Neeves
Well-known member
You are correct, slightly windy - and you obviously have the perfect rode. I am sure others will take note and copy your practices.
Take care, stay safe
Jonathan
An Anchor Thread! Grab your beers and popcorn.
- Thread starter KeelsonGraham
- Start date
Take care, stay safe
Jonathan
boomerangben
Well-known member
Haha thank you, yes 20m not mm. when you draw only a foot and actively seek out shallow water 25m of rode is plenty and yes it is oversized, simply because 6mm is smallest common chain and 8mm is more comfortable to handle than small dia ropes. But we have anchored comfortably in a couple of gales in the Hebrides. With the centre board and rudder up we do sheer about quite a bit but no uncomfortable snatch loads
But I enter my own example simply because we are all different. My real point is, if we know the maximum loads our rodes will experience, we can design our rodes to suit and control our own safety factors. If an elastic rode means you only ever see say 500kg and you are happy with a SF of 4 why make it any stronger than 6mm chain and 10mm rope? Two issues here of course, one: how many know what the loads they need to design for and two: deviating from the norm.
I am certainly coming at this from a theoretical standpoint point, but the whole point of snubbing is to reduce loads. If you can reduce loads consistently, you don’t need such a strong rode. A less strong rode means more snubbing effect and so on (although I doubt it would take long before optimisation). The issue is that some boats the dynamic loads due to shearing dominate, others current or wind will dominate (although theoretical windage drag is relatively small for a streamlined vessel).
NormanS
Well-known member
It's remarkable how on some of these "slightly windy" occasions, great clouds of spume are lifted off the surface of the sea, and go whirling past. Slightly windy - Ha!
boomerangben
Well-known member
If you are regularly in places like Loch Roag, doesn’t the Beaufort scale get recalibrated ie a Force 8 is a good drying breeze etc? ?.
I remember watching a 45’ yacht drag I think 2 or 3 anchors in Loch na Cuilce (Scavaig) and the Mallaig life boat saving the day, towing them to Soay. There were water spouts generated by the turbulence from the Cullins. I think the winds aloft (1000’)were about 50kts from the North so not enormous. In those conditions it might be easy to think it would be sheltered, but in fact probably worse than open water.
Supertramp
Well-known member
My memory of severe gales off the West of Scotland is as Norman S and Boomerang Ben. Ferocious gusts, mini whirlwinds and wind driven spray. Not in all places but definitely near the Cuillins, Sleat and the far NW. No option of moving, especially in a smaller boat. Total dependence on the anchor and no help anywhere near. I think Chile may be similar.....
We have drifted from the OP's question and their beer and peanuts are probably exhausted.
But it has produced a variety of options and opinions.
Jonathan - what is the best way to attach a storm bridle to my 10mm chain? My short bridle uses a good quality chain hook which works well.
We have drifted from the OP's question and their beer and peanuts are probably exhausted.
But it has produced a variety of options and opinions.
Jonathan - what is the best way to attach a storm bridle to my 10mm chain? My short bridle uses a good quality chain hook which works well.
geem
Well-known member
.
Sounds like a great opportunity for a snubber
Neeves
Well-known member
Go to you nearest supplier of lifting gear and buy one of their eye hooks, the eye takes a splice, and use that. Buy a 10mm G100, grossly overstrength but they are cheap, not worth trying to save pennies. Hooks are easy to attach. Don't use a 'claw' they are a bit fiddly to apply and downright difficult to release. The down side to lifting tackle is that it is painted, not gavalised. Buy 2 and when the first looks a bit rusty, retire (short term) and use the spare. Clean the old one, paint and it will become your spare.
You could buy a cast stainless hook from a chandler but they have a dubious origin and having bent our Witchard hook and seen others bend them (that article on the Med storm) I'd suggest the lifting industry will be more reliable.
But if you are using a hook already - you know the ins and outs.
Hooks come in 2 forms, eye hooks and clevis hooks. Clevis hooks take a chain, eye hooks take a splice. You could splice to a chain - but its simpler to splice to the eye.
These are clevis hooks, the one on the left is the style, excepting its not an eye hook (see below), that I suggest, the one on the right is a better, newer design, but they are more expensive and not necessary.
