Thimbles for 1x19 1/4'' splices

[klubko]

Many thanks. My wire will be SS 6mm. What about the forces that might flatten the thimble? I have no idea how much can SS thimbles take? Apprentice recommends solid thimbles to deal with this issue. Any thoughts on that?
Thanks Petr

[Brian Duff]

what is the piece of rigging to control (loads involved) ?

[klubko]

Shrouds, stays, all under 4000lb.

[klubko]

Hello,
do you think that SS thimbles could take such loads?
Many thanks
Petr

[Brian Duff]

Although many boats were(and are) rigged with plain thimbles (Alberg 30, for one) and they seem to work alright for quite a while, over time the thimbles either crack or deform.

Some of the rigs I have seen made this way are 30 yrs old and haven't cracked or deformed, while othertimes we see thimbles crush after one sail. I think if the loads are around 1/2 of the rated cable load the thimble will probably be fine.

Calling the thimble manufacuturer and asking for the load rating for use on a 7/16" pin (or whatever size your using) is your best bet for an absolute answer.

[klubko]

Many thanks. Petr

[Brion Toss]

Hello,
There are three problems with 1x19 on thimbles. One is that 1x19 puts more load on less area, so thimble deformation or failure is a frequent problem.
Next, 1x19 is not happy with a tight radius; it is weaker when bent too much, so a wider than usual thimble is important.
Finally, turnbuckles and tangs nowadays are sized for 1x19 swages and the like, so you can't solve the above problems by going with oversize thimbles.
That's why Herreshoff pattern 1x19 thimbles are the best solution. Not cheap, but of course they last forever. Have you tried Port Townsend Foundry?
I have seen rigs with lighter, narrower thimbles. As Brian noted, some were fine, and some weren't, indicating that some boats are loaded more heavily than others. It's a bad idea to assume that the standing rig -- or any other boat component -- will be lightly loaded, just to rationalize taking a shortcut or making a cost savings. The rig is not there to suit your situation. Quite the opposite.
Fair leads,
Brion Toss

[klubko]

Hello,
thanks for the comment. I was looking around and rationalizing, but it really seems that 1x19 with "some normal" thimbles would be a risky way to go. We are cruising boat, so ease of repair and low cost (and other virtues mentioned in Apprentice and elsewhere ) are on the top of the list. So we started to think about 5/16 7x7, which we could use with normal thimbles as I understand and might be in the end: easier to do and cheaper.

Any practical comments on that? I know 7x7 will have to be larger (I decided to go safe with 9/32" 1x19 or 5/16" 7x7) and perhaps not as handsome. More flexing too.

There is one question for the 1x19 and bronze thimbles option: the Apprentice doesn't mention insulating the wire from the bronze thimble. Is it not necessary? Should I rather go with galvanized wire instead of SS?

Also please comment on the longevity. With mechanical terminals people say, change at least every 10 years (we are/will be in tropics, so perhaps even sooner) (well be bought a boat with swages and 15 year old rigging ). From what I hear about splices, they can last much longer. This is very appealing too (of course with periodic inspection).

Didn't know about Port Townsend, will write them now, Many thanks.

(There is still the option to get Norseman in the end, but that's a boring idea... )

Many thanks
Petr

[Brian Duff]

"The rig is not there to suit your situation. Quite the opposite. "

Is this becasue we only engage in 'Yachting' under sail these days ?

I had alway assumed the great variety of rig design and type is just becasue every task under sail we needed to complete required a different process, or rig to handle it...

I am not saying that you shoud sail across the Atlantic in a Bolger Tortise, but boats should most certainly be built to your requirements, be it budget, cruising grounds, or storage needs, whatever. Just pay attention.