Anchor rode length?

[Murv]

Our rode (learned a new word today ) is all chain.
Reading up, it appears that this is unsuitable and I should change it to 12mm nylon rope with just a short length of chain.

How long should the total length be? I've read it should be 4-7x the length of your anchorage depth, but for example, that would mean around 3000' of rope to anchor in the deepest part of the English channel. I assume you'd just motor somewhere shallower if you had to anchor?
What's a good "rule of thumb" length of rode for a newby boater in the south East planning on tidal river and inshore coastal work?

 

[sailorman]

Our rode (learned a new word today ) is all chain.
Reading up, it appears that this is unsuitable and I should change it to 12mm nylon rope with just a short length of chain.

How long should the total length be? I've read it should be 4-7x the length of your anchorage depth, but for example, that would mean around 3000' of rope to anchor in the deepest part of the English channel. I assume you'd just motor somewhere shallower if you had to anchor?
What's a good "rule of thumb" length of rode for a newby boater in the south East planning on tidal river and inshore coastal work?

i have 20m of 8m/m chain with 30 m of 18m/m anchorplait on the East Coast.
last yrs holiday i had 60m x 8m/m chain + 50m 16m/m anchorplait for CI & North Brittany

i would keep what you have

 

[Murv]

i have 20m of 8m/m chain with 30 m of 18m/m anchorplait

i would keep what you have

*Sigh* too much to learn!

But the nylon offers shock protection that the chain doesn't, as well as being lighter.
Please understand that I'm in no position to argue here, I don't have a clue!

Why would you keep the chain?

 

[nigelmercier]

Our rode (learned a new word today ) is all chain.

Providing it is long enough, that's fine. Otherwise extend it, but keep the chain.

 

[Salty John]

There's nothing wrong with an all chain rode - it's my preferred arrangement.
Your ground tackle should be suitable for the depth of anchorage and type of bottom you typically anchor in, with some allowances for anchoring in non-typical circumstances - but not in the excessive depths you indicate.

Here's some thoughts: http://www.saltyjohn.co.uk/resources/haphook.pdf

You'll find a vast array of often contradictory opinion if you google enough. Eventually experience will tell you when you have a system that's right for you and you'll be able to add your own opinion to the brew.

 

[Boathook]

Our rode (learned a new word today ) is all chain.
Reading up, it appears that this is unsuitable and I should change it to 12mm nylon rope with just a short length of chain.

How long should the total length be? I've read it should be 4-7x the length of your anchorage depth, but for example, that would mean around 3000' of rope to anchor in the deepest part of the English channel. I assume you'd just motor somewhere shallower if you had to anchor?
What's a good "rule of thumb" length of rode for a newby boater in the south East planning on tidal river and inshore coastal work?

Nothing wrong with all chain, just very heavy and you may well need a windlass.
Regarding length required, how long is a piece of string. Use a chart to get some idea of depths in the area you will be boating and don't forget that the depths need to be high water, multiply this by 5 and this will give you a length. I have always got connected and ready to use just under 60m of rode (16m 8mm chain and the rest 18mm 3 strand nylon). I have a spare 100m of 14mm nylon just in case and cruise the channel.

Also use google and look up all the other anchor threads that have been posted here over the last few years.

 

[Rossynant]

As you have it, keep it. Chain will not chafe, tangle over everything Your Precious One and yourself included, cut on something sharp. For elasticity a short piece of nylon warp can be tied to it - not disconnecting the chain should the rope break.
May be not the best idea for your boat exactly, but is there already. Buy another, short piece (10 m chain enough but listen to neighbors) nylon rode to it. 50 meters is as good as any, depends, usually 30 will be used but more should be there. For offshore some 100 m is useful, in two-three separate lengths that can be joined if necessary is more convenient.

 

[prv]

Our rode (learned a new word today ) is all chain.
Reading up, it appears that this is unsuitable and I should change it to 12mm nylon rope with just a short length of chain.

Let me guess, been reading American websites? They seem to have a thing about anchoring with rope, whereas in this country we prefer all chain if possible. The only reason to use part rope is if the chain would weigh your bow down too much, which might be the case in small boats or planing motorboats.

How long should the total length be? I've read it should be 4-7x the length of your anchorage depth, but for example, that would mean around 3000' of rope to anchor in the deepest part of the English channel. I assume you'd just motor somewhere shallower if you had to anchor?

Anchoring in the middle of the Channel

Actually, racing sailing boats might do that if the wind drops, as they're not allowed to use engines, but nobody else does. You don't really want to anchor "out at sea" if you can help it, you will be very uncomfortable unless it's flat calm.

The old rule of thumb was 3 x depth for chain, 5 x depth for rope, though a lot of people will let out more than this if there's room, it doesn't do you any good in the locker. However, that's a rule of thumb for the sort of depths that people normally anchor in. If it's very much deeper, then you don't need to multiply the depth by so many times.

