Chain Versus Rope Scope ?

[cfarrar]

Tom,

You recommend plenty of chain for "catenary," but a lighter anchor to protect the windlass? The general consensus in this thread is to put the extra weight into the anchor and go with lighter, stronger chain. The reasons are pretty well described. - Colin

[jeremiason]

I am not advocating "Lighter" anchor... I am stating use a proper sized anchor in combination with your chain wieght in regards to the windlass capacity.

As far as the conseness, I my humble opinion, you are basically saying "I don't carry enough rode, so I purchased a bigger anchor".

If you have proper chain scope, an "Oversized" anchor is not needed, because it should not be pulled on unless you end up in very severe wind conditions (Hurricane).

The goal that should be obtained is: Have enough chain scope out to NOT pull on your anchor. This can be obtained by increasing your scope as wind conditions rise. Using chain rode will probably not exceed 7 to 1 in all but a large hurricane for most vessels of any size.

Now before someone repeats the earlier message about how big an anchorage is or the 1000 feet of chain comment.... Remember, as the vessel size and weight increase so does the size and weight of the chain. So the size of the anchorage and the weight of the chain, theyare relative to your vessel size.

Now for the people with boats that cannot accomodate an all chain rode, they should consider the largest anchor their windless or their crewman can pull, because the line does not have enough weight to pull down on the line and cause cantanry.

With a line rode the anchor will be pulled on in much lighter winds and the stretch of the line will cause more force on the anchor and weaken its holding faster. Because of that bounce (Stretch of the line) and pull on the anchor, a larger anchor would be appropriate.

Originally Posted by cfarrar

Tom,

You recommend plenty of chain for "catenary," but a lighter anchor to protect the windlass? The general consensus in this thread is to put the extra weight into the anchor and go with lighter, stronger chain. The reasons are pretty well described. - Colin

[s/v Jedi]

Tom,

I suggest that you read some of the links already posted here. With 300' of chain aboard (I even have 350') you will pull that tight in way less than hurricane force winds, or you have a wildly oversized chain for your boat.

ciao!
Nick.

[foolishsailor]

Originally Posted by roverhi

Nothing quite so much fun as a group of boats anchored on chain that get joined by a boat using a rope rode. A nice compact group of anchored boats turns into a CF as the rope rode boat wanders all over the ground on it's light weight 7-1 scope.

This is the same thing i have experienced and why i use all chain. I have a relatively lightweight, for a crusing boat, aluminum 40' boat and when she is on a rope rode with ossilating winds she jumps about like a colt. I was in isla grande in brasil sitting on the beach trying to enjoy a caipirinha when a light squall came up over the island out of nowhere. The winds barely got over 30 but were highly variable and ossilating at least 45 degrees. The boat was jumping all over the place. As all of the boats around me were on chain it was actually dangerous as the boat was veering at the other boats.

This was the first time i had anchored with rode on this boat as i normally keep full chain, but as i had just had my chain and primary shipped off to be re galvinzed i had to sit on this configuration for 2 weeks.

Never dragged and as others said it was just as secure however it was less than comfortable and with even a mild blow a bit dangerous in the anchorage.

After a coue of days though i at least didnt have anymore neighbors.

Havent sat on rode since and wont plan too based on this experience.

[boatman61]

Originally Posted by cfarrar

Tom,

You recommend plenty of chain for "catenary," but a lighter anchor to protect the windlass? The general consensus in this thread is to put the extra weight into the anchor and go with lighter, stronger chain. The reasons are pretty well described. - Colin

Oi..... who yu calin Genurul conchensus.....

[jeremiason]

I carry 300 feet of 5/16" high test chain and a 25 kg Rocna, both of which are recommended by the manufactures as appropriate for the size of boat/windlass.

If your rode is pulling on your anchor, what precludes you from letting out more scope?

Even in an anchorage 50 feet deep, you are at 6 to 1 scope at 300 feet of chain, well under you limitations... If the anchorage is so small and the water so deep, I ask why would you anchor there to begain with?

On my current boat, we have experienced winds up to 54 knots at anchor. At no time did I have to exceed 6 to 1 scope to keep from pulling on the anchor. I did ease the chain from 5 to 1 to 6 to 1 to keep from pulling on the anchor when the windless high 50 knots.

