NormanS
Well-Known Member
Interesting. Do you know of many anchor chains breaking?
If you like to know the anchor load and minimal chain length... here is the tool to do it...
- Thread starter MathiasW
- Start date
thinwater
Well-Known Member
I bet you are right. the BF scale is universal, but we would abbreviate it BFS on this side of the pond.
Mathias: If that is the case, it is not a useful description of snubber stretch IMO. It's not something the sailor can determine ahead of time. Many will never have anchored exposed to F8; in fact, they are smart to have avoided that, and they won't be on the bow with a ruler when it is blowing! I think you need to ask breaking strength, stretch at 8% BS, and length. In that way, you have both the spring rate and the range of stretch. Otherwise, for them to estimate the stretch at F8 is a trial and error solution using your software. I think we need to ask them to really describe the snubber, not say "good," which will mean something very different to different users (Some here think that means 8 feet of stout line, and some think it means 50 feet of perfectly sized climbing rope.) It is just as important a variable, in many situations, as chain size.
I do like the idea. Keep up the work!
Another reason for the AP is that while some folks have sailed the same general sort of displacement mono in the same waters for 40 years, others alternately sail boats from 1-20 tons, in waters from 2-10 meters, with all sorts of bottoms and all sorts of weather patterns. It's easy to believe what we know personally is the full universe. This variability starts a lot of arguments on forums, but it is also their value.
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Neeves
Well-Known Member
Different conditions in different locations.
On the New South Wakes coast, but consider from Brisbane south to the bottom SE corner of Australia (which thus includes part of Victoria and Queensland), we have some very large bays that are open to the Tasman Sea. The seas to the south enjoy swells, not unusually of 11m that then extend, of diminishing height, all the way up the coast. We can have swells off Sydney of 11m such that very large commercial vessels are not allowed to enter Sydney Harbour and are forced to steam up and down the coast till the seas abate - great fun if its a cruise ship
. Though many of the large bays are protected from the southerly winds the swells creep round and into the bays - with surf on the beaches. The swells can be sufficient when anchored in 5m of depth for the hull of an adjacent yacht to disappear in the trough. These bays make good anchorages from the Southerly winds but this same winds generate chop - one is then fighting to compromise the swells that are now approaching from the north (having crept round the headland) and the chop and wind from the south. Too close to the shore and the swells start to build up, too far from the shore and the chop and wind are more of an issue. The latter, the wind, can be a real problem as it might average a southerly direction it gusts maybe 30 degrees either side of Southerly.
But with a big swell the depth is going to vary considerably and the rode is going to be constantly moving, up and down from the swell, and up and down (to a different frequency) from the chop. Fortunately tides are only around 2m.
We find the best practice is to deploy 2 anchors roughly facing the extremes of the wind veer.
The benefit of the big swells is that surfers love them - which is why surfing is common all the way up the coast - 12 months of the year.
We do have navigable rives along the coast - but they are protected by bars which are easy to cross in calm weather but decidedly dangerous in big swells.
No one with any intelligence will sail south in big swells (and accompanying seas) with a head wind of 35 knots (despite the lift of 4 knots from the southerly running East Australian Current) - and these large open bays make for the only shelter.
On chain breaking - historically there were reports of chains breaking - over the last 10 or 15 years reports have all but disappeared. Snubbers fail, but not chain.
Most yachts have historically been equiped with a G30 chain which for 8mm chain, would have a MBS, minimum
) of 3t but commonly and UTS (Ultimate Tensile strength ) of near 4t. There has been, is a, migration to use of a G40 chain - but it seems unnecessary (though if it allows you to sleep better - spend the money). The WLL, Working Load Limit of 8mm G30 would be 750kg - and it is unlikely that a yacht using the correctly sized chain of 8mm will ever suffer a 750kg tension (for G40 think 1,000kg). The chain will have been Proof Tested to 2 x WLL, so 1,500kg. However the snubber which will have been sized for its elasticity and will have a lower MBS and UTS than the chain and 'ages' based on the number of stretch cycles it endures - will fail, unless replaced to a schedule (we have had 2 snubbers fail).
For a mixed rode the rope portion is chosen to match, or be better then, the strength of the chain. Being bigger the textile portion will last than a snubber - but would also potentially be the weak link (and not offer the elasticity of a snubber - but still some elasticity). If a snubber fails the chain is the ultimate fall back and a separate short strop protecting the windlass is strongly recommended (and the spare snubber).
