wrote in message
...
On Sat, 15 Sep 2007 14:02:45 GMT, (Richard
Casady) wrote:

On Sat, 15 Sep 2007 16:11:47 +0700, wrote:

A simple example: You decide you want to buy a barrel of crude oil,
the price is in the newspaper every day, right? Now tell me what a
barrel of oil is? Right off the top of my head I can think of several
different sizes of barrels, 55 gal., 44gal., 200 Ltrs., etc.

Bad example. The petroleum barrel has been 42 gallons since they used
old herring barrels to haul crude in horse drawn wagons. It is a
recognized item in the list of internationally accepted weights and
measures. My calculator has it as 42 gal per bbl. By the way, a 55 gal
drum holds that much so that you get 50 gal liquid capacity plus the
necessary expansion space. So it's actually a round number.

Casady


No, good example as my company worked for just about every
international oil company in Indonesia and every one of their
contracts defines a "barrel" in the preamble to the contract. By the
way is not 42 US gallons, it is 42 US gallons at 60 degrees F at sea
level. :-)

What's the temperature have to do with anything? I know what you're
gonna say. You're gonna say volume decreases with temperature decrease
and vice versa. But does that not also hold true for the measuring
container?

It's the same thought process those dummies who say to loosen the
standing rigging for the winter storage period because the stays and
shrouds shrink with the cold. But, I suppose they think the aluminum
mast doesn't also shrink? Duh!

Ya gotta think outta the box, man.


Wilbur Hubbard

On Sun, 16 Sep 2007 13:08:32 -0400, a troll wrote:

a "barrel"... is not 42 US gallons, it is 42 US gallons at 60 degrees F at sea
level. :-)


What's the temperature have to do with anything? I know what you're
gonna say. You're gonna say volume decreases with temperature decrease
and vice versa. But does that not also hold true for the measuring
container?
It's the same thought process those dummies who say to loosen the
standing rigging for the winter storage period because the stays and
shrouds shrink with the cold. But, I suppose they think the aluminum
mast doesn't also shrink? Duh!
Ya gotta think outta the box, man.
Wilbur Hubbard

Oh dear,
I am going to regret this: the troll's not only wrong,
but ugly about it too!

Gas expands in volume 950 ppm per deg C
So it's important to sell by mass (which is invariant) or
by volume at a set temperature.

It's not a lot in a tank of gas (so much for filling up in the cold
pre-dawn) but it mounts up if you sell by the million barrels.

Steel and aluminum expand at different rates:
the linear rates are Steel 12 ppm /degC, Aluminum 24 ppm /degC

So the time to ease the stays is when leaving a boat in warming
weather, if at all. A sample 50 ft mast might need two or three
turns easing on each rigging screw for 30 degrees C temp rise. But
more care is needed with plastic rigging.
That can really change with temperature.

Brian Whatcott Altus OK

On Sun, 16 Sep 2007 13:08:32 -0400, "Wilbur Hubbard"
wrote:


wrote in message
.. .
On Sat, 15 Sep 2007 14:02:45 GMT, (Richard
Casady) wrote:

On Sat, 15 Sep 2007 16:11:47 +0700, wrote:

A simple example: You decide you want to buy a barrel of crude oil,
the price is in the newspaper every day, right? Now tell me what a
barrel of oil is? Right off the top of my head I can think of several
different sizes of barrels, 55 gal., 44gal., 200 Ltrs., etc.

Bad example. The petroleum barrel has been 42 gallons since they used
old herring barrels to haul crude in horse drawn wagons. It is a
recognized item in the list of internationally accepted weights and
measures. My calculator has it as 42 gal per bbl. By the way, a 55 gal
drum holds that much so that you get 50 gal liquid capacity plus the
necessary expansion space. So it's actually a round number.

