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Widebeam Anchor Advice Please


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Hi there

 

We have a widebeam which weighs approx 27 ton although we hope we never have to use an anchor as we are moving around this summer and want to make sure we have one especially on the thames and kennet and avon we have been looking at anchors that are suitable.

 

We have been advised to get a 20kg danforth, would anyone agree with that size and type of anchor who has a similar boat.  I really dont know anything about the type or weight required so would really appreciate some guidance.  Also we would want to keep it in the engine bay when not moving so dont want something too huge 

 

Thanks

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Danforth are often seen on narrow boats they have two main advantages, cheap and fold flat, a bit like some IKEA furniture. 

There are several threads on anchors which you should read.

 

I have a 57ft NB, and I singlehand, so the anchor needs to stop and hold me first time.

I have a Mantus.

I have six metres of heavy Calbrated chain, ten would be better. 

I have a Green pin bow shackle and a Green pin D shackle.

I have 33 metres anchorplait with an hard eye splice. 

 

A 56lb mud Weight may also be useful. 

 

You are not going to find anyone who happens to have a barge and who has done any anchor testing on the Thames

 

The size of your ground tackle is not determined by the size of your engine room so much as the size of your crew. 

Anchoring on the Thames will not be a regular experience, I think it will be more often done in an emergency situation, when the prop has fouled for example, or when the engine has failed and you are heading toward a weir. 

If you want to practice deploying an anchor, a 20kg Danforth on 20 metres of rope might be a good idea, the Danforth could be kept on the roof, on a pallet, at the front end of the boat.

Your surveyor will advise on the strength of the point of attachment, not much use if the T point is not up to the job. 

PS use the search facility, and gather some more information. Essentially many people will never have deployed their anchor, and if it did not hold in an emergency, they probably gave up boating! 

Edited by LadyG
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3 hours ago, Lisa009 said:

Hi there

 

We have a widebeam which weighs approx 27 ton although we hope we never have to use an anchor as we are moving around this summer and want to make sure we have one especially on the thames and kennet and avon we have been looking at anchors that are suitable.

 

We have been advised to get a 20kg danforth, would anyone agree with that size and type of anchor who has a similar boat.  I really dont know anything about the type or weight required so would really appreciate some guidance.  Also we would want to keep it in the engine bay when not moving so dont want something too huge 

 

Thanks

Lady G has advised that there are many threads on this subject and I would suggest that reading them is the first step. You will find a plethora of posts on the pros and cons of anchors and  I suspect that you will also get plenty of advice in  response to this post, with a variety of views which may confuse rather than define an absolute answer so best of luck! 🙂

 

Howard

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3 hours ago, Lisa009 said:

Also we would want to keep it in the engine bay when not moving so dont want something too huge 

 

I'm afraid that is rather a strange view to take, surely the criteria is "I want an anchor that'll stop my 27 tonne barge from going over a weir" rather than I want something that'll fit in a certain space.

 

Just a couple of points about the suggestion you have received :

 

1) A Danforth anchor is a very old design, was good at the time, but has very poor performance compared to modern anchors. It is often chosen by boaters who have no knowledge of anchoring, and want something to tuck away in a locker.

 

2) A 20kg anchor of pretty much any design is too light for your boat.

 

To buy a suitable anchor, that will work, you will be looking to spend around £1000 Happy to suggest options if you wish.

The only '20kg' anchor that may be suitable is the Fortress FX85 at a cost of £1800.

Heavier anchors of other designs are available at lower cost.

 

 

Here is a reply I made to a similar question some time ago :

 

 

 

 

There will shortly be a comment that 'anchoring at sea' is very different to anchoring on a River - and - yes I agree, it is.

 

Anchoring at sea is a normal practice undertaken most nights, it is planned and considered and a suitable spot chosen, the anchor is carefully, and correctly deployed, and the boat reversed to help the anchor set, if the anchor 'drags' you simply pull it back in, motor back to your chosen spot and repeat the process until the anchor sets properly.

 

Deploying an anchor on a river will generally be during a 'brown trouser' moment, the engine has stopped, gearbox not working (or whatever). You now need an emergency brake (to stop you going over a weir ?) and the anchor needs to work and set properly and be able to bring the boat to an emergency stop instantly, FIRST TIME, EVERYTIME, as there is unlikely to be time to pull it back in and re-set again.

 

So, yes anchoring on a River is different and actually is much more demanding than anchoring at sea.

