Anchors Aweigh!

[Richard10002]

11 hours ago, mrsmelly said:

And if you have knocked yourself out hitting the boat or tumbled in due to a medical problem will you be able to stand up?

No... why do you ask?

Presumably your self inflating life jacket will sort you out until help arrives.

I was merely pointing out that even the most experienced may not think of trying to stand up in what might be 3 or 4 ft of water, (or mud).

[Richard10002]

11 hours ago, Naughty Cal said:

We rarely used to wear ours on the non tidal Trent until the lock keepers asked us one day to keep an eye out for the body of a fellow boater. 

He had been knocked off the back of his narrowboat when the rudder struck something and the tiller swung around sending him off the back of the boat. 

Since then we always wear them on the Trent and other larger rivers.

 

You will need more then 10' of chain.

3 x (the depth plus the distance from where the chain leaves the boat), is generally a minimum at sea, and 5 x is preferable. Not sure if there is any reason why it should be different inland, (rivers or canals).

[MtB]

On 06/04/2017 at 00:07, Richard10002 said:

3 x (the depth plus the distance from where the chain leaves the boat), is generally a minimum at sea, and 5 x is preferable. Not sure if there is any reason why it should be different inland, (rivers or canals).

 

You haven't read the thread have you?!

A boat in the current of the 0.5mph we are talking about can be held by a tree twig caught in the side hatch.

(Gwarn, ask me how I know...)

[rusty69]

7 hours ago, Mike the Boilerman said:

 

You haven't read the thread have you?!

A boat in the current of the 0.5mph we are talking about can be held by a tree twig caught in the side hatch.

(Gwarn, ask me how I know...)

That's just the imaginary current. In reality it is only theoretical. 

[Alan de Enfield]

7 hours ago, Mike the Boilerman said:

 

You haven't read the thread have you?!

A boat in the current of the 0.5mph we are talking about can be held by a tree twig caught in the side hatch.

(Gwarn, ask me how I know...)

But its amazing how a little bit of wind can hold you onto a pontoon, or, even make turning (with the engine) very difficult.

Maybe you only 'go out' on days with no wind and 'no flow' on the river.

A (say) 15,000 kg boat travelling at around 1 foot per second (roughly 0.5 mph) has a huge kinetic energy. I would rather rely on a 'purpose designed hook' than on hopefully snagging a twig.

EK = 1/2 MV2  so this fictional 15 tonne boat, at 0.5mph takes 37.5KJ of energy to stop it moving.

 

If you now double the speed (due to adding in a factor of the wind) to 1 mph you are actually quadrupling the Kineteic energy.

 

Have you ever tried to hold off a boat from hitting a pontoon ? That's the energy your 'twig' has to overcome. 

Edited April 6, 2017 by Alan de Enfield

[Chewbacka]

I would suggest that on any river where one can not easily walk to the bank there should be an anchor.  The question then is how big?  So if you are only a fair weather sailor and will not go out in strong wind or when there is any appreciable flow, then a smallish anchor with chain and rope etc will eventually stop and hold your boat until help arrives.  If you will go out in more challenging times - even if you did not intend to - then you need a bigger anchor.  If you are the sort of person that might go out when the river is in flood and the tide is going out and flowing faster then your boat can go under full power you will need a massive anchor. 

But then if you were totally risk adverse you would never go boating as it is too risky driving on the roads to get to where the boat is moored.

 

Same as life jackets, I don't wear one when it is shallow enough to easily walk to the bank, but on the G&S canal, especially if single boating I always wear one.  It all depends upon our own level of happiness with the risks involved.

Edited April 6, 2017 by Chewbacka

[Murflynn]

1 hour ago, Alan de Enfield said:

But its amazing how a little bit of wind can hold you onto a pontoon, or, even make turning (with the engine) very difficult.

Maybe you only 'go out' on days with no wind and 'no flow' on the river.

A (say) 15,000 kg boat travelling at around 1 foot per second (roughly 0.5 mph) has a huge kinetic energy. I would rather rely on a 'purpose designed hook' than on hopefully snagging a twig.

EK = 1/2 MV2  so this fictional 15 tonne boat, at 0.5mph takes 37.5KJ of energy to stop it moving.

 

If you now double the speed (due to adding in a factor of the wind) to 1 mph you are actually quadrupling the Kineteic energy.

 

Have you ever tried to hold off a boat from hitting a pontoon ? That's the energy your 'twig' has to overcome. 

your a better man than I am Gungadin, if you can so easily equate energy to the force that needs to be exerted by the twig.  I see no mention of the deceleration, which should be the critical factor in your example.

