Why won't a Spade Bite

[Don C L]

Originally Posted by Panope

I don't mind at all as long as you're covering the airfare!

oops!

let me go get a lottery ticket... hang on a minute.

[SailingHarmonie]

Originally Posted by sailingharry

And a better question for those of us who are willing to doubt their all-knowing-ness. If it was their technique, what was wrong?

100% technique. They were following advice I have heard in many places that usually goes like this: "Let out half of your expected scope and then tie it off to "set the anchor", then let out the rest of your scope."

They were trying to "set" the anchor on a short scope, when it didn't grab, they would pull it up and try again... and again... and...

The exact opposite approach has always worked for us. We drop the anchor, and drift away while letting out the full scope we intend to use before pulling on it. When we do that our anchor just dives into the bottom and the boat snaps to a stop right away. If we are in a crowded anchorage, and need to swing on a shorter than normal scope, we will actually set the anchor on a long scope, dig it in, then pull rode in to where we need to be.

We had been using the same procedure for years when Peter Blake, inverntor of the Rocna, wrote it up:

1. Don’t drag the anchor while trying to set it. With the old generation Plough type anchors it was traditional to use lots of chain and drag them, usually some distance to get them to set, often on the second or third try. With Rocna and Vulcan, you want to avoid any pull before sufficient scope is paid out.
2. When deploying the anchor drop out your scope at 5:1 (water depth + anchor roller above water X 5 ). Try not to drag the anchor before at least 3:1 is deployed.
3. When deployed let the boats backward momentum and or wind set the anchor rather than engine power initially. Other than low rev’s to get the boat moving in the right direction don’t back down on the unset anchor with any power.
4. You should feel the anchor start to set as the rode takes up. Only then by all means use some engine power to complete the set and reassure yourself it is in. However, I don’t recommend any more than 25% revs until the anchor has had a few hours to work itself in.
5. If you do ever have to re-set the anchor always clean the old mud off first before redeploying – otherwise caked mud can interfere with subsequent sets.

I have never understood the logic of trying to "set" the anchor on a short line. What is the first thing you do if an anchor does not grab the bottom? LET OUT MORE RODE! So why set on a short line??? This is especially true with any of the roll bar anchors which do not like to be dragged across the bottom without digging in.

[sailingharry]

Originally Posted by SailingHarmonie

100% technique. They were following advice I have heard in many places that usually goes like this: "Let out half of your expected scope and then tie it off to "set the anchor", then let out the rest of your scope."

Aha! So our success has not been dumb luck (or a great anchor). I agree with you, I've never understood the idea of setting the anchor with less than the optimum scope. Or at least the amount you intend to spend the night with.

But I'm not going to completely discount the virtues of dumb luck and great anchors.

[Exile]

Originally Posted by SailingHarmonie

100% technique. They were following advice I have heard in many places that usually goes like this: "Let out half of your expected scope and then tie it off to "set the anchor", then let out the rest of your scope."

They were trying to "set" the anchor on a short scope, when it didn't grab, they would pull it up and try again... and again... and...

The exact opposite approach has always worked for us. We drop the anchor, and drift away while letting out the full scope we intend to use before pulling on it. When we do that our anchor just dives into the bottom and the boat snaps to a stop right away. If we are in a crowded anchorage, and need to swing on a shorter than normal scope, we will actually set the anchor on a long scope, dig it in, then pull rode in to where we need to be.

We had been using the same procedure for years when Peter Blake, inverntor of the Rocna, wrote it up:



I have never understood the logic of trying to "set" the anchor on a short line. What is the first thing you do if an anchor does not grab the bottom? LET OUT MORE RODE! So why set on a short line??? This is especially true with any of the roll bar anchors which do not like to be dragged across the bottom without digging in.

Most helpful, thanks. I actually had never heard this, instead always opting to follow the conventional wisdom of initially setting on a shorter scope with my Manson Supreme (rollbar anchor). Rarely if ever have had a problem but there's always the "next" time. I'd be interested in others thoughts on this.