The idea is for the chain to run along the bottom before it meets the anchor. If you were to anchor in the middle of the Channel, your cable could hang vertically for most of the depth and just a bit at the bottom at an angle towards the anchor - so it might be less than twice the depth. On the other hand, if you anchor off a beach in a small boat in 1m of water, you will need more than 3m of chain for the anchor to dig in rather than be lifted by the upward angle of the chain.

Pete

 

[onesea]

Our rode (learned a new word today ) is all chain.
Reading up, it appears that this is unsuitable and I should change it to 12mm nylon rope with just a short length of chain.

How long should the total length be? I've read it should be 4-7x the length of your anchorage depth, but for example, that would mean around 3000' of rope to anchor in the deepest part of the English channel. I assume you'd just motor somewhere shallower if you had to anchor?
What's a good "rule of thumb" length of rode for a newby boater in the south East planning on tidal river and inshore coastal work?

All chain is considered the best for anchoring, certainly if I was going to spend nights holding on in a gale all chain is best.

The compromise is you pay a weight penalty, hence a speed penalty .

If you bought the boat and its what she has got I would sail with it first and see..

Some boats like chain forward to keep them trimmed nicely others do not.

What boat do you have?

I would say enough rode to safely anchor in the deepest safe anchorage you foresee.

You will learn quickly there are no straight answers LOL..

 

[rob2]

You don't say how long the chain is...? Many people prefer all chain rodes, they do tend to give a more sedate experience. A lot of boats, particularly mobos will sheer about in the wind and this happens more with a rope than chain. It's all to do with the keel configuration and windage - sailing boats with deep keels stay still when a flat bottomed, planing mobo will just slide around in the wind.

Chain forms a catenary due to its weight and has to be dragged around by the boat which often has all the energy taken out of it just lifting the chain to a straight line. Rope is more inclined to be held bar taught in a breeze and offers no resistance to the boat moving around. In a crowded anchorage, a boat with all rope will often swing differently from those around it with chain and as the rope rode requires a substantially larger scope than chain it can cause collisions. Chain at least 3 x depth, rope at least 6 x depth, or thereabouts.

Don't worry about the deepest part of the channel, you wouldn't want to anchor out there! Just think of yourself bobbing around in front of an oncoming supertanker with a half hour job to haul in all that rode. A good anchorage is in suitably shallow water with good protection form the current (and forecast) wind.

Rob.

 

[Steve C Cronin]

*Sigh* too much to learn!

But the nylon offers shock protection that the chain doesn't, as well as being lighter.
Please understand that I'm in no position to argue here, I don't have a clue!

Why would you keep the chain?

Because two forces(three really) keep you in place using an anchor.

One is a horizontal pull on the anchor, which needs this to stay dug in and even seek to dig in deeper. Since your boat will always be above the anchor, something heavy like chain is the most efficient at turning your boat's angled pull into a horizontal one in the shortest distance.

Two, the combined weight of ALL your ground tackle (another "NEW" expression for you!), anchor and chain, is a very important factor in holding you safe apart from the actual grip of the anchor itself.

And the Third, not to be overlooked, is the actual friction between chain and seabed. Try pulling your anchor chain across the surface of the laying-up hard single handed and compare this to pulling a rope and you'll see what I mean.

Rope rodes can also be a menace to others since you need a far bigger swinging circle and it often catches the unwary who don't notice your "odd-one-out" approach until it's too late and they've got you around their prop. A chain will hang straight down in a near calm but a rope can still be lying out for quite a distance dangerously, just below the surface.

As to "Shock protection", the chain by it's very nature lies in an extendible, geometric curve called a "catenary" which acts like a spring and is fine for most situations, however a short length of rope can be introduced, to prevent chain "growl" or excessive snatching in extreme conditions being transferred to the boat, with one of these

or by just threading a couple of metres of rope from a foredeck cleat, through the chain and back to the cleat and letting the chain hang slack between it and the bow roller.

 

[sarabande]

chain provides a form of 'elasticity', as the catenary (the arc between the boat and the anchor on the seabed) will absord the usual surges and heaves of being at anchor.

If you could state the size of the chain (diameter of the steel rod from which the links are made, preferably in mm) and the length, it would be helpful.


You may wish to have a nylon warp as an extender for the chain in unusual circumstances, and also as a tow rope, not only for yourself, but for any totally becalmed raggies who might need a lift home .

 

[PeterWright]

Shock absorption

It's a myth that chain offers no shock absorption. Because of its substantial self weight, the chain will always lie in a curve (a catenary for the mathematically minded) unless the load is infinite (and it would break well before that anyway!). As the tension increases, the curve reduces. It's response to shock loads is a little more complex, as you have to provide for the acceleration of each link transverse to the line between the two ends - suffice to say it allows the boat end to move away from the anchor, the energy being absorbed in accelerating all those links between you and the anchor. For this reason, a heavier chain not only has a higher breaking load, it also suffers lower dynamic loads when you're anchored in a heavy seaway.

