fredrussell
Well-Known Member
I love the fact that the OP, himself going on at some length about a subject most of us are sick to the back teeth with, is telling us to “get a life”!!! Pot, kettle, black?
Mantus M2 vid vs Delta
- Thread starter Neeves
- Start date
MM5AHO
Well-Known Member
It's true that half of John Knox's testing was done on Longniddry beach near Edinburgh. (and the rest in the sea on the west coast). But there's validity in beach testing in so far as it goes. It eliminates some of the many variables that can unintentionally be introduced in pull testing from a boat. Good experimental design is to have a test that measures relative performance between the samples under test without other variable that cloud the issue. Beach testing can do a lot of that. A simple example is scope. Scope translates to angle of the rode off horizontal. In tidal locations the depth is changing continuously, so angle of pull is changing. In beach testing any obstruction (small rock for example) can be seen and that test repeated without interruption. It can't normally be seen underwater.
That said, it can't have been all that pleasant standing in ankle-deep cold water for many hours on many days over a period of 5 years developing a science based testing technique and then doing comparative tests across a range of anchors (before he inverted his own). I'd much rather be on a boat!
thinwater
Well-Known Member
...I have to agree with you regarding price. From what I can see Rocna will charge whatever the market will bare and people are happy to pay it because they believe it is best....
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Bare markets scare me.
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Bare markets scare me.
thinwater
Well-Known Member
RichardS
N/A
Neeves
Well-Known Member
Reading and contribution g to any thread is voluntary.
I'm not keen on threads on exhaust elbows, nor solar panel regulators and a variety of other things. Most anchor threads have the word anchor in the title - why not simply skip them. The solution appears to lie in your own hands.
Jonathan
Neeves
Well-Known Member
Fun stuff. At least they are getting better!
I'm not so sure. The anchor seems, M2, to engage, quickly, as does the M1, it dives (a bit) and then seems to bottom our - and drags at shallow depth with the top of the shank permanently exposed.
I test with a variant on John Knox testing. I test in the intertidal zone, but underwater, then dig the anchors out when the tide has receded. Digging our usually takes longer than the test as most modern anchors bury to around their shank length deep.
coopec
N/A
Well I've just spent the morning tidying up my shed and came across my anchors - Manson 60ib Plough and a 27 kg Danforth. (The yacht is a Roberts 43ft 12 tonne long keel) Do I need anything else? Maybe a Manson Supreme 27kg?
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Neeves
Well-Known Member
"Oh and with sublime gratitude if anybody has a non-riding sail method of diminishing veering about"
We have a pair of 820 kg bilge keels, so just park on the beach. They haven't dragged yet so prove that Johnathan's thesis of 'smaller is better' isn't true. Instead big is best.
Hang on, Johnathan said the Mantus has equal holding to a Delta, but the video proves otherwise. Johnathan, you lie like "cheap NAAFI watch"
Point taken, I omitted to mention - except on hard beach sand - I excuse my own omission on the basis that most people don't anchor on hard beach sand.
If my error is defined as lying - it was unintentional and I apologise.
Thank you for pointing out the error of my ways - healthy criticism is valueable.
Jonathan
Neeves
Well-Known Member
I found our Manson plough unreliable - maybe I needed to be more patient and master its idiosyncrasies. I lacked that patience.
Jonathan
langstonelayabout
Well-Known Member
I’m still amazed that no one tries to replicate the ‘other’ true test of anchoring, the one that the Danforth types are traditionally poor at, yes the 180 degree change of pull direction that happens in many places about every 6 hours.
I respect the testing that has been done over many different places around the world but a straight pull is only 50% of the story. I’d dearly love to see the ‘re-set’ reliability stats of the different designs. Then I could anchor and sleep undisturbed for the whole night or set my alarm clock to wake me at the turn of the tide. Either way I’d have confidence I wouldn’t end up drifting in a shipping lane or on a local beach.
Do those assembled here believe that change of tide ‘re-set’ should become a part of the anchor testing regime?
I respect the testing that has been done over many different places around the world but a straight pull is only 50% of the story. I’d dearly love to see the ‘re-set’ reliability stats of the different designs. Then I could anchor and sleep undisturbed for the whole night or set my alarm clock to wake me at the turn of the tide. Either way I’d have confidence I wouldn’t end up drifting in a shipping lane or on a local beach.
Do those assembled here believe that change of tide ‘re-set’ should become a part of the anchor testing regime?
coopec
N/A
I've often thought about change of wind direction and change of tidal flow and how different types of anchors would cope.
Surely an anchor with a swinging shank would handle wind changes more effectively?
I don't know whether it is normal practice in the cruising world but do they set two anchors at night? ( I know I'd sleep a lot better)
Neeves
Well-Known Member
The 'get a life' was aimed at the individual who had the Mods give men the Spanish Inquisition treatment when I initiated a thread on Viking anchors - sorry if you took it personally.
Anchor testing, as Geoff commented on Prof Knox investments, is hard work and arduous and everyone finds fault.
This is another example. Its not perfect - maybe you can do better.
Anchor Resetting Tests - Practical Sailor
These tests, which could have enjoyed a bit more time, took 5 people all day. Hopefully they provide some of the answers for Noelex, Langstonlayabout and Coopec
There are other areas, how does one conduct a test simulating the effects of chop, what other tests would satisfy those who want to be educated (or entertained, to better define the effect of veering. Importantly who is going to pay for it. Forum threads are commonly initiated by people looking for help and support, from member(s) - noting the plural. Not many threads are commenced to educate and those that pertain, as such, usually have some hidden agenda.