[rusty69]

I must admit to never having been on the upper reaches of the Thames. It sounds like from mtb's description that it must be heavily tree-lined on both sides along its entire length with twigs galore to grab onto around every bend. 

Perhaps a good place to pick up free Firewood. 

Edited April 6, 2017 by rusty69

[mrsmelly]

9 hours ago, Richard10002 said:

No... why do you ask?

Presumably your self inflating life jacket will sort you out until help arrives.

I was merely pointing out that even the most experienced may not think of trying to stand up in what might be 3 or 4 ft of water, (or mud).

You do actualy find in real life situations that people immediately try to stand up or that is the case I have found in such situations. Whilst recovering people from the Trent ( usualy idiots who had jumped in ) we found they usualy swimmed ashore without assistance. I have 3 different boatmasters licences and each test I had with the MCA involved lifting people out of the water. It has to be said though that most of us ( myself included ) are rather stupid when it comes to common sense boating decisions. As a for instance I am boating this afternoon but as I am on a narrow canal I will not be wearing one of my many self inflating lifejackets and if I fall off and bash my head..................arent we mostly anyway daft?

[mrsmelly]

3 minutes ago, rusty69 said:

I must admit to never having been on the upper reaches of the Thames. It sound like from mtb's description that it must be heavily tree-lined on both sides along its entire length with twigs galore to grab onto around every bend. 

Mike is correct. It is very heavily wooded along many stretches and often they actualy encroach on the channel. The upper thames is VERY twisty and VERY narrow for a river and you would most certainly end up in the side/trees on many parts of it. In the most part the Thames is a pussy cat much less challenging than say the Severn or the Trent can be.

Edited April 6, 2017 by mrsmelly

[Neil2]

11 minutes ago, mrsmelly said:

You do actualy find in real life situations that people immediately try to stand up or that is the case I have found in such situations. Whilst recovering people from the Trent ( usualy idiots who had jumped in ) we found they usualy swimmed ashore without assistance. I have 3 different boatmasters licences and each test I had with the MCA involved lifting people out of the water. It has to be said though that most of us ( myself included ) are rather stupid when it comes to common sense boating decisions. As a for instance I am boating this afternoon but as I am on a narrow canal I will not be wearing one of my many self inflating lifejackets and if I fall off and bash my head..................arent we mostly anyway daft?

That brings me back to the point I made earlier, what is the point of carrying an anchor if you choose not to wear a life jacket?  Most folk on the river do not wear life jackets, therefore no point carrying an anchor.

[rusty69]

1 minute ago, Neil2 said:

That brings me back to the point I made earlier, what is the point of carrying an anchor if you choose not to wear a life jacket?  Most folk on the river do not wear life jackets, therefore no point carrying an anchor.

If you did carry an anchor it would be easier if you had a life jacket, unless it was a really big one in which case you would probably sink anyway. 

[mrsmelly]

1 minute ago, Neil2 said:

That brings me back to the point I made earlier, what is the point of carrying an anchor if you choose not to wear a life jacket?  Most folk on the river do not wear life jackets, therefore no point carrying an anchor.

You are of course correct. To add to it though why do numpties like myself and others who always wear a lifejacket on rivers ( I do ) but never wear one on a canal? Water is water and trying to breathe it whilst lying face down in a canal is just as hard as breathing river water.

[Neil2]

11 minutes ago, mrsmelly said:

You are of course correct. To add to it though why do numpties like myself and others who always wear a lifejacket on rivers ( I do ) but never wear one on a canal? Water is water and trying to breathe it whilst lying face down in a canal is just as hard as breathing river water.

I can only agree and I'm a confirmed life jacket wearer.   What is even more amazing is the last few times we have been through Harecastle tunnel I have been the only skipper wearing a jacket despite the advice from CRT and despite most folk knowing that someone lost their life for want of wearing one.   A clear cut case of "it won't happen to me"...

[rusty69]

9 minutes ago, mrsmelly said:

You are of course correct. To add to it though why do numpties like myself and others who always wear a lifejacket on rivers ( I do ) but never wear one on a canal? Water is water and trying to breathe it whilst lying face down in a canal is just as hard as breathing river water.

I always where one after heavy rain. You never know when you might end up face first in a puddle. 

