Rig Tuning

Larry Gotch asked if there was a correct tension setting for the shrouds.

You've asked a good question. I don't have an answer in specific pounds for the shrouds, but I have set the backstay gauge at 2,000 pounds for going upwind (back down to 1,200 off the wind or at rest.) There is probably a wide range of pounds depending on whether you have rod or wire rigging, and what size rigging, and what material.

Over many years of setting up masts, my technique has been to, first, loosely put the spar in the boat.

Adjust the fore and aft rake with the forestay and backstay. I generally like the mast on our Islander within an inch of vertical when there is about 1,000 pounds on the backstay. Checking vertical is easy - just hang a weight on the main halyard so it hangs just above the boom. Then measure the distance from the halyard to the mast.

Next, use the main halyard to see if the top of the spar is over the center of the boat. A rough approximation is if the weight on the main halyard is hanging directly over the boom. (There will be enough wind, wave or just you walking around to make it obvious this is not precise.) Alignment is done (assuming a wire, or no-stretch halyard) by holding it down to the main chainplate on each side to see that it is the same length. (If the halyard doesn't reach the deck, lash on a metal tape measure, which also makes it easy to measure to an eighth of an inch.) Adjust the main shrouds until the halyard measures exactly same to port and starboard chainplates. This will center the top aloft. Take up two or three more full turns on both of the main shrouds. Be careful and make the turns exactly, it's easy to confuse half turns with full turns. Then tighten the intermediates and lowers to hand tight. They should be just slightly looser than the main shrouds.

The next step may seem rather funny, but it does work. Rock the boat. Yes, stand at the centerline, step out to one side grabbing the rigging and throwing your weight outboard like you might on a swing. Then, as the boat moves a little your way, time your return inboard just as the top of the mast starts back to center. But continue on across the boat, grabbing the opposite rigging and hanging out there to accelerate the roll. (Feet on the cabin top edge, hands on the main shroud.) Repeat this process about 5-8 times until there is a good roll going. (This is best done in flat water tied to a mooring or just drifting - it won't work with tight dock lines.)

Now for the value of this caper. Immediately lay your head along the aft side of the spar, sight up along the aft edge and watch the shape as the boat takes up at the end of the roll. If the top of the mast seems to fall away in a curve to leeward, check to be sure that it happens equally on each side. If it does, the first adjustment would be to tighten the upper shrouds, but be sure to tighten both sides the same amount to preserve the centering of the top. If the shape is different on each roll, it is likely that the lowers are tighter on one side than the other. Adjust the lowers so the shape is the same on both sides, then tighten the uppers. If the middle of the mast falls to leeward, tighten the lowers. If the top of the mast still appears to fall off to leeward, you may have tightened a lower excessively on one side. The Islander has a design weakness in that the aft lower is only fastened to the deck, rather than being connected to a bulkhead which transmits load to the whole hull structure. Do the primary lower adjustments with the forward lower, keeping the aft lower slightly looser. (Some boats have been modified to either install a bulkhead below the aft lowers, or rigged a turnbuckle and wire to a pad glassed to the hull behind the bunk (starboard) and cabinet (port).

Repeat the process several times until the mast appears to remain straight on rolls to port and starboard.

The last step is going sailing upwind in a moderate breeze - say 10-12 knots. If the leeward rigging is loose, tighten to take out the slack, counting the turns for each shroud. Then tack and make the same adjustment on the other side. While doing this, again check that the mast remains straight looking up the back side of the mast. Repeat several times, and check again under 15-18 knot conditions and you should have a good set. This method will eventually achieve a tension which is sufficient to keep the mast aligned when under sail - the goal of a good set. Since this load is what the boat experiences under sail, it should not be too much to strain the boat or the rig.

I hope this is of some help. I'd be happy to hear any other opinions on the subject.

Clear Sailing, Rick Van Mell, vanmells@ix.netcom.com


Here is some input from regular winner Lou Zevenov from Diana.

Wind(app. knots) Backstay (in.) Sag in.( when beating)
0-10 1 10
11-15 2 10
16-20 21/2 10
21-25 3 10
26+ depowered 31/2 12


Rake @ dock is about 4in. aft @ truck.
Diana is raced in the old school of relatively loose lowers and upper tension only as necesary to keep the mast straight in max. wind.
Truck of the mast is allowed to fall-off but not hook .
Off-the-wind backstay is released 1to 2 in.
All of this is approximate.

