Why won't a Spade Bite

[carstenb]

So an anchor thread - Yah!!!

A bit of history first. My wife and I have been global cruising for the past 7-8 years and in that time have been on the hook perhaps 2000 nights. We have a Mantus and the motto on board our boat is "In Mantus we trust".

In those 2000 nights we have dragged once and the mantus has failed to bite first time twice

The past several weeks we have been sailing some friends boat in Greece. It has a Spade. I was interested in how this would perform since Spade anchors generally get great reviews.

Our experience so far:

1- The spade seems to fail to bite first time about 50% of the time. Meaning we have to reanchor.
2- When other boats have ripper our anchor out of the substrate when they have upped anchor ( a very common occurrence here in Greece as anchor lines are frequently crossed) the Spade has failed to bite when I try to set it again by hauling in on the rode - even stopping every couple of meters to give it a chance to bite.

We put out plenty of scope so that shouldn't be an issue. We do know that we have to be careful with sea grass (we are not complete amateurs). In the pas 8 years we have anchored in most every kind of substrate so there really isn't anything unusual about Greece).

So - any opinions about why we can¨t get this Spade to bite? We never have problems with our Mantus

[Don C L]

Noelex and Panope would know, but I think I recall that sometimes when the spade is on its side it will slide along and the tip won't get enough bite to dig in and rotate the anchor up. The Mantus, being flatter on the bottom (I think, isn't it?) will probably land flat and then once pulled is lifted so the tip digs in right away. This is all just conjecture on my part. I gotta go back and check the videos those guys put up. I bet the Spade would benefit from wider wings on the aft end to prevent it from falling over.
I wonder if there is a difference in shank angle between the two also.

[carstenb]

Originally Posted by Don C L

Noelex and Panope would know, but I think I recall that sometimes when the spade is on its side it will slide along and the tip won't get enough bite to dig in and rotate the anchor up. The Mantus, being flatter on the bottom (I think, isn't it?) will probably land flat and then once pulled is lifted so the tip digs in right away. This is all just conjecture on my part. I gotta go back and check the videos those guys put up. I bet the Spade would benefit from wider wings on the aft end to prevent it from falling over.
I wonder if there is a difference in shank angle between the two also.

I'm hoping both Noelex and Panope (who has tested more anchors than anyone on the planet) will chime in on this thread

[s/v Jedi]

Does it still have it’s lead ballast in the point? Is the shank still straight?

Is it steel or aluminum?

[carstenb]

Originally Posted by s/v Jedi

Does it still have it’s lead ballast in the point? Is the shank still straight?

Is it steel or aluminum?

Steel. Shank is straight and still has the lead

Anchor is only 2 years old

[Panope]

Carsten,

On at least two occasions, Steel Spade anchors have been found to have the incorrect amount of lead ballast. A theory is that the factory thought they were ballasting an ALUMINUM version (needs less lead) by mistake.

The first was an S80 that I bought second hand for next to nothing. It was missing a substantial amount of the required ballast. I never tried using the anchor before adding the correct amount of lead, but I suppose the price was an indication of how well the anchor performed for the previous owner.

The other occurrence that I am aware of was depicted in this thread: https://www.cruisersforum.com/forums...00-259981.html

If the correct amount of lead is in fact present, then the only other problem with the anchor that I can dream up, is perhaps the hollow shank has become fully packed with seabed material - thus disrupting the balance of the anchor.

Assuming the anchor is normal, the chain attachment is correct (shackle not bound-up sideways), and enough chain is present to have a horizontal pull during the setting process, then that leaves SEABED TYPE as the only other variable that I can think of.

Do you have any clues about the seabed material make-up?

P.S. The setting performance of your M1 Mantus just might have spoiled you for life

[SailingHarmonie]

Originally Posted by carstenb

So an anchor thread - Yah!!!

A bit of history first. My wife and I have been global cruising for the past 7-8 years and in that time have been on the hook perhaps 2000 nights. We have a Mantus and the motto on board our boat is "In Mantus we trust".

In those 2000 nights we have dragged once and the mantus has failed to bite first time twice

The past several weeks we have been sailing some friends boat in Greece. It has a Spade. I was interested in how this would perform since Spade anchors generally get great reviews.

Our experience so far:

1- The spade seems to fail to bite first time about 50% of the time. Meaning we have to reanchor.
2- When other boats have ripper our anchor out of the substrate when they have upped anchor ( a very common occurrence here in Greece as anchor lines are frequently crossed) the Spade has failed to bite when I try to set it again by hauling in on the rode - even stopping every couple of meters to give it a chance to bite.

We put out plenty of scope so that shouldn't be an issue. We do know that we have to be careful with sea grass (we are not complete amateurs). In the pas 8 years we have anchored in most every kind of substrate so there really isn't anything unusual about Greece).

So - any opinions about why we can¨t get this Spade to bite? We never have problems with our Mantus

Just a question for the insanely curious: Was your friend happy with the performance of his Spade? Or did he cuss at it?