If you note the one on the left - the crown or the link, the curved part, sits in a 'female' recess, it cuddles the crown. The actual link in the jaw of the link sits on those protuberances - so both links take the tension. The one on the right does the same - but it a a bit more cuddly
I have my hooks galvanised and for a clevis hook I've devised a way to stop the chain falling out. I have not had chains falling out of hooks, but others do, keep the hook under tension, the lazy loop of chain is sufficient, and all will be well.
We use a chain hook as our chain lock, in case the bridle fails and we use it on passage, if the clutch slips the anchor will not self deploy. We are using a dyneema strop attached to a strong point. The numbers on the hook mean 6mm chain, G100 quality/strength.
We don't use a hook for our bridle but a bridle plate, this is the one made in Ukraine.
If you are now confused -keep asking the questions
Jonathan
Neeves
Well-known member
Neeves
Well-known member
I knew you have made a mistake, obviously -but I thought it gave opportunity for some humour (I have a twisted idea of humour). I have discovered that you can buy high tensile 4mm chain - but I'm not sure how it is used as there are no devices, shackles, hooks etc etc made to fit a reputably made 4mm chain (I'm puzzled). I don't recall who made it Rud or Pewag (I think) and I would have considered it, instead of our 6mm chain, if I had 'found it' and found how it could be used.
Ah! We draw a meter but don't anchor too close to shore as the waves tend to stand up as they approach shore. By the time you have taken into account tides - we usually anchor in 4-5m. Our 75m is thus more than adequate and we have never deployed it all
Most, or much, of our ground tackle (yours and ours) is designed round a safety factor of 4, shackles, chain. With caution it does not seem unreasonable to extend the same factor to cordage. Much of this is back of an envelope data but.
Nylon stretches 40% to failure. Based on a 4:1 safety factor and a 10m snubber then 1m of elasticity would be a good safe limit. More stretch would be better but then you need a longer snubber (and why ours can be 30m). If you buy a decent suitcase scale and attach to your snubber end (use a Prussic knot) you can make a stab at tension based on how the snubber stretches. You can also measure tension in the chain, same way, at lower wind speeds and then extrapolate (or find someone who will lend you a load cell - and then you might not need to extrapolate).
In the description of west coast, Scotland, strong winds - some of the winds are not average winds - they are the bullets 'generated' by the topography, they may, and probably do come as sudden gusts from different directions - some different in direction to the forecast - these bullets can cause shearing or yawing - nothing to do with average wind nor the propensity of the yacht to yaw. Riding sails will, if anything exacerbate the issues. Such shearing will cause snatch loads - and an optimisation based on a less gusty anchorage may not be relevant - you need to think of the extremes.
Take note - if you are using a snubber - it is a consumable, it will be consumed. Carry a spare and be geared up for the unexpected. Storms, forecast as being of storm force, seem to be more prevalent than I recall - if my recollections are correct then our kit needs to take these changes into account - a greater need for a storm snubber - if you are venturing far from home waters with no-where to scurry to. When a snubber fails the sound is like gunshot - you will not miss it (we have broken two).
Jonathan
Supertramp
Well-known member
Thank you. Clear advice and I agree about the lifting industry rather than chandler's. My aim is for a double bridle led down the side decks giving at least 10m of rope.Go to you nearest supplier of lifting gear and buy one of their eye hooks, the eye takes a splice, and use that. Buy a 10mm G100, grossly overstrength but they are cheap, not worth trying to save pennies. Hooks are easy to attach. Don't use a 'claw' they are a bit fiddly to apply and downright difficult to release. The down side to lifting tackle is that it is painted, not gavalised. Buy 2 and when the first looks a bit rusty, retire (short term) and use the spare. Clean the old one, paint and it will become your spare.
You could buy a cast stainless hook from a chandler but they have a dubious origin and having bent our Witchard hook and seen others bend them (that article on the Med storm) I'd suggest the lifting industry will be more reliable.
But if you are using a hook already - you know the ins and outs.
Hooks come in 2 forms, eye hooks and clevis hooks. Clevis hooks take a chain, eye hooks take a splice. You could splice to a chain - but its simpler to splice to the eye.
