Second anchor

HoratioHB

HoratioHB

Well-Known Member
Joined
2 Oct 2006
Messages
895
Location
Near Plymouth
sowethereyet.blogspot.co.uk
The current SWMBO made me leave sunny St Lucia for a very grey and dull Plymouth just to see the kiddies for Christmas - serves her right shes now got a cold. However with some time on my hands and decent internet I though I would pose a question that has been bugging me for some time.

'Its gonna be windy tonight so I am going to put out a second anchor' is often heard. I've done this myself several times and am beginning to think its actually a bad idea. This is despite reading the article in this months YM about the yacht DreamTime in Belize. My second anchor is a bloody great Fortress which is on 10 metres of 8mm chain and then string whereas my main Delta is on 10mm chain, so getting the two to share the load is just about impossible. This then means that the second anchor is really just there as back up should the first one drag. However many anchorages I end up get pretty crowded and by the time the boat had dragged back and settled on the second anchor I may well have hit someone else. Should they both drag I've then got a nightmare situation of trying to recover two anchors and only one is on a windlass the second one has to be pulled up by hand. In Grenada the other day a really nasty squall came through and a boat started dragging down on me - I had to motor out of his way and then re-anchor as he ended up where I was. Had I put a second anchor out it could have been really messy.

What do the jury think?
Is there a way of getting two anchors with different types of rode to load share? (apart from a Bahamian before someone mentions it).
Personally I am thinking of partitioning my anchor locker and fitting the Fortress on the bow next to the Delta so I can drop it in a hurry if necessary, but sticking to one unless I have lots of room. After all if its that windy I tend to stay up on anchor watch anyway.
 
Thanks for the link, but there appears to be an underlying assumption in that article that the two rode materials are the same, and I like most people have heavier all chain on one anchor and mainly nylon on the other. The article, like all I've read seem to ignore this fact. If I put 60 Meters of 10mm chain on both and kept them in the bow (the only realistic place) my boat would be way out of trim because of the weight.

Tandem mooring is an option but I've hear some interesting stores of how it can fail and once again with two types of anchor with different holding powers how do you set it to work and share the load???
 
If only there was a way to combine anchors, battery charging and the build quality of Bavaria's!

I agree with the original post but wondered if the primary purpose of the second anchor is to prevent heavy swinging/yawing and the resulting shock loads breaking out the main anchor?
 
Hi HB
Funny you should bring up this xmas chestnut!
Got the weather forcast for St Martin at 5pm and it contained the phrase "gust's to 50mph" so out came the second (40lb Pipper) and as the wind was not due to shift but just increase I used the In Line Tandem method as it does increase the holding power of both anchors at the same time. Our primary Anchor is great upto about 40/45 knts depending on the bottom composition. But if I want to sleep during the Christmas Winds that occur Annually then 2 anchors will let me sleep without jumping out of bed at every loud noise
(SWBMO prefers that I sleep as well).

Happy Xmas
Mark n Lee
 
I've got 25m 7mm chain and 50m octoplait on the kedge.

Quite frequently use it in conjunction with the bower on 65m chain + 20m textile rode, usually at 90 degrees when expecting a wind-shift, but nearly as often from the stern to keep from swinging, either into others anchored or keep 90 degrees to a swell.

Found both completely satisfactory.

Never had a drag under such a deployment so can't comment on getting them up in the event of a drag.
 
A professional yacht thief told me how to do it (long story how I came upon the advice). He would steal the yacht then anchor it in a bay off the Spanish coast for a few weeks until the heat was off, then pick it up. His trick was two anchors nose to tail with a few metres of chain in between. Our new bower is usually fine but in poor holding or bad weather I shackle on a Danforth behind the bower, hanging from 2m of chain. Forget the 8mm or 10mm issue....the strength of the chain is much greater than the strength of typical cleats or samson posts. The time chain and tackle gets damaged is when recovering the tackle with a very short scope out. Then the forces can be horrendous.
 
[ QUOTE ]
Anchors in tandem? I've had no probs with 2 x 25kg danforths linked nose to tail by 7m of 12mm chain, then 50m 10mm chain.

[/ QUOTE ]

I did that in puerto Andraitx during a storm in 1979 on the boat in my avatar.

The winch couldn't even start to lift the first one and being single handed motoring it out didn't work either.

I still suffer with an occasional bad back as a result.
 
Ineresting - but most of you who tandem anchor seem to have two anchors of the same type - I don't as I wanted to have some variety for different bottoms. Now gonna seriously think about a second Delta. Luckily in the Caribbean there is rarely a big wind shift and even rarer for a tide shift to affect the boat unless the wind is very light. My boat does sail up to the anchor and I had a riding sail made to reduce it which works well but backwinds the wind generator. So I think I might also experiment with the Fortress out at 90 degrees and see if that cuts the swinging down.
Just seen the Caribbean weather forecast - might have to apologise to SWMBO about coming home - looks pretty windy!!!

Oh and Happy Christmas everybody.
 
