Huge Danforth

[Nomad Willy]

Looks like the Gearld Ford uses a danforth type anchor.
Does that make them a modern design?

 

[Toadhall]

Nope.
Means it was low bid.

 

[Mako]

I wonder if he has trouble resetting when the tides turn

 

[amdavis]

Ford anchor

The anchor on G R Ford only weighes in at 15 ton's, half of a Nimitz class anchor. Chain is smaller also, only 130 lbs per link ( x's 1300 ft.)

 

[PM]

only 15 tons ? Sounds like a lot, especially times 2

pete

 

[Nomad Willy]

An anchor design that started in 1938 (eighty years ago) still to be manufactured today is one long ride for anchors. Probably only a rock on a rope has a longer history.

I still have a 22lb Danforth w forged shank and flukes.
Now that I no longer have my boat I wish I could try it at long scope and full reverse on my little 30’ Willard.
The old Dan is leaning against the garage and I admire it every time I go by. Is there any anchor being made today that has a forged fluke and shank?

 

[Mako]

Hey Willy. I had a 22 Dan on my 20’ panga when I was in the Persian Gulf. It was tough setting in all the limestone and hard pan, until I sharpened the fluke tips like a knife. Helped a lot. Still a great anchor, pushing the better part of a century.

 

[Nomad Willy]

Stil have this 32lb Danforth
I ‘m in Concrete. $25 will deliver to Burlington near I5.
Eric 360 202 8815

 

[Nomad Willy]

Stil have this 32lb Danforth
I ‘m in Concrete. $25 will deliver to Burlington near I5.
Eric 360 202 8815

 

[psneeld]

off the net....

Huntington Ingalls Industries‘ (HII) Newport News Shipbuilding division has successfully tested the new light-weight anchor system aboard the US Navy’s Gerald R Ford-class nuclear-powered aircraft carrier, Gerald R Ford (CVN 78).

 

[Mambo42]

Ships this size don't lie on their anchor, it is the chain that is keeping them in place. That said, nowadays most carriers don't spend a lot of time in port anymore. Showing the flag has become a thing of the past. With the busy schedule carriers have nowadays the crews hardly get any time off. I even hear that deployments are now 9 months instead of the 6 months in the past. All that due to a shortage of carriers and and increasingly more unstable world.

 

[Mako]

"Newport News Shipbuilding division has successfully tested the new light-weight anchor system"

So this revolutionary new anchor is actually just an 80 year old Danforth, just manufactured freakin' huge? Wow, what a feat of modern engineering

 

[Comodave]

Ships this size don't lie on their anchor, it is the chain that is keeping them in place. That said, nowadays most carriers don't spend a lot of time in port anymore. Showing the flag has become a thing of the past. With the busy schedule carriers have nowadays the crews hardly get any time off. I even hear that deployments are now 9 months instead of the 6 months in the past. All that due to a shortage of carriers and and increasingly more unstable world.

Maybe not quite that bad.

• Standard deployment: The standard deployment schedule for a carrier is seven months.
  
  
• Extended deployments: In recent years, some carriers have deployed for up to nine months. For example, the USS Abraham Lincoln's 295-day deployment was the longest carrier deployment since the end of the Cold War.
  
  
• Carrier strike group rotation: The U.S. Navy regularly rotates strike groups overseas for six to eight months

 

[Mambo42]

Maybe not quite that bad.

• Standard deployment: The standard deployment schedule for a carrier is seven months.
  
  
• Extended deployments: In recent years, some carriers have deployed for up to nine months. For example, the USS Abraham Lincoln's 295-day deployment was the longest carrier deployment since the end of the Cold War.
  
  
• Carrier strike group rotation: The U.S. Navy regularly rotates strike groups overseas for six to eight months

I follow Ward Carrol on Youtube. As a former military pilot myself I still take interest in current military life. Ward addresses the current issues with the carriers on a regular basis. He also has access to the top brass, interesting interviews I must say and the developments are not that great. Longer periods from home and shorter periods at home. Some come home and after less than 6 months they are sent out again. It is putting a lot of stress on the crews, on the families and on the ships themselves.
We also see this in other countries, longer deployments, more often away from home and in my home country that has been the cause of a lot of personnel not extending their contracts. In the last decades, with the budget cuts that did not directly cause a problem in recruiting, but now that the budgets start to grow again (at least in Europe) it will become a problem. We simply cannot find personnel anymore that is willing to put up with being away from home for such long periods. And that will put even more strain on the personnel we currently have.
With Russia and China rattling the chain on the doors of NATO it could become interesting in the coming years.

