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Old 04-05-2014, 13:46   #136
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pirate Re: Bigger is better, part 2

Long overdue AT. I admire your vast patience.

Now, let's talk fishing. And guns n stuff.
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Old 04-05-2014, 14:12   #137
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Re: Bigger is better, part 2

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Long overdue AT. I admire your vast patience.

Now, let's talk fishing. And guns n stuff.
ParaOrdnance p12- 45

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Old 08-05-2014, 15:44   #138
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Pushing the Envelope – tron vs mech

Not sure what thread this should go in so I tossed a coin


I’m just back from discussions with the client of my client. An unhappy client of my client.
Even they are not the ‘end user’: they supply complete factories of machinery to the end user.

The client of my client has been pushing my client to push the performance envelope of a mechanical component (a crucial, large, high-value component).
They’ve been doing this for well over a decade, for successive generations of their product.

Effectively they want more ‘yield’ from the same sized (and ideally, less expensive) component. And time after time, we’ve pulled assorted rabbits out of various hats in order to make that happen. (I’m the guy who has to dream up how and where to pull them out, and my client has to turn my ideas into metal)
The ‘comc’ have adopted a number of tactics, such as wanting, for instance, to be told what Factor of Safety I was working to, in order to see if I was being inappropriately prudent.
(A bit like asking the designer of a flat-bed truck, rated at 2500kg payload, to specify what safety factor the truck was designed to)

Now it has apparently come unstuck: not with a breakage, but with a “fail-safe” condition: in other words, it refuses (for reasons of inherent physics) to lower a load.
(A load which is more than it has ever had to lower in the past, and approximately twice what the same size and configuration of component was required to lower twelve years ago. And which, it will probably turn out, is a little more than they asked us to accommodate. They’re dealing with a raw material of variable density)

At every stage, I have patiently explained to them that, as in investments, higher yields generally involve higher risks. And in return they have nodded impatiently, with slightly glazed eyes, wanting to return to the conversation about how much more they can ask of us, and how much less they can pay for it.


And this thought just occurred to me: there’s a parallel with what I see happening in the sailing community.

For which I blame my generation: the youngest generation who saw humans reach for the stars (OK, to be pedantic, the moon) and grasp it. The same generation who entered the workforce at the same time as the mighty microprocessor. Steve Jobs’ generation.

We have become accustomed to things routinely happening which are too good to be true. Every year, things which were impossible last year are already mundane.

And compounded over several years or decades it becomes eyewatering.
If I had paid for the memory upgrade my supplier did not even bother to charge me for on my last design computer, at the same rate per megabyte I once paid to upgrade my Mac Plus from 1 to 4MB, it would have cost $1.75 million.

At the dawn of the electronic era, the ceiling is so far beyond our perception that apparent miracles are happening routinely. We build this into our expectations.

But at the dusk of the mechanical era, we are pressed against the ceiling, in places, and it hovers closely overhead in others.

I suggest it’s worth bearing this in mind when we contemplate applying the “Liberace” principle (“you can’t have too much of a good thing”) in areas where electronics cannot save our sorry arses.

Can you use, for instance, ultra-high performance chain, intended for carefully lifting known loads under controlled conditions, as anchor chain?
And can you persuade the supplier this is a good idea?

The answer to the first question is, certainly you can.
If you’re not charging your passengers, you can do whatever you want.

And possibly given time, and by asking for more rabbits to be discovered attempting to hide under various hats, you could achieve the second, although as niche customers, cruisers don’t have much leverage.

But don’t come crying to me when your high-yield investment decision turns bad.

(Thanks, I feel better now. It wasn’t about you!)
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Old 08-05-2014, 16:27   #139
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Re: Bigger is better, part 2

Thanks Andrew,

Sticking with chain - one unknown you have not mentioned is what happens to HT chain, the G70, G80 and G100 (and even G120s) when they are galvanised (and I use the word galvanised loosely - but still stick to a process suitable for an anchor chain)?

All of these chains are tempered but galvanising of any (most?) form introduces heat and that heat will impact the performance, or specification, of the chain - referring back to one (some) of your earlier posts - the heat will re-arrange the atoms.