[sailingharry]

Originally Posted by Exile

Most helpful, thanks. I actually had never heard this, instead always opting to follow the conventional wisdom of initially setting on a shorter scope with my Manson Supreme (rollbar anchor). Rarely if ever have had a problem but there's always the "next" time. I'd be interested in others thoughts on this.

This of course proves the point that there is rarely one right answer to any question. Your success makes it clear that your approach is appropriate, at least for you.

I will, of course, mentally disagree with you. [emoji16]

[Exile]

Originally Posted by sailingharry

This of course proves the point that there is rarely one right answer to any question. Your success makes it clear that your approach is appropriate, at least for you.

I will, of course, mentally disagree with you. [emoji16]

My success thus far you mean. Always room for improvement. Besides, I'm sure it's only a matter of time.

[Panope]

Paraphrasing something that forum member "Thinwater" once said:

'For rodes that contain a significant amount of chain, any discussion about anchor scope that does not include depth, is meaningless'.

I could not agree more.

For example, it is entirely possible that people are reliably setting their anchors in very deep water at less than 2:1 scope, while others have great difficulty setting in very shallow water at 4:1.

If the water depth is not mentioned, the above could be a source of great confusion.

[sailingharry]

Originally Posted by Panope

For example, it is entirely possible that people are reliably setting their anchors in very deep water at less than 2:1 scope, while others have great difficulty setting in very shallow water at 4:1.

I once spent a night with 2:1 scope. Fortunately, the weather was settled. I would have put out more but then I would have been aground. But, as Panope has indicated, the water was deep. 75 ft of water, 150 feet of rode. All chain.

[CarlF]

I suspect that the anchor has a manufacturing defect that makes the shank to tip geometry wrong.

Why? Because the OP is clearly very experienced with anchoring. He knows how to anchor. And technique is just not very important with a Spade except in soupy mud. On the other hand, we have 50 years of legions of experienced cruisers who swear by the Spade (including me). It's reputation is that it sets very quickly in the most difficult bottoms. I cruise Maine and New England where hard bottoms and grass is common. I've never had an anchor that sets so well. I believe it sets better in hard bottoms because of the weighted tip and narrow initial width of the fluke. I've had much more problems with wide (even if sharp) tip of my old Rocna skipping along a hard or grassy bottom. I owned an ultra on a previous boat. It also set beautifully in heavy grass and weed.

The only well documented weakness of the Spade I know of (besides the galvanizing) is in soupy mud where the relatively small fluke area doesn't give great holding unless you work it deep into the mud by occasional gentle use of reverse over an hour or so. Spade owners learn this trick.

As to the OP's anchor. With any anchor, the angle of the shank to the fluke is critical to setting. The Spade has a complex trianglular shank welded out of three pieces and a complex socket it has to fit into. It seems quite possible that a welding error at the factory put it a few degrees off. Without another anchor to compare it to, this could be impossible to identify by looking at it.

When I was researching my Spade purchase I came upon a report by a long time galvanized Spade owner who replaced his with a stainless version. For whatever reason it wouldn't set (or reset) nearly as well as the galvanized one. It seemed like an entirely differnt anchor. As with the OP here, it wasn't a small difference.

[Captain Bill]

I once set a delta in 50ft of water on a pretty scoured bottom to do some scuba diving. I put out 150ft of chain and back down gently as I figured that since I would be following the anchor chain down I could set it where I wanted if I was uncomfortable with the way it was set. Since it was only for a dive I wasn't terribly concerned with it holding long term. The wind was blowing about 10 at the time. When I got in the water I saw that the chain was hanging straight down until it touched the bottom and the chain was laying like a long series of S's snaked across the scoured bottom with absolutely no tension on it at all. The anchor itself was laying on its side with the point hooked on a small projection. Just for fun I picked up the anchor and hooked it under a small nearby ledge. I set it back on top of the ledge just before ascending. It really didn't matter because the 100 feet of chain still snaked across the bottom and hadn't moved a bit. That really made me more comfortable about shorter scopes in deep water. The weight of that hanging chain really does a lot. Keep in mind that I have a very high windage vessel and the wind had increased to about 12 while we were down and that chain had not moved more than 5 feet laterally from where it started. It had not straightened any of the S's out of the chain laying on the bottom.