 

[psneeld]

When the US Navy has to pay enormous bonuses to convince people to take command of an aviation squadron, something is terribly wrong.

Most guys I know in the USCG would have PAID money to be selected for an air command... know I would have... it was the true pinnacle of many careers.

But back to the anchor..... the only pictures I have seen aren't all that revealing, but it looks similar to a Danforth design but with some tweaks

 

[luna]

Ships this size don't lie on their anchor, it is the chain that is keeping them in place.

You have previously posted your belief that large ships rely only on their chain lying on the seabed to restrain their movement.
In addition, in the past you have also detailed your own calculation method to arrive at how much chain to have in contact with the seabed in order to safely stay in place.

Both the belief and the calculation I believe border on the bizarre.

Here is why.

On the Oil Companies International Marine Forum's website is an Anchor Systems Environmental Load Calculator where you enter in all kinds of data about the ship, the sea bed, the wind, the current and the anchor, then press "Calculate" to determine the load and then you can select what size of anchor system is required.
You would think that if the chain was relied upon to restrain the ship there would be at least one data point required about the chain. There is not, not even one.

Here, look for yourself. Anchoring Systems Environmental Load Calculator

If you move down to a boat about our size, a sailor (we won't hold that against him) named Alain Fraysse wrote quite an exhaustive article about 15 years ago on all things anchoring.

Here it is: rode body

It can be a difficult read for those who have no time for equations, as there are a lot of them.
For the meat and potatoes on this issue just go to Forces, scroll down to Clause 3, that is titled Bottom and read the first sentence in the 2nd paragraph...........Twice.

Further, ask yourself this question. Why would all these anchor manufacturing companies spend the time and $ to design, build, test, market and then mass produce anchors if all we need is chain on the seabed?
Being quite a smart group, you would have thought we would have seen through the anchor guys ruse long ago.

Finally, I would be interested in Steve Goodwin of S/V Panope's take on this notion of the chain does all of the work and no load is on the anchor.

 

[psneeld]

I too have often heard that anchoring ships is a different concept to a certain degree than small vessels.

I don't know about other places, but the USCG usually directs ships to motor on their ground tackle when winds reach a certain level. I have often thought around 35 knots. They also maintain round the clock watches. They are required to anchor in very specific locations. I would NOT classify anchoring stationary rigs such as oil platforms and ships together.

While I am not sure ship anchors are considered irrelevant, they aren't always considered as the primary component of ground tackle as they are in small craft. The article linked above specifically uses the word "yacht" and seems to be geared only towards them. It also mentions relatively light weight anchor rodes, which in ship rode description is just the opposite. At some point there is probably overlap though.

Here is but one example of the "generalization" of ship's anchor chain importance.

16. Vessel Anchoring - USC Sea Grant

USC Dornsife The Urban Ocean Program

dornsife.usc.edu

This length serves two purposes: first, it gives the ship ample room to swing on the chain without placing excess strain on it; second, the weight of the chain and its friction on the ocean floor is the force that actually secures the ship in place, so a large volume of the deployed chain is important.

For me like many discussions on TF, at some point one can piece together different procedural puzzles presenting in boating endeavors. There is usually some overlap in completely (seemingly) opposing opinions, theories and operational practices and when I understand that overlap, the the puzzle becomes clear.

 

[luna]

Ooops, pressed wrong button!

 

[luna]

I too have often heard that anchoring ships is a different concept to a certain degree than small vessels.

I don't know about other places, but the USCG usually directs ships to motor on their ground tackle when winds reach a certain level. I have often thought around 35 knots. They also maintain round the clock watches. They are required to anchor in very specific locations. I would NOT classify anchoring stationary rigs such as oil platforms and ships together.

While I am not sure ship anchors are considered irrelevant, they aren't always considered as the primary component of ground tackle as they are in small craft. The article linked above specifically uses the word "yacht" and seems to be geared only towards them. It also mentions relatively light weight anchor rodes, which in ship rode description is just the opposite. At some point there is probably overlap though.

