genie, shut up.

Subject: Why need anchor chain?
From: Gene Kearns
Date: 9/18/2004 7:46 PM Eastern Daylight Time
Message-id:

On 18 Sep 2004 21:15:33 GMT, (JAXAshby) wrote:

What happens during the interaction of forces on the rode would be
most fascinating.

a way to simplified look at it is to consider the chain/rode/line to have
zero
weight pulled between two points (say 100 feet apart), then hang a 1# weight
in
the center point and check how much strain it put on the end points when the
weight hangs 20 feet, then 10 feet, then 5 feet, then 1 foot, then 1 inch,
then
1/10th inch. Just use trig to figure the forces.

So.... we just used intuitive trig to figure out why (1) we use scope
with an anchor and (2) why we don't tie boats to the dock with chain.
Now *that* is some real science......

And your "simplified look" does not apply.... an anchor rode does not
employ both ends at the same "Y" value.... therefore assumptions of
Y=Y'=0 do not obtain and is, therefore, the root cause of your lack
of understanding in this area. There isn't *anything* *attached* to
the middle.


the forces get out of hand ********VERY******** quickly. Even worse, is
that
the weight in the middle (or chain) has momentum as the boat rocks, so the
"natural" position of the weight overshoots and makes for seriously high
g-loads.


There is no weight "in the middle" (other than the weight of the rode)
.... so you put two anchors on the same rode? Odd.

Using that concept, most people use kellets and think it is a good and
useful idea.

--



Grady-White Gulfstream, out of Southport, NC.

http://myworkshop.idleplay.net/cavern/ Homepage
http://www.southharbourvillageinn.com/directions.asp Where Southport,NC
is located.
http://www.thebayguide.com/rec.boats Rec.boats
at Lee Yeaton's Bayguide

"JAXAshby" wrote in message
...
genie, shut up.

Subject: Why need anchor chain?
From: Gene Kearns
Date: 9/18/2004 7:46 PM Eastern Daylight Time
Message-id:

On 18 Sep 2004 21:15:33 GMT, (JAXAshby) wrote:

What happens during the interaction of forces on the rode would be
most fascinating.

a way to simplified look at it is to consider the chain/rode/line to
have
zero
weight pulled between two points (say 100 feet apart), then hang a 1#
weight
in
the center point and check how much strain it put on the end points when
the
weight hangs 20 feet, then 10 feet, then 5 feet, then 1 foot, then 1
inch,
then
1/10th inch. Just use trig to figure the forces.

So.... we just used intuitive trig to figure out why (1) we use scope
with an anchor and (2) why we don't tie boats to the dock with chain.
Now *that* is some real science......

And your "simplified look" does not apply.... an anchor rode does not
employ both ends at the same "Y" value.... therefore assumptions of
Y=Y'=0 do not obtain and is, therefore, the root cause of your lack
of understanding in this area. There isn't *anything* *attached* to
the middle.


the forces get out of hand ********VERY******** quickly. Even worse, is
that
the weight in the middle (or chain) has momentum as the boat rocks, so
the
"natural" position of the weight overshoots and makes for seriously high
g-loads.


There is no weight "in the middle" (other than the weight of the rode)
.... so you put two anchors on the same rode? Odd.

Using that concept, most people use kellets and think it is a good and
useful idea.



http://www.johnsboatstuff.com/Articles/anchor.htm

" Having a lot of sag in the rode reduces shock loads "

Isn't that what started this whole argument? Anchor chain introduces sag in
the rode. Sag in the rode reduces shock loads. So I guess I was right when
I said that anchor chain acts as a shock absorber, eh jaxie?

yo-yo, the shock absorbing capability is dependent on how much sag is in the
(inelastic) chain. lots of sag, lots of shock absorbtion. less sag, a hell of
a lot less absorbtion. little sag, almost no shock absorbtion.

"NOYB"
Date: 9/18/2004 10:11 PM Eastern Daylight Time
Message-id:


"JAXAshby" wrote in message
...
genie, shut up.

Subject: Why need anchor chain?
From: Gene Kearns
Date: 9/18/2004 7:46 PM Eastern Daylight Time
Message-id:

On 18 Sep 2004 21:15:33 GMT, (JAXAshby) wrote:

What happens during the interaction of forces on the rode would be
most fascinating.

a way to simplified look at it is to consider the chain/rode/line to
have
zero
weight pulled between two points (say 100 feet apart), then hang a 1#
weight
in
the center point and check how much strain it put on the end points when
the
weight hangs 20 feet, then 10 feet, then 5 feet, then 1 foot, then 1
inch,
then
1/10th inch. Just use trig to figure the forces.

So.... we just used intuitive trig to figure out why (1) we use scope
with an anchor and (2) why we don't tie boats to the dock with chain.
Now *that* is some real science......