Regards, Lou Zev louzev@comcast.net




The age of rigging is another subject for discussion. The surveyors seem to be leaning toward replacement after 8-10 years. A number of the boats have original rigging Ė pushing 20-25 years. There is no "correct" answer, since wear and tear depend a lot on the type of sailing the boat has seen and the water itís been sailed in. However, if your rigging is beyond ten years old, keep a very close eye on its condition. Check for hairline cracks at all the fittings. If you find any broken strands, donít procrastinate!

Our Secretary, Gary Salvo, is going through the rerig/repaint process right now (Jan í98), complete with changing over to all-line halyards. If interested, contact him at grsalvo@pacbell.net.

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Roller Furling

From: John Melton
Sent: Wednesday, May 01, 2002 10:57 AM
Subject: Request for Roller Reefing Info

I'm a new member as of this year, but I haven't been able to participate in any of the club functions as yet. I just bought my Islander 36 in September of 2001. I'm in the process of looking into adding roller reefing to my 1977 Islander 36 "Freedom Won". I would like some recommendations for people/organizations that have done good work for other members in the past. I would like a general idea of things and pit falls to watch out for and of course price considerations. Any help that I receive will be greatly appreciated.

john.melton@ varian.com
Varian Medical Systems
Phone: 650-424-6080

John,

I had a Harken 1.5 unit installed on my I-36 at the end of 1999, so I've had about 18 months of experience with it. It was installed by South Beach Riggers 415-974-6063, for $2800. (Some people have put on the next larger size, a 2.0.)

There is an additional cost for converting your existing sails with hanks to a luff tape. This was about $400 per sail - done by North Sails. You may find a sailmaker who could do it for a little less, or less per sail if you do a couple at once.

One of the considerations when laying out your line is which side to come down, and how to lead the line. I happen to have mine on the starboard side (which is less common) because my spinnaker pole is already on that side and my shore power is run there too, so I've kept all of the "clutter" on one side. A common practice is to attach lead rollers or blocks to the lifeline stations. I chose to lead my line outside the stantions aft of the mast to keep the line out of the walking area on the deck. I did this by having the installers bolt small lead blocks to the toerail. I think there are just three, but they keep the line completely out of the way. The line terminates in a ratchet block with a cam cleat which is attached to the bottom of the stern pulpit stantion. It was recommended by the installers and has worked without a hitch. This arrangement has worked very well and it is right at the helm station so I can single handedly set and furl the jib from the helm.

It's worked without fail so far. It unrolls and rolls up relatively easily under most conditions. It is important to keep some tension on the jib sheet as you furl to get the sail tight around the headstay. I do this one of two ways: hold the furling line in my right hand and the sheet in the left and just move from starboard to port; or leave one turn of line around the winch. The first way works very nicely in lighter conditions, the second in heavier air where you need both hands on the furling line. In the heaviest of winds (say around 23+) I have put the pulling line on a winch to get it started due to the weight of wind in the sail while headed on roughly a close hauled course. The most strength is required when you start to furl since that is when there is the most sailcloth exposed. It gets easier as you roll it in.

I hose off the drum when I wash down at the end of a sail.

Being a racing man for most of my life, I was slow to go to roller furling, but my wife is it's biggest fan since I don't have to run forward to raise and lower the jib in the wild conditions on the Bay. I can (and often have) set and furled the jib while she's below.

Give me a call if you have any further questions.

Good luck,

Rick Van Mell vanmells@ix.netcom.com
Vanishing Animal
650-962-1515






John,

I've been happy with the Furlex system I installed about four years ago. However, I'd recommend looking at the reviews done by Practical Sailor. If you don't subscribe, you might be able to find them in the library or go to www.practical-sailor.com where you can subscribe yourself or order copies of articles.

I think that Furlex, Profurl, and Harken are all good systems and there may be others. I bought my Furlex (a type C) both because it was well reviewed and because I got a good deal on the system from a sailmaker in Seattle. It was the previous year's model that had never been picked up by the person for whom it was originally ordered. The main drawback was that it does not permit an adjustable headstay, although the lack of the feature does get the furler a little closer to the deck. It hasn't been a problem for me since the backstay can be tightened. I think that their newer models do allow the forestay adjustment.

Another good research method is to just walk the docks and see what most folks in your area use and get opinions there as well.

Geoff Feiler
S/V Zoe
Anchorage, Alaska


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