These are clevis hooks, the one on the left is the style, excepting its not an eye hook (see below), that I suggest, the one on the right is a better, newer design, but they are more expensive and not necessary.
View attachment 145523
If you note the one on the left - the crown or the link, the curved part, sits in a 'female' recess, it cuddles the crown. The actual link in the jaw of the link sits on those protuberances - so both links take the tension. The one on the right does the same - but it a a bit more cuddly
View attachment 145524
I have my hooks galvanised and for a clevis hook I've devised a way to stop the chain falling out. I have not had chains falling out of hooks, but others do, keep the hook under tension, the lazy loop of chain is sufficient, and all will be well.
View attachment 145525
We use a chain hook as our chain lock, in case the bridle fails and we use it on passage, if the clutch slips the anchor will not self deploy. We are using a dyneema strop attached to a strong point. The numbers on the hook mean 6mm chain, G100 quality/strength.
View attachment 145526
We don't use a hook for our bridle but a bridle plate, this is the one made in Ukraine.
If you are now confused -keep asking the questions
Jonathan
NormanS
Well-known member
The Cuilce is a fantastic place, but well worth a avoiding in strong winds! I reckon that a F6 SWly outside, gives a SEly F8 in the anchorage.
. A strong Nly tends to come barreling down vertically. Much better to go along, in a Nly, to Camusunary. The wind there will still be strong, blowing down the glen, but at least it's steady.NormanS
Well-known member
Jonathan, in your post No 149, you touch on wind gusts coming from different directions, causing yawing. You say that, "Riding sails will, if anything, exacerbate the issues". Is this from your own experience?
I find this very surprising, as a user of a riding sail, whose purpose is to weathercock the boat, to bring her head to wind. Without the riding sail, if a gust comes on the beam, I find that the boat tends to yaw away from the wind, until she is brought up short by her anchor. I find that the effect of the riding sail, giving greater windage aft, greatly reduces this yawing. In what way do you think it makes it worse? Do you have actual experience of using a riding sail?
I find this very surprising, as a user of a riding sail, whose purpose is to weathercock the boat, to bring her head to wind. Without the riding sail, if a gust comes on the beam, I find that the boat tends to yaw away from the wind, until she is brought up short by her anchor. I find that the effect of the riding sail, giving greater windage aft, greatly reduces this yawing. In what way do you think it makes it worse? Do you have actual experience of using a riding sail?
Neeves
Well-known member
No experience, at all.
Simply the idea that a riding sail is meant to keep a yacht head to wind. If the wind is coming on the beam, then its not keeping the yacht head to wind, The riding sail when the wind gust is coming on the beam simply increases windage, yes you will turn to face the wind, but the next gust maybe from the other gust direction.
When we have experienced such wind - we have laid securement from bow and stern. The bullets may be intense but they don't last long. A cat, or any multihull, does not heal in the wind, it would simply swing. Having 'anchors' of both bow and stern is simply does not move.
The anchors do not need to be 'anchors' as shore lines work well, which is why they are so common in Patagonia and sometimes Tasmania.
We have secured using 2 anchors off the bow and one shore line off the transom and one anchor of the bow and 2 shore lines.
Because the yacht is now, effectively, stationary there is little tension from sideways pull on the actual anchors.
There is no right way, nor wrong way, to anchor - its what works for you at the time. You do need to know the ideas and have the kit to deploy - which is why we have 3 anchors each capable of acting as a bower or primary anchor and why old halyards, which may be dyneema, are not 'retired' but ready to become shore lines.
Jonathan
NormanS
Well-known member
I did wonder if you had tried a riding sail, when you stated that they made the situation worse. It's a pity to put out misleading statements, when in general, people respect your opinions. As the user of a riding sail in fairly extreme weather, I know about their benefits, and was astonished at your statement.
I don't like using shore lines with anchor(s), because used conventionally, there is every chance of being held beam on to the wind. What I have done, on occasion, is to have a shore line, but attach it to the anchor chain below the level of the keel. This, similar to a Bahamian Moor, allows the boat to lie head to wind.
Neeves
Well-known member
I am willing to learn.