 

There are any number of articles about anchoring 'sea-boats' but (seemingly) non about emergency anchoring of River boats, so we can only try and extrapolate the knowledge of 250,000+  'coastal boaters' to the 80,000 inland waterways boaters.

 

An extract from an article I found (so as not to influence the discussions with my own experiences)

 

It is interesting to note that using the same length of rope as you would chain gives you a much reduced 'holding power', so, a scope of 4/1 rope will only provide about 55% of the anchor holding power' as when using a 4/1 scope of chain.

 

"Scope" is the ratio of depth to length, (so, for example, a scope of 10/1 means that for every metre of water depth you need 10 metres of Chain / Rope)

 

What Length of Mooring Chain Should I Use?

During the last seven and half months, I spent 129 days anchored (out of 228) in 61 different anchorages. The mean water depth was 6.50 meters and the scope 5/1. The total length of the anchor chain was about 30 meters, of which 23.5 meters was lying on the bottom (30 - 6.50 m) Therefore, I believe a length of about 25 meters is perfect. If the water height is less, then you will be anchoring with an all mooring chain line... if the wind build up, you can pay out more scope but the wind will push the boat and the mooring chain will not chafe on the bottom.

What Length of Anchoring Rope Should I Use?

Holding is in direct relation to the pulling length of the rope... (Or more accurately, the pulling angle). Generally speaking, with a scope of 4/1 you will have about 55 % of the maximum holding of the anchor, with a scope of 6/1 about 70 % with a scope of 8/1: 80 % and with 10/1 about 85 % the maximum. - 100% holding will be achieved with a horizontal rope or an "Infinite/1 scope.

Increasing the scope will be efficient up to 10/1 - With more than 10/1; a large increase in the scope will give only a negligible increase in holding. Therefore, the total length of the rope has to be adapted in relation with the conditions you are expecting to meet, and should be about ten times the maximum depth you expect have to anchor in. (I suggest 100 meters).

Edited by Alan de Enfield
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Just as an example here is  a table showing the MINIMUM suggested anchor size against boat weight, (for a 30 tonne boat it is 40kgs)

 

This should be stowed on the bow of the boat ready to be deployed, you will not easily be 'packing it away' every day..

 

A forum menber @blackrose has a similar boat to yourself, I'm sure he'd be happy to post pictures of how his anchor is mounted.

 

 

 

Screenshot (205).png

Edited by Alan de Enfield
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39 minutes ago, Alan de Enfield said:

This should be stowed on the bow of the boat ready to be deployed,

Which of course raises the question of what happens if you deploy the anchor from the bow while heading downstream on a river which is narrower than the length of the boat.

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8 minutes ago, David Mack said:

Which of course raises the question of what happens if you deploy the anchor from the bow while heading downstream on a river which is narrower than the length of the boat.

 

One of the perils of being on small rivers. If you get wedged then at least you won't be going anywhere, and you can get down and sort the problem out.

or, if the river is that small then just drift into the side (hopefully before you get to the unguarded weir)

 

There are always reasons not to do something, maybe don't even carry an anchor in case you cannot recover it.

 

Or, carry an anchor that you can easily lift and take to the stern, knowing full well that it is insufficient to take the load of a 27 tonne barge coming to a halt. (Often called a false sense of security).

Edited by Alan de Enfield
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1 hour ago, howardang said:

Lady G has advised that there are many threads on this subject and I would suggest that reading them is the first step. You will find a plethora of posts on the pros and cons of anchors and  I suspect that you will also get plenty of advice in  response to this post, with a variety of views which may confuse rather than define an absolute answer so best of luck! 🙂

 

Howard

 

That is because there is no absolute answer unless you can accurately predict what the river bed will consist of and that is impossible. Some anchor designs are better on some beds types than others.  One most suitable for mud may just bunce over rock.

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We will have the same question in a few months. Alan's says a 40kg anchor is the suggested weight for a widebeam bit the OP wanted one they could lift, hence 20kg. 40kg great if you have a windlass.

 

I can lift 25 kg bags of coal but it's getting harder so I too would be looking at 20kg but with more chain to help.

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8 minutes ago, pearley said:

We will have the same question in a few months. Alan's says a 40kg anchor is the suggested weight for a widebeam bit the OP wanted one they could lift, hence 20kg. 40kg great if you have a windlass.

 

I can lift 25 kg bags of coal but it's getting harder so I too would be looking at 20kg but with more chain to help.

 

The fact I suggested a 40kg anchor is not because it is a widebeam, but because of the weight, be it a 30 foot long NB, or a 70 foot WB, beam is (almost) irellevent.

