"Harry" wrote in message
m...
On 6/22/10 6:24 AM, W1TEF wrote:
On Mon, 21 Jun 2010 22:47:10 -0400, Wayne.B
wrote:

On Mon, 21 Jun 2010 22:24:27 -0400,
wrote:

The A-7 Polyform bouy holds 161.6 gallons of air which ~~ mumble -
mumble - carry the six, add four, times 12, price of tea in China ~~
works out to...24.8 something or other cubic feet? That right?

I'm getting about 20 cubic feet assuming 8 gallons per cube, or about
1200 pounds of buoyancy. That's a big-un, should do the trick if we
can get the chain to slip and have enough static engine thrust. Nice
solution if you've got the room for a big buoy like that. Any idea
what they cost, and what the deflated size is? A couple of them might
be useful as hurricane fenders.

http://www.polyformus.com/doc/product_a7.htm

My personal solution is to use a chain hook led to a 3,000 lb
Come-a-Long. I've tested it enough to know that it works but it would
take a while to bring up the anchor from 40 ft. The nice thing is
that Come-a-Longs are relatively cheap and don't take up a lot of
space. A multi-part block and tackle led to a chain hook or rolling
hitch should be workable also if you have enough mechanical advantage.

That was going to be my next solution. I've never had much luck
trying to snag a hunk of chain on the bottom though even at 40 feet. I
also thought we were talking deeper than 40 feet.

Mechanical advantage would be a good way. If you used two four rove
blocks in series - that works out to something like 35 lbs (I think).
You could hang the blocks off the boom - should be solid enough for 35
lbs.


Are you planning to tie an anti-gravity belt onto what you are trying to
lift with the boom? Whatever blocks you have attached to the boom, the
boom is going to "feel" the full weight of what is solely attached to it.
Of course, I was only an English major in college, not a hard-science
wizard like you...

Carry on.
Cassiday and I gave the answer around 9:05. Your English majoring helped you
to parrot the answer along with the addition of your usual snide remarks.
Carry on.

"Harry" wrote in message
news
On 6/22/10 12:15 PM, Moose wrote:
wrote in message
m...
On 6/22/10 6:24 AM, W1TEF wrote:
On Mon, 21 Jun 2010 22:47:10 -0400, Wayne.B
wrote:

On Mon, 21 Jun 2010 22:24:27 -0400,
wrote:

The A-7 Polyform bouy holds 161.6 gallons of air which ~~ mumble -
mumble - carry the six, add four, times 12, price of tea in China ~~
works out to...24.8 something or other cubic feet? That right?

I'm getting about 20 cubic feet assuming 8 gallons per cube, or about
1200 pounds of buoyancy. That's a big-un, should do the trick if we
can get the chain to slip and have enough static engine thrust. Nice
solution if you've got the room for a big buoy like that. Any idea
what they cost, and what the deflated size is? A couple of them might
be useful as hurricane fenders.

http://www.polyformus.com/doc/product_a7.htm

My personal solution is to use a chain hook led to a 3,000 lb
Come-a-Long. I've tested it enough to know that it works but it would
take a while to bring up the anchor from 40 ft. The nice thing is
that Come-a-Longs are relatively cheap and don't take up a lot of
space. A multi-part block and tackle led to a chain hook or rolling
hitch should be workable also if you have enough mechanical advantage.

That was going to be my next solution. I've never had much luck
trying to snag a hunk of chain on the bottom though even at 40 feet. I
also thought we were talking deeper than 40 feet.

Mechanical advantage would be a good way. If you used two four rove
blocks in series - that works out to something like 35 lbs (I think).
You could hang the blocks off the boom - should be solid enough for 35
lbs.


Are you planning to tie an anti-gravity belt onto what you are trying to
lift with the boom? Whatever blocks you have attached to the boom, the
boom is going to "feel" the full weight of what is solely attached to
it.
Of course, I was only an English major in college, not a hard-science
wizard like you...

Carry on.
Cassiday and I gave the answer around 9:05. Your English majoring helped
you
to parrot the answer along with the addition of your usual snide
remarks.
Carry on.




Asshole that you are, you think I read every post here? Sorry. Never was
true, never will be true.

Who is Cassiday?

Apology to Casady.
You read all of my posts. Who do you think you are kidding?

On 6/22/10 12:26 PM, Moose wrote:


Apology to Casady.
You read all of my posts. Who do you think you are kidding?



No...I don't. Sorry. Sorry for your ego, too. And it doesn't matter
which of your many IDs here you use. Your **** smells the same no matter
whose ID you use to post it.

On Tue, 22 Jun 2010 11:24:29 -0400, W1TEF
wrote:

What you are effectively doing is reducing the
amount of energy required to move the 350 pounds by the use of
mechanical advantage. It seems like you are only lifting 35 pounds.

