Photos of Anchors Setting

[noelex 77]

This was a Delta in light weed. 7m @ 4:1.

They dropped several times and in each case the anchor failed to bite. On the final drop I think they realised that the anchor was not holding the reverse engine force and just let the anchor slowly come to a stop.

There was a long drag mark. The anchor has made some attempt to dig into the underlying substrate, but when feeling with my fingers the penetration was minimal.

[Hydra]

I wonder if the galvanisers got it wrong and assumed the Delta had lead ballast behind a cover plate (as some convex plow anchors do). With lead or steel ballast behind a cover plate there is a danger of explosion when re-galvanising without adequate vent holes. Consequently before re-galvanising they drilled a "vent" hole into what they thought was the cover plate, but was actually solid steel.

The "vent" hole taking less than an ounce of lead (which is very little) also fits in with this theory. Rather than refilling gaps in the ballast chamber, the lead was simply refilling the drill hole.

Let's reproduce Archimedes' idea: fill a large basin with water, up to the brim, then plunge the anchor in it and measure the volume of overflowing water, equal to the volume of the anchor. Then, weigh the anchor to measure its mass.

The density is the ratio of mass to volume: kg/m3. If the anchor is made of steel, its density should be between 7750 and 7950 kg/m3. If it's higher, one can assume there is lead inside.

Another way of doing it is to measure the "apparent weight" of the anchor in water, by hanging it under a balance, and compare it to the weight in air: if the reduction due to buoyancy is about 13%, the anchor is made of steel. If the reduction is lower (less volume for the same weight), there is a heavier metal inside.

Alain

[sanibel sailor]

Originally Posted by Hydra

Let's reproduce Archimedes' idea: fill a large basin with water, up to the brim, then plunge the anchor in it and measure the volume of overflowing water, equal to the volume of the anchor. Then, weigh the anchor to measure its mass.

The density is the ratio of mass to volume: kg/m3. If the anchor is made of steel, its density should be between 7750 and 7950 kg/m3. If it's higher, one can assume there is lead inside.

Another way of doing it is to measure the "apparent weight" of the anchor in water, by hanging it under a balance, and compare it to the weight in air: if the reduction due to buoyancy is about 13%, the anchor is made of steel. If the reduction is lower (less volume for the same weight), there is a heavier metal inside.

Alain

Way too much time on your hands...

[JPA Cate]

Hydra:

Wonderful! But where would you get the scales accurate enough to measure such a small percentage difference? Seems like the accurate measure is the trick.

Thank you for posting such innovative and at the same time backwards-looking [;-)] concepts.

Ann

[malbert73]

Of course this will not work if there's a void in the toe..


Sent from my iPad using Cruisers Sailing Forum

[kas_1611]

Originally Posted by Hydra

Let's reproduce Archimedes' idea: fill a large basin with water, up to the brim, then plunge the anchor in it and measure the volume of overflowing water, equal to the volume of the anchor. Then, weigh the anchor to measure its mass.

The density is the ratio of mass to volume: kg/m3. If the anchor is made of steel, its density should be between 7750 and 7950 kg/m3. If it's higher, one can assume there is lead inside.

Another way of doing it is to measure the "apparent weight" of the anchor in water, by hanging it under a balance, and compare it to the weight in air: if the reduction due to buoyancy is about 13%, the anchor is made of steel. If the reduction is lower (less volume for the same weight), there is a heavier metal inside.

Alain

If anyone wants to do this in American then it is 2747 lbs/barrel for steel displacement. Just in case you were wondering

Keiron

[wsmurdoch]

After checking Lewmar's web site, I wrote them yesterday...

I have a 35 lb Simpson Lawrence Delta galvanized steel anchor that I have owned for a long time. When I had it re-galvanized, a hole appeared in the apex of the triangular metal plate of the ballast tip under the bar. Other than some discoloration there was no indication that a hole was present before the anchor was re-galvanized.
1 . What is (was) the purpose of the hole? I note that the drawing of the Delta anchor on this web site shows a solid steel ballast tor the galvanized anchor and a lead filled tip for the stainless steel anchor. I had previously assumed that the ballast tip of all the Delta anchors was filled with lead.
2. What is the difference in the Delta anchors stamped "Simpson Lawrence" and those not stamped?
3. What is the difference in the anchors with a red label and those with a blue label glued on the anchor. I've seen both.

Lewmar replied today...

Thank you for contacting Lewmar.
Can you please send me a picture of this hole?
To the best of my knowledge the units are solid manganese steel, there is no lead in them or the stainless versions for that matter. The only anchors we offer with a lead tip are the DTX anchors but those are just a year or two old.
This stamping you refer to, is it in the metal of the anchor itself or simply on a decal? A picture of this as well would be appreciated.
As to the labels, the coloring does not give any indication as to a change in the anchor itself, it is only cosmetic and the changes to the labels are just cosmetic as well.
Please let me know and I will do all that I can to help.
Josh

I sent Lewmar the three pictures I previously posted along with this note...

