Hi Wind Magic,
My boat has one set of lower shrouds forward of the upper shrouds, and one aft. They attach to the mast at the speaders by way of a couple of plates which are through bolted to the mast and each other: http://www.swainsons.com/gallery/dis...p&cat=0&pos=22
The upper shrouds have attachments on the upper end which accept a bolt, and again they're both through-bolted to the mast, about eight inches below the mast cap.
The fore and backstays attach to the cast aluminium mast cap by way of cotter pins through the casting, securing them in vertical channels cast into the cap.
At the deck level, the shrouds and stays (with the exception of the forestays) are all attached to stainless steel chainplates 3/8" (7mm) thick by way of stainless swivels and bottle screws, and these pass through the deck and are bolted to substantial knees (roughly triangular in section and about 12" high, 5" deep and 1 3/4" thick) which were glassed into the hull when she was originally laid up. At the stern I have a supplementary knee in the centre of the boat (although no chainplate is attached to it) as she was also offered with a single backstay option.
The forestays are attached to the stem head fitting via bottle screws, swivels and a tri-angular tension equalising plate.
In terms of tensioning the rig, I've only had to mess about with the fore-and backstays so far, but I put them back on by reconnecting all of them and gradually tensioning them enough to take the sag out of the wires with the mast vertical (as squinted up from lying flat on the deck). I then put enough tension in the backstays to introduce the four or so inches of backwards bend that I like in the mast, and then dial up the tension on each stay evenly so as to be able to deflect the wire by not more than 6 inches when holding onto it 5 feet above the deck plate and leaning back on it (i weigh approx 200 lbs and I'm just over 6 feet tall, so those who can be bothered with the trigonometry can work out the deflective load I'm putting on the wire - It just seems about right to me)
The way to tension the shrouds, so I'm told, is to tension them equally so that the stick is vertical, then go out sailing, and while the boat is heeled check the tension on the leeward shrouds. If they're slack, do them all up a few turns, tack, do the shrouds up on the new leeward side up the same number of turns, and then check the tension again (just with your hand). The tension is right when the leeward shrouds are just
taut - not hanging like washing lines, and not as stiff as rods.
Brion Toss's website www.briontoss.com
has some good info / links for rigging and the Good Old Boat website has some more stuff.
Rather than re-run the standing rigging on your boat, if you feel uncertain about it, why not have a rigger check it for you and replace any wires / connections that he feels aren't up to scratch. You might then also ask him about installing running backstays to give you some additional security in heavy weather.
What is your boat?