Here is but one example of the "generalization" of ship's anchor chain importance.

16. Vessel Anchoring - USC Sea Grant

USC Dornsife The Urban Ocean Program

dornsife.usc.edu

This length serves two purposes: first, it gives the ship ample room to swing on the chain without placing excess strain on it; second, the weight of the chain and its friction on the ocean floor is the force that actually secures the ship in place, so a large volume of the deployed chain is important.

For me like many discussions on TF, at some point one can piece together different procedural puzzles presenting in boating endeavors. There is usually some overlap in completely (seemingly) opposing opinions, theories and operational practices and when I understand that overlap, the the puzzle becomes clear.

The Canadian Coast Guard directs ships in Vancouver Harbour to start their engines when sustained winds reach about 30 Knots. In these conditions I have never seen an instance where the ship has engaged their propellor to take some load off of the ground tackle. That in a 30+ Knot wind would indeed be a delicate dance. Should the ship drag, a pilot is brought onboard and tugs reposition the ship.

So when, under what conditions, do you think that a ships anchor is to be not "considered as a primary component of the ground tackle"?

I included the small boat anchoring article as the poster that I previously referenced has in the past explained in great detail how he calculates the amount of chain that he feels is sufficient to hold his boat in moderately severe conditions without relying on an anchor whatsoever.

Be it a ship or your trawler, if indeed you rely on only the chain to keep you from moving, in order to determine how much chain is required there must be some kind of calculation done that would include the coefficient of friction for chain interacting with various seabeds. This methodology of course would have to be confirmed by full size testing on the seabeds, just like what anchors go through now.
Where is this testing info?

Further, when conditions arise that the loads on the anchor chain increase substantially a large portion of the chain lifts from the seabed, resulting in a significant reduction in the friction between the chain and seabed. Perfect, when you need it most your ability to stay put is diminished!

Good thing we have anchors.

 

[Mambo42]

You have previously posted your belief that large ships rely only on their chain lying on the seabed to restrain their movement.
In addition, in the past you have also detailed your own calculation method to arrive at how much chain to have in contact with the seabed in order to safely stay in place.

Both the belief and the calculation I believe border on the bizarre.

Here is why.

On the Oil Companies International Marine Forum's website is an Anchor Systems Environmental Load Calculator where you enter in all kinds of data about the ship, the sea bed, the wind, the current and the anchor, then press "Calculate" to determine the load and then you can select what size of anchor system is required.
You would think that if the chain was relied upon to restrain the ship there would be at least one data point required about the chain. There is not, not even one.

Here, look for yourself. Anchoring Systems Environmental Load Calculator

If you move down to a boat about our size, a sailor (we won't hold that against him) named Alain Fraysse wrote quite an exhaustive article about 15 years ago on all things anchoring.

Here it is: rode body

It can be a difficult read for those who have no time for equations, as there are a lot of them.
For the meat and potatoes on this issue just go to Forces, scroll down to Clause 3, that is titled Bottom and read the first sentence in the 2nd paragraph...........Twice.

Further, ask yourself this question. Why would all these anchor manufacturing companies spend the time and $ to design, build, test, market and then mass produce anchors if all we need is chain on the seabed?
Being quite a smart group, you would have thought we would have seen through the anchor guys ruse long ago.

Finally, I would be interested in Steve Goodwin of S/V Panope's take on this notion of the chain does all of the work and no load is on the anchor.

It is not that I meant that the anchor does nothing, what I meant was that the anchor holds the chain in place, but does not hold the boat in place.
A lot of people depend solely on the holding power of the anchor, but they forget that if the shank gets raised there is now an upward movement which basically means the anchor has lost holding power. Raise the shank above 25 degrees and you will have lost all holding power, which means the anchor will drag.
The idea is therefore to have enough chain out so that the shank will always remain level with the sea bed. Once you do that the anchor cannot drag (unless the sea bed is rock or sea weed and is therefore not set).

I found a simplistic video explaining the practice of large ships and this is exactly what I meant in my posts. It is also what I do. I calculate the forces the wind can put on my boat. I have provided tables with forces per m2 for each Bft. So you multiply the m2 of windage you have (usually the front part of the boat) with the forces per m2. Thus you get the total forces on the boat (pushing it backwards). What you need to do then is to compensate those forces with the chain and the anchor. What I do is basically the same as the large vessels do. They make sure there is always some chain on the sea bed and therefore the anchor will have the maximum holding power and all it does is hold the chain in place.
Also, if the chain is resting on the sea bed it will have resistance from the sea bed, which is added holding power.

