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Old 06-02-2009, 17:37   #31
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my boat weighs four and a half tons when it is on the land I can't move it at all when its in the water I can move it easily with one hand, this is because the upthrust provided by the water is equal to the weight of the volume of water it displaces. so if the rock weighed one ton (metric) and had a volume of say 1/2 a cubic meter the water would provide an upward force of 500 kg so the rock would weigh 500kg in the water. Hope this makes sense.
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Old 07-02-2009, 05:23   #32
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my boat weighs four and a half tons when it is on the land I can't move it at all, when its in the water I can move it easily with one hand, this is because the upthrust provided by the water is equal to the weight of the volume of water it displaces. so if the rock weighed one ton (metric) and had a volume of say 1/2 a cubic meter the water would provide an upward force of 500 kg so the rock would weigh 500kg in the water. Hope this makes sense.
It makes perfectly sense..

This principle has already be explained some time ago by a sailor called Archimede :

Archimedes' Principle

Archimedes' principle is the fundamental natural law of buoyancy, first identified by the Greek mathematician and inventor Archimedes in the 3d century BC. It states that any object floating upon or submerged in a fluid is buoyed upward by a force equal to the weight of the displaced fluid.
This buoyant force is caused by the weight of the fluid, which causes the fluid pressure to increase steadily with increasing depth from the surface. Any submerged object is subject to a greater pressure force on its lower surface than on its upper surface, creating a tendency for the object to rise. This tendency is counteracted by the weight of the object, which will sink if it is heavier than the surrounding fluid and will rise if it is lighter. If the object weighs the same as an equivalent volume of the fluid, it will be in equilibrium and remain motionless. Buoyancy may be thought of as the density of a fluid relative to the densities of objects submerged in it
From this we find two equations:

Density = Mass / volume

Buoyancy = ( density of the object - density of the fluide) x ( volume of displaced fluid)

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Old 07-02-2009, 06:12   #33
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Fisherman...where to get?

Checked a couple of sites including WM and I can't find a fisherman anchor. A freind has one where the cross bar at the top slides out of position for easy stowing. Where do I get one of those?
I can easily budge or move a 100 lb rock to get at the lobster underneath it. It takes a lot more effort on the surface. Archemdies is right. While a pound of lead weighs the same as a pound of feathers on land the water displacement changes everything.
And as far as dead fish on the anchor... thats just plain dumb. Worms are much better.
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Old 07-02-2009, 12:07   #34
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A friend has one where the cross bar at the top slides out of position for easy stowing. Where do I get one of those?
.
«Where do I get one of those?” - Try in Maritime museums

The one you are talking about seems to be the Northill anchor- This is a very common model here in Brazil among all fisherman boats:



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Old 07-02-2009, 17:10   #35
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Northill anchor
Going by your photo it looks like it would be really effective. Never herd of it here in the UK. Are there any reports on ts holding properties?
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Old 08-02-2009, 04:01   #36
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This type of anchor is very common here in Brazil, nearly all fisherman boats are equipped with local production.
- One advantage of this anchor is the ease of manufacturing and as the « blades » are larger than the ones of the Fisherman anchor, its holding is slightly better...
- One serious disadvantage, like the Fisherman anchor, the mooring rode can be easily trapped by the free blade or by the strut...

But this anchor is still an anchor of the past, and weight for weight « New Gen » anchors are BY FAR much more efficient...

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Old 08-02-2009, 07:02   #37
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Is this what you are looking for - Defender has several sizes

Storm Anchor
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Old 16-02-2009, 20:19   #38
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When its time, a Paul E Luke storm anchor would be my choice.

Storm Anchors
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Old 17-02-2009, 04:40   #39
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When its time, a Paul E Luke storm anchor would be my choice.
Waaaooooohhh!.. What a modern, very exciting product!!!

Did you think also about using a KILICK anchor?? This type of anchor has much more "LONG TERM" experience, and is still in use (and is also very cheap)



It is also dismountable, so you can easily store it in your bilge, and if the weather is becoming very bad, you just have to change the stone to increase the weight!..

