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Old 28-02-2019, 15:10   #1
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Mantus rode

So, I have a 35 lb Mantus on a rode 5/8" x 200' 8-strand spliced to 3/8"x15' d4 chain. This was built for my present 36 Hunter, 12,000 lbs + crew + gear.
Trading up to a 40' , 18,000 lbs + crew + gear.

This anchor felt oversized for the 36, so I'd like to think its more appropriate for the new boat. Plan on replacing the present 15'of chain with a longer length, somewhere between 50 & 100', but this is guesswork.

I'm in New England, if I anchor in 40' thats a lot, and 200 nylon+100 chain is over 7:1. That sounds like quite a bit. 100' of chain is 140 lbs + 35 lbs, all on the nose. 50 ft of chain cuts thats down to 105 lbs, but I'm thinking I should split the difference.

Is my thought process prioritizing the wrong thing here? How out of whack is all this? I just spoke to a friend with a 42' 24,000 lb boat (+ +) & he's carrying 300' of chain!

Thx for the thoughts,
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Old 28-02-2019, 16:06   #2
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Re: Mantus rode

My personal opinion, a 35 lb anchor is a bit undersized for a 40' boat. I have a 42' 24,000 lb sailboat and have a 65 lb Mantus. My last boat was 34' and I had a 35 lb plow and thought that was just barely adequate.

I guess it will depend to some degree on when and where you anchor. If only daytime in uncrowded, protected harbors then 35 would probably be fine 99% of the time but a 45 lb would be better and if anchoring overnight you would sleep more soundly with a 55 lb.

On the other hand, the rode sounds just fine, even for a larger anchor.
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Old 28-02-2019, 16:50   #3
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Re: Mantus rode

To skew your perspective a little more, we’ve got a 32’ 15000# boat with a 45lb mantus, 225’ of 5/16” G4 and 250’ of 5/8” octoplait and 1000 watt windlass on the bow.


IMHO the 35 lb hook isn’t quite large enough for a 40’ boat.
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Old 28-02-2019, 16:56   #4
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Re: Mantus rode

I have a 42ft, 33000lb boat at last haul out before moving aboard. I feel more comfortable with a 65lb but may need to run a 55lb due to my furler being so low.

Curious to know if your concerned regarding the weight on the bow while anchored?
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Old 28-02-2019, 17:54   #5
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Re: Mantus rode

We run a 85# mantus with 300ft of 5/16 chain on our 47,000 pound 46ft boat. We sleep soundly knowing we’re not going anywhere.
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Old 28-02-2019, 18:29   #6
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Re: Mantus rode

Quote:
Originally Posted by apirate View Post
We run a 85# mantus with 300ft of 5/16 chain on our 47,000 pound 46ft boat. We sleep soundly knowing we’re not going anywhere.
I too would sleep soundly with that I'm guessing fully loaded my 42ft boat pushes 40k lbs. Theres a large chance I'll be able to make the modifications needed to fit the 65lb mantus but I'll be running 3/8" ht chain. I wouldnt want to go anything lower than 55lb though :/
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Old 04-03-2019, 21:29   #7
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Re: Mantus rode

I currently have an 85# Mantus on our 33,000# 50' boat. 275' of 5/16 G70 plus 250' of 5/8" nylon (from an older boat).

I'll likely move up to a 105# Mantus and add a second 275' length of G70 when we get serious about cruising.
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Old 07-03-2019, 09:09   #8
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Re: Mantus rode

Quote:
Originally Posted by TommmD View Post
So, I have a 35 lb Mantus on a rode 5/8" x 200' 8-strand spliced to 3/8"x15' d4 chain. This was built for my present 36 Hunter, 12,000 lbs + crew + gear.
Trading up to a 40' , 18,000 lbs + crew + gear.

This anchor felt oversized for the 36, so I'd like to think its more appropriate for the new boat. Plan on replacing the present 15'of chain with a longer length, somewhere between 50 & 100', but this is guesswork.

I'm in New England, if I anchor in 40' thats a lot, and 200 nylon+100 chain is over 7:1. That sounds like quite a bit. 100' of chain is 140 lbs + 35 lbs, all on the nose. 50 ft of chain cuts thats down to 105 lbs, but I'm thinking I should split the difference.

Is my thought process prioritizing the wrong thing here? How out of whack is all this? I just spoke to a friend with a 42' 24,000 lb boat (+ +) & he's carrying 300' of chain!

Thx for the thoughts,
Hi Tomm,

I am a marine service provider and consult a lot of boaters on ground tackle.

Everything may be tempered by how much you intend (and really will) anchor out.

If you only anchor out one night, when the forecast is fair, 3 times per year, one doesn't have to be quite so serious about their ground tackle.

For someone living aboard, ensuring the wake up where they go to sleep, regardless of the weather, is much more important.

I could be wrong, but it sounds like you have been hand bombing the ground tackle.