Situation - we are suffering from bullets of wind emanating from a direction at 90 degrees to each other. The bullets are sufficiently strong and sudden that the yacht, mono, near us is being laid over , we just have spray all over the windows from water lifted off the surface as we swing round and are pulled up short against the snubber. Shortly later we are hit by another sharp gust, at 90 degrees to the earlier one. The gusts are sufficiently sharp and strong the swivel of the monohull fails and they lose their anchor. We are able to lend them an anchor and we deploy shorelines - primarily as our swing room needs to be large and we are in the best shelter (off Bass Strait). Using an anchor and shore lines means we don't swing and there is room for other yachts. We are not using anchors for the shore lines - there are plenty of trees (but being a National Park its actually illegal to tie to trees - but ignore that as the only access is a very long rugged walk). Our rodes are short - to ensure we neither run into each other, nor the nearby rocks.
The mono we are anchored near are a UK citizen and an Oz citizen, they have sailed across the Atlantic, Cape Horn, across the Pacific and are working toward Adelaide, against the prevailing;ing winds, as this is her home town.
The forecast for Bass Strait is a Storm warning, which is why we sit out the weather for 2 days - if anyone seeks shelter they would not want to venture back out.
Interestingly it was perfectly feasible for one person to hold the shore line without much effort - the problem develops when the vessels picked up speed and then were brought up short against the rode (in our case a snubber).
It was disconcerting to suffer the continual movement - as the fear always is that wth constant veering hold is reduced.
Tell me, and anyone else interested, the benefits of a riding sail, over shore lines or a second and third anchor.
Jonathan
NormanS
Well-known member
It seems that you are writing about a situation where, previously, you have castigated others for allowing themselves to suffer. You often tell people that because of wonderful weather forecasting, they should have gone to better shelter. Interesting that you didn't take your own advice!
We, and our boat, always prefer lying head to wind, hence the use of a riding sail.
Maybe with a catamaran having the wind on the beam is not such a big deal, but the monohull which you mention was "laid over", so not so pleasant for them. I think you already know my opinion about swivels. Unnecessary, and as you demonstrate, dangerous.
Nothing wrong with having line(s) ashore, but for a monohull in a situation where gusts are coming at 180°, not pleasant at all. That is why, as I said, I can get the best of both worlds by, if I feel the need for the extra security and reduction in swinging circle, having a shore line secured to the anchor chain below the level of the keel. That way, the boat is moored securely between the shore and her anchor, but still free to swing head to wind. Monohulls and catamarans behave very differently. For your, and others, information, what a riding sail does very effectively, by giving some extra windage aft, is to ensure that as far as possible, the boat remains head to wind, and is therefore not laid over in squalls. There's nothing funny about having your broth spilling out of your soup bowl.
doug748
Well-known member
Those people with sloops, who may like to equip themselves with an efficient riding sail , might like to see the late Piota's design and explanation:
Piota – Riding sail
"SETTING :
The following sequence presets it before hoisting. (the main halyard is used to support the boom to release the topping lift for the riding sail)
1 The tack has a D-ring for a strop to the mainsheet track, or two spliced lines, pre-set to length, angled forward and outboard to strongpoints (in Piota's case, cleats on the coamings).
2 The clews are spread apart by a light spar poked into the cringles (or D-rings): permanently spliced sheets are doubled under the sternrail inboard of its stanchions, and back to the
clews; secured by eye-splices over the spar or clips to the D-rings.
3 The topping-lift is clipped to the head: a rapid hoist & tension on a winch: sail set!
The trick, at the design stage is to make a mock-up of the sail edges in 'string' and adjust dimensions (sail and spar) so that when fully hoisted and tensioned the luff is clear of the boom,
the sheets bisect the clew angles (with the spar in place), and the spar is clear of the backstay, (either ahead or abaft). Contrary to what might be expected, it is neither necessary nor desirable to attach anything to the backstay. When the dimensions are all compatible and the sail is set flying it is stable; and silent!
Specification of the sail for Piota:
Dimensions: (Hollows in brackets): Luff, 8ft (1.5in.) : Leech, 9ft.8in (1. 75in) : Foot, 5ft.6in (1.0in) Cloth: a light polyester (dinghy) sailcloth. (Preferred to spinnaker nylon, which distorts too much underload)
To join the twins: lay one on top of the other, corners corresponding, then turn the top one over like a page of a book to leave the luffs edge-to-edge: Join with 2" flat webbing: (it stiffens and rounds the luff: no eddies, no turbulence!)