Casady


No, good example as my company worked for just about every
international oil company in Indonesia and every one of their
contracts defines a "barrel" in the preamble to the contract. By the
way is not 42 US gallons, it is 42 US gallons at 60 degrees F at sea
level. :-)

What's the temperature have to do with anything? I know what you're
gonna say. You're gonna say volume decreases with temperature decrease
and vice versa. But does that not also hold true for the measuring
container?

It's the same thought process those dummies who say to loosen the
standing rigging for the winter storage period because the stays and
shrouds shrink with the cold. But, I suppose they think the aluminum
mast doesn't also shrink? Duh!

Ya gotta think outta the box, man.


Wilbur Hubbard


Willie-boy I got admire you. you are the perfect example of the old
adage that, "fools rush in where wise men fear to tread".

A "barrel of oil" is a standard of volume measurement used in the Oil
Industry. Just like gallon or liters, and since the volume of most
liquids change with temperature or pressure the temperature of the
liquid and pressure the liquid it is exposed to is specified.

A standard contract definition will be something like "a barrel" shall
be defined as 42 US gallons at 62 degrees F, at sea level.

In reference to rigging changes at different temperatures they
certainly do change in length with changes in temperatures. You can
look up the coefficient of expansion of aluminum and stainless on the
web or in most engineering handbooks. Of course, in winter the colder
temperatures will cause the spars and rigging to contract and the
aluminum mast will contract more then the stainless rigging so your
comments on the necessity to loosen rigging for temperature change in
winter is correct.


Bruce in Bangkok
(brucepaigeATgmailDOTcom)

On Mon, 17 Sep 2007 19:16:16 +0700, wrote:

.....
In reference to rigging changes at different temperatures they
certainly do change in length with changes in temperatures. ...
in winter the colder
temperatures will cause the spars and rigging to contract and the
aluminum mast will contract more then the stainless rigging so your
comments on the necessity to loosen rigging for temperature change in
winter is correct.


Bruce in Bangkok

I'd hate anyone to take a Troll's sneer at face value like that.
I'm thinking of a race boat with a carbon fiber composite mast.
This material can have an extremely low thermal coefficient - as low
as 1 ppm /degC.

Most rigging would shrink more in Winter (but a few would expand when
chilled, wouldn'tcha know?)

Brian W

On Mon, 17 Sep 2007 23:06:17 GMT, Brian Whatcott
wrote:

On Mon, 17 Sep 2007 19:16:16 +0700, wrote:

....
In reference to rigging changes at different temperatures they
certainly do change in length with changes in temperatures. ...
in winter the colder
temperatures will cause the spars and rigging to contract and the
aluminum mast will contract more then the stainless rigging so your
comments on the necessity to loosen rigging for temperature change in
winter is correct.


Bruce in Bangkok

I'd hate anyone to take a Troll's sneer at face value like that.
I'm thinking of a race boat with a carbon fiber composite mast.
This material can have an extremely low thermal coefficient - as low
as 1 ppm /degC.

Most rigging would shrink more in Winter (but a few would expand when
chilled, wouldn'tcha know?)

Brian W


Well, if you are designing a high tech racing boat why not use high
tech synthetic rope for rigging. some of it is stronger then stainless
cable and nearly zero stretch.


Bruce in Bangkok
(brucepaigeATgmailDOTcom)

On Tue, 18 Sep 2007 07:31:15 +0700, wrote:


Most rigging would shrink more in Winter (but a few would expand when
chilled, wouldn'tcha know?)

Brian W


Well, if you are designing a high tech racing boat why not use high
tech synthetic rope for rigging. some of it is stronger then stainless
cable and nearly zero stretch.


Bruce in Bangkok
(brucepaigeATgmailDOTcom)

I can visualize various combinations of rig and mast , it's true. But
a zero-stretch line does not always imply a zero thermal coefficient
line, I don't believe.

Regards

Brian W

"Brian Whatcott" wrote in message
...
On Tue, 18 Sep 2007 07:31:15 +0700, wrote:


Most rigging would shrink more in Winter (but a few would expand when
chilled, wouldn'tcha know?)

