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Go Back   SailNet Community > On Board > Gear & Maintenance > Which Anchor?
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Thread: Which Anchor? Reply to Thread
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Topic Review (Newest First)
02-29-2012 11:28 AM
ccriders Thanks to everyone for your responses. I've concluded the following:
1. 30 ft of 1/4" hi test chain
2. 250 ft of 1/2" 8-strand rode
3. Manson Supreme 25 lbs.
Here on the Texas coast a very typical scenario is for the wind to move from the dominant southeast into the south and then quickly veer to north as a front passes through to then settle into the northeast. While one should probably have two anchors out for this kind of situation, it sounds like the Manson Supreme is capable of handling the wind shifts.

So not the new question to Manson Supreme users; "What is the best bow roller for the Supreme?"
John
02-27-2012 07:48 PM
blt2ski I have a 7.5kg/16.5lb bruce knock off also on my 28' 7K boat, 15' of chain, and 250' of 3 strand, no issues in puget sound. Never dragged etc. Now a danforth style.......I've tossed all of them! never again, even for a race bouy! As said, if you get a wind/current shift, they seem to not want to reset.

I may at some future time up the chain one size along with 30'. I'm not planning on going to a 10Kg size any time soon. Altho I am looking for a 5kg size and 5-10' of chain to use for "race rule/spec" need the anchor on the bow. Keep the big boy below. As also said, one needs to know the "HOW" you plan to use the anchor as much as the style. I will say, in puget sound, many many bruce style anchors on the bows of boats.

Another local a few months back spent an enormous amount of time trying to set an aluminum fortress for RC duty. not sure it is what I want either, except for the "race" spec or a stern anchor/kedge type situation. Once set, specs show it to be a solid holding anchor!

Marty
02-27-2012 07:03 PM
killarney_sailor
You are half right

Quote:
Originally Posted by jfdubu View Post
I use a 15lb bruce knock off w/20' of 5/16 ht chain and "not sure how many ft of 1/2" three braid rode. 28' boat at 8k loaded. IMHO you can't beat a bruce lb for lb.

John
Pound for pound you certainly can beat a Bruce - even a real one. On the other hand, dollar for dollar a Bruce knock-off does pretty well.
02-27-2012 01:45 PM
jfdubu I use a 15lb bruce knock off w/20' of 5/16 ht chain and "not sure how many ft of 1/2" three braid rode. 28' boat at 8k loaded. Never had any troubles hitting and holding with this set-up even in 35 knot winds in Great salt Pond, BI. And my boat swings like a $3 --, you get the point. IMHO you can't beat a bruce lb for lb.

John
02-26-2012 10:21 PM
INMA I use a fortress SX7 with 8 meters of 5mm chain and 50 meters of 10mm nylon rope on my 24 foot trailerable yacht.

I also have a Manson Plough with 10 meters of 10mm chain and 50 meters of 10mm nylon line.

The plough anchor is used on weed and hard bottoms where the weight is needed to develop hold.

The Fortress is used on mud and sand bottoms where the anchor will dig in deep and hold.

I am not sure about all the other brands mentioned but having had the Fortress hold overnight with big winds then taken a long time to haul it because it had a huge lump of mud the size of a wheelbarrow stuck to it; I sleep well with the Fortress, it works and its light weight is a bonus for my aging body.

All the chain mentioned would be fine with a windlass but hauling it aboard manually in a rough anchorage would not be my favourite task.

I mainly anchor in very well sheltered anchorages for ease of anchoring and comfort. An 800kg 24 foot yacht is not comfortable in the more exposed anchorages.
02-26-2012 12:21 PM
stevensuf plastimo kobra 2, very well priced and gets great results in most tests
02-25-2012 05:55 PM
mitiempo I think the all chain question is easy on a larger boat with a windlass. On a smaller boat - 27' in my case and a bit lighter than the original poster's boat - a combination chain/nylon rode is best where the weight is put into the anchor for best setting and ultimate holding power.
02-25-2012 02:04 PM
MedSailor
Quote:
Originally Posted by klem View Post
Slightly off the original topic but still worth discussing is the length of chain that you use. Many of the posters have suggested that more chain will increase the holding power of your anchor but I don't agree with this in most practical circumstances. Having an all chain rode is ideal if your boat can take the weight because of chain's resistance to chafe but it won't help in ultimate holding power.

