Snubbers

[Star-Lord]

on this occasion the snubber was on port forward cleat - I prefer one side or the other - a bridle would be nice and have tried them but this method is best for my boat (for now! bridles have been tried etc etc) it was at least 15m this one - I have a 20m one as well before changing hooks - and this looks like 14mm? I use 16mm for long ones now.

 

[Star-Lord]

And anyone wondering about the chain - it is cromox G6 PLUS Electro Polished Stainless Steel Anchor Chain AISI318LN Obv a compromise! The Aqua 7 did not last long and needed knocking down every 10m or so - had a few hairy moments scuttling down below to knock it all over etc etc. Now the chain just slips in nicely. The windlass loves it. Ideally 10mm galvanised would be my weapon of choice - sometimes think I should have changed up to 10mm windlass when I got the Maxwell... Just remembered the 10mm windlass did not fit - the motor is a bit larger - anyway this chain is guaranteed against corrosion for 3 years and at the end of 3 years you can send it back to the factory for testing and polishing etc and they will guarantee it again for a couple more years - I think. Not as strong as Aqua 7 but stronger than all the other 8mm chain and after two years of Aqua 7 the rust has eaten away a good 1mm anyways.

 

[sailaboutvic]

All this talk of snubbers failing, just when they are most needed, demonstrates the absolute necessity of having the chain properly made fast. Vic hasn't answered my question, but I can only assume that his chain was just left on the windlass gypsy, and when the load came on it, the brake, if it was on, was insufficient to hold it. There's a lesson to be learned there.

Sorry Norman I miss that posting .
Yes the chain was left on the windlass but the windlass also as a brake ,
In my defence , the forecaster show not one int that any weather let alone thunderstorm anywhere to worry about other wise the second snubber would had been put on between the windlass and the bow roller ,
But the grave mistake I did make was ,
was the second I got out of bed when the wind was probably no more then 25 kts , at that point not going forward and set the second snubber .
The problem wasn't the brake and thank god too other wise I would has lost the lot.
What was happening was as the bow was pitching wildly the sudden drop would make the chain jump and lump of chain would run out till the slack was taken up and the chain once again locked on the gypsy .
I could see this even in the dark when I was on the bow ,
It's also why when I was trying to fit the second snubber the hook came away , the sudden snatch .

But it always easier to look back and say I should had done this or that .
Looking back now I been better off to just wrap a rope over the chain first to secure the chain then put the second snubber on.

 

[Neeves]

And anyone wondering about the chain - it is cromox G6 PLUS Electro Polished Stainless Steel Anchor Chain AISI318LN Obv a compromise! The Aqua 7 did not last long and needed knocking down every 10m or so - had a few hairy moments scuttling down below to knock it all over etc etc. Now the chain just slips in nicely. The windlass loves it. Ideally 10mm galvanised would be my weapon of choice - sometimes think I should have changed up to 10mm windlass when I got the Maxwell... Just remembered the 10mm windlass did not fit - the motor is a bit larger - anyway this chain is guaranteed against corrosion for 3 years and at the end of 3 years you can send it back to the factory for testing and polishing etc and they will guarantee it again for a couple more years - I think. Not as strong as Aqua 7 but stronger than all the other 8mm chain and after two years of Aqua 7 the rust has eaten away a good 1mm anyways.

Star Lord, nice set up.

Do you use the Mantus swivel (that you mention)?

I'd have bought the Cromox hook, that matches the chain.

But then I don't trust Mantus, very innovative, but too, too many errors.

Jonathan

 

[Roberto]

Really the use of long snubbers is recent and those that use them are on a steep leaning curve.

Recent?
Erm, perhaps in the English speaking sailing world: the first articles/studies about snubbers and rode elasticity appeared in France in the 90s, namely Alain Fraysse attempt at explaining the reduction in peak loads with the addition of textile rope to chain rode.
A few years ago, a more in-depth analytical treatment of snubbers, rubber compensators, approximation of gusts action, etc has been made by F. Allest, see the excel file below, unfortunately only in French. As to credentials, he is the former head of ESA space launch activity, and responsible of all the Ariane rocket development since the beginning.
http://artimon1.free.fr/TableurlignedemouillageArtimonversionV6protegee.zip

I'd say long snubbers have had supporters, users and curious/analytically minded people around for more than two decades

 

[Neeves]