The solution is to have a first bower anchor that is big enough and have plenty of chain. The problem remains that it is the sheering about that breaks out the anchor and causes dragging. Anchors that are big enough almost never drag from a direct pull unless you lay one out in soup.
If faced with very strong winds, the second anchor should be used to prevent sheering. Classicly, veer about 10 times the depth on the bower and then, when just to one side of the wind line let go the second bower with 4 times the depth of chain on it. The second anchor will inhibit sheering about.
I have been doing this now for over 60 years and get little trouble unless some twit anchors over the top of me, or (once) the point of the CQR went neatly into a discarded bean can.
For cruising boats (forget racing) when you want to sleep at night:
1. Have BIG anchors (about 30% over the standard yottie tables)
2. Have two of them at least.
3. Have them on chain cable. Yachts over 35 feet 10mm, over 45 feet 12mm. It is difficult to get 7/16" nowadays but that was very useful.
4. Have your foremast in a tabernacle, and for very violent winds (over F10) lower the mast. She'll lie much more peacefully.
Lastly, when faced with a violent wind F11, and one anchor short, we laif to a stern anchor with the tiller well lashed. She rode quiet as a mouse with no sheering.
Study the tachts centre of lateral resistance and the way it changes as she moves through the water.
Happy Anchor watch.
 
By coincidence we put out a second anchor two days ago - forecast gradient winds 25 to 30 knots, squalls to 40 knots.

Main anchor is CQR on 30 metres of chain (we have 60 metres but couldn't put out more, boats too close). Second anchor Fortress on 15 metres of chain and 20 metres of warp. We are hanging off both of them with no problems. What we do is wait until the bows are into wind and tighten the warp on the second anchor until the load is shared between the two anchors. Obviously as you swing more load moves to one of the anchors. However we cut down swinging with a riding sail. It all works fine.

I wouldn't go the anchors in line route unless you have dive kit and can set them both by hand. Normally if one sets it stops the other one setting.
 
[ QUOTE ]

'Its gonna be windy tonight so I am going to put out a second anchor' is often heard. I've done this myself several times and am beginning to think its actually a bad idea. This is despite reading the article in this months YM about the yacht DreamTime in Belize. My second anchor is a bloody great Fortress which is on 10 metres of 8mm chain and then string whereas my main Delta is on 10mm chain, so getting the two to share the load is just about impossible. This then means that the second anchor is really just there as back up should the first one drag. However many anchorages I end up get pretty crowded and by the time the boat had dragged back and settled on the second anchor I may well have hit someone else. Should they both drag I've then got a nightmare situation of trying to recover two anchors and only one is on a windlass the second one has to be pulled up by hand.

[/ QUOTE ]

I share your concerns about managing 2 anchor lines if you drag. With a small crew in high wind conditions I don’t feel it is practical, unless you are prepared to cut loose one anchor (and to buoy this introduces the real possibility of getting it caught around the prop)
I also believe it is impossible to share the load between the anchors, so the increased holding ability of the second anchor is marginal.
Tandem anchoring solves these problems, but raises new significant concerns such as setting both anchors and the effect of major wind shifts.
I think the answer is to have a single large high quality anchor that has enough holding ability.
After dragging my plough anchor all over the Med I purchased a larger Rocna and I am hoping this will be the ideal solution. Initial results are excellent, but I have yet to experience the more extreme conditions that will put it to the test.
 
Just a little addition.
During my apprenticeship, I was told by an excelelnt seaman with decades of experience that it is not the anchor that holds the ship, but the chain cable, and the anchor only holds the end of the chain in one place.
Also, most anchors break out because of a sideways pull, and this is the reason the CQR was designed with a hinge. It was designed for the old Imperial Airways fflying boats which were notoriously agitated.
I have tried most anchors at one time or another and have found that lb for lb they do not differ that much, which reinforces the advice in para 1 above.
 
I've never fancied anchors in tandem. One or other is going to take most of the load and as a result the lightly loaded one will not dig in. In a general way the more iron you have down the better. Maybe a single anchor with a heavy "angel" is a better combination than tandem anchors.
I still favour two independent anchors as the best option in marginal conditions.
 
I hang my Danforth 2m behind the bower (Delta) on its own 2m chain. So the Delta hits the bottom first and the main rode pays out behind it....then the Danforth touches the bottom and 2m later the join between the Danforth chain and the main rode are nearing the bottom.

We haven't done it often enough to be able to cite any statistics but it does seem to work.

As for bringing it up again, in very deep water when we have later laid to our 'emergency' 25mm octoplait rode, we have not yet had a problem. I do have a radio remote control of the windlass so I am very flexible. Even with one anchor (Delta) on occasions I have to motor it out to save the windlass.

With anchors and anchoring... there are few bad anchors and plenty of bad bottoms.
 
[ QUOTE ]

I have tried most anchors at one time or another and have found that lb for lb they do not differ that much, which reinforces the advice in para 1 above.

[/ QUOTE ]

The Med is a wonderful laboratory you can observe many boats anchoring an then snorkel over and see how well buried their anchors are. Their are major and consistent differences between anchor types. Independent anchor tests verify that their is an order of magnitude difference in holding power between designs, at least in relatively firm bottoms (if you forgive the expression).
There are arguments as to which anchor is best, or to which anchor is best in a specific bottom type, but with respect I cannot see any evidence to support the contention that they are LB for LB similar.
300LB and 5000LB force plus are not similar in any language.
 
You must log in or register to reply here.

Other threads that may be of interest

B
Help to test new Anchor App on Android
Replies
1
Views
938
Brendan01
B
N
Viking AnchorsI
Replies
0
Views
124
Neeves
N
S
What are these for?
Replies
13
Views
700
Refueler
Refueler

Share this page

Top