The vast majority of the time, the ultimate holding power of your setup is not an issue, the force on the rode goes up as approximately the square of the windspeed. Taking a design load of 1500 lbs for the OP's boat, that likely equates to 60 knot steady winds or even more depending on the sea state. During a breezy day, the load is more likely to be on the order of 2-300 lbs max. On these days, the weight of the chain will improve catenary which helps holding power and provide a bit of shock absorption. However, on the days where the ultimate holding power of the anchor is tested, the chain will be essentially a straight line. Another benefit on the calmer days is a reduced swing circle provided that it matches the other boats around you.

There is only 1 way for the chain to increase the ultimate holding power of the anchor and that is by changing the angle of pull on the anchor. In calmer conditions, chain achieves this through catenary. However, in extreme conditions, the chain is straight and it provides the same angle of pull as a piece of line. In these conditions, the only way to change the angle of pull is to increase scope. A good measure of whether there is sufficient scope is whether there is always at least 1 link of chain laying on the seabed. Since chain can only transmit force in tension and not bending, if even only 1 link is lying on the bottom, then the angle of pull is as low as it can be. In truly extreme situations, even this is not possible.

There are also 2 ways that a rode can lower the loads on the anchor for given conditions making it less likely that you will drag. The first way is by damping out dynamic loads that occur as the boat moves around. Chain does a very poor job of this in extreme situations because it is essentially already stretched to its maximum by being in a straight line and has no more give. Nylon line is an excellent shock absorber whether it is employed in a mixed rode or as a snubber. The other way to decrease the pull on the anchor is by the rode acting as an anchor itself and having resistance in the bottom. While it sounds like this should be a big benefit, it has been shown that there is almost no increase in holding power. Recently, I dragged 50' of 3/4" chain across a gravel parking lot and through the mud by hand and I am certainly no Hulk Hogan and this was big chain. Additionally, it must be remembered that in extreme conditions, the chain is not in contact with the bottom anyways.

You do need to keep enough chain in the rode to help the anchor set initially. Anchors set at relatively low loads so it does not take that much chain to keep the last few links on the bottom. In the OP's case 20' would probably be fine for all situations.

I hope that I have convinced you that during conditions where ultimate holding power matters, chain will not significantly increase it. The only way to increase holding power is by going to a bigger or different style anchor. To keep the shock loads down on your ground tackle, you should either use a mixed rode or a snubber. There are very good reasons to use more chain or all chain such as chafe resistance. Personally, I feel that mixed rodes are the best option for smaller boats that don't anchor in coral and all chain rodes are best for larger cruising boats. Like everything in boating, it is a balancing act but the weight should be put into the anchor not the rode.
Agreed. I LOVE chain, but I love it for being able to have less scope out and thus fit into a crowded anchorage. I also think it has benefit in helping an anchor reset as wind and current change. I believe it does this by keeping the pull angle very low as the boat swings around its anchor.

I totally agree though that it doesn't help much with ultimate holding power. More so I agree that too much emphasis is put on ultimate holding power when ease/quickness of setting and ability to reset have more real-world value.

I'm a big fan of the Fortress for example and used it as my primary for 100+ nights in a long cruise up the inside passage. It takes more skill to set and be sure it's set than a Bruce or other types though. It also doesn't set quickly where you drop it (as my Bruce does). This can be problematic in a tight spot such as when you stern-tie, or are trying to fit into a crowded anchorage. When stern tying it doesn't do you any good to have the anchor set 2 boat lengths closer to shore than you wanted. Part of my problem though, may have been that I used 55' of chain, when you're supposed to used 6' only on the fortress and initial setting on short scope is also recommended, which I didn't do.

MedSailor
02-25-2012 01:12 PM
klem Slightly off the original topic but still worth discussing is the length of chain that you use. Many of the posters have suggested that more chain will increase the holding power of your anchor but I don't agree with this in most practical circumstances. Having an all chain rode is ideal if your boat can take the weight because of chain's resistance to chafe but it won't help in ultimate holding power.