Recent?
Erm, perhaps in the English speaking sailing world: the first articles/studies about snubbers and rode elasticity appeared in France in the 90s, namely Alain Fraysse attempt at explaining the reduction in peak loads with the addition of textile rope to chain rode.
A few years ago, a more in-depth analytical treatment of snubbers, rubber compensators, approximation of gusts action, etc has been made by F. Allest, see the excel file below, unfortunately only in French. As to credentials, he is the former head of ESA space launch activity, and responsible of all the Ariane rocket development since the beginning.
http://artimon1.free.fr/TableurlignedemouillageArtimonversionV6protegee.zip

I'd say long snubbers have had supporters, users and curious/analytically minded people around for more than two decades

Totally agree - we are discussing semantics. 'Recent' to me is in the last 20 or 30 years. I consider what we now call New Gen anchors as 'recent' - except that the first NG anchor was, in my book, Spade (and also Fortress through its use of novel materials) both late 80s or early 90s. The introduction of the NG anchors has changed anchoring completely and heralded a new era in reliable use of a yacht for anchoring overnight (supported by GPS - introduced and popularised in the same time frame).

However my use of the word recent was not referring to when first mentioned (I'm sure there might have been earlier mentions) but when they started to become accepted and commonplace. They are still largely ignored in Oz and are still largely ignored by many in the UK, Europe and America. But I do see and read of greater acceptance now and I still see people arginine against them. Long snubbers have been largely ignored, I'd say until 'VERY recently' - maybe the last 10 years - so we have known about them but not used them (in the same way that the revolutionary Spade has taken decades to be recognised as a major step forward in design - and then copied to become the much vaunted Rocna).

To underline the lack of acceptance - look at the bridles of modern catamarans, most of which now come from French yards, the country of source of your quotes and link, the bridles are such they look strong enough to lift the completed yacht by crane - and will have no elasticity at all. Acceptance is not recent - snubbers are not accepted at all! (by the multihull builders). But then the builders don't accept downsized high tensile chain either - and surely the builders are people who should know, of modern anchors, snubbers and HT (lightweight) chain. Another facet of a lack of acceptance - most yachts sold in Europe (and Australia) come from French yards. The yachts commonly come complete, to the new owner, with halyards, sheets, sails, anchor chain and anchor - how many come with a decent, even 10m, snubber and hook/soft shackle.

Lots of Contradictions.

Jonathan

Jonathan

 

[sailaboutvic]

Jonathan our first port of call after the strom was Trapani, sicily
Needed urgently to get my eye seen too.
quite a lot of marinas around there and not short of yachts and power boats .
I when into 7 chandler to buy a new hook to replace the one we lost ,
The make of type didn't matter at that point, it could be replace when we had more time for a better , not one had a hook and all said they don't keep them .
Some was puzzled what they where used for .

 

[Star-Lord]

Star Lord, nice set up.

Do you use the Mantus swivel (that you mention)?

I'd have bought the Cromox hook, that matches the chain.

But then I don't trust Mantus, very innovative, but too, too many errors.

Jonathan

Yes the Mantus swivel is amazing. So the windlass loves it - chain twist is a problem long gone and an unexpected benefit - unlike the Kong Swivel - is it also self rights the anchor! Every set up world differently!

Ast to snubbers being a recent thing for cruising boats... I think in the past - like 60's and 70's and before people would have used a bit of chain and then mainly a rope rode which would have acted the same as a snubber.

 

[sailaboutvic]

Yes the Mantus swivel is amazing. So the windlass loves it - chain twist is a problem long gone and an unexpected benefit - unlike the Kong Swivel - is it also self rights the anchor! Every set up world differently!

Ast to snubbers being a recent thing for cruising boats... I think in the past - like 60's and 70's and before people would have used a bit of chain and then mainly a rope rode which would have acted the same as a snubber.

I know my early boats before going off cruising all had say 10 mts of chain and the rest was rope rode.
Now I keep rope out of the locker, carrying the amount of chain we do , it would only just sit there getting wet and rotting ,

 

[Neeves]

Yes the Mantus swivel is amazing. So the windlass loves it - chain twist is a problem long gone and an unexpected benefit - unlike the Kong Swivel - is it also self rights the anchor! Every set up world differently!

Ast to snubbers being a recent thing for cruising boats... I think in the past - like 60's and 70's and before people would have used a bit of chain and then mainly a rope rode which would have acted the same as a snubber.

The Mantus swivel is a marvel of design - but it is so larger it detracts from the performance of the anchor.