Brian W


Well, if you are designing a high tech racing boat why not use high
tech synthetic rope for rigging. some of it is stronger then stainless
cable and nearly zero stretch.


Bruce in Bangkok
(brucepaigeATgmailDOTcom)

I can visualize various combinations of rig and mast , it's true. But
a zero-stretch line does not always imply a zero thermal coefficient
line, I don't believe.

Regards

Brian W

There is a new rigging material out which is exactly that: high-tech
synthetic rope with a protective covering. Don't recall the name of it, but
it's very lightweight and exceptionally strong. At least in theory. Jury's
still out on how it works in the real world.

On Mon, 17 Sep 2007 22:36:37 -0500, "KLC Lewis"
wrote:


"Brian Whatcott" wrote in message
.. .
On Tue, 18 Sep 2007 07:31:15 +0700, wrote:


Most rigging would shrink more in Winter (but a few would expand when
chilled, wouldn'tcha know?)

Brian W


Well, if you are designing a high tech racing boat why not use high
tech synthetic rope for rigging. some of it is stronger then stainless
cable and nearly zero stretch.


Bruce in Bangkok
(brucepaigeATgmailDOTcom)

I can visualize various combinations of rig and mast , it's true. But
a zero-stretch line does not always imply a zero thermal coefficient
line, I don't believe.

Regards

Brian W

There is a new rigging material out which is exactly that: high-tech
synthetic rope with a protective covering. Don't recall the name of it, but
it's very lightweight and exceptionally strong. At least in theory. Jury's
still out on how it works in the real world.

Take a look at the pendulum of a grandfather clock. They cleverly
arrange brass and steel so that the assembly has a zero temperature
coefficient. If the rigging stays the same length while the aluminum
mast increases in length, the rig will get tighter. Not what you want.

Casady

On Mon, 17 Sep 2007 22:36:37 -0500, "KLC Lewis"
wrote:


"Brian Whatcott" wrote in message
.. .
On Tue, 18 Sep 2007 07:31:15 +0700, wrote:


Most rigging would shrink more in Winter (but a few would expand when
chilled, wouldn'tcha know?)

Brian W


Well, if you are designing a high tech racing boat why not use high
tech synthetic rope for rigging. some of it is stronger then stainless
cable and nearly zero stretch.


Bruce in Bangkok
(brucepaigeATgmailDOTcom)

I can visualize various combinations of rig and mast , it's true. But
a zero-stretch line does not always imply a zero thermal coefficient
line, I don't believe.

Regards

Brian W

There is a new rigging material out which is exactly that: high-tech
synthetic rope with a protective covering. Don't recall the name of it, but
it's very lightweight and exceptionally strong. At least in theory. Jury's
still out on how it works in the real world.

Going back at least ten years a Farr 40-something, named Millennium,
was using some sort of high strength synthetic for running back stays.
Of course, these really only have to be low stretch but it shows a
trend.

Bruce in Bangkok
(brucepaigeATgmailDOTcom)

On Sep 17, 5:36 pm, "KLC Lewis" wrote:
... There is a new rigging material out which is exactly that: high-tech
synthetic rope with a protective covering. Don't recall the name of it, but
it's very lightweight and exceptionally strong. At least in theory. Jury's
still out on how it works in the real world.

PBO covered with cheaper (!) carbon is available from several
suppliers. It has been used for years by all of the top long distance
racers with good results. In the lab it lasts longer than wire but it
is very vulnerable to UV attack (hence the carbon outer layer). The
expense and need to keep it perfectly covered make PBO an unlikely
choice for cruising. There is a new version of Dynema that was
specifically developed for standing rigging. Dynema (made under
license as Spectra in the US) is great stuff and ideal for rigging
except that it is subject to creep (slow, plastic elongation under
continuous load). Dynema sk 78 greatly reduces creep and is as good
or better than PBO on paper and it is much cheaper. It may well be
the future of rigging even for cruising boats but for now wire, rod or
dyeform are the only really attractive options for high load standing
rigging on cruising boats.

-- Tom.