Adjusting Your Rig

[Harvester]

Great post, Giu!

Precisely I have a problem with the rigging and I was looking for an expert to help me fix it.

Only one suggestion, I am not acquainted with the cable measurements (1/4, 3/16, 5,16). Do you have at reach the equivalence in mm for you neighbours? (Well, I am not exactly your neighbour because I'm Catalan so we have Spain in between.... )

Thanks a lot!

[Giulietta]

Originally Posted by Harvester

Great post, Giu!

Precisely I have a problem with the rigging and I was looking for an expert to help me fix it.

Only one suggestion, I am not acquainted with the cable measurements (1/4, 3/16, 5,16). Do you have at reach the equivalence in mm for you neighbours? (Well, I am not exactly your neighbour because I'm Catalan so we have Spain in between.... )

Thanks a lot!

Actually the tables I have are in millimiters. But for the guys here at sailnet I had to covert from KN and Kg to Inches and Pounds.

Here is a tble I made in Excel and took a snap shot, that should make it clear for everyone in Inches and Millimiters, KN, Kg and Lbs.

[sailingdog]

Nicely done.

[Harvester]

Originally Posted by Giulietta

Actually the tables I have are in millimiters. But for the guys here at sailnet I had to covert from KN and Kg to Inches and Pounds.

Here is a tble I made in Excel and took a snap shot, that should make it clear for everyone in Inches and Millimiters, KN, Kg and Lbs.

Yuppi!
Double thanks!
I'll be working on it this weekend.

[rabbit238]

In order to check the lateral position of the mast use the main (or jib for fractional rig) halyard and swing it to the port and starboard rails.

Don't forget to sight up the mast to look for bends. The lower shrouds can be used to straighten some of the bends. Often times the lowers are set looser to allow for mast bend. In fact in some racing classes the lowers are adjusted according to the wind speed.

[runner]

Newby questions. How do you tension the shrouds on a three stay rig where the mast comes down after each use? How do you bend the mast with a three stay rig and no aft stay? The thin metal strip shrouds have to be disconnected to adust them. You place the mast thru the deck, connect the shrouds, connect the fore stay, pin the foot, and then you final tension the shrouds using the fore stay turnbuckle on my boat. There are upper turnbuckles on the upper ends of the flat metal strip shrouds. I could make balancing adjustments to balance the tension side to side with a ladder and the oak tree in the yard the way it is set up. Should the turn buckles be at the deck and the end that has to be taken loose to adjust be attached to the strap on the mast? Do you reverse them to get the adjustment made and then put them back as they were?
How much fore stay tension do you use when you have a mast that uses the deck as a pivot point?
How much rake is correct on a comet class boat with a shorter mast? It came adjusted for a foreward rake.
Does sail type change the answers? I have old canvas sails.

Sorry for all the questions, but I am trying to learn as much as I can before I do something really dumb from not knowing the correct procedures.

[GaryHLucas]

Giu,
There is something wrong with your statement that 1mm of stretch = 5% of breaking load. This has to be 1mm of stretch per 1 meter of length, or some other ratio. I used to build a system that used a 1/4" cable 800 feet long. Proper tension on that system was to stretch the cable 8 FEET!

[Giulietta]

Originally Posted by GaryHLucas

Giu,
There is something wrong with your statement that 1mm of stretch = 5% of breaking load. This has to be 1mm of stretch per 1 meter of length, or some other ratio. I used to build a system that used a 1/4" cable 800 feet long. Proper tension on that system was to stretch the cable 8 FEET!

Maybe it was the way I wrote it.

Originally Posted by Giulietta

c) Now for the main shrouds, if you don’t have a Loos, or are just a cheap person, you can use a measuring tape. I did for many years.

You will need to attach a tape of at least 2 meters to the shroud, so that the zero or the beginning of the tape starts at the turnbuckle.

The rule is simple each 1mm of stretch means 5% of the breaking load, and that is valid for ANY CABLE IN A SHROUD, no matter what the diameter is!!!

[KeelHaulin]

Originally Posted by GaryHLucas

I used to build a system that used a 1/4" cable 800 feet long. Proper tension on that system was to stretch the cable 8 FEET!

Yes; that was why I did the calculation on page 3 to show what theoretical length would be needed to stretch a cable to 15% break strength. It's dependent on the pre-tensioned length of the wire (and type of metal); not diameter.

15% break strength on an 800' (type 316) cable would be to stretch it approx. 6 feet. (Not accounting for thermal expansion or weight); so depending on the type of wire you were probably at about 20% break strength or a bit higher.

Giu's rule-of-thumb will put approximately 20% breaking strength into the shroud if you stretch 1mm per meter of cable. So a mark at 1 meter should move up 1mm on a scale attached to the shroud swage. For 10% breaking strength stretch 1mm per 2 meter length measurement.

[Giulietta]

Keel, I am not going to argue this anymore.

You surely have heard about Selden masts, right?

Please allow me to redirect you to their shroud adusting manual.

PAge 30

PAge 31

PAge 39

I am sure your calculations are all correct and such..I got this this morning off the net by googling tension shrouds, and found this manual.

There are several more with the same instructions.