Wrong. The energy is one foot pound per pound per foot. Duh.
Mechanical advantage can reduce the _force_ while incrieasing the
distance, with the total energy required remaining the same.

Casady

On Tue, 22 Jun 2010 12:22:12 -0400, W1TEF
wrote:

No - he misunderstood the nature of the answer. Yes, the weight is
still 350 pounds. What you are effectively doing is reducing the
amount of energy required to move the 350 pounds by the use of
mechanical advantage. It seems like you are only lifting 35 pounds.

Yeah, I got that... I thought he was talking about 35 pounds on the boom
holding the tackle..

I'd have to ask Wayne, but I think he uses the boom for the rib and
that whole rig has to weigh in at or around 350 lbs - maybe not.

We use a block and tackle arrangement to lift the boom (tilt it up)
with the RIB dinghy attached. The RIB with full fuel tanks, two
small anchors, security locks/cables, safety gear, etc., weighs
somewhere around 400 pounds. Because the block and tackle is pulling
diagonally from the top of the trawler mast, the actual initial force
required is greater than 400 lbs if you solve the vector diagram. For
discussion purposes, let's call it 500 pounds. The block and tackle
is in two parts: a 7 to 1 pulling a 2 to 1 for a theoretical total
mechanical advantage of 14 to 1. Our old nemesis friction steps into
the picture however and reduces the advantage by some significant
amount, probably around 30% which results in a real advantage of
about 10 to 1, requiring a 50 pound downward pull to lift the boom. As
the boom rises above horizontal the vectors add up more favorably so
that by the time the boom is at 45 degrees, the pull required is less
than 30 pounds.

On Tue, 22 Jun 2010 11:56:24 -0500, Richard Casady
wrote:

Wrong. The energy is one foot pound per pound per foot. Duh.
Mechanical advantage can reduce the _force_ while incrieasing the
distance, with the total energy required remaining the same.

Actually the total energy required increases because of the friction
inherent in the block and tackle assembly.

"TopBassDog" wrote in message
...
On Jun 21, 9:49 pm, "nom=de=plume" wrote:
"Wayne.B" wrote in message

...

On Mon, 21 Jun 2010 18:46:59 -0600, Canuck57
wrote:

The problem: The anchor windlass has failed in some unfortunate way,
and not easily repaired. How do you retrieve your expensive anchor
and chain?

Drag the bottom with hook the right size to snag the chain.

Then what ?

Blame Obama.

No need to blame him for your petty anchor problems, D'Plume. He's
doing enough to catch hell for.

You're the one with the petty problems.

"Wayne.B" wrote in message
...
One of my recent students who shall remain nameless, failed to
complete a homework assignment after apparently losing interest in the
subject. Therefore I will throw it open to the group.

You are in a 40 something boat, power or sail makes no difference,
anchored in over 40 feet of water with 3/8ths chain and a 60 pound
anchor. The combination of chain and anchor weigh about 150 pounds
not counting the large mud ball that wants to come up also, easily 200
pounds total. The chain and anchor are worth something over $1500
and not easily replaced in remote locations.

The problem: The anchor windlass has failed in some unfortunate way,
and not easily repaired. How do you retrieve your expensive anchor
and chain?

You'll notice that Larry never once acknowledged his statement "cut and run"
was fundamentally wrong. You'll also notice that I gave a rather complete
solution to this question, and all the "men" have refused to comment on it,
even the "expert" Wayne.

"nom=de=plume" wrote in message
...

"Wayne.B" wrote in message
...
One of my recent students who shall remain nameless, failed to
complete a homework assignment after apparently losing interest in the
subject. Therefore I will throw it open to the group.

You are in a 40 something boat, power or sail makes no difference,
anchored in over 40 feet of water with 3/8ths chain and a 60 pound
anchor. The combination of chain and anchor weigh about 150 pounds
not counting the large mud ball that wants to come up also, easily 200
pounds total. The chain and anchor are worth something over $1500
and not easily replaced in remote locations.

The problem: The anchor windlass has failed in some unfortunate way,
and not easily repaired. How do you retrieve your expensive anchor
and chain?

You'll notice that Larry never once acknowledged his statement "cut and
run" was fundamentally wrong. You'll also notice that I gave a rather
complete solution to this question, and all the "men" have refused to
comment on it, even the "expert" Wayne.


Run it by us again and I promise I will comment on it.

In article ,
says...

On Tue, 22 Jun 2010 11:56:24 -0500, Richard Casady
wrote:

Wrong. The energy is one foot pound per pound per foot. Duh.
Mechanical advantage can reduce the _force_ while incrieasing the
distance, with the total energy required remaining the same.

Actually the total energy required increases because of the friction
inherent in the block and tackle assembly.

Ok, now that's getting picky, but I was thinking along the same lines
trying to set an analogy with moving ten pound logs Couldn't account
for all the extra walking.

Scotty, now, out you go!!!


--
Rowdy Mouse Racing - We race for cheese!