The link you sent basically is the same, he also calculates the forces that are on the hull, but he differs in approach after that. Instead of letting the chain do all the work he uses the holding power of the anchor as well. The risk being that the forces will be greater than expected, lifting the shank up and pulling the anchor out of the sea bed.

 

[psneeld]

Just repeating what a lot of ship savvy guys have told me and some articles I have read (as in the passage I posted)

When the average small boat uses chain weight in nearly/in excess of the anchor weight I will see your point a bit better. I believe the OP has often suggested that you use a portion of really heavy anchor chain (much like ships entire chain does) up next to your anchor to help avoid changing the catenary as much. This is partially that overlap that I do understand.

Just to be clear, I think much of the discussion in my point of view, isn't about eliminating anchors all together. To disregard the size/weight of chain in the equation when it clearly has substantial effect when anchoring doesn't make any sense to me.

 

[rslifkin]

Keep in mind that ships tend to anchor in deeper water, and the deeper the water gets, the more effective chain catenary becomes (even at relatively short scope). It's very hard to pull the catenary out of 300 feet of chain in 80 feet of water, but much easier to pull the catenary out of any length of chain (even an impractical 300 feet) in 10 feet of water.

Anchoring is hard to compare between ships and smaller boats in general for several reasons. First, ships have far less concern for the weight of ground tackle, as it'll never be heavy enough to be a concern for carrying it. Second, larger vessels are proportionately easier to anchor, as they're much heavier relative to their windage, so they're far less reactive to wind gusts, sea state, etc. And because they're much larger relative to any sea state, the amount of anchor load imparted by that sea state is relatively smaller. And to top it off, their anchoring expectations are different. No ship expects to anchor and leave things unattended for hours. They're going to have a 24/7 anchor watch and they'd also rarely anchor in conditions as severe as many of us plan for as a worst case.

 

[luna]

I think we can both agree that in order to be the most effective the load on the anchor needs to be horizontal or parallel with the seabed.
Where I disagree with you is when I read statements like this:

It is not that I meant that the anchor does nothing, what I meant was that the anchor holds the chain in place, but does not hold the boat in place.

Really, understanding that the boat and anchor are connected to the chain, holding the anchor end of the chain in place, holds the boat in place.

And this:

The link you sent basically is the same, he also calculates the forces that are on the hull, but he differs in approach after that. Instead of letting the chain do all the work he uses the holding power of the anchor as well.

I think we can also agree that if you and your all chain rode were anchored in 30' of water with 150' of chain out and there was 120' of chain on the seabed, you anchor is resisting no loads. It's just dug in there. The chain is doing all of the work, no anchor required. Until things change, which they will.

But where we differ is that once the boat is subjected to some kind of force that loads the chain to the point where about 20 of the 120' of chain is now lifted off of the seabed, now I would expect that the chains resistance to dragging along the seabed is less than the forces acting on the chain.
In this fictitious example, at this point even though you have 100' of chain on the seabed you would drag if you did not have an anchor.
The exact relationship between how much chain is lifted and how much remains on the seabed relies on a lot of thing that I have never seen quantified. Have you?

If you do not drag then you are not "letting the chain do all of the work" and you must be using "the holding power of the anchor as well." Yes, the anchor is holding by way of the chain, the boat in place.

There are no other explanations.

 

[psneeld]

Once again...discussing small vessel anchoring versus ship anchoring...

But this Luna quote in post #16 ....."You have previously posted your belief that large ships rely only on their chain lying on the seabed to restrain their movement.
In addition, in the past you have also detailed your own calculation method to arrive at how much chain to have in contact with the seabed in order to safely stay in place.
Both the belief and the calculation I believe border on the bizarre."

I find it bizarre that you find 2 of us TFers and 2 separate outside links posted (many more out there) "off base" showing the difference between the necessity of an anchor and it's rated holding power for small boats and the anchor generally a placeholder (that of course needs some holding power) for ships where percentage wise, would be totally unsuitable for small craft.