Bumping the rigging up one size (wire) do I compensate for streched old wire?

[Eastward ho 24]

May be a silly question but... My mast is down I've added thicker chainplates , knees, and a compression post to xfer the load to the lead. So my standing rigging can used replaced my plan is to : bump up one size I'm just gonna do the back stay right now while it's down and do the rest one atcat a time with the mast up. Do I just measure my old wire and order the same length? Will the new stress of thicker wire tensioned properly change that measurement?

[a64pilot]

I don’t think the wire is under enough tension to stretch it, I’m sure mine isn’t.
However don’t go on what I say, ask a Rigger.

[Shoalcove]

I’d just use the same length assuming that your turnbuckles had appropriate amounts of adjustment available. Is your old wire inadequately sized? There are some downsides to adding unnecessary weight aloft.

[HankOnthewater]

Although the title of the linked thread doesn't really indicate the relevance, there are a lot of posts there, dealing with the question to upsize rigging.... or not.
http://www.cruisersforum.com/forums/...ng-217604.html

[Eastward ho 24]

My rigging is original design by the naval architect Bob Poole so he'd know enough to size it correctly( I can only assume)..it's a down Easter 32 . Heavy displacement I don't " think" the weight will hurt her. It's a cutter rig with no running backs and it's got a yankee. I'm gonna be adding a big Genny and and possibly a spinnaker so..the current rigging just has a puny look and feel to it, and was possibly designed to just meet the loads of the Yankee and staysail ( but more on the conservative side)? But it does or did have Wood spreaders, a compression post that was just floating on cockpit floor, and no running backs . So me and Bob Poole may disagree there. Trying to gear up for big water and distant shores and with my inexperience I'd like to feel confident passing time Hove to etc. So peace of mind might be key here.

[Eastward ho 24]

P. S I've had 2 old timers comment how small the rigging is. Soo you know how that seed gets planted..

[MicHughV]

the way I did it many years ago was to replace all the s/s rigging at the same time...with the mast down, I fitted a swaged end on the upper end (I could have used a sta-lok fitting here, but in the interest of saving some money, went the swage route)
As a side note, the swage fittings would all be upside down and therefore not prone to water collecting and causing crevice corrosion. Then I cut each wire a tad longer than I thought I might need. All the wires were than re-attached to the various points on the mast.
Then I re-stepped the mast and had it tied down with the various and sundry halyards.
I started with the 4 lowers. With the mast in place it was short work to measure the wire, cut it, install the sta-lok, install the turnbuckle and tighten it up.
Next up was the upper shrouds. Same drill.
My mast had double backstays and as well as a forestay and inner stay. These came next.
Finally, the mast had some running backstays, but as these had a rope pulley system to tension them, the lower ends were also swaged. See above comment.
The whole operation was done in one afternoon.
All the sta-loks got a little dab of 5200 before screwing down the top cup to provide additional protection from salt water crevice corrosion.
Ok, now I will admit, I had a mobile rigging expert assist me as he had all the required tools for swaging, etc...plus, I purchases all the new new wire and sta-lok fittings from him at a substantial discount.
I had originally gone to our local marine store and priced out what new wire, fittings, etc, would cost me....( a lot $$$) so I snooped around and found this mobile rigger. He works up and down the coast and apparently does a roaring business. His prices, including his labor was easy half the price of the marine store, so this was a no -brainer.
A little bit of internet searching my provide a source for such a rigger and better prices for the required components.

[psk125]

At first, bumping up the size of your standing rigging sounds reasonable. Bigger is better. Stronger. Longer-lasting. Why not? One possible reason is safety. You are planning for distant shores and big water, what could be wrong with stronger rigging? Imagine a worst-case storm scenario: rolling or pitchpoling. With your "puny" rigging, the mast and sails are carried away. Luckily your deck-stepped mast leaves no hole in the deck and your ballast turns you right-side up: you're shaken but essentially intact. Would stronger rigging break the same way, or would it hold, tearing out the chainplates, wrenching the bowsprit off, and compromising the hull-deck joint while opening huge holes for water to pour into? There's a lot of power involved with tons of water working with a forty-foot lever arm. Bob Poole may have been thinking of this when he sized the rigging, but he's no longer around to ask. Perhaps up-sized rigging would still give way before ripping off the deck. It might be wise to discuss this "upgrade" with a naval architect who is not trying to sell you rigging before jumping into it.

[Eastward ho 24]

Hmmm well put

[RaymondR]

I would definitely extend that compression post down onto the keel and if the wire looked a bit puny take a very good look at the chain plates and how they transmit the loads into the hull as well.

[Paul L]

Putting more weight into the rig is not going to improve the boats sailing. Because of the leverage, adding 20lbs to the rig is simlar to cutting off maybe 200lbs from the keel. Have you looked at the working load and breaking load for the rig wire sizes as a direct replacement?

[Dogscout]

Originally Posted by Paul L

Putting more weight into the rig is not going to improve the boats sailing. Because of the leverage, adding 20lbs to the rig is simlar to cutting off maybe 200lbs from the keel. Have you looked at the working load and breaking load for the rig wire sizes as a direct replacement?

This is a great response to the question.

Engineers tend to have this "Make it an Inch" mentality. When the calculation says that the proper size is 7/8", many engineers will just say "Make it an Inch". (yes I'm one too, retired after 30 years) This built in a extra and raised the threshold. Then the accountant said that we have to reduce cost so just put in the minimum and perhaps the engineer said well we can get by with 15/16"

My point is that there is likely some overbuild in the original rig. Upsizing just add complications like having to upsize fittings and pins Etc.

[Neptune's Gear]

Nope. Going up a size is more weight aloft. The naval architect who designed your boat selected a rigging size to suit the requirements and loading on your vessel. The chainplates, frames, beams, compression posts and hull strength are designed in balance. The rig is usually a designed fuse - the rig will fall off before a chain plate pulls etc.

Also, proper rigging tension of caps is generally around 15% of B/L for 1x19 wire. This is to minimize stretch, shock loads etc. 15 % of the next size up is significantly more. It can bend the boat and cause other structural issues. If your rig is not tensioned to this level, performance is compromised on almost all vessels. A great reference is Ivar Dedekam's book "sail and rig tuning"

Finally, as one post above says - weight aloft is BAD. A lot of time and effort has gone into keeping the centre of gravity low.
Simply that you need to ask this question shows that you dont know as much as the designer of your vessel. Unless instructed to by a professional designer, leave the sizing as is. IMO.

[Maclir]

Another point often overlooked, is rig tension. With heavier wire it can be difficult to achieve the appropriate tension

[a64pilot]

I think you need to get a good rigger involved, it’s what they do for a living.
You may be adding stresses that were in the original design and may need larger wire, or you may not. Anyone here can only speculate, It’s time I believe to hire a Pro, at least for the advice.