anchor weights (buddy)

[briangal]

I am trying to find details about the effectiveness of anchor weights ( americans call them anchor buddy ).

I recall an article in PBO around 1998 /2000 where this product was thouroughly dismissed as a waste of money.

Can anyone point me in the right direction to find this report or any other details that may help.

 

[john_morris_uk]

There was a Kiwi (prety sure it was Kiwi anyway) site that had a whole load published on anchor chums a while ago. I only know because a chap at work who I occasionally sailed with printed off a load of pages from it to give to me as he thought I might be interested. It might have referred to the device as an 'angel' - sorry I can't remember more. He's retired now, but if you are desparate I'll phone him up.

 

[briangal]

Thanks John,

I am based in NZ I recall they called it an angel, interesting you call it an 'anchor chum.' They seem like a lot of extra work, particularly if they dont work. The vessel we are having trouble anchoring fast is a 45 ft flying bridge motor yacht Rivera 45

 

[Anonymous]

[ QUOTE ]
The vessel we are having trouble anchoring fast is a 45 ft flying bridge motor yacht Rivera 45

[/ QUOTE ]What problems are you having? Chums aren't the only solution although they are very useful in certain conditions - in particular when you need a shorter rode than you would like due to close proximity of other anchored vessels, size of anchorage or length of rode carried.

The type of anchor, quantity of chain and anchoring technique are all more important than chums and they need to be addressed first. Earl Hinz is the author of the most popular textbook called 'The complete book of anchoring and mooring' which will no doubt be on display at the Boat Show if you are going.

David

 

[john_morris_uk]

Don't mind what I call it. I've never used one myself, although its in the back of my mind/armoury of things that might work in some circumstances/if the need arises.

I know that one company was manufacturing weights to add to an anchor line and I think it was them who names it a 'chum'.

As one wit said, another anchor would be good to add to your line - but it would be better on the end than hanging down as a weight: anchoring with tandem anchors is another trick that works very well.

 

[snowleopard]

there are two main benefits of chums-

by adding to the weight of the cable it reduces the tendency to snatch

if it is lowered far enough to rest on the bottom most of the time it will reduce your tendency to sail about in an anchorage (in light conditions)

it will not add much to the holding power of the anchor as the cable will be pulled straight when there is enough load to pull the anchor out.

 

[Robin]

Brian

The real problem surely is the anchor system or method. I wouldn't be very happy at anchor if I thought I was only staying put with the (dubious) assistance of a weght hanging on the anchor cable!

This is time IMO to go back to 1st principles. You need a good anchor design/type for the conditions you anchor in, of sufficient weight and on a proper chain rode. The anchor needs to be carefully and gradually dug in astern until you are sure it is holding.

Do your problems perhaps stem from a Boatbuilder supplied anchor, chosen perhaps for its compact size (read price) and easy 'designer' stow on the bow type features? I ask because often I have seen high windage powerboats with what I would consider as very small anchors.

Robin

 

[macca]

Anchor weights are marketed by a company in New Zealand - see www.anchorbuddy.co.nz I believe they are made of zinc and slide down your anchor chain.

My Dad used a home-made version (a steel weight of around 5 kg) off the West Coast of Scotland for many years. This was easier to use than a second anchor, and provided improved holding in nasty weather without ridiculous amounts of chain.

 

[boomerangben]

The main benefit of an angel is to reduce the cable angle at the anchor and therefore reduce the risk of break out. You might be correct to consider that a mooring system as failed if chain at the anchor is lifted off the seabed hence an angel is very useful. You can achieve the same using heavier or more chain but an angel would be cheaper. However sizing and positioning the angel would be important and I don't know of any rules of thumbs for doing this.

 

[duncan]

[ QUOTE ]
You might be correct to consider that a mooring system as failed if chain at the anchor is lifted off the seabed

[/ QUOTE ]
I rather hope not!
Most anchors retain a high percentage of their holding through the initial 'lifting' of the stock (10%) and it is one of the primary measurable efficiencies of an anchor as to the relationship between this angle and holding efficiency.
It is from this relationship that the rules of scope are effectively drawn up as beyond 6:1 there is no improvement in the relationship between this angle and load.
Finally, as is obvious from the above, whilst it may seem logical to apply any additional weight top the end of the stock, or a short distance up the rode, in order to improve the angle of pull thisis not necessarily the best move as any additional weight in the anchor itself will also increase the holding power (because it brigs a substantial increase in working area with it) - and with some anchors this can be very significant eg imagine the effect of a 6 kg chum on the holding of a 6kg fortress at 6:1 scope, then compare it to the holding of a 12kg fortress at the same scope - my money (or life) is on the latter.
As said above the chum works great in light lunch hook conditions where you want to shorten up the swinging and reduce snatch on an all chain rode.

 

[hylass]

You will find a very interesting Web page where you will have all mathematic formulas in relation with the mooring: http://alain.fraysse.free.fr

In accordance with this web page, the "anchor Buddy" or "Chum" or "Angel"... doesn't seem to be very efficient...

I fully agree with the PBO conclusions "It's as a waste of money."

 

[Sea Devil]

I used a home made 'anchor buddy' for years - brilliant - the biggest advantage is if there is a swell coming in it stops the chain tightening and keeps the cantanery low in the water - greatly increases the holding power of the anchor in deeper water. I use to use my 'buddy' as a matter of course every time I planted the pick... Mind you I was a liveaboard and was always on anchor.

when I got to New Zealand I purchased a proper 'buddy' called an 'Anchor Chum' and it is superb - very well made - nice roller to run down the chain and a stainless gate to keep it on the chain -

 

[seaesta]

I have found these effective on my small 25 foot yacht. As I have no anchor winch so the weight of anchor i can use is limited by what I can haul up by hand. The anchor weight is pulled up first. It certainly helps me to sleep better at anchor knowing I have this extra weight. (especially after that unforgettable night when I woke up bouncing on a rocky kelp bed in the Farnes after my anchor dragged)

There have been lots of inconclusive forum debates about these devices in the past but I would now not be without mine.

