very small for a 30 footer. Time for a new gauge.

Thank you sir. I can't find any documentation online re wire size for 29.9. I did find one spec at Mauripro that said the forestay is 7/32, which is larger than I measured it to 3/16 so it makes sense that the shrouds are probably 3/16 as I measured them at 5/32.

I had measured using the gauge but also the Jeff Micrometer - a small Crescent wrench clamped onto the cap shroud then measured the opening with a tape. Came out to exactly 2.5/16ths so I figured 5/32. :-D Yep time for a new gauge...And a micrometer.

 

[Skipper]

Nope, it MUST fit 'exactly' or the data and its result will be in error. Get a caliper or micrometer, etc., measure the diameter of each 'wire' to the closest mm or 1/32" Your wire is probably 3/8" or 9mm ..... and your gage may be 'too small'; .... not to worry, as there is another (easy) way to do this. You can do this yourself: In that URL I previously listed --> go to that website --> go to page 29 (Folding rule method) and follow the directions using a 'meter stick' If your tension gage turns out to be too small and that 'folding rule method' of rig tension seems confusing ... let us know When you respond, also PM me so I'll know that youre waiting for an answer. Hope this helps.

Thank you Rich.
I had used the sequence from long ago rigging smaller boats. Great info thanks again I'll let you know how it goes. Will be a couple days till I get back to the boat.