I think you are correct - the 'cheap', reliable electric windlass has allowed the use of the all chain rode and the mixed rode has slipped, almost, into history. At the time no-one remarked on the snubbing ability of the mixed rode. Our 30m snubbers/bridle plus chain is effectively 'forward to history' - its a mixed rode in a different format. There are very few revolutionary ideas - we are just re-hashing what was second nature 50 years ago.

Jonathan

 

[Neeves]

Jonathan our first port of call after the strom was Trapani, sicily
Needed urgently to get my eye seen too.
quite a lot of marinas around there and not short of yachts and power boats .
I when into 7 chandler to buy a new hook to replace the one we lost ,
The make of type didn't matter at that point, it could be replace when we had more time for a better , not one had a hook and all said they don't keep them .
Some was puzzled what they where used for .

Vic, your eye is more important than anything, break that habit of a lifetime - take a marina berth for a few days where there is reliable medical support - don't take any chances. Vic - I mentioned contacting a specific anchor maker - he might have a spare hook that he can get to a mutually convenient location - give it a try.

Short term use a soft shackle - you will find a hook (you might even like the soft shackle).

The absence of hooks underlines what I observe - snubbers are not highly accepted.

Jonathan

 

[Star-Lord]

The Mantus swivel is a marvel of design - but it is so larger it detracts from the performance of the anchor.

I think you are correct - the 'cheap', reliable electric windlass has allowed the use of the all chain rode and the mixed rode has slipped, almost, into history. At the time no-one remarked on the snubbing ability of the mixed rode. Our 30m snubbers/bridle plus chain is effectively 'forward to history' - its a mixed rode in a different format. There are very few revolutionary ideas - we are just re-hashing what was second nature 50 years ago.

Jonathan

We have discussed the weight issue of the Mantus Swivel before. I disagree. It has been tested in well over 50 knots. Maybe it suits my anchor because it has a hollow shank with a lump of lead in the tip. A 30kg Spade may be the ideal anchor for the Mantus Swivel.

 

[Star-Lord]

 

[Neeves]

We have discussed the weight issue of the Mantus Swivel before. I disagree. It has been tested in well over 50 knots. Maybe it suits my anchor because it has a hollow shank with a lump of lead in the tip. A 30kg Spade may be the ideal anchor for the Mantus Swivel.

No - you are lucky that you are using one of the best anchors on the market, though a bit dated now. Your anchor would work better without the mass of the swivel - it has nothing to do with weight, but physical size. Your anchor was not designed to carry a big lump at the shackle point.

You will have noticed that your anchor shank is profiled to allow it to cut into the seabed. I wonder why it was designed to cut more effectively? Your anchor shank also narrows toward the shackle point - again - I wonder why? You might also recall that Peter Smith used, and spruiked, his anchor shank - it was thin because he used a HT steel, Bis80 (this came back to bite them later). I wonder why he wanted a thin shank? You will notice the original Bruce had a chamfered and thin shank, as does the Fortress to allow the shank to cut into the seabed and the Excel, Supreme and Vulcan also have thin shanks. Peter Smith has also profiled the thin shank of the Vulcan - I wonder why all of these anchors are designed with such thin shanks.....?? and some are profiled.

If you look at oil rig fabricated anchors they have twin, thin shanks that are braced - I wonder why they are so thin.

Jonathan

 

[Star-Lord]

No - you are lucky that you are using one of the best anchors on the market, though a bit dated now. Your anchor would work better without the mass of the swivel - it has nothing to do with weight, but physical size. Your anchor was not designed to carry a big lump at the shackle point.

You will have noticed that your anchor shank is profiled to allow it to cut into the seabed. I wonder why it was designed to cut more effectively? Your anchor shank also narrows toward the shackle point - again - I wonder why? You might also recall that Peter Smith used, and spruiked, his anchor shank - it was thin because he used a HT steel, Bis80 (this came back to bite them later). I wonder why he wanted a thin shank? You will notice the original Bruce had a chamfered and thin shank, as does the Fortress to allow the shank to cut into the seabed and the Excel, Supreme and Vulcan also have thin shanks. Peter Smith has also profiled the thin shank of the Vulcan - I wonder why all of these anchors are designed with such thin shanks.....?? and some are profiled.

If you look at oil rig fabricated anchors they have twin, thin shanks that are braced - I wonder why they are so thin.

Jonathan

We have discussed this already. You have a poor memory. Like it or not, I have real world proof that this set up works in sand and mud and weeds and less than ideal sand/rock. Sometimes you just have to admit that you do not know it all.

