hylas
New member
Re: Really Confused?
Well, why making things easy when you can make them complicated.. :0)..
For making the choice of the Good anchoring stuff, I will not base my reasoning on OPINIONS but in OBVIOUS technical FACTS...
To select an anchor, I will base my choice on three points:
Price
Weigth
Efficiency
PRICE:
Your anchor is your best insurance: - and, like your insurance, it seems expensive only before the accident occurs.
- When the weather will be very bad and that your boat will drag towards the rocks, it will be too late to regret the tens of Pounds saved on the purchase price
- If your boat is tossed on the shore, then it will be some thousands of Pounds which will make the difference..
- SECURITY and quiet nights at anchor doesn’t have a price..
WEIGHT:
The weight of your anchor has nearly no relation with the holding, holding is related to :
- The stability of your anchor
- Its surface area
- The shape of the holding surface
All recent tests have proved that aluminum anchors have the same holding than steel anchors of the same size (Practical Sailor, Bateaux, Voiles magazine.)
Meanwhile, WEIGHT is very important for the penetration of the anchor.
If you choose an aluminum anchor, privilege stables models, those with a penetrating angle like a « chisel » and with heavily ballasted tip. (I will come back on this topic latter on)
EFFICIENCY:
Penetration:
- To ensure a good holding, an anchor must first penetrate ,
- Regardless of the sea bottom type,
- As fast and deep as possible.
Holding:
- Regardless of the weather conditions, the anchor doesn’t break free
- Anchor stability
- Shape of the holding surface
PENETRATION:
Penetration is related to two factors:
1° - Penetrating angle : I will define the working angle of four classical tools:
a) Spreader: - a tool forming an angle with the material in front of it of less than 70 degres.
b) Scraper: - a tool forming an angle with the material close to 90 degres
c) Chisel: - a tool forming an angle with the material in front of it of about 120 degres
d) Razor: - a tool forming an angle with the material in front of it of more than 150°
- Out of these four tools, only the "chisel" has been concieved for penetration.. ask the Carpenter.!!..
- The penetrating edge has to be as sharp as possible...
2° Pressure on the tool:
More the pressure, easier will be the penetration... Obvious...
Look at the tip's weight repartition of some classical anchors: (from Practical Boat Owner, page 80 n° 391 - July 1999)
Fortress Bügel Britany Danforth CQR Delta Bruce SPADE
15 % 16% 17% 18% 18% 28% 38% 50%
The anchor having both the right penetrating « chisel like » angle and the most heavier tip, will have the maximum chance to penetrate, even in difficult sea bottoms such as hard sand, coral and weed…
HOLDING:
Holding is related to three factors:
-1° - Stability
-2° - Holding surface area
- 3° - its shape
1° - STABILITY:
In this regard, the conclusion of John Knox (P. 81 - PBO n° 427 July 2002)confirm completely my own observations as well as the results of the tests done by the French magazine "Voiles magazine":
- Generaly speaking , ALL HINGED ANCHORS are unstable (Plow anchors, fluke anchors…) Under strong pulls, they cork-screw and break free.. (and I can explain why..)
-Stable anchors of the new generation could slightly drag under strong wind gusts, but they keep a constant high holding and they will not break free sudently... (Very SAFE behaviour)
Holding surface: Try to pull one square meter of steel on the bottom, this is quite easy.. Now bury this plate of steel in the bottom an try again.. Holding has nearly no relation with the weight, but is related to:
- The surface area perpendicular with the direction of the pull..
The shape of this surface
a. a "wing" shape has an "holding" coeficient of 0.1
b. a "chevron" shape has an "holding" coeficient of 0.5
c. a "flat" shape has an "holding" coeficient of 1.1
d. a "concave" shape has an "holding" coeficient of 1.7
Or, a surface with a "Chevron" shape must be more than three time the surface with a concave shape to have the same holding..
As simple as this.. but:
lA good anchor must hold regardless of wind and /or current change of direction.
lIt sould not have the possibility to become tangled with the anchoring rode.
lIt should not require any specific anchoring technic.
lIt should ensure a snug bow fit
lUsed with an electric windlass, it should ensure a self launching an retrieving .
lIt should be very strong…
As you may have seen, I didn't talk about one single brand name.. this will be YOUR resposibility..
Take all models, and check which one has all thoses characteristics.. Then you can be sure you have made the GOOD choice..
Mmmm... Exhausted too..
If you are interested, next time we can talk about the mooring rode.. and I will explain up to my own opinion... no: - FACTS, why the rode has to have some chain and then rope.. and how to safely connect chain and rope.. which scope is the best?? And so on..