Tabling: I had lee-lines and foot-lines put in to deal with any flutter, but there is none. Fittings: D-rings (or cringles large enough to accept a spliced sheet and tapered end of the spar) .§QM : I use a boathook with a plastic fitting at both ends (to avoid having to stow an extra spar)."
Our comrade Piota did a lot of serious sailing in Scotland and points north.
.
Piota – Riding sail
"SETTING :
The following sequence presets it before hoisting. (the main halyard is used to support the boom to release the topping lift for the riding sail)
1 The tack has a D-ring for a strop to the mainsheet track, or two spliced lines, pre-set to length, angled forward and outboard to strongpoints (in Piota's case, cleats on the coamings).
2 The clews are spread apart by a light spar poked into the cringles (or D-rings): permanently spliced sheets are doubled under the sternrail inboard of its stanchions, and back to the
clews; secured by eye-splices over the spar or clips to the D-rings.
3 The topping-lift is clipped to the head: a rapid hoist & tension on a winch: sail set!
The trick, at the design stage is to make a mock-up of the sail edges in 'string' and adjust dimensions (sail and spar) so that when fully hoisted and tensioned the luff is clear of the boom,
the sheets bisect the clew angles (with the spar in place), and the spar is clear of the backstay, (either ahead or abaft). Contrary to what might be expected, it is neither necessary nor desirable to attach anything to the backstay. When the dimensions are all compatible and the sail is set flying it is stable; and silent!
Specification of the sail for Piota:
Dimensions: (Hollows in brackets): Luff, 8ft (1.5in.) : Leech, 9ft.8in (1. 75in) : Foot, 5ft.6in (1.0in) Cloth: a light polyester (dinghy) sailcloth. (Preferred to spinnaker nylon, which distorts too much underload)
To join the twins: lay one on top of the other, corners corresponding, then turn the top one over like a page of a book to leave the luffs edge-to-edge: Join with 2" flat webbing: (it stiffens and rounds the luff: no eddies, no turbulence!)
Tabling: I had lee-lines and foot-lines put in to deal with any flutter, but there is none. Fittings: D-rings (or cringles large enough to accept a spliced sheet and tapered end of the spar) .§QM : I use a boathook with a plastic fitting at both ends (to avoid having to stow an extra spar)."
Our comrade Piota did a lot of serious sailing in Scotland and points north.
.
Neeves
Well-known member
I can see how a riding sail steadies a yacht when the winds are relatively stable in direction and not composed of random bullets at 90 degrees.
We did as I preach. We had a Storm forecast and we calculated we could make the crossing from Tasmania over Bass Strait in time. The future forecast were for more strong wind events. We could sit tight or make the crossing as the following strong winds would offer a down wind sail for us to sail quickly to the bottom right had corner of Oz and then up the east coast. . We made the crossing uneventfully and made for Refuge Cove in Wilsons Prom. We were totally unaware that the cove offers refuge to anything except bullets. The rest is history, as defined above. We used shore lines and anchors to secure Josepheline, we suffered....nothing. We secured ourselves to allow room for anyone else taking refuge.
What you don't quite explain is how a riding sail keeps you head to wind, without yawing, when head to varies by 90 degrees every few minutes. One minute you are head to wind and the next minute the wind is at 90 degrees - somehow your yacht needs to rotate through 90 degrees - without healing (possibly exacerbated by the riding sail which adds extra windage. - or you would spill your broth).
Now is your chance. With your demand for brevity - and no repetition, please explain. I'm eager for knowledge and I do not criticise the actions of others as I am sure they can justify their comments. Photos help. I understand how a riding sail works, I can see how to build one, and instal - I cannot get my head around its value in unstable winds.