Jonathan
Anchor testing, as Geoff commented on Prof Knox investments, is hard work and arduous and everyone finds fault.
This is another example. Its not perfect - maybe you can do better.
Anchor Resetting Tests - Practical Sailor
These tests, which could have enjoyed a bit more time, took 5 people all day. Hopefully they provide some of the answers for Noelex, Langstonlayabout and Coopec
There are other areas, how does one conduct a test simulating the effects of chop, what other tests would satisfy those who want to be educated (or entertained, to better define the effect of veering. Importantly who is going to pay for it. Forum threads are commonly initiated by people looking for help and support, from member(s) - noting the plural. Not many threads are commenced to educate and those that pertain, as such, usually have some hidden agenda.
Jonathan
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thinwater
Well-Known Member
vyv_cox
Well-Known Member
Here is a real life example. Wind was around F4 from about south, veered to NW force 7 overnight. Anchor is a large Manson Supreme, 33 kg(?), 12 mm chain, 55ft boat. The anchor has simply rotated, not dragged to any visible extent.
Our 15 kg Rocna behaved identically.
coopec
N/A
Here is a real life example. Wind was around F4 from about south, veered to NW force 7 overnight. Anchor is a large Manson Supreme, 33 kg(?), 12 mm chain, 55ft boat. The anchor has simply rotated, not dragged to any visible extent.
Our 15 kg Rocna behaved identically.
WOW! That is impressive.
I've been thinking of getting a 27kg Manson Supreme but you've sold me! Thanks.
Neeves
Well-Known Member
Vyv's photos stunningly show, he has another of his Rocna (as he says) very similar - clearly indicate that with a 'slow' change in wind direction - and in this case of increasing windspeed both the Rocna and Supreme react to the change by slowly swing to face the new wind direction. They don't break free and reset - they offer reliability. This characteristic is common in most modern anchors, Spade, Rocna, Supreme, Excel, Ultra - its 'nothing special'
The tests I did, Post 33, were of a more abrupt wind change - a thunderstorm cell passing overhead or maybe a tide change with an aggressive tidal flow (like 5 knots). In sudden changes of wind direction an anchor does not have time to slowly adjust and will break out. Different mechanism. One of the bendy shank Rocnas was subject to such a thunderstorm cell (in the Caribbean) and the shank bent - but it only bent because the fluke was effectively immovable (so all credit to the hold of the fluke). If the anchor had been less deeply set (for whatever reason) it would have been pulled out and had need to re-set - itself. The anchor was replaced FOC and is quoted in the YM Cox/Neeve 'Bendy Shank' article.
I did another test in which well set anchors were subject to snatch loads with destruction of shanks, and in one case the fluke.
Bends and Breaks: Anchor Shank Strength - Practical Sailor
The only shanks that withstood the tests were 800 MPa steel shanks - everything else failed. Some note was taken of the tests and the shank of the Super SARCA was upgraded to 800 MPa steel and the fluke of the alloy Excel redesigned. Fortress did not alter their shank (but did send me a replacement -under their 'no questions asked policy'.
Jonathan
RupertW
Well-Known Member
I have observed similar many times with a Delta - but with slow wind changes building up to 25-30 knots in the new direction over a couple of hours. I haven’t snorkelled after abrupt changes but they didn’t cause a noticeable drag - but might have been a metre or two I didn’t notice from the boat.Vyv's photos stunningly show, he has another of his Rocna (as he says) very similar - clearly indicate that with a 'slow' change in wind direction - and in this case of increasing windspeed both the Rocna and Supreme react to the change by slowly swing to face the new wind direction. They don't break free and reset - they offer reliability. This characteristic is common in most modern anchors, Spade, Rocna, Supreme, Excel, Ultra - its 'nothing special'
The tests I did, Post 33, were of a more abrupt wind change - a thunderstorm cell passing overhead or maybe a tide change with an aggressive tidal flow (like 5 knots). In sudden changes of wind direction an anchor does not have time to slowly adjust and will break out. Different mechanism. One of the bendy shank Rocnas was subject to such a thunderstorm cell (in the Caribbean) and the shank bent - but it only bent because the fluke was effectively immovable (so all credit to the hold of the fluke). If the anchor had been less deeply set (for whatever reason) it would have been pulled out and had need to re-set - itself. The anchor was replaced FOC and is quoted in the YM Cox/Neeve 'Bendy Shank' article.
I did another test in which well set anchors were subject to snatch loads with destruction of shanks, and in one case the fluke.
Bends and Breaks: Anchor Shank Strength - Practical Sailor
The only shanks that withstood the tests were 800 MPa steel shanks - everything else failed. Some note was taken of the tests and the shank of the Super SARCA was upgraded to 800 MPa steel and the fluke of the alloy Excel redesigned. Fortress did not alter their shank (but did send me a replacement -under their 'no questions asked policy'.
Jonathan
LittleSister
Well-Known Member
On the subject of Mantus videos, I don't know if it's been posted before but the one below is rather mind-boggling. What were they thinking? (See also the comments people have made on YouTube about it!)
RichardS
N/A
That's the clincher for me. My mind is made up.
I will, in future, use one Mantus rather than my five other anchors.
Simples!
Richard