I made mine from an old stainless steel tea pot (yep Im a Brit). I put a good sized shackle in the pot and then filled it a little at a time with molten lead. So the tea pot is in effect a corrosion resistant outer skin on a big lump of lead. This works well. It has great holding properties of itself in very soft mud and is easily washed off - it has enabled me to "kedge" to one side when my prop got fouled in the Caledonian canal.

A previous model I made was quite flat in section. This tended to wave about like a fish lure in strong tides and the increased drag offset much of the advantage of the device - hence the optimum tea pot shape in the current version.

I think you would have to be a right wuss to buy rather than make one of these.

Martin

 

[MedMan]

I have never used a chum on my main anchor chain - the extra weight created by using 10mm chain rather than 8mm chain already does that for me and far more effectively at that. However, whenever I set a second anchor for whatever reason it is always on rope and then I always deploy a chum. I do so, not only to improve the angle of the rope to the anchor, but even more importantly, to keep the rope down out of the way of propellers on passing boats. For this reason I deploy the chum by sliding it down the anchor rode checked by a 5 to 10 metre length of 10mm rope. I know it would be more effective in a blow if it were nearer the anchor, but it would not be so good at keeping the rode out of the way of props which is my number one priority.

Oh yes - I nearly forgot. To make my chum I drilled 12mm holes through all my diving weights which I carry anyway. When I need the chum I just thread them onto a length of 10mm stainless studding with a locknut at the bottom and a threaded eye at the top. Once my second anchor is out (usually laid by dinghy) I get in the dinghy with the chum and just use a short length of 10mm line tied around the rode and through the eye. Always remember: carry nothing on your boat that doesn't have at least two uses!

 

[hylass]

Efficiency of a \"Chum\"..

All those reported experiences are too limited to be a good proof of the efficiency of a chum.

A Chum could have three different purposes:
- To increase the holding of an anchor by reducing the pulling angle
- To increase the damping effect of a mooring line
- To reduce the swinging area of an anchored boat

The problem is that the position of the chum along the mooring line will be completely different in relation with the requested purpose:
- To increase the holding of an anchor, the weight has to be as close as possible to the shank of the anchor
- To increase the damping effect, the weight has to be located at the middle of the line
- To reduce the swinging area, the weight should be at approximatively one time the water height..

Quite difficult for this poor Chum to be everywhere at the same time.. then two solutions:

1°) to use three different chums, one near the shank of the anchor, one in the middle of the line and the third one at one lenght equal to the water height.. Not so easy

2°) the chum you will use, will be, for ease of handling reasons, limited at around 10 kg.. or aproximatively the weight of 4.5 meters of 10 mm chain.. So, put 5 more meters of chain and you will nearly (except for the swinging area) achieve the same results.. (at lower cost and ease of use..) (or 9 meters for the equivalence of a 20 kg Chum)

Now, about the diminution of the swinging area.. this is only valid with light winds.. As soon as the wind build up, the 10 kg chum will be soon lifted up, and will no longer be efficient..

Also, in a crowded anchoring area, it is not wise to have a different swinging characteristic than all others anchored boats.. it is much better to move at the same time and on the same way than others anchored boats.

Now think about the efficiency of a 10 (20?) kg chum.. in relation for example with the force exerted on a 10 meters boat, by 45 knots of wind: 820 daN.. what action could have a so small 10 kg weight?? (0,01 %) Just ridiculous..

The main action of a chum is mainly a psychological one, one the mind of users.. it gives a (false) sensation of security..

Abstract from http://alain.fraysse.free.fr (sorry the mathematic formulas as well as the photo, can't be reproduced..)

2. Kellet (or Chum)

In the previous page, formula (1.2) gave the critical value Fc that lifts an homogeneous rode completely:
(1.2)
If we add a weight K at distance Lk from the bow (fig. 1.6), what improvement can we expect beyond Fc?


Figure 1.6 - Kellet

The equations of this problem are discussed in the static theory chapter. There is no simple expression of the result, but if we assume the scope is greater than 3:1, an acceptable approximation (with less than 6% error) is given by:
(1.6)
These expressions show the improvement equals the kellet weight K multiplied by the ratio Lk/H. Consequently, the best improvement is obtained by putting the kellet near the anchor, where it equals the kellet weight K multiplied by the scope N.

With the same kellet in the middle of the rode, the improvement would be halved.

An all-textile rode with a kellet close to the anchor has the same performance as an all-chain rode of same length, with only half the total rode weight. This confirms that concentrating the weight down the rode, if possible, would be much more effective than spreading it along the rode.

Unfortunately, handling capabilities limit the weight of actual kellets around 22 kg (50 lb), which is insufficient in severe wind conditions unless the scope is very large.

In addition, using a kellet does not significantly improve the swinging radius R.

 

[Lash]

Can't find anything in back copies of PBO around the time you mention, but Yachting World did a test on a German weight in July98 and that jammed on chain any bigger than 5/16, so it didn't suit me. Yachting Life Nov 2002 tested the NZ one around Scotland and as that is where my boat is, I was very interested to read that Dave Morgan thought the chain model was brilliant and he 'wouldn't be without one now in Scottish waters'. He was right. It is brilliant and very well made. Also, Yachting Monthly in Oct 2003 rated the buddy as essential equipment to have on your boat.
I know some guys love formulas but in practice if my boat stops swinging wildly and I sleep better at night, my buddy is worth its weight in gold.