 

I'm afraid that comes back to the point, why waste you money buying something that 'will not do the job', particularly when it is a safety related feature - would you buy a CO alarm and take the batteries out, safe in the knowledge you had a CO alarm fitted ?

 

"If in any doubt about anchor selection always use a bigger anchor, in bad weather or engine failure, it is the only thing you can rely on to save the lives of you and your crew".

 

Wise words from an article on safe anchoring.

Edited by Alan de Enfield
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3 minutes ago, Tony Brooks said:

 

That is because there is no absolute answer unless you can accurately predict what the river bed will consist of and that is impossible. Some anchor designs are better on some beds types than others.  One most suitable for mud may just bunce over rock.

I completely agree,  However, where it is relatively straightforward to discover the nature of the bottom at sea, by consulting a chart, it is not so easy to find out the same information for rivers, so anchor choice will boil down to making an arbitrary decision after wading through all the varying advice.

 

It is also worth remembering that anchoring in lumpy water situations is very common and well understood, and of course experience in those situations can be helpful when considering anchoring on rivers. After all, the general principles of good seamanship don't change. However,  it is a procedure that is very seldom carried out on inland waters, so there is not a large fund of actual experience to draw on,  especially anchoring in emergencies.

 

Howard 

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The chain should be as long as you can afford, store. It is as important a part of holding the boat as the anchor, on rocky seabed it is more important than the anchor. Remember as long as you can get the anchor over the side it will pull the chain (violently) over the side. A scared person will move things they normally can't. When you have fixed the problem and are recovering the anchor Archimedes principle helps, and you have time to rig up a block and tackle for the last bit.

Hopefully you never need to find out.

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Parglena (60x11'6 35tonnes) had a 30kg Danforth and 50m chain, spent  a few nights at anchor in the east coast estuaries with no dragging. 

Most days it was hard to weigh anchor and always ended up driving over it to break it out. Mind you it is slightly muddy out there.

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The mounting point for the bitter end (where the rope is fastened) should be ridiculously strong, boats steer into the current slowly when anchoring then reverse back slowly letting the chain and rope out as they go. So when they tie off and let the anchor hold the boat it is a gentle affair. Nothing like 30 tonnes moving a 2 knots being jerked to a stop.

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14 minutes ago, Detling said:

The mounting point for the bitter end (where the rope is fastened) should be ridiculously strong, boats steer into the current slowly when anchoring then reverse back slowly letting the chain and rope out as they go. So when they tie off and let the anchor hold the boat it is a gentle affair. Nothing like 30 tonnes moving a 2 knots being jerked to a stop.

Unless you are in 'brown trouser moment', and have never experienced anything like this before. This will be the case for many inland waterway boaters who need to deploy an anchor, so quite likely I would have thought.

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43 minutes ago, howardang said:

I completely agree,  However, where it is relatively straightforward to discover the nature of the bottom at sea, by consulting a chart, it is not so easy to find out the same information for rivers, so anchor choice will boil down to making an arbitrary decision after wading through all the varying advice.

 

It is also worth remembering that anchoring in lumpy water situations is very common and well understood, and of course experience in those situations can be helpful when considering anchoring on rivers. After all, the general principles of good seamanship don't change. However,  it is a procedure that is very seldom carried out on inland waters, so there is not a large fund of actual experience to draw on,  especially anchoring in emergencies.

 

Howard 

 

1 hour ago, David Mack said:

Which of course raises the question of what happens if you deploy the anchor from the bow while heading downstream on a river which is narrower than the length of the boat.

This is where the 56lb mud weight comes in, or the proper anchor which you decided to store in the engine compartment!

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2 hours ago, Alan de Enfield said:

Just as an example here is  a table showing the MINIMUM suggested anchor size against boat weight, (for a 30 tonne boat it is 40kgs)

 

This should be stowed on the bow of the boat ready to be deployed, you will not easily be 'packing it away' every day..

 

A forum menber @blackrose has a similar boat to yourself, I'm sure he'd be happy to post pictures of how his anchor is mounted.

 

 

 

Screenshot (205).png

 

you don't state what conditions were assumed  ..............  in a Force 8 off a lee shore? ........................  on the Thames while cruising in good weather?

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54 minutes ago, LadyG said:

 

This is where the 56lb mud weight comes in, or the proper anchor which you decided to store in the engine compartment!

All I can say is that I considered my Danforth to be no more than a mud weight and hoped that in the event of an emergency deployment it would slow the boat enough to allow me to ferry glide to the bank. If it managed to bite then so much the better but I never expected it to. That depends on ones ability to ferry glide though.

