National 12

General Boards => General National 12 chat => Topic started by: Kyle Carruthers on May 08, 2019, 04:28:58 PM

Title: N1992 rigging plan, mast and boom used
Post by: Kyle Carruthers on May 08, 2019, 04:28:58 PM
Hi folks, i have been the owner of N1992 for a few years now and something has never seemed right with the rigging setup. The boom seems to drop quite severly at an angle as you go aft and the mast doesnt actually have a forestay! I was wondering if anyone can direct as to the type of mast/boom originally used on this boat and whether there are any rigging plans used for a boat of the squid type?

Cheers in advance.
Title: Re: N1992 rigging plan, mast and boom used
Post by: johnk on May 09, 2019, 09:09:10 AM
I used to crew in a Squid. It had a Proctor D mast with no spreaders or diamond stays. I believe that some boats used a Proctor C mast with diamond stays. It did have a forestay (required by the rules in thse days). We measured the mast rake by using a spirit level to level the top of the centreboard case and put a weight on the end of the main halyard. This was about 20cm aft of the mast at deck level. Naturally you needed a calm day!
In your case, I would hoist the jib reasonably tight and measure the mast rake with any deck level chocks in to have little bend in the mast. If the rake is very different from 20cm, adjust the shroud lengths to get 20cm of rake. You can get shroud length adjusters from a chandler or use a rope lashing. If the latter use a STRONG dyneema rope.
When the mast rake is where you want it, you should adjust the jib fairlead position or move the jib tack up or down to get the jib to set properly.
I hope that this will be of some help. Do raise any further questions here.
Title: Re: N1992 rigging plan, mast and boom used
Post by: NTOACertification on May 09, 2019, 10:29:38 AM

If the boat does not have a forestay then the mast must have a pin or bolt through the heel and mast step to prevent it jumping out, and also the mast gate should be  strong enough to retain the mast after a jib halyard failure.
If this is not the case then fit a wire forestay with a rope lanyard to the stem fitting. This lanyard should be quite slack and not be under tension except in a halyard failure. In other words the rig tension is derived from the shrouds and jib luff wire/halyard with the forestay always slack and not taking any of the tension off the jib luff.

Re: the boom droop:The roping ( Luff and Foot) in old sails often shrinks and prevent the sail from being set to its proper dimensions. This makes the boom droop at the transom.  To check this, first make sure you can hoist the mainsail right to the top of the mast ( there should be a black band painted at the top). If you can't hoist the sail right to the top then the luff rope in the sail may well have shrunk. To verify this, with the sail off the boat, hold the head and tack of the sail between two people ( or tie the head to a post), you should then be able, without too much effort, to pull the luff taught with no wrinkles left in the sail. If you cannot do this then the rope needs to be released at the tack.
Depending on the age of the sail you may be able to undo the stitching, near the tack or cunningham hole, which is holding the rope in place.
With the rope free at the bottom you should then be able to stretch the sail taught. The rope will then probably run up the luff tape and you can use a needle and whipping twine to sew it in it's new position. You may also be able to insert below the end of the existing rope, and stitch, a short bit of rope to keep the sail strong.  If the sail is not loose footed you should do a similar exercise on the foot of the sail. If you don't want to do this work yourself a sailmaker would be able to do this for you.

When the rig is set up the rigging should be pretty tight, the rake should be 200-250 mm measured at the gooseneck.

Please re-post if you have any other queries.