The failure point on the rode is likely to be the snubber (we carry spares), shackle or swivel - rather than the chain. Both the shackle and swivel might fail through incorrect choice - there are still many questionable swivels and shackles in use and owner inattention plays a large role. Personally I know of one chain failure (French chain) in the last 20 years but I am aware of a number of swivel and shackle failures. People still use 'unrated' shackles sourced from a hardware store, often of a size smaller than the chain. Interestingly the people who use inadequate shackles and unnecessary swivels are the same people who use inadequate, and commonly, no snubbers (at all) - and are obviously not readers of the YBW Forum.
Jonathan
On the New South Wakes coast, but consider from Brisbane south to the bottom SE corner of Australia (which thus includes part of Victoria and Queensland), we have some very large bays that are open to the Tasman Sea. The seas to the south enjoy swells, not unusually of 11m that then extend, of diminishing height, all the way up the coast. We can have swells off Sydney of 11m such that very large commercial vessels are not allowed to enter Sydney Harbour and are forced to steam up and down the coast till the seas abate - great fun if its a cruise ship
. Though many of the large bays are protected from the southerly winds the swells creep round and into the bays - with surf on the beaches. The swells can be sufficient when anchored in 5m of depth for the hull of an adjacent yacht to disappear in the trough. These bays make good anchorages from the Southerly winds but this same winds generate chop - one is then fighting to compromise the swells that are now approaching from the north (having crept round the headland) and the chop and wind from the south. Too close to the shore and the swells start to build up, too far from the shore and the chop and wind are more of an issue. The latter, the wind, can be a real problem as it might average a southerly direction it gusts maybe 30 degrees either side of Southerly. But with a big swell the depth is going to vary considerably and the rode is going to be constantly moving, up and down from the swell, and up and down (to a different frequency) from the chop. Fortunately tides are only around 2m.
We find the best practice is to deploy 2 anchors roughly facing the extremes of the wind veer.
The benefit of the big swells is that surfers love them - which is why surfing is common all the way up the coast - 12 months of the year.
We do have navigable rives along the coast - but they are protected by bars which are easy to cross in calm weather but decidedly dangerous in big swells.
No one with any intelligence will sail south in big swells (and accompanying seas) with a head wind of 35 knots (despite the lift of 4 knots from the southerly running East Australian Current) - and these large open bays make for the only shelter.
On chain breaking - historically there were reports of chains breaking - over the last 10 or 15 years reports have all but disappeared. Snubbers fail, but not chain.
Most yachts have historically been equiped with a G30 chain which for 8mm chain, would have a MBS, minimum
) of 3t but commonly and UTS (Ultimate Tensile strength ) of near 4t. There has been, is a, migration to use of a G40 chain - but it seems unnecessary (though if it allows you to sleep better - spend the money). The WLL, Working Load Limit of 8mm G30 would be 750kg - and it is unlikely that a yacht using the correctly sized chain of 8mm will ever suffer a 750kg tension (for G40 think 1,000kg). The chain will have been Proof Tested to 2 x WLL, so 1,500kg. However the snubber which will have been sized for its elasticity and will have a lower MBS and UTS than the chain and 'ages' based on the number of stretch cycles it endures - will fail, unless replaced to a schedule (we have had 2 snubbers fail).For a mixed rode the rope portion is chosen to match, or be better then, the strength of the chain. Being bigger the textile portion will last than a snubber - but would also potentially be the weak link (and not offer the elasticity of a snubber - but still some elasticity). If a snubber fails the chain is the ultimate fall back and a separate short strop protecting the windlass is strongly recommended (and the spare snubber).
The failure point on the rode is likely to be the snubber (we carry spares), shackle or swivel - rather than the chain. Both the shackle and swivel might fail through incorrect choice - there are still many questionable swivels and shackles in use and owner inattention plays a large role. Personally I know of one chain failure (French chain) in the last 20 years but I am aware of a number of swivel and shackle failures. People still use 'unrated' shackles sourced from a hardware store, often of a size smaller than the chain. Interestingly the people who use inadequate shackles and unnecessary swivels are the same people who use inadequate, and commonly, no snubbers (at all) - and are obviously not readers of the YBW Forum.
Jonathan
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MathiasW
Well-Known Member
No, I do not know of any chain personally that has broken, but the load peaks can do all kind of other damages on the foredeck...
thinwater
Well-Known Member
In the US grade 43 is the same price as grade 30, and most windlasses come with e G43 wheel. So really, a simple choice.