You may have been astonished by my comments but I'm sufficiently ignorant such that I think a sudden wind gust of 35/40 knots hitting a riding sail at roughly 90 degrees will cause the yacht to heal and then yaw as it comes head to wind. As the gusts cycle through this 90 degree pattern you will then heal and yaw back - I'm obviously lacking in any intelligence, hence my hunger for knowledge, so please explain. The ideas of a riding sail has great attraction if it can obviate the need for yawing (and were we to own a mono - negate any need for the yacht to heal). I'm much more concerned about spilling my Shiraz than the broth. Currently and in my ignorance the idea of shore lines (which you reject outright) is increasingly attractive - as the yacht does not move and as you can secure a mono hull (or multi) almost on the beach (calculating depth at low tide) as the yacht is stationary and its position predictable (its stationary) you can move away from the bullets (the shore being more sheltered) .
This is Refuge Cove, below, the winds have abated and we are both waiting for the seas to smooth out. We have 2 anchors deployed and one shore line attached to a stern bridle and a tree on shore, we could,have buried a Fortress. The yacht has one anchor and 2 shore line to two trees. The gusts were directed from the right to left - the yachts are roughly aligned east/west and the average wind was SWly. We are anchored transom to the wind as this allows a greater length of deployed chain and allows us to get closer to the shore (and shelter) The picture is taken from the northerly shore looking slightly west of south. As you can imagine from the limited view of the anchorage - it seems sheltered, hence Refuge Cove.
I have this nagging idea that if you had turned up with your riding sail and need for room it might have been a bit of a pinch, but we could have shuffled up - if you had retired the riding sail in favour of shore lines. But maybe your explanation will explain.
Further south still, in SW Tasmania its a bit more like the Scottish outer isles. We do have trees, (below) this is one of them, with Josepheline just visible between the tree trunk and the rock at anchor in Bramble Cove (named after HMS Bramble). We are climbing Mount Misery, lovely and evocative name
. The next land (beyond the small rocky islands), you cannot quite see it, is Patagonia, through the Roaring Forties and across the Southern Ocean. When Storm force winds are forecast we move inland through Port Davey ( see 2nd pic below the channel roughly middle of the picture exiting left). Like the Scottish western islands - not many trees but no people, no houses, no roads, no mobile phone - just SSB.
2nd
I may give the impression we need trees, big ones, to provide shore lines. We carry 4 anchors each of which is sized to be the bower, or primary. The total weight of our 4 anchors is 32kg, they are all aluminium. We can bury the anchors above the tide line - or use then as,,, well..anchors. Our 6mm rode is 75m, our second rode is 55m, 15m x 6mm and 40m of 3 ply 12mm, and we carry enough cordage, mooring warps, retired halyards for 2 decent shore lines or rodes. We also carry short lengths 2 x4m of 8mm chain (from our previous rode) to put round rocks for our shore lines. We have never deployed more than 3 anchors in one anchorage.
Contradictorily up in Port Davey, to the left of the above photo is one of the locations where the endangered Orange Bellied Parrot , one of 3 migratory parrots, lives in the summer. They share the location with banks of Black Swans (which become increasingly attractive when you tire of crayfish
)Take care, stay safe
Jonathan
NormanS
Well-known member
I can remember meeting Piota on several occasions in various anchorages. With our boat being a ketch, the rigging of a riding or anchor sail, is even easier. The mizzen mast has a track, so we made the double luff of the sail with slides to fit. Like Piota, we have a spreader bar between the two clews. Ours is a telescopic boathook. The sheets from the clews are sheeted to the extreme corners of the stainless steel bulwark rail, and to give extra stability to the rig, second sheets go across to their opposite corners.
I think our boat is a bit bigger and heavier than Piota, and accordingly our sail is bigger:
Luff, 3.25m. Leach, 3.9m. Foot, 1.83m. It's made of heavy material, the same cloth as our storm jib. We only use it when required in strong winds, and it does an amazing job of keeping the boat head to wind, and not heeling over in gusts.
Neeves
Well-known member
I'm astonished Norman, lost for words - that having been critical of me for saying a riding sail does not cope with bullets at 90 degrees. If an expert such as yourself cannot say that I am wrong. I can only assume my analysis is correct.
I asked you to post a picture of your bent link after you accused me of copying yours - I can only assume you withdraw your unfounded accusations. Possibly the similarity between your bent link and the almost identical Oscalluti device gave you pause for thought.
Unless you can support your accusatory posts - it might be better not to make them. Maybe also wonder - why do you make them?
Yes - I'm annoyed
Jonathan