And your "simplified look" does not apply.... an anchor rode does not
employ both ends at the same "Y" value.... therefore assumptions of
Y=Y'=0 do not obtain and is, therefore, the root cause of your lack
of understanding in this area. There isn't *anything* *attached* to
the middle.


the forces get out of hand ********VERY******** quickly. Even worse, is
that
the weight in the middle (or chain) has momentum as the boat rocks, so
the
"natural" position of the weight overshoots and makes for seriously high
g-loads.


There is no weight "in the middle" (other than the weight of the rode)
.... so you put two anchors on the same rode? Odd.

Using that concept, most people use kellets and think it is a good and
useful idea.



http://www.johnsboatstuff.com/Articles/anchor.htm

" Having a lot of sag in the rode reduces shock loads "

Isn't that what started this whole argument? Anchor chain introduces sag in
the rode. Sag in the rode reduces shock loads. So I guess I was right when
I said that anchor chain acts as a shock absorber, eh jaxie?

No kidding. With no sag, the anchor pulls loose...something even *you*
agreed with. Since anybody with a boat can tell you that anchors actually
work and don't pull loose most of the time, it stands to reason that there
must be a lot of sag in the line under most conditions. With me so far?

If there's a lot of sag in the line, then the sag provides absorption of
shock loads...just as I stated.









"JAXAshby" wrote in message
...
yo-yo, the shock absorbing capability is dependent on how much sag is in
the
(inelastic) chain. lots of sag, lots of shock absorbtion. less sag, a
hell of
a lot less absorbtion. little sag, almost no shock absorbtion.

"NOYB"
Date: 9/18/2004 10:11 PM Eastern Daylight Time
Message-id:


"JAXAshby" wrote in message
...
genie, shut up.

Subject: Why need anchor chain?
From: Gene Kearns
Date: 9/18/2004 7:46 PM Eastern Daylight Time
Message-id:

On 18 Sep 2004 21:15:33 GMT, (JAXAshby) wrote:

What happens during the interaction of forces on the rode would be
most fascinating.

a way to simplified look at it is to consider the chain/rode/line to
have
zero
weight pulled between two points (say 100 feet apart), then hang a 1#
weight
in
the center point and check how much strain it put on the end points
when
the
weight hangs 20 feet, then 10 feet, then 5 feet, then 1 foot, then 1
inch,
then
1/10th inch. Just use trig to figure the forces.

So.... we just used intuitive trig to figure out why (1) we use scope
with an anchor and (2) why we don't tie boats to the dock with chain.
Now *that* is some real science......

And your "simplified look" does not apply.... an anchor rode does not
employ both ends at the same "Y" value.... therefore assumptions of
Y=Y'=0 do not obtain and is, therefore, the root cause of your lack
of understanding in this area. There isn't *anything* *attached* to
the middle.


the forces get out of hand ********VERY******** quickly. Even worse,
is
that
the weight in the middle (or chain) has momentum as the boat rocks,
so
the
"natural" position of the weight overshoots and makes for seriously
high
g-loads.


There is no weight "in the middle" (other than the weight of the rode)
.... so you put two anchors on the same rode? Odd.

Using that concept, most people use kellets and think it is a good and
useful idea.



http://www.johnsboatstuff.com/Articles/anchor.htm

" Having a lot of sag in the rode reduces shock loads "

Isn't that what started this whole argument? Anchor chain introduces sag
in
the rode. Sag in the rode reduces shock loads. So I guess I was right
when
I said that anchor chain acts as a shock absorber, eh jaxie?

yo-yo, IF you had some ham you could have some ham and eggs IF you had some
eggs.

let us look at your useless statement.

No kidding. With no sag,

there is ALWAYS some sag, even with all nylon

the anchor pulls loose...something even *you*
agreed with. Since anybody with a boat can tell you that anchors actually
work and don't pull loose ------------------ most of the time
------------------- , it stands to reason that there
must be a lot of sag in the line ---------------------- under most conditions
----------------------. With me so far?

If there's a lot of sag in the line,

as stated above, there is ALWAYS some sag

then the sag provides absorption of
shock loads...just as I stated.

but ------------------ how much --------------------------- absorbtion? 20
G's is more than the boat can take. In fact, on a 20,000# boat, 2 G's is more
than most anchor chain can begin to hold.

How much is 2 G's? it is stopping short in 4 inches when moving 8 feet per
second. Think of the wave action needed to make a boat move 8 feet in a
second. On a 20,000# pound boat that would be a 40,000# strain on the chain,
anchor, deck chocks.









"JAXAshby" wrote in message
...
yo-yo, the shock absorbing capability is dependent on how much sag is in
the
(inelastic) chain. lots of sag, lots of shock absorbtion. less sag, a
hell of
a lot less absorbtion. little sag, almost no shock absorbtion.