The vast majority of the time, the ultimate holding power of your setup is not an issue, the force on the rode goes up as approximately the square of the windspeed. Taking a design load of 1500 lbs for the OP's boat, that likely equates to 60 knot steady winds or even more depending on the sea state. During a breezy day, the load is more likely to be on the order of 2-300 lbs max. On these days, the weight of the chain will improve catenary which helps holding power and provide a bit of shock absorption. However, on the days where the ultimate holding power of the anchor is tested, the chain will be essentially a straight line. Another benefit on the calmer days is a reduced swing circle provided that it matches the other boats around you.

There is only 1 way for the chain to increase the ultimate holding power of the anchor and that is by changing the angle of pull on the anchor. In calmer conditions, chain achieves this through catenary. However, in extreme conditions, the chain is straight and it provides the same angle of pull as a piece of line. In these conditions, the only way to change the angle of pull is to increase scope. A good measure of whether there is sufficient scope is whether there is always at least 1 link of chain laying on the seabed. Since chain can only transmit force in tension and not bending, if even only 1 link is lying on the bottom, then the angle of pull is as low as it can be. In truly extreme situations, even this is not possible.

There are also 2 ways that a rode can lower the loads on the anchor for given conditions making it less likely that you will drag. The first way is by damping out dynamic loads that occur as the boat moves around. Chain does a very poor job of this in extreme situations because it is essentially already stretched to its maximum by being in a straight line and has no more give. Nylon line is an excellent shock absorber whether it is employed in a mixed rode or as a snubber. The other way to decrease the pull on the anchor is by the rode acting as an anchor itself and having resistance in the bottom. While it sounds like this should be a big benefit, it has been shown that there is almost no increase in holding power. Recently, I dragged 50' of 3/4" chain across a gravel parking lot and through the mud by hand and I am certainly no Hulk Hogan and this was big chain. Additionally, it must be remembered that in extreme conditions, the chain is not in contact with the bottom anyways.

You do need to keep enough chain in the rode to help the anchor set initially. Anchors set at relatively low loads so it does not take that much chain to keep the last few links on the bottom. In the OP's case 20' would probably be fine for all situations.

I hope that I have convinced you that during conditions where ultimate holding power matters, chain will not significantly increase it. The only way to increase holding power is by going to a bigger or different style anchor. To keep the shock loads down on your ground tackle, you should either use a mixed rode or a snubber. There are very good reasons to use more chain or all chain such as chafe resistance. Personally, I feel that mixed rodes are the best option for smaller boats that don't anchor in coral and all chain rodes are best for larger cruising boats. Like everything in boating, it is a balancing act but the weight should be put into the anchor not the rode.
02-25-2012 11:27 AM
HUGOSALT OP
"I normally anchor in mud, but who knows what I may find. My current set-up is a no name danforth style anchor with 5 feet of chain (coated) and 200 feet of 7/16 3-strand nylon, which came with the boat. I figure that this is the minimum set-up for normal conditions. I would like to add a more robust system giving me more confidence that I'm secure when the wind gets up unexpectedly in the middle of the night.p.s.
I'm now over 68 and not as robust as in the past and have to be able to handle the anchor alone. "
John,
Suggest if your current "no name danforth style" anchor is properly sized that you extend chain to approx. 30' and use when you
anchor in known good bottom in benign conditions for afternoon.
Will be easier to handle than below suggest...
Also suggest you go with Manson Supreme 25 for other situations
...questionable bottom, unsettled weather, overnight.

Reason for going against conventional wisdom and basicly using a
lunch hook (your current set up plus more chain) is that your
biggest problem with the Manson Supreme will come when it comes
time to haul back on board by hand...it sticks good...something you don't want to do every day...but something you will be happy to do after a rough night and it has done its job.

Above is based on my experience on my 30', (8500#)in mostly sand and mud, with danforth and 50' chain up to 30 kts consistant wind...if questionable weather/several days anch out comes Delta 35
Above may help keep you on the water for years to come...
or maybe you can angle for a windlass for your next birthday!
Best,
Hugo

hopefully replacing danforth with Manson Supreme 25 this spring
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