Standing rigging

jfkal

jfkal

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I intend to replace my standing rigging. Some of the shrouds and the baby-fore- stay are currently 7mm the rest is 8mm wire. Am I introducing any harm replacing the 7mm with 8mm as well? I intend to do this to reduce cost and variations.
Please let m ehave your comments.
 
From 7mm to 8mm it should be ok, you should be much more cautious if considering a bigger increase in diameter.
Sure bigger is better, but at some point you should make also bigger turnbuckles and above all bigger chainplates and bigger hull attachments. Cable should work as the weak link, otherwise you risk to lift the whole of your fore deck, or snap the chainplate attachment from the hull leaving a new -unplugged- through hull... better let the cable go first and dimension it accordingly.
 
Understand.

Fore and backstay are 8mm already to are the top shrouds. Just the shrouds to the second spreader and the baby stay are 7mm. Guess ther upgrade on three out of nine wires should be okay ?!
 
Understand.

Fore and backstay are 8mm already to are the top shrouds. Just the shrouds to the second spreader and the baby stay are 7mm. Guess ther upgrade on three out of nine wires should be okay ?!
 
I have to disagree with that as a general concept. Although in this case I don't think he will come to any harm - it is certainly not always the case that "bigger is better".

Thicker ropes / wire can lead to greater strain on the fittings (as it absorbs less of the load) and so can lead to gear failure.

Changing the relative thicknesses of the rigging will also affect the way the mast behaves under loading, but probably not likely to be serious.
 
Yes, upper intermediate shrouds and babystay are normally less stressed than say forestay or lower shrouds, so an upgrading there should do no harm.
If you were to hoist an enourmous storm jib under bft9 winds on the baby then it would be a concern!
 
Go for all 8mm, it will make it simple if you need to carry spare at anytime and norseman type terminals for repair.
 
Same point really, but I am curious to know answer. Presumably boat builders use optimum thickness, taking everything into account, or is there an element of costs saving by using minimum thickness adviseable.
When time to renew should you look to "beef up" original thickness with a view to decreasing risk of losing mast. Never thought about risk of chainplates etc being ripped out. I thought replacement of thicker standing rigging was one of the areas where normal spec boats were prepared for blue water, or am I totally off beam here. Any riggers out there?
 
It is not necessarily a good idea. Assuyming that the original strength was properly designed, then:
- you increase the weight of the rigg and shift the overall weight balance
- reduces the stability of your boat
- strenght of whole rigg is matching, strengthening the standing rigging, will the other parts hold the loads?
Altogether, why change ?
chris
 
Assumming the wire size is correct at the moment there is no need to change it.
The size has a designed in safety factor so the rigging is already oversized.
Last time I checked 8mm wire was more expensive than 7mm and so are all the terminals.
Tuning may be more difficult depending your setup.

Cheers

The Lash
 
Good question. I guess cost reasons are a main factor here. My gut feel is that 1 mm increase should not lead to catastrophic chainplate failure (all go to the same chainplate arrangement anyway). Agreed that I should not double the size.
I rather have one type of turnbuckle and end fitting and besides no one has 7mm stuff here in Singapore anyway.
Think I go for the 8mm. Will keep you posted if I keep the mast and lose the deck.....

And --- do not assume that boat builders scarifice their margin for your safety. That's were the coast guard comes in .....
 
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