[Chewbacka]

40 minutes ago, Neil2 said:

That brings me back to the point I made earlier, what is the point of carrying an anchor if you choose not to wear a life jacket?  Most folk on the river do not wear life jackets, therefore no point carrying an anchor.

So if I had forgotten to put on my life jacket, engine stops, close to and drifting towards a weir would you advise dropping the anchor first or putting on a life jacket???

[rusty69]

1 minute ago, Chewbacka said:

So if I had forgotten to put on my life jacket, engine stops, close to and drifting towards a weir would you advise dropping the anchor first or putting on a life jacket???

Answer. You should already have your lifejacket on

[Chewbacka]

1 minute ago, rusty69 said:

Answer. You should already have your lifejacket on

I fully agree that you should, but if you didn't I would drop the anchor first.  I didn't understand why not having or wearing a lifejacket makes having an anchor pointless.

[rusty69]

5 minutes ago, Chewbacka said:

I fully agree that you should, but if you didn't I would drop the anchor first.  I didn't understand why not having or wearing a lifejacket makes having an anchor pointless.

I agree. I too would drop the anchor first, although there is the argument that while deploying the anchor you are at greatest risk. On the other hand if your not wearing one you are less likely to get caught up on it. 

[MtB]

On 06/04/2017 at 10:15, Chewbacka said:

So if I had forgotten to put on my life jacket, engine stops, close to and drifting towards a weir would you advise dropping the anchor first or putting on a life jacket???

 

Now we are getting back to the point. Which weir, an can you post up a photo of it please?

I contend there are no weirs on The Thames you'll be able to get anywhere close to, with or without a running engine.

Edited April 6, 2017 by Mike the Boilerman

[MtB]

The wind will almost always take you to the bank first, and you twirl sedately in slow motion along the river. 

[rusty69]

15 minutes ago, Mike the Boilerman said:

 

Now we are getting back to the point. Which weir, an can you post up a photo of it please?

I content there are no weirs on The Thames you'll be able to get anywhere close to, with or without a running engine.

I humbly apologize for causing all the confusion. My flippant remark regarding a weir should never have been made. I apologize to mtb and all those concerned. A weir is definitely not a danger on the non tidal Thames and as such an anchor is not required for this type of Hazzard. 

The offending words:-

"You may be surprised at what you can lift when you are heading into danger."

"What danger would that be then, exactly?"

"A weir"

[MtB]

On 06/04/2017 at 11:07, rusty69 said:

I humbly apologize for causing all the confusion. My flippant remark regarding a weir should never have been made. I apologize to mtb and all those concerned. A weir is definitely not a danger on the non tidal Thames and as such an anchor is not required for this type of Hazzard. 

The offending words:-

"You may be surprised at what you can lift when you are heading into danger."

"What danger would that be then, exactly?"

"A weir"

 

Going round in circles here. Which weir, exactly?

I contend they are all securely barraged off to protect idiot boaters from going over them. Do you know of one that isn't?

[rusty69]

Just now, Mike the Boilerman said:

 

Going round in circles here. Which weir, exactly?

I contend they are all securely barraged off to protect idiot boaters from going over them. Do you know of one that isn't?

That is what the apology is for. 

[Richard10002]

10 hours ago, Mike the Boilerman said:

 

You haven't read the thread have you?!

A boat in the current of the 0.5mph we are talking about can be held by a tree twig caught in the side hatch.

(Gwarn, ask me how I know...)

Thread drift ? (See what I did there  )

I dont know the non tidal Thames so, assuming you are correct, the answer to the OPs question is "you dont need an anchor".

I also dont know where he got his "advisory" information from but, if it is some kind of official information, and it mentions anchors, it couldn't say that an anchor is not needed, as there would be one accident involving injury and/or damage, where an anchor would have helped, and a compensation claim would likely follow.

My comment on length was on the basis that the thread had drifted to the point where length was being discussed - one could deduce that this was a circumstance where it had already been decided that an anchor would be carried. It is true that, in benign conditions, an appropriate length/weight of chain sitting on the bottom will hold a boat in position but, add a small current and some moderate wind, (F4 or F5), and a boat will put some tension on the anchor rode.

Given the above, there is no point having 1 x depth, as the anchor wont touch the bottom, and a reasonable minimum is 3 x depth. (actually depth + distance to waterline). 5x is reasonable, and 7x at the other extreme.

For those who say having an anchor would be a waste as it would probably never be used - come and take a look in some of the lockers in my boat.... it's so long since I had a look in them, I dont even know what's in there. Adding an anchor would be no more of a waste than some of the junk I might need one day