MathiasW
Well-Known Member
Thinwater, thank you for this feedback. And yes, you may well be right that this is not the best possible description of snubber stretch. I have been thinking really a lot about this, tossing ideas back and fourth, and eventually I arrived at this compromise. Here are some of my thoughts in the process:
- I might be wrong, but I think most people will not know the breaking load of their snubber, nor by how much it would stretch at a given load, as the starting position for most is just some rope of unknown quality they happen to have, which acts as a snubber. (I started that way, the shipyard had supplied the rope...) So, if the tool requires to enter these values, they will give up. Of course, there are experts around like you or Jonathan, which do know these values, but they are a tiny minority.
- The value by how much a snubber stretches at 8 BFT / BFS (40.2 kn) is relatively easy to measure / extrapolate to, using a yard stick. Or rather a metre stick I should say.
And true, you would not want to measure at 8 BFT, really. If you assume the snubber to be linear in its characteristics (which it isn't, but the free tool assumes this, anyway), you can measure at, say, half the wind speed, so 20.1 kn, and then multiply the result by 4, as the wind force goes up by a factor of 4 when you double the wind speed. Or you measure by a third of 8 BFT, and then multiply by 9. Tips for doing this are described in the manual. It may be as 'simple' as spanning the snubber along the entire deck, at one end fixed, and then measure at the other end with a luggage scale or crane scale that gets pulled by a winch. The tool will tell you how much load there is for your vessel at a given wind strength - you just punch in 0 for anchor depth and no swell. All you need to do now is to turn the winch handle until your scale shows the required load value and then measure the resulting stretch on your deck. That is the snubber calibration. This can and should be done in the harbour. And yes, this is still rather complicated, but many just do not have the manufacturer's data sheet for their snubber / bridle. I do not have it, for instance. But I can measure wind speed and lengths quite easily on my boat, and I do have a crane scale to measure loads. So, this is all possible in Expert Mode. And it needs to be done only once... - In Basic Mode I settled for qualitative descriptors for the snubber like GOOD, or LOUSY, as again my assumption is that most people do not know their snubber very well and would find it difficult to put in real data sheet numbers. So, this way, they can get at least started. They may indeed initially be using a wrong qualifier, believing their snubber to be GOOD, when in fact it is not. They might catch this discrepancy when they get startled about this very long snubber stretch the tool predicts for their snubber, when they have never seen it for real with their snubber. Like one person in this thread did. Then they need to conclude that perhaps their snubber is not GOOD according to the tool, and perhaps they need to use the qualifier POOR instead as it gives a better agreement to what they are seeing. Now, there are admittedly a lot of 'ifs' in this line of reasoning, but if all goes along these lines, then the advantage is that the tool tells the user straight into the face that his/her snubber is not GOOD, but POOR, and that feedback might trigger some action to get a better snubber. So, in some sense, this approach is an educational one, really.
- The other advantage of describing the snubber by its stretch at 8 BFT is that this is the only parameter that is really needed. I do not need to know its length, nor its stretch per meter at this and this force. It also has the charm that it automatically includes the vessel characteristics, as a vessel with more windage area will pull harder at the same wind speed. So, a snubber that gets stretched at 8 BFT by 1.6 metres, and which my tool thus would qualify as EXCELLENT, may for a much smaller vessel only lead to a stretch of 0.4 metres, which my tool would qualify as GOOD only. So, we know that a snubber needs to fit to the vessel in its characteristics, and this is automatically taken care of by using this qualitative descriptive approach.
- If you do happen to have the data sheet for your snubber, then entering it into the tool is admittedly a little difficult at the moment. It can be done and I am working on a Tip in the description how to do this. Essentially, if you assume a linear snubber, it all boils down to scaling law again. I might at some point add another point in the pull down menu for snubber quality to enter these values directly, but it is going to be a bit messy internally in the tool and I want to keep the interface as simple as possible. So, I need to prepare this step very well.
I think these were my main reasonings why I chose the snubber description as I did. I am more than happy to hear other proposals, or what others find easier to do. It has to be as easy as possible in Basic Mode. In fact, somebody somewhere else said the other day, it is a great tool, but he wants to see a level easier than the Basic Mode. That is a challenge.