"NOYB"
Date: 9/18/2004 10:11 PM Eastern Daylight Time
Message-id:


"JAXAshby" wrote in message
...
genie, shut up.

Subject: Why need anchor chain?
From: Gene Kearns
Date: 9/18/2004 7:46 PM Eastern Daylight Time
Message-id:

On 18 Sep 2004 21:15:33 GMT, (JAXAshby) wrote:

What happens during the interaction of forces on the rode would be
most fascinating.

a way to simplified look at it is to consider the chain/rode/line to
have
zero
weight pulled between two points (say 100 feet apart), then hang a 1#
weight
in
the center point and check how much strain it put on the end points
when
the
weight hangs 20 feet, then 10 feet, then 5 feet, then 1 foot, then 1
inch,
then
1/10th inch. Just use trig to figure the forces.

So.... we just used intuitive trig to figure out why (1) we use scope
with an anchor and (2) why we don't tie boats to the dock with chain.
Now *that* is some real science......

And your "simplified look" does not apply.... an anchor rode does not
employ both ends at the same "Y" value.... therefore assumptions of
Y=Y'=0 do not obtain and is, therefore, the root cause of your lack
of understanding in this area. There isn't *anything* *attached* to
the middle.


the forces get out of hand ********VERY******** quickly. Even worse,
is
that
the weight in the middle (or chain) has momentum as the boat rocks,
so
the
"natural" position of the weight overshoots and makes for seriously
high
g-loads.


There is no weight "in the middle" (other than the weight of the rode)
.... so you put two anchors on the same rode? Odd.

Using that concept, most people use kellets and think it is a good and
useful idea.



http://www.johnsboatstuff.com/Articles/anchor.htm

" Having a lot of sag in the rode reduces shock loads "

Isn't that what started this whole argument? Anchor chain introduces sag
in
the rode. Sag in the rode reduces shock loads. So I guess I was right
when
I said that anchor chain acts as a shock absorber, eh jaxie?

"JAXAshby" wrote in message
...
yo-yo, IF you had some ham you could have some ham and eggs IF you had
some
eggs.

let us look at your useless statement.

No kidding. With no sag,

there is ALWAYS some sag, even with all nylon

Once again...NO KIDDING. I already said that.


the anchor pulls loose...something even *you*
agreed with. Since anybody with a boat can tell you that anchors
actually
work and don't pull loose ------------------ most of the time
------------------- , it stands to reason that there
must be a lot of sag in the line ---------------------- under most
conditions
----------------------. With me so far?

If there's a lot of sag in the line,

as stated above, there is ALWAYS some sag

Correct...just as I stated.



then the sag provides absorption of
shock loads...just as I stated.

but ------------------ how much --------------------------- absorbtion?
20
G's is more than the boat can take. In fact, on a 20,000# boat, 2 G's is
more
than most anchor chain can begin to hold.

It doesn't matter. The fact of the matter is that the anchor rode provides
shock absorption...just as I stated.



How much is 2 G's? it is stopping short in 4 inches when moving 8 feet per
second. Think of the wave action needed to make a boat move 8 feet in a
second. On a 20,000# pound boat that would be a 40,000# strain on the
chain,
anchor, deck chocks.

Your math is wrong.

It doesn't matter. The fact of the matter is that the anchor rode provides
shock absorption...just as I stated.

bull****. as you stated.

On a 20,000# pound boat that would be a 40,000# strain on the
chain,
anchor, deck chocks.

Your math is wrong.

tell it to your phsyicists at at any local college, yo-yo.

"NOYB" wrote in message ...
"JAXAshby" wrote in message
...


How much is 2 G's? it is stopping short in 4 inches when moving 8 feet per
second. Think of the wave action needed to make a boat move 8 feet in a
second. On a 20,000# pound boat that would be a 40,000# strain on the
chain,
anchor, deck chocks.

Your math is wrong.

Starting with boat travelling at 8 ft/sec, a 2 g force will require 6
inches to stop the boat, and the boat will come to a stop in 1/8th of
a second.

To stop a boat travelling at 8 ft/sec within 1 second, the force
required is 1/4 g and the distance to stop is 4 feet.

To move a boat starting from standstill to 8 feet away within 1
second, the accelleration needed is 1/2 g and the speed attained at
the end of that 1 second of accelleration would be 16 ft/sec.

v(t)=at, d(t)=(1/2)at^2 and all that.

%mod%

"JAXAshby" wrote in message
...
yo-yo, IF you had some ham you could have some ham and eggs IF you had
some
eggs.

let us look at your useless statement.

No kidding. With no sag,

there is ALWAYS some sag, even with all nylon

And if this is true as you say there is always shock absorption available
according to your reasoning.