rig tension
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Dick Heijdra
May 26, 2009, 3:36:32 PM5/26/09
to j92o...@googlegroups.com
When I compared my standing rigging to another J92, I found my rigging to be much more slack. Does anyone has info on rig-tensioning?
Kind regards,
Dick Heijdra
dh | OFFICE
Overschiese Dorpsstraat 124
3043 CV Rotterdam
Todd Aven
May 26, 2009, 4:35:22 PM5/26/09
to J/92 Owners Forum
Dick,
You'll want to be a bit cautious comparing rig tension with another boat, because the rig must be set up to match the design of the mainsail. Your sailmaker would be a good source of advice on appropriate tension settings.
I have a bunch of notes at home on rig tension and will share those tonight.
Cheers,
Todd
Todd Aven
May 27, 2009, 12:52:08 AM5/27/09
to j92o...@googlegroups.com
The numbers I use are based on the Loos PT-1 and PT-2 gauges. The PT-2
is required for the Cap and D1 shrouds, which are 7/32" 1x19. The PT-1
is required for the D2 shrouds, which are 5/32" 1x19.
Here's a good reference on the Loos gauges, http://www.download.ts.it/olisails/tensiometri_looseco.pdf, and it includes calibration charts to get the tension readings in pounds or kilograms. Note that some of the tension settings exceed the top range of the pounds/kilograms charts, so it's easier to compare based on the Loos numbers whenever possible.
The numbers listed below are the direct readings on the Loos gauges in order Cap/D2/D1.
Currently I am set at 38/36/37, which is suited for moderate breeze (10-15kts).
Last summer I went with 34/38/37, which worked well in light airs (<10kts).
A previous owner's notes indicate they used 1600lbs (35.5?) on the Caps and 1400lbs (34.5) on the D1's (no listing of the D2 tension).
I also found notes from someone, I believe Mark Melchior / Full Tilt, with tension readings in pounds for various wind speeds.
Make sure when you are measuring your rig tension that you have no backstay/forestay tension and that all of your halyards (including main halyard) are completely slack. Also keep in mind that headstay length/tension has a significant impact on performance.
Cheers,
Todd
Here's a good reference on the Loos gauges, http://www.download.ts.it/olisails/tensiometri_looseco.pdf, and it includes calibration charts to get the tension readings in pounds or kilograms. Note that some of the tension settings exceed the top range of the pounds/kilograms charts, so it's easier to compare based on the Loos numbers whenever possible.
The numbers listed below are the direct readings on the Loos gauges in order Cap/D2/D1.
Currently I am set at 38/36/37, which is suited for moderate breeze (10-15kts).
Last summer I went with 34/38/37, which worked well in light airs (<10kts).
A previous owner's notes indicate they used 1600lbs (35.5?) on the Caps and 1400lbs (34.5) on the D1's (no listing of the D2 tension).
I also found notes from someone, I believe Mark Melchior / Full Tilt, with tension readings in pounds for various wind speeds.
| Melchior 0-5 | Melchior 5-10 | Melchior 10-15 | Melchior 15+ |
| 12-1400 | 1500 | 1600 | 2000 |
| 800 | 900 | 1000 | 1000-1200 |
| 1000 | 1200 | 1400 | 17-1850 |
Make sure when you are measuring your rig tension that you have no backstay/forestay tension and that all of your halyards (including main halyard) are completely slack. Also keep in mind that headstay length/tension has a significant impact on performance.
Cheers,
Todd
Ragtime!
May 27, 2009, 4:09:17 PM5/27/09
to J/92 Owners
Hi Dick,
Here is a link to an old but good tuning guide for the "classic" J/92:
http://www.ullmansailssandiego.com/ullman-j92-rig-sail-tuning-guides.php
My tuning approach has evolved over the 6-7 years I've owned the
boat. The constants have been the need to maintain headstay tension
for pointing in heavy air (especially if you steer to the luff
telltails on the jib), and keeping the mast at full rake. Most owners
keep the upper shrouds very tight (1,800-2,000#).
On our fractional rigs, it is important for the shroud tensions, mast
position, prebend and mainsail luff curve to work together for the
best performance.
My first racing main was cut for some mast prebend and tight lower
shrouds. Now I sail with no prebend and looser lowers, and have
shortened the headstay slightly. My newer racing main was designed
accordingly. I always put some bend in the rig via the backstay but
starting with no prebend allows for good mainsail shape over a broader
wind range.
The other change is I increased the intermediate shrouds from 5/32"
wire to 3/16". We tend to tighten those beyond the recommended
tension and sure enough, I broke one in an ocean race.
How much wind do you typically race in?
Bob J.
#18
On May 26, 12:36 pm, Dick Heijdra <d...@dhoffice.nl> wrote:
> When I compared my standing rigging to another J92, I found my
> rigging to be much more slack. Does anyone has info on rig-tensioning?
>
> Kind regards,
>
> Dick Heijdra
> dh | OFFICE
>
> Overschiese Dorpsstraat 124
> 3043 CV Rotterdam
> T +31 (0)10 4624588
> E d...@dhoffice.nlhttp://www.dhoffice.nl
Here is a link to an old but good tuning guide for the "classic" J/92:
http://www.ullmansailssandiego.com/ullman-j92-rig-sail-tuning-guides.php
My tuning approach has evolved over the 6-7 years I've owned the
boat. The constants have been the need to maintain headstay tension
for pointing in heavy air (especially if you steer to the luff
telltails on the jib), and keeping the mast at full rake. Most owners
keep the upper shrouds very tight (1,800-2,000#).
On our fractional rigs, it is important for the shroud tensions, mast
position, prebend and mainsail luff curve to work together for the
best performance.
My first racing main was cut for some mast prebend and tight lower
shrouds. Now I sail with no prebend and looser lowers, and have
shortened the headstay slightly. My newer racing main was designed
accordingly. I always put some bend in the rig via the backstay but
starting with no prebend allows for good mainsail shape over a broader
wind range.
The other change is I increased the intermediate shrouds from 5/32"
wire to 3/16". We tend to tighten those beyond the recommended
tension and sure enough, I broke one in an ocean race.
How much wind do you typically race in?
Bob J.
#18
On May 26, 12:36 pm, Dick Heijdra <d...@dhoffice.nl> wrote:
> When I compared my standing rigging to another J92, I found my
> rigging to be much more slack. Does anyone has info on rig-tensioning?
>
> Kind regards,
>
> Dick Heijdra
> dh | OFFICE
>
> Overschiese Dorpsstraat 124
> 3043 CV Rotterdam
> T +31 (0)10 4624588
Dick Heijdra
Jun 2, 2009, 2:59:26 AM6/2/09
to j92o...@googlegroups.com
Hello Bob, thanks for the info. My rig is set up very loose by its former owner. I will experiment with a Loose gauge to find out what happens if I tighten things up. So far my boat seems very fast so something has to be allright... We usually sail in about 10-20knts. Since I only own the boat for a couple of months now, I am still on a steep learning curve. But enjoying every minute!
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