 

[Neeves]

We have discussed this already. You have a poor memory. Like it or not, I have real world proof that this set up works in sand and mud and weeds and less than ideal sand/rock. Sometimes you just have to admit that you do not know it all.

I freely acknowledge my knowledge is limited and I am often wrong.

I am quite happy to repeat a message, I don't forget. Its like snubbers - repetition makes their use more common. The danger of course is when the wrong message is repeated - but the forum seems fairly robust and trolls and spruikers are soon shot down.

Sadly the US Navy, the oil rig industry, research at the prime Universities researching anchor performance all say the same thing.

The size of the rode, its physical volume (or the area presented to the seabed) impact anchor performance - negatively.

This conclusion has been adopted by the makers of our anchors by, without exception, minimising shank thickness (resulting in the need to use expensive high tensile steels). This commonality is not copying but is based on hard science (for which we pay - the anchors are more expensive to make, the steel costs more, the welding needs much more care).

My comments are simply a reiteration of many research projects and real life experience from a number of independent sources.

There is simply too much, independent and identical conclusions to try to argue against it - don't shoot the messenger - do the research.

The fact your experience of real world proof demonstrates that you have a very effective anchor - it does not negate the wealth of data contradicting your position. Basically your anchor is sufficiently effective that it can carry the detrimental impact of the large swivel - that may not be the case for those who are not using an anchor as good as yours.

The danger is that someone considers that a man who chooses a Spade anchor and Cromox chain knows what he is talking about and has put his money behind his conclusions. Extrapolating - they then think that the Mantus Swivel is the best thing since sliced bread - unappreciative that it might be a marvel of engineering and an innovative design and can be carried by the Spade anchor (due to its superior design) and then match the swivel with a lower performing anchor.

I am quite happy to make my comments when the opportunity arrises such that owners may see another side to a story and I might even lead a believer to allow me to repeat my message. Devious - no doubt - effective, no idea.

Mantus anchor shank bent, the anchor performs poorly, their oringal chain hook I found defective and poorly tested, it was oringally then withdrawn for all sizes except 6mm/1/4" but has now been withdrawn completely (no reasons given). I believe the swivel to be oversized.

An Inquiry into Anchor Angles - Practical Sailor

I don't know of any other marine supplier with the number of questionable products.

And, No - I am no longer offered Mantus products to test

I am unaware of any other marine supplier with a catalogue of errors.

Take care, stay safe

Jonathan

 

[sailaboutvic]

Vic, your eye is more important than anything, break that habit of a lifetime - take a marina berth for a few days where there is reliable medical support - don't take any chances. Vic - I mentioned contacting a specific anchor maker - he might have a spare hook that he can get to a mutually convenient location - give it a try.

Short term use a soft shackle - you will find a hook (you might even like the soft shackle).

The absence of hooks underlines what I observe - snubbers are not highly accepted.

Jonathan

Its hard to brake life time habit ?
We manage to order a two new hooks should arrive after the Bank Holiday weekend here in Malta .
Star Lord.... we all swear by our equipment until they let us down.
my snubbers have seen us throught more stronger blows the the other week but now they have let me down I'm looking to replace them with something better ,
Admitlly if I didn't keep using then for as long as I did , they may not at snap
So I can only blame myself.

 

[Neeves]

Vic,

When you get your new hooks can you post a pic, - I'm interested in what is available.

I have posted this before, I think, or one similar.

Most hooks from the lifting industry come painted, or powder coated. I strip the paint with paint stripper and have them galvanised, the dark gray ones are galvanised.

The stainless hook is a typical Oz chandler sourced hook, I would not use them, note that the 'inside' of the jaw of the hook has a sharp edge, 2 actually one on each side - but that specific hook is there to illustrate the gate I make. I don't like the claw either prone to falling off and if a product of the lifting industry they are so well made they are difficult to disengage - unless you line the claw up perfectly - so difficult if you are in a hurry. They are commonly used in the transport industry for load restraint and come in a G70 spec. The 3 left hand hooks comes as G80 or G100 specs and are all specified as not impacting chain strength. The G80 hooks can be really cheap - the G100 hooks a bit more expensive, but not wallet threatening

The three left hand hooks are from the lifting industry, the far left is 'state of the art'. The far left hook - the tension is imposed on the link in the jaw resting on that 'sloping' surface (at the bottom) and by the crown of the next link that sits in two little recesses about half way down the jaw. The pin is a waste of time - bends easily - I replace with a bicycle spoke (hard drawn steel), I fill the hole with Sika, insert the piece of spoke and then rotate the pin as the Sika sets off. The Sika stops the pin falling out - but you need to be careful when you retrieve.