I find a lot of sailors who are emotionally and financially invested in the anchor they have, have a huge blind spot to its failings. Kind of like being in love...

[rslifkin]

If you pull it up after it fails to set, is it packed with a huge glob of mud? Or is it still anchor shaped? And are there scuff marks on the top of the shank to indicate it may have ended up dragging upside down?

I've gotten the upside-down drag with my Vulcan when I found some junk on the bottom once. Tried 3 times, no set. Every time it came up with mud and scuff marks on the shank, but a clean fluke. The last time it came up with some bits of plastic snagged on the shackle, which confirmed there was something down there. Moved the boat to a different spot, tried again, and it set exactly as expected. When pulling it up later, the anchor showed the same mud, so the bottom wasn't any different, just a difference in junk on the bottom or not.

[carstenb]

Originally Posted by Panope

Carsten,

On at least two occasions, Steel Spade anchors have been found to have the incorrect amount of lead ballast. A theory is that the factory thought they were ballasting an ALUMINUM version (needs less lead) by mistake.

The first was an S80 that I bought second hand for next to nothing. It was missing a substantial amount of the required ballast. I never tried using the anchor before adding the correct amount of lead, but I suppose the price was an indication of how well the anchor performed for the previous owner.

The other occurrence that I am aware of was depicted in this thread: https://www.cruisersforum.com/forums...00-259981.html

If the correct amount of lead is in fact present, then the only other problem with the anchor that I can dream up, is perhaps the hollow shank has become fully packed with seabed material - thus disrupting the balance of the anchor.

Assuming the anchor is normal, the chain attachment is correct (shackle not bound-up sideways), and enough chain is present to have a horizontal pull during the setting process, then that leaves SEABED TYPE as the only other variable that I can think of.

Do you have any clues about the seabed material make-up?

P.S. The setting performance of your M1 Mantus just might have spoiled you for life

Steve
I’ll check those items you mentioned when we pull the hook next time. Off hand there doesn’t seem to be any visual reason for it not to bite. The shank is straight. Looks like it has the correct amount of lead and the shackle is correctly mounted

Re substrate. Generally there is sand sea grass or gravel/stones. Obviously sea gras will not allow the anchor to bite but the other substrates should be ok

Well we love our mantus and have zero desire for anything else. But a 50% failure rate with a spade seems wxtreme

[carstenb]

Originally Posted by SailingHarmonie

Just a question for the insanely curious: Was your friend happy with the performance of his Spade? Or did he cuss at it?

I find a lot of sailors who are emotionally and financially invested in the anchor they have, have a huge blind spot to its failings. Kind of like being in love...

The owner loves his spade actually switched from a mantus

[carstenb]

Originally Posted by rslifkin

If you pull it up after it fails to set, is it packed with a huge glob of mud? Or is it still anchor shaped? And are there scuff marks on the top of the shank to indicate it may have ended up dragging upside down?

I've gotten the upside-down drag with my Vulcan when I found some junk on the bottom once. Tried 3 times, no set. Every time it came up with mud and scuff marks on the shank, but a clean fluke. The last time it came up with some bits of plastic snagged on the shackle, which confirmed there was something down there. Moved the boat to a different spot, tried again, and it set exactly as expected. When pulling it up later, the anchor showed the same mud, so the bottom wasn't any different, just a difference in junk on the bottom or not.

The anchor comes up clean Once it was packed with grass the other times clean

[Panope]

Originally Posted by SailingHarmonie

I find a lot of sailors who are emotionally and financially invested in the anchor they have, have a huge blind spot to its failings. Kind of like being in love...

I can report that having a vast anchor harem is cure for this problem.

I have no idea if this applies to humans.

[skyl4rk]

The mantis works better because the blade is sharper and the angle is designed to dig in rather than plow through.

[hlev00]

Our Spade has worked great in many different types of seabeds. As you noted, grass can be an issue. We are careful to lay the chain out as we drift back, not dropping all the chain at once.

What size is your boat and what size is the spade?

[noelex 77]

One thing to check is that the shackle or swivel cannot jam at an unfair angle. This is a common cause of anchors behaving poorly, but I think it is likely you just noticing a fundamental difference between the two anchor designs.

One of the great strengths of the Mantus M1 is its ability to reliably set in a wide range of substrates. The most common reason for an anchor not setting is failure of the initial tip penetration. Once the tip has started to dig in, the force exerted on the rode can be converted into the anchor burying sucessfully.

The combination of a high tip weight and the very thin tip profile of the Mantus M1 means it is very rare for the anchor not to be able to cut into the substrate. The Spade shares the high tip weight, but the more bulky fluke design fails to initially penetrate into the substrate more frequently.

This difference in initial setting reliability is most apparant in very hard sand and weedy substrates. The Mediterranean has many anchorages with what looks like perfect sand, but there is often a very hard sand layer just below this surface and this creates a barrier. This is why you are particularly noticing unreliable setting with the Spade in this region. The same problem will not occur in more friendly substrates such softer sand or mud.