If you choose to to defend you position by qouting the "Group" replies, I ask what if they are wrong?

The fact is regardless of the consense of the group... Most of the replies here assume the ground tackle is going to remain static, that no one is going to let out more scope as the force increases. This thought is condradictory to everything taught in most sailing schools, academies and maritime institutions thoughout the world.

I have been lucky in my sailing career and have never dragged an anchor in either recreational or commercial boating. I would like to think that part of that was a result of using the correct amount of scope and using a little bit of common sense on choosing an anchorage.

Originally Posted by s/v Jedi

Tom,

I suggest that you read some of the links already posted here. With 300' of chain aboard (I even have 350') you will pull that tight in way less than hurricane force winds, or you have a wildly oversized chain for your boat.

ciao!
Nick.

[DutchTreat]

Originally Posted by Dockhead

At some further point of increasing load, let's say for example at 30 knots, the chain becomes bar tight and ceases to add anything at all to holding. At that point 100% of the holding force comes from the anchor and 0% from the rode.

The chain still has it's inherent mass which would still add downward force to the anchor, even when bar tight. Sure, not 100% of it's mass, but a large enough fraction to have a positive affect on the holding power of the anchor.

Ha, or at least it does when I think about it, I am not talking from any real knowledge or experience here.

This has been an informative thread, for a newbie like me!

[s/v Jedi]

Originally Posted by jeremiason

I carry 300 feet of 5/16" high test chain and a 25 kg Rocna, both of which are recommended by the manufactures as appropriate for the size of boat/windlass.

If your rode is pulling on your anchor, what precludes you from letting out more scope?

Even in an anchorage 50 feet deep, you are at 6 to 1 scope at 300 feet of chain, well under you limitations... If the anchorage is so small and the water so deep, I ask why would you anchor there to begain with?

On my current boat, we have experienced winds up to 54 knots at anchor. At no time did I have to exceed 6 to 1 scope to keep from pulling on the anchor. I did ease the chain from 5 to 1 to 6 to 1 to keep from pulling on the anchor when the windless high 50 knots.

If you choose to to defend you position by qouting the "Group" replies, I ask what if they are wrong?

The fact is regardless of the consense of the group... Most of the replies here assume the ground tackle is going to remain static, that no one is going to let out more scope as the force increases. This thought is condradictory to everything taught in most sailing schools, academies and maritime institutions thoughout the world.

I have been lucky in my sailing career and have never dragged an anchor in either recreational or commercial boating. I would like to think that part of that was a result of using the correct amount of scope and using a little bit of common sense on choosing an anchorage.

Tom, what you say means that you could have just dropped the chain without anchor overboard for your complete sailing career because your chain has never pulled on the anchor. This also means that your anchor was never buried in the seabed because it needs to be pulled on, to do that.

I will say that with the 50 knots and your 6:1 scope of maximum 300' chain out, it is impossible you didn't pull the anchor.

Most of us set the anchor by using the engine in reverse. With the engine in reverse, even at full rpm's, the force put on the system is less than when you get 50 knots of wind.

I have a bit of experience with anchoring too and have not dragged in anything which included two hurricanes and up to 120 knot winds. And I have never seen a boat that never put a pull on their anchor.

ciao!
Nick.

[s/v Jedi]

Originally Posted by DutchTreat

The chain still has it's inherent mass which would still add downward force to the anchor, even when bar tight. Sure, not 100% of it's mass, but a large enough fraction to have a positive affect on the holding power of the anchor.

Ha, or at least it does when I think about it, I am not talking from any real knowledge or experience here.

This has been an informative thread, for a newbie like me!

Oh my, now we get Vollenhovense Bollen in Canada?!

I have sailed one of those many times in my teenage years in Holland!

cheers,
Nick.

[jeremiason]

Nick...

I have over 30 years of recreation sailing experience and 6 years of commercial experience, in both teaching and operations. With that, I do not consider myself an expert in any field of sailing or marine operations, but do believe I am experienced...

Making assumpsions like that in your previous post is offensive, not productive and certainly not worth commenting on...