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Old 17-02-2009, 07:28   #40
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in defence of the fisherman

Quote:
Originally Posted by Boomp View Post
Checked a couple of sites including WM and I can't find a fisherman anchor. A freind has one where the cross bar at the top slides out of position for easy stowing. Where do I get one of those?
I can easily budge or move a 100 lb rock to get at the lobster underneath it. It takes a lot more effort on the surface. Archemdies is right. While a pound of lead weighs the same as a pound of feathers on land the water displacement changes everything.
And as far as dead fish on the anchor... thats just plain dumb. Worms are much better.
There are several consignment shops in your area that should have one. Try Wickford marine consignment in Wickford R.I., tell Sam that Bruce sent you.

When I was cruising on Amphora, I carried a Bruce, a Danforth, and a 70lb. Fisherman. The Fisherman worked great in a weedy anchorage.
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Old 19-02-2009, 08:08   #41
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That brings to mind and old saying that opinions are like...... ah but you know the rest.




Quote:
Originally Posted by Ancora Latina View Post
Waaaooooohhh!.. What a modern, very exciting product!!!

Did you think also about using a KILICK anchor?? This type of anchor has much more "LONG TERM" experience, and is still in use (and is also very cheap)



It is also dismountable, so you can easily store it in your bilge, and if the weather is becoming very bad, you just have to change the stone to increase the weight!..

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Old 19-02-2009, 10:11   #42
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I believe the Paul Luke is the Herreshoff version of the Fisherman style anchor right? Almost bought one years ago, seems to me the anchor has a great amount of surface area and would dig in deep in addition to would work well for rocky situation. Drawback though is not friendly to bow roller storage for everyday use. Make a good storm anchor for the bilge though....
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Old 19-02-2009, 10:18   #43
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I believe the Paul Luke is the Herreshoff version of the Fisherman style anchor right? Almost bought one years ago, seems to me the anchor has a great amount of surface area and would dig in deep in addition to would work well for rocky situation. Drawback though is not friendly to bow roller storage for everyday use. Make a good storm anchor for the bilge though....
Info here

It is modelled after the Herreshoff (fisherman) anchor. It is easily stowed. It is also good as a stern anchor when using a Med moor bow to the dock.

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Old 19-02-2009, 10:55   #44
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Paul Luke, Herreshoff and others... are slight variations over the classical Fisherman anchors designed during antique Roman and Greek period...

Fortunately, since this antic time, many things have been improved... including anchors...

WEIGHT for WEIGHT, they are many anchors, including « new gen » anchors, which are much more efficient for penetration AND holding, including in weed and rocks.

Think of what could happen the day where you will have to face very strong winds with an obsolete and inefficient anchor... It will be too late to change your mind.

I wish all of Fisherman anchor’s users to never have to face such bad weather conditions...
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Old 19-02-2009, 16:48   #45
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Paul Luke, Herreshoff and others... are slight variations over the classical Fisherman anchors designed during antique Roman and Greek period...

Fortunately, since this antic time, many things have been improved... including anchors...

WEIGHT for WEIGHT, they are many anchors, including « new gen » anchors, which are much more efficient for penetration AND holding, including in weed and rocks.

Think of what could happen the day where you will have to face very strong winds with an obsolete and inefficient anchor... It will be too late to change your mind.

I wish all of Fisherman anchor’s users to never have to face such bad weather conditions...
The Paul E Luke is a fantastic anchor because you can have one three times the specified weight for your boat stowed in the bilge for emergency use, I mean when it gets really windy, yeah I agree there are modern anchors are technically better and I would love one for my boat but where can I store a 30kg (60lb) anchor low down in my 27 foot cruiser? a Luke fits easily in the bilge. By the way my boat circumnavigated 1990 - 93 with a 20kg (40lb) bruce as the main anchor and anchoring was the preffered method for staying overnight, The Bruce got bent in a collision with a coaster in China, back in the UK I returned the Bruce for repair, they straightened it and regalvanised it free of charge, what service
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