Cheers, Mathias
thinwater
Well-Known Member
The breaking strength of the snubber is... obvious. They bought it or can look it up. If their interest is so superficial they do not know the BS of the snubber and chain, I seriously doubt they would use or understand the AP.Thinwater, thank you for this feedback. And yes, you may well be right that this is not the best possible description of snubber stretch. I have been thinking really a lot about this, tossing ideas back and fourth, and eventually I arrived at this compromise. Here are some of my thoughts in the process:
- I might be wrong, but I think most people will not know the breaking load of their snubber, nor by how much it would stretch at a given load, as the starting position for most is just some rope of unknown quality they happen to have, which acts as a snubber. (I started that way, the shipyard had supplied the rope...) So, if the tool requires to enter these values, they will give up. Of course, there are experts around like you or Jonathan, which do know these values, but they are a tiny minority.
- The value by how much a snubber stretches at 8 BFT / BFS (40.2 kn) is relatively easy to measure / extrapolate to, using a yard stick. Or rather a metre stick I should say.
- In Basic Mode I settled for qualitative descriptors for the snubber like GOOD, or LOUSY, as again my assumption is that most people do not know their snubber very well and would find it difficult to put in real data sheet numbers. So, this way, they can get at least started. They may indeed initially be using a wrong qualifier, believing their snubber to be GOOD, when in fact it is not. They might catch this discrepancy when they get startled about this very long snubber stretch the tool predicts for their snubber, when they have never seen it for real with their snubber. Like one person in this thread did. Then they need to conclude that perhaps their snubber is not GOOD according to the tool, and perhaps they need to use the qualifier POOR instead as it gives a better agreement to what they are seeing. Now, there are admittedly a lot of 'ifs' in this line of reasoning, but if all goes along these lines, then the advantage is that the tool tells the user straight into the face that his/her snubber is not GOOD, but POOR, and that feedback might trigger some action to get a better snubber. So, in some sense, this approach is an educational one, really.
- The other advantage of describing the snubber by its stretch at 8 BFT is that this is the only parameter that is really needed. I do not need to know its length, nor its stretch per meter at this and this force. It also has the charm that it automatically includes the vessel characteristics, as a vessel with more windage area will pull harder at the same wind speed. So, a snubber that gets stretched at 8 BFT by 1.6 metres, and which my tool thus would qualify as EXCELLENT, may for a much smaller vessel only lead to a stretch of 0.4 metres, which my tool would qualify as GOOD only. So, we know that a snubber needs to fit to the vessel in its characteristics, and this is automatically taken care of by using this qualitative descriptive approach.
- If you do happen to have the data sheet for your snubber, then entering it into the tool is admittedly a little difficult at the moment. It can be done and I am working on a Tip in the description how to do this. Essentially, if you assume a linear snubber, it all boils down to scaling law again. I might at some point add another point in the pull down menu for snubber quality to enter these values directly, but it is going to be a bit messy internally in the tool and I want to keep the interface as simple as possible. So, I need to prepare this step very well.
I think these were my main reasonings why I chose the snubber description as I did. I am more than happy to hear other proposals, or what others find easier to do. It has to be as easy as possible in Basic Mode. In fact, somebody somewhere else said the other day, it is a great tool, but he wants to see a level easier than the Basic Mode. That is a challenge.
Cheers, Mathias
Not one person in 10 on this forum would follow your "measure stretch" reasoning. It was sound, but I can find the stretch of any line on-line in 30 seconds, so why would I bother? And they don't know the load in ANY wind, except by trial and error, because they don't have a load cell. If they did... they wouldn't really need the ap.
Stretch at 15% BS is a common spec, available for any rope bought in the US. Use that. For example from the west marine catalog, NER nylon DB:
- Breaking Strength: 8000 Pounds
- Color: White/Gold
- Boat Length: 32 to 37 Feet
- Core Fiber: Nylon
- Cover Fiber: Nylon
- Diameter: 1/2 Inch
- Quality: Premium
- Stretch: 6.5% Stretch at 15% of Breaking Strength
- Type: Double Braid
Easy. Took me less than 30 seconds to find it.
Wing Mark
Well-Known Member
The nylon rode didn't save them.
They were not in any danger, they just chose to anchor waiting for the tide.
MathiasW
Well-Known Member
ok, fair enough, I get your point. It seems the US is ahead of Germany at least. In Germany some ropes offered in shops have a BS specification, but only very few have a stretch specification, if at all. Just checked with two of the leading online shops in Germany, and they do not specify it at all. Couldn't find any rope with a stretch information in those two shops actually, and they a very big shops as far as Germany goes...