Lets just say, my experiences and trainning differer from yours signifiantly and therefore have differerent opinions...

Good luck and fair winds...

Originally Posted by s/v Jedi

Tom, what you say means that you could have just dropped the chain without anchor overboard for your complete sailing career because your chain has never pulled on the anchor. This also means that your anchor was never buried in the seabed because it needs to be pulled on, to do that.

I will say that with the 50 knots and your 6:1 scope of maximum 300' chain out, it is impossible you didn't pull the anchor.

Most of us set the anchor by using the engine in reverse. With the engine in reverse, even at full rpm's, the force put on the system is less than when you get 50 knots of wind.

I have a bit of experience with anchoring too and have not dragged in anything which included two hurricanes and up to 120 knot winds. And I have never seen a boat that never put a pull on their anchor.

ciao!
Nick.

[boatman61]

Originally Posted by DutchTreat

The chain still has it's inherent mass which would still add downward force to the anchor, even when bar tight. Sure, not 100% of it's mass, but a large enough fraction to have a positive affect on the holding power of the anchor.

Ha, or at least it does when I think about it, I am not talking from any real knowledge or experience here.

This has been an informative thread, for a newbie like me!

Another factor is the slope of the bottom... wind onshore vs offshore... tidal weak/strong... eg my hook is set in 7 metres but with the wind blowing onshore my depth is 5 metres.... 500metres from shore out of wave action....that makes things different regarding angle of pull.. choose your anchorage.. not everyone else's
I'll stick with my standard Bruce and all standard chain with long rode in my less frequented anchor spots...
That way I get to watch yachts in reverse... not be one of them..

[Bash]

Originally Posted by NorthPacific

Anchoring in coral.

Chain and then rode or all chain?

Suggestions

Please don't anchor in coral. That fouls the nest for all of us.

[s/v Jedi]

Originally Posted by jeremiason

Making assumpsions like that in your previous post is offensive, not productive and certainly not worth commenting on...

Lets just say, my experiences and trainning differer from yours signifiantly and therefore have differerent opinions...

Good luck and fair winds...

Tom, I do not question your experience. I just think that you never actually dove on your anchor at 35-40 knots of wind or more, because the chain is really going to pull on the anchor then and it is your anchor that is holding your boat, not the chain. Your position that you can prevent pull on the anchor by putting out a 5:1 scope for up to more than 50 knot winds is not really defensible. This is not opinion, this is how it is.

I do understand that you don't want to continue this discussion, which sounds like a good plan to me.

ciao!
Nick.

[Dockhead]

Originally Posted by s/v Jedi

Tom, what you say means that you could have just dropped the chain without anchor overboard for your complete sailing career because your chain has never pulled on the anchor. This also means that your anchor was never buried in the seabed because it needs to be pulled on, to do that.

I will say that with the 50 knots and your 6:1 scope of maximum 300' chain out, it is impossible you didn't pull the anchor.

Most of us set the anchor by using the engine in reverse. With the engine in reverse, even at full rpm's, the force put on the system is less than when you get 50 knots of wind.

I have a bit of experience with anchoring too and have not dragged in anything which included two hurricanes and up to 120 knot winds. And I have never seen a boat that never put a pull on their anchor.

ciao!
Nick.

+1

My chain goes bar tight at about 30 knots of wind. I have experienced it many times. I have 100 meters (330 feet) of 1/2" chain which weighs nearly half a ton. When I am expecting the wind to kick up, I let it all out, attach two different snubbers, and lash on a stout chain stopper to keep the forces off the windlass.

If it were true that just letting out more chain will always hold you, then we wouldn't need anchors at all. I'm not sure how we would even set our anchors, if that were true. I think that it is not.

[s/v Jedi]

Originally Posted by Dockhead

If it were true that just letting out more chain will always hold you, then we wouldn't need anchors at all. I'm not sure how we would even set our anchors, if that were true. I think that it is not.

Exactly. We go from miracle anchors to no anchor needed if enough chain in threads here on CF.

I get a bit dizzy when I think of the starting cruisers that believe all that and come and anchor next to us

And by the way, with a 25kg anchor on a 47' boat I would also pray that the chain helps hold me in place.

ciao!
Nick.