Also referring back to your previous missive on stress/strain and extension. On further research I note some chain makers are making HT chain, say G100, with an extension at break of 10% but others are making the same chain, obviously not the same but similar, with an extension of 20% at break. It does not matter if the chain is 6mm (1/4 inch) or 12/13mm and (1/2 inch) the chain will still have an extension of 20%. It will still have, about, 3 times the breaking strength of a G30, of the same size. If we take 2 chains of the same strength, a G100 and a larger G30 then they will have the same breaking strength (that's the basis of comparison) the smaller G100 will have an extension of 20% and the G30 an extension of, only, 15%. If the ability to absorb energy is the area under the curve then the G100 curve has more area (than the G30 curve). The yield of the G100 might be higher than the G30, or might not?

And then we need to ponder on what those atoms have got upto when we galvanise. But it is possible to galvanise G100 with significant impact on strength or retain at least 95% of strength (vary the process/technology) and anything in between.

But I cannot accept that we have reached the limits of mechanical properties. If we accept this as basis for the future, or past, we would not be using HT steels nor aircraft grade aluminium alloy in anchors, we would never have bothered with carbon in resin, sails nor fishing rods and no-one would be using G120 chain for lifting. And what would we do, especially in Australia, without nano technology in sunscreen.

Like your clients - I can feel your eyes glazing over


Jonathan
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Old 08-05-2014, 17:34   #140
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pirate Re: Bigger is better, part 2

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Thanks Andrew,

Sticking with chain ... Like your clients - I can feel your eyes glazing over

Jonathan
Nah Cap, that's all the rest of the CF readers. It was a real good go but maybe time to move on. I am.
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Old 08-05-2014, 18:11   #141
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Re: Bigger is better, part 2

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Nah Cap, that's all the rest of the CF readers. It was a real good go but maybe time to move on. I am.
Do not give up - I appreciate fully the application is different but the US Navy are not using G120 Gal chain to tie down tanks (or large tracked vehicles) on landing craft in support of US chain makers. They use such products for sound and well researched reasons (the results of which are hidden in 'secret' documents). G70, in its raw state is a transport chain, is being advocated in a gal form as an anchor chain - so I've seen nothing yet that might not suggest that gal G80 might not be better. I would not advocated G120, one step at a time! Some people, who have not accepted we have reached the limits of physical engineering, have taken traditional (and less traditional) galvanising for application on HT chain. I like to have an open mind.

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Old 18-05-2014, 09:34   #142
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Re: Bigger is better, part 2

The first concern when reading about lighter chain in this blog was the effect to catenary. Started googling the subject and found this article which is good read:

Catenary & Scope In Anchor Rode: Anchor Systems For Small Boats

Quote from article:
"The practical upshot to this as it will interest most boaters is that the lore of heavy chain is demonstrably false as it applies to small boats and modern anchors. Chain is still necessary for a number of other reasons, but it need not be unnecessarily heavy. "

Even if it may not be hurting my overall cruising performanace it is still disconcerting to have marbles roll toward the bow because of the weight of 300 feet of chain in the chain locker.
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Old 19-05-2014, 08:04   #143
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Re: Bigger is better, part 2

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Do not give up. I like to have an open mind.
Jonathan

Hello Jonathan

Congratulations for making 1000 posts on CF

You may be somewhat of enfant terrible here, but surely You successed in being inspirational

My very best regards

Tomasz
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Old 19-05-2014, 08:45   #144
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Re: Bigger is better, part 2

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G70, in its raw state is a transport chain, is being advocated in a gal form as an anchor chain.
You are right, of course, but (it is always some "but") I looked to some manufacturers sites and found that G70 is being advocated as stronger alternative for the same weight, not as a mean of having lighter chain. Small difference in wording, but also conservative and safe approach of manufacturers...
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Old 20-05-2014, 10:59   #145
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Re: Bigger is better, part 2

Jonathan,

may be You missed this, but I started the new thread, regarding fail-safe anchor chain or rather most fail-safe material for it. Somewhat similar to this thread, but from little different point of view. Will be interesting to have Your input on this


Best regards


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