This does not mean it is absolutely not available, but it is certainly not at the tip of one's finger tips in Germany. When searching on the Liros page, for instance, one finds some information for a 30% load, in the form of an inequality, but that may be good enough. For Gleistein I found a diagram one can work out the stretch spec from for some of their ropes, but again not entirely straightforward and I do not know how complete this diagram is.So, it would at least seem it is not standardised how to specify the stretch characteristics of a rope across the world...
Still, I will give this some thoughts. Thanks for this input. Perhaps I can find a way to allow alternative means to specify the rope...
Cheers, Mathias
MathiasW
Well-Known Member
ok, fair enough, I get your point. It seems the US is ahead of Germany at least. In Germany some ropes offered in shops have a BS specification, but only very few have a stretch specification, if at all. Just checked with two of the leading online shops in Germany, and they do not specify it at all. Couldn't find any rope with a stretch information in those two shops actually, and they a very big shops as far as Germany goes...
So, it would at least seem it is not standardised how to specify the stretch characteristics of a rope across the world...
Still, I will give this some thoughts. Thanks for this input. Perhaps I can find a way to allow alternative means to specify the rope...
Cheers, Mathias
So, couldn't sleep...
The conversion between these different specs should be straightforward:
Let Stretch_@_X%_BL be the stretch at X % of the breaking load (which you calculate as length of snubber times the stretch at X % BL per running metre, or foot, whatever your unit of choice is, as provided in the data sheet)
Let X%_BL be X % of the breaking load
And let LD_@_8_BFT be the anchor load of your vessel at 8 BFT - which the app will calculate for you when you have specified your vessel characteristics (so either windage area or vessel length and vessel type) and then punch in 40.2 kn for 8 BFT, 0 metres anchor depth, and 0 kn vessel velocity @ anchor.
Then, assuming a linear snubber, the snubber stretch @ 8 BFT is given by Stretch_@_X%_BL * LD_@_8_BFT / X%_BL
I do not know how this scaling approach is called in English. In German it is called Milchmädchendreisatz... (the story being the milk girl bringing the milk to the market would get, say, two pennies for a pint of milk, four pennies for two pints, and six pennies for three pints...) Actually, make that beer...
So, it requires to do a few arithmetic steps, but then one has the data needed for the app. It would be a quick fix, but it works now. And it works for 15%, 30%, whatever manufacturers choose to specify their ropes with.
Cheers, Mathias
NormanS
Well-Known Member
Mathias, In #106 you claim that F8 is 42.2 knots. It isn't, and in my mind, casts doubt on all your other figures. ?
thinwater
Well-Known Member
So, couldn't sleep...
The conversion between these different specs should be straightforward:
Let Stretch_@_X%_BL be the stretch at X % of the breaking load (which you calculate as length of snubber times the stretch at X % BL per running metre, or foot, whatever your unit of choice is, as provided in the data sheet)
Let X%_BL be X % of the breaking load
And let LD_@_8_BFT be the anchor load of your vessel at 8 BFT - which the app will calculate for you when you have specified your vessel characteristics (so either windage area or vessel length and vessel type) and then punch in 40.2 kn for 8 BFT, 0 metres anchor depth, and 0 kn vessel velocity @ anchor.
Then, assuming a linear snubber, the snubber stretch @ 8 BFT is given by Stretch_@_X%_BL * LD_@_8_BFT / X%_BL
I do not know how this scaling approach is called in English. In German it is called Milchmädchendreisatz... (the story being the milk girl bringing the milk to the market would get, say, two pennies for a pint of milk, four pennies for two pints, and six pennies for three pints...) Actually, make that beer...
So, it requires to do a few arithmetic steps, but then one has the data needed for the app. It would be a quick fix, but it works now. And it works for 15%, 30%, whatever manufacturers choose to specify their ropes with.
Cheers, Mathias
The stretch is not linear with stress and it depends on the weave, but a first approximation is good enough. In fact, it is probably sufficient to specify rope diameter and material (nylon I would think). Approximate stretch and strength can be derived from that. I would go farther and round down a little (say, 6% stretch at 15% BS for all nylon) because stretch diminishes slightly with aging. 3-strand and climbing ropes are better, but his will give a conservative result for the basic version. The expert version could give more options.
ean_p
Well-Known Member
I think he lists it as 40.2 knots which is the upper value of the F8 wind speed range. The mean being 37knots. Would suggest that for a calc then better to use the upper value than the mean as it errs on the safe side.
MathiasW
Well-Known Member
I said 40.2 kn, and this is the top end of 8 BFT. The disadvantage of the BFT scale is that is is a range and not a precise wind speed. So I settled for the top of the range.