Fair winds and peaceful anchorages
Alain d'HYLAS
Well, why making things easy when you can make them complicated.. :0)..
For making the choice of the Good anchoring stuff, I will not base my reasoning on OPINIONS but in OBVIOUS technical FACTS...
To select an anchor, I will base my choice on three points:
Price
Weigth
Efficiency
PRICE:
Your anchor is your best insurance: - and, like your insurance, it seems expensive only before the accident occurs.
- When the weather will be very bad and that your boat will drag towards the rocks, it will be too late to regret the tens of Pounds saved on the purchase price
- If your boat is tossed on the shore, then it will be some thousands of Pounds which will make the difference..
- SECURITY and quiet nights at anchor doesn’t have a price..
WEIGHT:
The weight of your anchor has nearly no relation with the holding, holding is related to :
- The stability of your anchor
- Its surface area
- The shape of the holding surface
All recent tests have proved that aluminum anchors have the same holding than steel anchors of the same size (Practical Sailor, Bateaux, Voiles magazine.)
Meanwhile, WEIGHT is very important for the penetration of the anchor.
If you choose an aluminum anchor, privilege stables models, those with a penetrating angle like a « chisel » and with heavily ballasted tip. (I will come back on this topic latter on)
EFFICIENCY:
Penetration:
- To ensure a good holding, an anchor must first penetrate ,
- Regardless of the sea bottom type,
- As fast and deep as possible.
Holding:
- Regardless of the weather conditions, the anchor doesn’t break free
- Anchor stability
- Shape of the holding surface
PENETRATION:
Penetration is related to two factors:
1° - Penetrating angle : I will define the working angle of four classical tools:
a) Spreader: - a tool forming an angle with the material in front of it of less than 70 degres.
b) Scraper: - a tool forming an angle with the material close to 90 degres
c) Chisel: - a tool forming an angle with the material in front of it of about 120 degres
d) Razor: - a tool forming an angle with the material in front of it of more than 150°
- Out of these four tools, only the "chisel" has been concieved for penetration.. ask the Carpenter.!!..
- The penetrating edge has to be as sharp as possible...
2° Pressure on the tool:
More the pressure, easier will be the penetration... Obvious...
Look at the tip's weight repartition of some classical anchors: (from Practical Boat Owner, page 80 n° 391 - July 1999)
Fortress Bügel Britany Danforth CQR Delta Bruce SPADE
15 % 16% 17% 18% 18% 28% 38% 50%
The anchor having both the right penetrating « chisel like » angle and the most heavier tip, will have the maximum chance to penetrate, even in difficult sea bottoms such as hard sand, coral and weed…
HOLDING:
Holding is related to three factors:
-1° - Stability
-2° - Holding surface area
- 3° - its shape
1° - STABILITY:
In this regard, the conclusion of John Knox (P. 81 - PBO n° 427 July 2002)confirm completely my own observations as well as the results of the tests done by the French magazine "Voiles magazine":
- Generaly speaking , ALL HINGED ANCHORS are unstable (Plow anchors, fluke anchors…) Under strong pulls, they cork-screw and break free.. (and I can explain why..)
-Stable anchors of the new generation could slightly drag under strong wind gusts, but they keep a constant high holding and they will not break free sudently... (Very SAFE behaviour)
Holding surface: Try to pull one square meter of steel on the bottom, this is quite easy.. Now bury this plate of steel in the bottom an try again.. Holding has nearly no relation with the weight, but is related to:
- The surface area perpendicular with the direction of the pull..
The shape of this surface
a. a "wing" shape has an "holding" coeficient of 0.1
b. a "chevron" shape has an "holding" coeficient of 0.5
c. a "flat" shape has an "holding" coeficient of 1.1
d. a "concave" shape has an "holding" coeficient of 1.7
Or, a surface with a "Chevron" shape must be more than three time the surface with a concave shape to have the same holding..
As simple as this.. but:
lA good anchor must hold regardless of wind and /or current change of direction.
lIt sould not have the possibility to become tangled with the anchoring rode.
lIt should not require any specific anchoring technic.
lIt should ensure a snug bow fit
lUsed with an electric windlass, it should ensure a self launching an retrieving .
lIt should be very strong…
As you may have seen, I didn't talk about one single brand name.. this will be YOUR resposibility..
Take all models, and check which one has all thoses characteristics.. Then you can be sure you have made the GOOD choice..
Mmmm... Exhausted too..
If you are interested, next time we can talk about the mooring rode.. and I will explain up to my own opinion... no: - FACTS, why the rode has to have some chain and then rope.. and how to safely connect chain and rope.. which scope is the best?? And so on..
Fair winds and peaceful anchorages
Alain d'HYLAS