Here are two photos of the hole, one in shade and one in the sun.
In this third photo I have a vernier caliper inserted into the hole to measure the depth. The bottom of the hole was quite rough. I'm measuring into a "well" in the very rough metal inside. I later filled the hole with about an ounce of plumbers solder after heating the tip with a torch. Also, in this view you can see the Simpson Lawrence trademark box stamped into the underside of the tip.
Bill Murdoch

And, the final reply from Lewmar...

Thank you for the pictures and email.
I have never seen a hole like this before.
I know the tips aren’t lead filled so the only other thing I can think of would be that it was something that happened during the manufacturing process, like an air bubble or something similar.
Simpson Lawrence and Lewmar were merged in the late 90’s but for as long as I have been around, going on 10 years now, I have never seen an SL logo on the anchors themselves. I would say it was something Simpson Lawrence did when they were a lone entity and was changed in the intervening years.
Let me know if you have any questions,
Josh


So, Noelex, you may be quite right. Perhaps the galvanizers drilled the hole.

[Sos]

If there wasn't already a hole I am sure the galvanizers would have drilled one. They are very wary about voids and that is the only way of checking.

[Boatguy30]

I'm thinking the original UK made anchors had lead tips. It would be difficult to drill a hole there wouldn't it with the cross bar in the way of swinging the drill in square?

[noelex 77]

Originally Posted by Hydra

Let's reproduce Archimedes' idea: fill a large basin with water, up to the brim, then plunge the anchor in it and measure the volume of overflowing water, equal to the volume of the anchor. Then, weigh the anchor to measure its mass.

Thanks Hydra. I think your ideas would work with some careful measurements. Lead is much denser than steel.

It is a pity that we need to even contemplate such measures. The manufacturers should make it clear if the ballast is lead or steel and more importantly if the ballast chamber is solid or a cover plate. The latter is going to be hard to pick with measurments.

[noelex 77]

Originally Posted by wsmurdoch

After checking Lewmar's web site, I wrote them yesterday...

Thanks WSMurdoch for following this up. The information helps everyone. I have tried emailing anchor manufacturers with technical questions, often with little success. Lewmar deserve credit for answering.

I can understand the galvaniser's caution. As I understand it, if there is simply a cover plate welded over the ballast chamber with little venting the air pocket exploding can spray molten zinc over the personel. The Delta and Kobra (plus others) have a solid balance chamber so this risk does not apply.

There are many designs of convex plow anchors, and even as someone interested in anchors, I find it hard to keep up so I can imagine if galvanisers had a bad experience with a similar looking anchor, they would be especially cautious.

The hole they drilled was unnecessary, but will not have done any practical harm. Filling with lead probably helped the balance.

You have a special WSMurdoch modified Delta with extra tip weight .

[ImaginaryNumber]

A few of the pitfall of setting anchors possibly not mentioned earlier...

https://www.youtube.com/watch?v=y3WveEZykJ8

https://www.youtube.com/watch?v=b7pRfix_sNg

And then there is always anchor retrieval problems...

https://www.youtube.com/watch?v=sAWBRPZZcUA

[noelex 77]

Sorry, I am bit behind with these anchors. There are still loads to come from this season.

This was a Claw (a Bruce copy) that was used as a stern anchor. It was dropped via the tender in shallow water in a rocky patch to stop the stern swinging.

Judging by the bent tip on one of the flukes it was a trick he had used before. The rope is attached to a float to help pull the anchor out backwards if it snags in the rocks. I am not sure how the rope managed to get so tangled, but it was not making much difference.

[noelex 77]

How to anchor with a scope of 1:1 .

Well, I am not sure this even qualifies as anchoring, but is more like controlled dragging. This anchor was dropped by local tourist boat in 5m of water. They stopped in the bay for only an hour or so to give the guests a swim in a nice spot before moving on.

The anchor is not really working as an anchor normally would, it is just a dead weight. I would not recommend this short a scope, but it is worth noting that most anchoring advice is related to spending overnight at anchor. If just stopping for a short time to swim or lunch in settled conditions when someone will be watching the boat at all times and there are no very nearby hazards, there is no need to bother with laying out lots of chain and rigging a snubber etc. I would use more than 1:1, but less than 3:1 in moderate depths with an anchor that performs well at short scopes is still OK. My large Mantus will hold full reverse at 2:1 in a good substrate, so there is plenty of security for a short stop in light winds.

[Jim Cate]

G'Day, Nolex,

That anchor is interesting in that it appears the fluke tips can't engage the seabed! Not a great design... but it draws pretty patterns in the sand!

Jim