Navtec chain plate tension

[GeoBay]

I have no problems rigging my boat as far as mast rake, mast collumn, shroud tension, etc. Boat is rigged with Navtec rod rigging. However not really sure what the proper tension should be for the Navtec chain plate tie rod system from the base of the bulkhead to the u- bolts on deck. They obviously have to work together for the rig to be one continuous pull from top to bottom. Any thoughts?

[david samuelson]

When you tighten the shrouds it pulls the sides of the ship together a little. Now I am assuming your mast is keel stepped. When the two sides come closer together the deck bows upwards. The tie rod is to prevent the deck moving up. Ideally, when the rigging is all slack you tighten the tie rod hand tight and then maybe add one turn.
Also, if you have halyards coming back to the cockpit they pass through mast-base blocks. When you pull up a sail the load on the halyard will try to lift the deck. Your tie rod will hold the deck down for you.

[Jim Cate]

Originally Posted by david samuelson

When you tighten the shrouds it pulls the sides of the ship together a little. Now I am assuming your mast is keel stepped. When the two sides come closer together the deck bows upwards. The tie rod is to prevent the deck moving up. Ideally, when the rigging is all slack you tighten the tie rod hand tight and then maybe add one turn.
Also, if you have halyards coming back to the cockpit they pass through mast-base blocks. When you pull up a sail the load on the halyard will try to lift the deck. Your tie rod will hold the deck down for you.

I think the OP isn't talking about the deck tiedown rod. Rather, he's interested in the rods that go from the inside of the deck under the "chain plate" u-bolts to tie points lower in the hull, on each side. I've seen such setups, but can't advise on proper tension.

OP, in your place I'd be contacting Navtec directly, or the builder of your boat. If those routes fail, a rigger who is used to dealing with race boats could offer advice.

Jim

[-bliss-]

On slack rig (and free spinning, well oiled tie rod turnbuckles), hand tight + ½- 1 turn sounds right. They shouldn’t be able to pull the deck downwards, they are there to prevent the forces of the rig from lifting the deck under tension. Just enough to eliminate movement. Can´t be more specific without knowing which boat we´re talking about, but if you have inline spreaders, comparing the movement of the door in the main bulkhead before and after rigging can give an indication of what´s going on..
-kjetil-