Have a look here:
Beaufort scale - Wikipedia
I took the m/s value and converted that, if I remember correctly...
MathiasW
Well-Known Member
exactly!
MathiasW
Well-Known Member
ok, thanks, that's a possible approach. One would need the snubber length as well, so three parameters would have to be provided.
thinwater
Well-Known Member
Really? Really?
Neeves
Well-Known Member
Forecast in Australia have dispensed, as far as I know, completely, with the Beaufort scale. Though confusingly we still use the words Gale and Storm technically and they have the same meaning (in terms of windspeed) as the Beaufort scale. But mention Beaufort Force 8 here and people will look blank. . In our forecasts the winds are in either Km/hr or Knots, depending on whether it is a terrestrial forecast or a marine forecast. When we listen to a terrestrial forecast I automatically convert, crudely, from km/hr to knots using a simply 2 conversion. An error of 2 knots is simply irrelevant and when deploying chain (and sizing a snubber).
Our marine forecast provide an average wind, of say 25-30 knots with the caveat
Wind and wave forecasts are averages, wind gusts can be 40% stronger and wave heights can be twice the average.
IN addition to the caveat the 'data' is a forecast - its not a certainty and conditions (the average) can be higher or lower than the forecast.
To quibble over a variant that you cannot actually measure, how many actually measure wind speed with sufficient accuracy to provide an accurate assessment of 'average' . When we anchor we are not interested in the average - we prepare for the gusts.
I actually disagree with Thins idea that people are not going to measure the stretch of thieir snubber when the conditions are taxing. Some members have commented on this thread that their elasticity accords with Mathias data - which suggest they do check. We have marks on our deck and the snubber and I do check, I walk to the bow, to ensure nothing has been forgotten and that the snubber is performing as it has done in the past. I check the lazy loop of chain as the wind increases to ensure it is sufficient and increase if the snubber is stretching more than I had anticipated. I find it difficult to conceive that an owner who has thought through and installed a long snubber will not be interested in how it performs and simply check for abrasion etc. Consequently I am sure those who believe in 'THIS is a SNUBBER' - as in Crocodile Dundee - thanks for the analogy, will know how much their snubber stretches and will roughly correlate that data with their idea of the average wind at the time and their scope. The data they derive will be crude, say 1m stretch for a 15m snubber - ignoring the idea it might actually be 1,137mm not 1,000mm.
A snubber needs to be designed for near the upper limits of expected everyday conditions and will be used for much more mild conditions. Having a storm snubber would show caution and is very easy to apply - if you plan ahead.
Snubbers are not a precision science - there are simply too many variables, the wind being the obvious one but also the swell, chop, change of scope ratio with tide etc - ball park figures are fine. The ideal diameter might be 9mm - you will find it very difficult to buy a 9mm rope.
- it will be either 8mm or 10mm - and I would tend to suggest using 8mm, as it has more elasticity - but use a longer length.A useful experiment for the non-believers.
Next time you are anchored (aim for 5/6m depth and 5:1 scope) apply (by whatever means you can) by a Prussic knot a long, say deck length, snubber (say a 10mm nylon mooring line) - simply lay it down one side deck.
Now take the tension in the rode on the snubber.
Now lift the lazy loop of chain, say when its blowing 30 knots, and see if you can hold the tension in the chain rode with your hands (unless you are a gorilla - impossible). You might be able to hold the tension in the chain in the lulls but as soon as the chain straightens?? Now go to the transom end of this temporary snubber and see if you can take the tension in the rode (even an undernourished wimp like me can take the tension). You may need to vary the conditions - if you use 12mm chain.
- I'm quoting from when we used 8mm chain.Take care, stay safe
Jonathan
thinwater
Well-Known Member
I carry two bridles (PDQ). One is a slender 7.4mm ice climbing rope, each leg about 35 feet long. The impacts are non-existant, and I use this when I suspect the holding is questionable (very soft mud or weeds). The other is 1/2-inch (25mm) x 35 feet and is used most of the time (no wear) and for big winds with good holding. However, I will still use the 7.4mm bridle in strong winds if the holding is questionable, because, in fact, it is still within its WLL (just barely) at 60 knots and will reduce the load on the anchor.
Yes, it is surprising how you can move the ends of a thin snubber in 25 knots and more. It's also fun to watch it work where it goes over the bow, stretching and retracting.
Yes, it is surprising how you can move the ends of a thin snubber in 25 knots and more. It's also fun to watch it work where it goes over the bow, stretching and retracting.