[Public-List] rigging
Gordon Laco
mainstay at csolve.net
Mon Jan 18 08:19:27 PST 2010
HI Don - I like Andersen best too... and as of this month I do them
for Canada (wish I knew that was coming before I got the ones I have
on the boat now...)
Hope to see you at a meeting some time - and also maybe sailing!
Gord
On 18-Jan-10, at 11:15 AM, Don Campbell wrote:
> Gord;
> Thanks. What I was quoting was their page of "typical" strengths
> for wire and ropes (none of which they make) and they also say the
> breaking strengths vary greatly by manufacturer. All the more reason
> to check the specs on the roll. Sorting out forces on blocks, never
> mind block WWL and breaking load is always something I find a bit
> tricky. As for winches, I am biased there to Andersens for my
> current uses, so would not consider specs in the Harken catalogue
> for them either.
> Don
>
> Gordon Laco wrote:
>> Good morning Don - Sorry I couldn't make it to the meeting.
>>
>> Be careful with the Harken catalogue when using it as a text for
>> strengths... that company is notorious for phrasing specifications
>> in a manner that can lead one assume an over estimated level of
>> performance (blocks and winch powers in particular)
>>
>> Gord
>>
>>
>>
>>
>> On 18-Jan-10, at 10:16 AM, Don Campbell wrote:
>>
>>>
>>> There has been an extensive discussion on mast beams and rigging
>>> and the pros and cons of various rigging systems. The over-riding
>>> consideration in any refit is safety and it is never the safety of
>>> the conditions that one decides to sail out of port in, but the
>>> conditions that one gets caught in while out that usually
>>> determine the maximum loading that we put our boats under. It has
>>> been shown many times that boats will take more than people in
>>> most of these circumstances so whatever the designer has done to
>>> make boats so they will weather a storm, they have done a fairly
>>> good job. However, they have done this using design principles
>>> which involve numbers and algorithms that dictate working load
>>> limits (WLL) and breaking load limits. Usually, we do not have
>>> those numbers at hand when we make decisions to repair or replace.
>>> The best we can do is look at materials for sale that seem to
>>> match what is there. We can also use recommended safety factors of
>>> 5x for loads not having to do with lifting people and 10x load if
>>> we are lifting people. That sets breaking loads at 5 x the WWL (so
>>> if you tension the rigging to 1000 lbs, you will need 5000 lb wire
>>> to be at that safety factor) and somewhere around 2500lbs if we
>>> are lifting people. Oversizing line is never a problem but it will
>>> put the breaking point of the system on whatever the next weakest
>>> link is.(chainplate bolts?)
>>> As an example problem of choices, the Harken catalogue gives
>>> measurements of breaking strengths of three 1/4" SS 1-19 wires:
>>> 302 is 8200 lbs, 316 dyform is 8844 lbs and 316 is 7090 lbs. I
>>> suggest that not many of us could tell the difference by looking
>>> at these three wire ropes and I have a suspicion that there are
>>> few of us who could say what Whitby originally put on our boat or
>>> what is on our boat now if we have replaced the rigging..
>>> I have taught the ropes and knots materials for the Canadian
>>> Power and Sail course for a number of years and what I tell my
>>> students every time is to know what you need and know what you are
>>> buying by manufacturers specifications given on the materials that
>>> you buy. If there are no specs given on the roll of rope, then you
>>> don't know if the roll of rope is first grade or seconds. Knowing
>>> what you need is not just 1/4" wire rope. It is what spec on 1/4"
>>> wire rope you feel will be safe ( I'm not a lawyer) for the worst
>>> conditions you will ever be out in and then will that provide the
>>> WLL or breaking strength that the designer has given in his
>>> drawings.
>>> I never rely on price to tell me what the value is of the
>>> product. Most often we get what we pay for. There are many times I
>>> have gone to commercial riggers - the people who do the rigging
>>> for cranes and commercial lifting devices - for wire rope because
>>> they always have the specs and usually do not price things with
>>> BOAT in mind. That way, I know what I am getting when I buy wire
>>> rope from them..
>>> Therefore the questions that I would ask you to sort out are do
>>> you know the design requirements for the products you are fixing
>>> or replacing? and does the product you are making or buying meet
>>> those specifications? If the answer for the second is that you
>>> don't know or that that product does not measure up to design
>>> requirement, my recommendation is DON"T BUY IT!
>>> We have been given 2 figures on rigging in this recent
>>> discussion, $1000, from a source in Florida and $2000 from others.
>>> What we don't know is whether both rigging purchases contain the
>>> same components for a start. If one is done with Nico press
>>> fitting and the other with Norsemen fittings, there is one
>>> difference. If turnbuckles were replaced in one but not the other
>>> is another significant difference. Make sure you know what
>>> comparative pricing does for you, and if you do go for a group
>>> purchase, make sure you get a well described spec list before you
>>> tender it. That way, your comparative pricing will be effective.
>>>
>>> Don #528 and #469
>>>
>>> Jonathan Adams wrote:
>>>> All,
>>>>
>>>> Mike and I have been communicating regarding a group buy of
>>>> rigging material either fabricated or just the materials. If
>>>> there are folks interested in participating in this, let me know.
>>>>
>>>> Also note that Gordon Laco has rigging material at great prices
>>>> for A30 members - I got my turnbuckles through him.
>>>>
>>>> Jonathan
>>>>
>>>>
>>>>
>>>>
>>>> ________________________________
>>>> From: Richard Cronk <manan at nb.sympatico.ca>
>>>> To: Public-List at lists.alberg30.org
>>>> Sent: Mon, January 18, 2010 7:15:19 AM
>>>> Subject: [Public-List] rigging
>>>>
>>>> Try Mac sails in Fla for rigging ..Got mine there and was 1/4
>>>> inch with fitting ..less than 1000;00
>>>> D
>>>> _______________________________________________
>>>> These businesses support your Association:
>>>> http://www.alberg30.org/store/A30supporters.html
>>>> Please support them.
>>>> _______________________________________________
>>>> Public-List mailing list
>>>> Public-List at lists.alberg30.org
>>>> http://lists.alberg30.org/listinfo.cgi/public-list-alberg30.org
>>>> _______________________________________________
>>>> These businesses support your Association:
>>>> http://www.alberg30.org/store/A30supporters.html
>>>> Please support them.
>>>> _______________________________________________
>>>> Public-List mailing list
>>>> Public-List at lists.alberg30.org
>>>> http://lists.alberg30.org/listinfo.cgi/public-list-alberg30.org
>>>>
>>>>
>>>>
>>> _______________________________________________
>>> These businesses support your Association:
>>> http://www.alberg30.org/store/A30supporters.html
>>> Please support them.
>>> _______________________________________________
>>> Public-List mailing list
>>> Public-List at lists.alberg30.org
>>> http://lists.alberg30.org/listinfo.cgi/public-list-alberg30.org
>>
>> _______________________________________________
>> These businesses support your Association:
>> http://www.alberg30.org/store/A30supporters.html
>> Please support them.
>> _______________________________________________
>> Public-List mailing list
>> Public-List at lists.alberg30.org
>> http://lists.alberg30.org/listinfo.cgi/public-list-alberg30.org
>>
>>
> _______________________________________________
> These businesses support your Association:
> http://www.alberg30.org/store/A30supporters.html
> Please support them.
> _______________________________________________
> Public-List mailing list
> Public-List at lists.alberg30.org
> http://lists.alberg30.org/listinfo.cgi/public-list-alberg30.org
1263831567.0
More information about the Public-List
mailing list