[carstenb]

Originally Posted by Panope

I don't mind at all as long as you're covering the airfare!

If Don is paying and you drop by we are on Poros and happen to have a couple of bottles of Ouzo............................

[carstenb]

Re deep water anchoring. We caught a fishing net off the coast of Portugal several years ago and wrapped a long piece of nylon rope around our prop and shaft. It was so tight that it had melted.

It took me about an hour with a very sharp knife to cut it all off (using diving tanks).

The water was 75 meters deep, we dropped all 100 meters of chain we have and our Mantus held just fine

[barcoMeCasa]

Originally Posted by Panope

Paraphrasing something that forum member "Thinwater" once said:

'For rodes that contain a significant amount of chain, any discussion about anchor scope that does not include depth, is meaningless'.

I could not agree more.

For example, it is entirely possible that people are reliably setting their anchors in very deep water at less than 2:1 scope, while others have great difficulty setting in very shallow water at 4:1.

If the water depth is not mentioned, the above could be a source of great confusion.

As a general rule of thumb I go with 20m + 2 x depth with 10mm chain which roughly seems to approximate the scope required so all the chain just stays on the seafloor for 200Kgf horizontal load. 15 * √depth even closer but no way will I do that in my head



https://www.desmos.com/calculator/th0ehkkz8t

Can't remember where the equation came from, think whatever site it was is gone but it does seem to tally well with Alain Fraysse site (won't open in brave for some reason here, but will in chrome)
Rode - Static Behavior

[GALAWA]

I have circum navigated and used a Spade anchor for years.
Spade has several shortcomings when comparered to, say, a Rocna.

1- Its shank is hollow ( contrary to Rocna)and is too easily bent when raising it in choppy wters while stuck in rocks. The slightest bend is revealed by the fact that it non longer stays vertical when digging in. More of a bend and it lays sideways and fails to dig in, even in plain sand.
2- It is poorly galvanized and starts rusting early (Quite shocking considering its exorbitant price )
3 - The lead poured in the open tip is not fully enclosed in watertight steel with 3 consequences
3-1 It is exposed to sea water contributing to galvanic corrosion between steel, lead and Zinc (which may contribute more to the early corrosion than poor galvinization)
3-2 The lead is poured in an undefined open volume inside the tip of the anchor. The quantity of lead poured being not defined by an enclosed volume is aproximate . I have seen several Spades which were significantly lighter than their nominal weight, for insuficient quantity of lead obviously.
3-3 In Guatemala, I have seen a Spade anchor sent for regalvanization.
This means dipping the anchor in molten Zinc. When the shiny regalvanized Spade was returned, the lead had melted and dropped out of the anchor.
No lead left,

My next anchor will be a solid steel Rocna !

[Kettlewell]

I have never understood the logic of trying to "set" the anchor on a short line. What is the first thing you do if an anchor does not grab the bottom? LET OUT MORE RODE! So why set on a short line???

You shouldn't "set" the anchor, but it helps to snub it periodically as you let out chain to first orient the anchor properly to the direction the chain will be pulling, and to get the sharp point to begin to penetrate the bottom. I Pay out chain until the anchor hits the bottom and then gradually pay out chain as the wind takes us away, periodically snubbing the chain as we drift back to the proper scope. We then put a snubber on it and back down with the engine to make sure it is dug in. Numerous times I have observed people drop quality anchors only to sail away fast downwind as they dump all the scope and proceed to rapidly back down hard, which is just about guaranteed to make the anchor skid across the bottom some distance before orienting itself and digging in. Along the way the anchor may pick up enough mud and weed to foul itself.