The stainless hook and the middle hook have an added gate. The stainless hook has a stainless gate retained by the clevis pin the galvanised hook I tapped before galvanising and then secured a thin piece of fibre glass as the gate and secured the gate with a pan head bolt. The hooks with gate can be operated one handed using the thumb to swing the gate. You might need to buy a slightly longer clevis pin to accomodate the extra thickness demanded for the stainless gate. The dimensions are simply those to allow the gate to swing but not too easily.

I have not found a way to make a gate for am eye hook (the eye is for a splice on the end of your snubber) - sewing is one way to make the eye.




Testing the Effects of Chain Hooks - Practical Sailor

Snubber Chain Hooks Revisited - Practical Sailor

This, below, better illustrates lifting hook in use.

These are 2 of the same hooks as above, stripped of paint

The left hand hook - the chain link in the jaw is sitting on that flat 'saddle' so the long of the link takes the tension, no point load. The crown of the next link, the yellow link facing is retained in a part of the casting sized to match the crown of the link - so the 2 links take the tension. The right hand hook - the link facing us is retained in 2 little dimples sized for the crown and the next link, our of focus and behind would, under tension, sit on the recessed slope (on the back side of the hook). In both cases the tension is split between 2 links.

These hooks, and all lifting components, are designed to be only used by the size of chain designated - in this case the clevis pin the slot within which the chain would be secured only accepts 6mm to a specific specification EN 818. The chain in the jaw is also 6mm and the slot is too narrow for 8mm chain and the thickness of the hook is too large for a smaller chain.

None of this is rocket science - why chandler hooks are not made to the same design is a mystery - but the lifting industry would laugh, or cry in horror, at our hooks.



Vic - I would have sent you a hook - but we use 6mm chain and I test 6mm components (I buy them and 6mm is the cheapest and the tensions needed for testing are lower)

Take care, stay safe

Jonathan

 

[JFowler]

Jonathan,

I’ve been following this thread with great interest!
The present set up on our 40’ BAV is a 12mm multiplait nylon bridle attached to the bow cleats with a st st chain hook as the photo. The blue rope is a retired bridle. The Chain Hooks are widely, cheaply available in UK. One is marked 2000lb WWL & the other 1200kg.
Following this thread I’ve ordered 10mm multiplait long enough to form a bridle to our midship cleats, which are 2/3 back to the stern. I’m going to attach 2 separate lengths to the chain hook using soft shackles.
The chain hooks look robust enough & in 12 years cruising the last 8 years in Greece have never been a problem- have I just been lucky?

 

[sailaboutvic]

Jonathan,

I’ve been following this thread with great interest!
The present set up on our 40’ BAV is a 12mm multiplait nylon bridle attached to the bow cleats with a st st chain hook as the photo. The blue rope is a retired bridle. The Chain Hooks are widely, cheaply available in UK. One is marked 2000lb WWL & the other 1200kg.
Following this thread I’ve ordered 10mm multiplait long enough to form a bridle to our midship cleats, which are 2/3 back to the stern. I’m going to attach 2 separate lengths to the chain hook using soft shackles.
The chain hooks look robust enough & in 12 years cruising the last 8 years in Greece have never been a problem- have I just been lucky?

J , I am so glad that that my posting at last have made someone take a good look at his snubber ,
It was the whole point of posting my accident,
Since this happen I been looking more carefully what other people are using and have to say I'm shocked , the bits of string some have and seen to get away with it , more then then half only got a short strop,
when there me putting all the knowledge I have over 40 years and getting caught out .
But I guess the different between sailor as my self who cruise and anchor in all weather and others who as soon as 20 kts are forecaster run for the first marina ,
which in my view isn't a bad idea , at less chance them dragging on to the rest of us .

The hook you have on the right is one we use to us and it self us well for many years until I retired it , its now in use again until the new hooks arrive,
We had a bungy that went around ths chain then hooked onto he hook to stop it falling off,
The only comment I would make with the snubbers in the photo is if they broke away from the eye of the hook you lose both rope , I alway perfir to have mine independ of each other on the hook so if one brake there still the other one , although a lot of good I did me , as there both end up breaking in the end.
As Jonathan says take them back as far as you can