The heavier the weather, the happier I feel with a good length of chain. If you have doubts about the integrity of whatever you secure the boat end of the rode to, Rossynant's suggestion is the best for further reducing shock loads - a length of multiplait nylon carrying the load in parallel with the 10m of chain at the boat end. The chain is then able to catch you if the nylon fails. You should not leave the rode held just by a windlass, except when using it as a fair weather lunch hook. Always see that the load is carried by the strongest point on your foredeck (sampson post, mooring cleats).

Sailorman's approach is typical good practice for yachties. Too much chain at the front and of our raggies adversely affects our performance. Racing types sometimes shift the anchor and rode to the centre of the boat to reduce weight in the ends, but its too much hassle for most cruisers. I suspect too much iron on the foredeck doesn't help the performance of planing mobo's either. When visiting places with a large tidal range we often extend our rodes with nylon, rather than carrying half a ton of extra galvanised iron at the pointy bit. But Sailorman still went for 60m of chain before adding the nylon in the Channel Islands. His posts are characterised by good seamanship.

You don't say how much chain you have, but I would certainly not discard any of it. If you wish, add some multiplait to extend the range oif places you can safely anchor. For the cruising area you suggest, you will not see a tidal range much above 5m. If you are willing to get a bit inshore before anchoring (2m charted depth) Sailorman's East Coast option would be more than adequate, giving you 50m of rode, a gnat's over 7x the depth at HW.

There's never too much to learn. The beauty of this boaty business is that you have the wondrful opportunity to learn more every day. My Mum told me that I was messing around in boats before I was born, and that's nearly 63 years ago; I still learn more every time I go sailing, and just love it!

Just seen that Sarabande beat me to it in a much less rambling style!

 

[GrahamM376]

*Sigh* too much to learn!

But the nylon offers shock protection that the chain doesn't, as well as being lighter.
Please understand that I'm in no position to argue here, I don't have a clue!

Why would you keep the chain?

Particularly when single handing, consideration has to be given as to whether you can lift long chain + anchor by hand in fairly deep anchorages with a good wind blowing or, whether you need a windlass.

We spend most of the year on anchor (avoid marinas) and have found all chain to hold better than chain/rope combination and far less sheering around. In light winds when a trip line is used and the boat has swung with the tide, the trip buoy is often abeam, showing it's sometimes the chain which is holding us, not the anchor.

To avoid snatching and possible damage, a snubber line should always be used, the simplest of which is a chain hook with a length of stretchy nylon rope long enough to go below the hull when riding the chain in wind over tide situations - it's better to have rope tight against the hull than chain. Cleat the snubber line then let a bit more chain out to allow for stretch, then cleat the chain off.

 

[temptress]

Our rode (learned a new word today ) is all chain.
Reading up, it appears that this is unsuitable and I should change it to 12mm nylon rope with just a short length of chain.

How long should the total length be? I've read it should be 4-7x the length of your anchorage depth, but for example, that would mean around 3000' of rope to anchor in the deepest part of the English channel. I assume you'd just motor somewhere shallower if you had to anchor?
What's a good "rule of thumb" length of rode for a newby boater in the south East planning on tidal river and inshore coastal work?

Keep the chain! Much safer anchoring.

 

[Stork_III]

Keep the chain! Much safer anchoring.

Make sure the Bitter end, the end at the boat, is fixed to boat, preferably with rope/line long enough to exit the anchor locker, so it can be cut away in extemis.

 

[GrahamM376]

You should not leave the rode held just by a windlass, except when using it as a fair weather lunch hook. Always see that the load is carried by the strongest point on your foredeck (sampson post, mooring cleats).

A mate tore the two rear studs out of his windlass and bent the front ones about 45 degrees during a rough night in Cemaes Bay. He'd never heard of a snubber line or about taking the chain off the windlass.

 

[Murv]

You will learn quickly there are no straight answers LOL..

Indeed!
I was kind of hoping for a "You need X metres" initial reply followed by a few "+1's"

Many thanks for all the informative info, interesting stuff.
Just to answer a couple of quick questions, the amount of chain I have is "some" and the link size is "medium."
Nope, I have no idea.
In my defence, we haven't used the boat yet (only to move it to it's present location) so it's just one of the things on the list.
I'll measure the chain length and link size at the weekend.

I'd assumed the English channel would be a worse case scenario for anchoring in the even of a breakdown but, of course, the auxhillary outboard would be used to get somewhere safer.


I probably should point out, in view of the large number of completely clueless posts I've made on here, that we are going to get some (lots!) of RYA instructor training before we even think of heading out on our own!

 

[GrahamM376]

I probably should point out, in view of the large number of completely clueless posts I've made on here, that we are going to get some (lots!) of RYA instructor training before we even think of heading out on our own!

Try to get an instructor on your own boat for a day or weekend and ask his advice about what you need or don't need.

 

[NormanS]

Don't be in such a tearing rush to change everything.