Angle of dangle

[Boatman]

Having always tensioned my rigging myself I went and got a professional to do the job, much to my surprise all the stays are somewhat loose, the rig seems to make weird and not so wonderful noises. Has anyone else had a similar experience or maybe I was over tightening the whole thing myself. Any books which anybody recommends would be interesting.

As I am sure the angle of dangle is very important for rig tension and longevity

Any coments ????

 

[vyv_cox]

Surprising. Every article and book I have ever read on this subject seems to agree - the leeward shrouds should just slacken when close-hauled in a force 3-4 carrying full sail. There are variations in the set-up procedure, some based on measuring stretch, some using a gauge, but all arrive at a similar conclusion. One fact that I have read several times, supported by my own observations, is that rigs fail more often by being too slack than too tight.

I have articles by Nigel Calder, printed in YM or PBO some years ago, that support this principle. There may well be something on the subject in his Boatowners Maintenance book, but there are many other, more rig-specialised books.

Your main check for now is that the mast remains in column and straight when sailing, or real problems may arise.

 

[jamesjermain]

I agree with Vyv. For performance it is almost true that the tighter the better. However, you don't want to over stress the fabric of the boat and if it is an older model, particularly wood, over tightening can cause damage. Some lightweight modern boats can also suffer from over tight rigging - check that the heads door still shuts!

A rigger of my acquaintance says that an averagely strong man using a pair of molegrips and an eight inch screwdriver as a lever cannot overtighten the rig of a 32 footer. I have my doubts.

JJ

 

[gunnarsilins]

Stretching the wire

I´ve seen some recomendations using a measuring tape, fix it along the stay so it´s end aligns with the endpiece. When tightening, measure the increasing gap between the end piece and the tape. This way the amount of force could easely be controlled. I remember a an article describing this method with different figures of strech given for different purposes, cruising or racing etc.
But personally I stick the old low-tech method by going to windward in decent breeze and check the leeward shrouds. As long as they´re not too loose I leave them as they are. The same applies to the forestay. I´m trying to judge what would be an acceptable sag, and leave it that way. I cannot see the point in putting a lot of stress into the yacht as long as I only cruise. No detectable movements and bends in the mast must be an indication of safe rig set-up, at least to my sense.

 

[seahorse]

Re: Angle of dangle-BOOK

"Haynes" of Workshop Mannual fame (for cars) do a very informative book on "Tuning & Rigging" mine was about £12 acouple of years ago. Money well spent.

 

[johnt]

we had this question earlier in the year Vyv ..slack rigging = mast failure because of snatch loading.

Slightly tight rigging is better than loose.
and the correct loading is 10-15% of the wires safe working load..which I would say means that the lee shroud shouldn't be loose at all!

 

[Guest]

Re: Stretching the wire

I go along with Gunnar on this, certainly for vessels with timber masts (which are of course more flexible than aluminium ones. )

For a cruiser, there's absolutely no point in trying to drive the heel of the mast down through its step, or hauling the chainplates up to meet the spreaders.

If the lee shrouds look tight but feel loose they're about right, in my book.

mikefield@woodenboatfittings.com

 

[vyv_cox]

Failures I have seen were not caused by snatch loading. In this case the shroud, or possibly fitting, would suffer an overload ductile (presumably) fracture, with evidence of necking.

The ones I have seen were fatigue fractures that occurred without exception just inside the rolled or swaged fitting on the wire. These are caused by bending movement between the fitting and wire, the point of highest stress. A significant problem with rotating masts, i.e. racing catamarans, but equally so with slack rigs.

 

[Guest]

Back to deadeyes and lanyards, Vyv?

mikefield@woodenboatfittings.com

 

[vyv_cox]

Absolutely right. Deadeyes and lanyards, in conjunction with wooden vessels and spars, were developed over centuries to a high level of understanding and were applied by professionals until quite recently. All-metal spars and rigging have had only a few decades of development, sometimes made by manufacturers (see the October "Cruising" supplement of PBO for some excellent examples of failure due to lousy design) who don't understand the principles of fatigue in design and then maintained by amateurs who often don't know or care how to do it. Come back in a century and maybe all will be right.