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2 hours ago, Alan de Enfield said:

 

"If in any doubt about anchor selection always use a bigger anchor, in bad weather or engine failure, it is the only thing you can rely on to save the lives of you and your crew".

 

Wise words from an article on safe anchoring.

A few moments thought will demonstrate it is simply untrue.  A bigger anchor might help halt the boat in some circumstances - but there are countless situations, bad weather or otherwise, where you would need rather more than an anchor to save your life.  

 

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2 hours ago, Detling said:

The chain should be as long as you can afford, store. It is as important a part of holding the boat as the anchor, on rocky seabed it is more important than the anchor. Remember as long as you can get the anchor over the side it will pull the chain (violently) over the side. A scared person will move things they normally can't. When you have fixed the problem and are recovering the anchor Archimedes principle helps, and you have time to rig up a block and tackle for the last bit.

Hopefully you never need to find out.

I would recommend that anchorplait, maybe 30 m of 24mm is used to attach the chain to the boat, this is to absorb shock, otherwise the jolt when the T piece thing is hit by the massive force exerted along the chain will almost inevitably lead to failure in the weakest link. 

Anchoring at sea in a controlled manner does not exert these massive forces as the anchor is deployed when the boat is not going forwards. 

Looking at the standard T piece on my narrow boat, I am pretty sure it is will be my weakest link, and once I let the anchor go, I'll feed the chain, and have the anchorplait feeding well but, I won't be hanging around to watch the end result.

Edited by LadyG
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3 hours ago, Alan de Enfield said:

 

The fact I suggested a 40kg anchor is not because it is a widebeam, but because of the weight, be it a 30 foot long NB, or a 70 foot WB, beam is (almost) irellevent.

 

I'm afraid that comes back to the point, why waste you money buying something that 'will not do the job', particularly when it is a safety related feature - would you buy a CO alarm and take the batteries out, safe in the knowledge you had a CO alarm fitted ?

 

"If in any doubt about anchor selection always use a bigger anchor, in bad weather or engine failure, it is the only thing you can rely on to save the lives of you and your crew".

 

Wise words from an article on safe anchoring.

I understood your original post perfectly but if you can't lift the thing over the side. Yes, a smaller anchor not ideal but,bad Tony said, hopefully it will slow you enough to get into the side.

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6 minutes ago, LadyG said:

I would recommend that anchorplait, maybe 30 m of 24mm is used to attach the chain to the boat, this is to absorb shock, otherwise the jolt when the T piece thing is hit by the massive force exerted along the chain will almost inevitably lead to failure in the weakest link. 

 

I agree with you, but the problem is that folks do not want to spend money on a complete anchoring system which they will never use (a bit like insurance is a 'waste of money' until you need it).

 

Paying £500+ for a suitably sized performace anchor, (A Danforth would be only £203, a Fortress would be £1800) and

Paying £200 for 10 metres of 16mm chain, (£20 per metre)and 

Paying £350 for 30mts of 24mm anchorplait (£14.34 per metre)

 

Short Link Chain - Galvanised - Commercial & Industrial Hardware from Absolute Industrial Ltd UK

 

Marlow Multiplait Mooring Rope | Octoplait - £3.78 : ropelocker, your online rope supplier, rope by ropelocker

 

 

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14 minutes ago, pearley said:

Yes, a smaller anchor not ideal but, bad Tony said, hopefully it will slow you enough to get into the side.

 

I HOPE never to need to use it in a time of emergency but it may happen.

 

I was involved in a 'rescue' of an NB whose engine failed and was drifting towards the weir at Crowell on the Trent.

His 15kg Danforth anchor (fractionally) slowed down the drift but did not stop it, had we not got a line aboard he'd have gone under the dolphins and over the weir.

Two boats tried & had a real struggle getting a line aboard, we each approached him about half-a-dozen times and each time the flow and currents 'swirled' us away.

 

How would you suggest that when drifting down the centre of a 100 yard wide the river, he could use the anchor to enable him to the side ?

 

The theories as proposed by some canal users do not stand up in practice and experience.

 

If the size of your boat dictates the use of an anchor that you are unable to manually handle then you either buy a boat that needs an anchor you can manually handle, or you put in place methods of deployment that does not require manual handling.

 

Ask @blackrose how his works.

Edited by Alan de Enfield
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  • 2 weeks later...

Here's a guy who has 122 anchor testing vlogs

 

He's American.

Edited by LadyG
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