Beware if you are switching up to a windlass, that you select the chain AND rode dimensions to suit the gypsy and vice versa.

Q1. Anchor.

Rule 1: Follow the manufacturer's recommendations for the standard anchor.

For the premium brands, (Rocna, Vulcan, Mantus, Ultima, etc.) you can pretty much go with their recommendation, for conditions up to about 40 knots.

Those who go bigger, put more weight at the bow, and strain on the boat and windlass, (or their back if hand bombing) when it isn't normally required. Temper this with how frequently unexpected squalls may be encountered.

Rule 2: Plan for the worst. If you may experience conditions greater than 40 knots, accommodate that by going up in anchor size and weight, or using multiple anchors. I recommend having a standard anchor, a storm anchor (50 - 100% bigger) and alternate technology anchors to suit different bottoms, (e.g. Danforth, Fortress, fisherman, plough, etc.)

Rule 3: Have at least your standard anchor at the ready, to deploy instantly in an emergency (e.g. engine quits while approaching a lee reef cut entrance).

Pule 4: Secure all anchors when underway. These can really become loose cannons and do a lot of damage if they let go, especially in storm conditions, where even being at the bow is dangerous. (I've done a lot of fibreglass repairs for customers due to this very reason.)

Q2. Chain.

Rule 1: If you will be anchoring in rock and coral, rope rode will chafe and set you adrift. You must have enough chain, so that what is laying on bottom, is chain.

Rule 2: Enough chain to provide the catenary to facilitate setting. To set an anchor properly, the rode must be virtually parallel to the sea bottom. If you have insufficient chain weight to hold this while backing up when you "cinch" the rode, the anchor is guaranteed not to set. (This is the number one cause of dragging.)

Rule 3: At least one boat length. This has been a long standing rule, and I believe it is again suitable for up to about 30 knots, if one really knows how to anchor well, consistently. For the less experienced, and heavier conditions, I don't believe this is enough. For a modern boat with a plumb bow, and high buoyancy forward, 300 ft of all chain rode is not overkill. For a traditional boat with fine entry and long overhangs, where it is important to keep weight out of the bow, I recommend a minimum of 2.5 times the LOA in chain.

Rule 4: Chain doesn't give. One cannot secure the boat to the ground tackle by chain alone or it could rip the boat apart in a blow. If you use a chain / nylon rode, you can just let out all the chain, with about a boat length of nylon, and that (with the catenary in chain below about 30 knots) will act as a decent shock absorber. Beyond these conditions, or for all chain rode, you will need a snubber.

Rule 5: The opposite end of the rode. The bitter end should be secured to the boat, such that if the boat dragged backwards at hull speed, with the anchor firmly set, and suddenly came up short at the end of the rode, the rode will remain secure to the boat, with no damage. (I have performed anchoring training for newbies on their boat, to find the rode bitter end, not even connected to the boat.) For all chain rode, you will also need a chain stopper, to ensure the load on the rode, is not transferred to the windlass.

Rule 6: Total rode length. For the standard rode, this needs to be at least 10 times the maximum depth + bow height, you ever expect to anchor in.

E.g., For bow height = 5 ft and max depth = 25 (Florida and Bahamas) you could get away with Rode Total = (5 + 25) X 10 = 300 ft.

To anchor in 50 ft of water, you should have Rode Total = (5+50) x 10 = 550 ft.

Some who use all chain rode, may claim less is acceptable. I disagree. Once one reaches a circuit wind velocity vs vessel windage (could be as low as 20 knots, especially if the boat your are considering is a deck salon with solar arch, dinghy on davits, and full enclosure) that removes the effective catenary in the chain, it acts pretty much identical to a nylon rode, and does not reduce the importance of total length vs depth any significant amount.

Hope this helps.
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Old 08-03-2019, 01:27   #9
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Re: Mantus rode

Tom, your anchor as stated by others is undersized. New generation secondhand anchors seem to fetch a good prices so perhaps consider changing it to meet the Mantus recommendations and either selling or keeping it as a second anchor.

https://www.mantusmarine.com/mantus-...-3088b152-cc33

They also have a good article on anchor rode:

https://www.mantusmarine.com/mantus-...e/rode-sizing/

Rocna also have a good article on catenary and anchor rodes worth reading:

http://kb.rocna.com/kb/Scope_vs_catenary

https://www.mantusmarine.com/mantus-...e/rode-sizing/

I disagree with Rod and whilst his advice isn't dangerous, it does warrant reading with a pinch of salt IMHO and comparing with what the manufacturers have published.

You haven't said what your new boat is, but I would be surprised if it can't accommodate 30kgs of anchor and 60m of chain plus a reserve rope rode on a 40ft yacht.

Pete
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Old 08-03-2019, 06:06   #10
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Re: Mantus rode

Quote:
Originally Posted by Pete7 View Post
I disagree with Rod and whilst his advice isn't dangerous, it does warrant reading with a pinch of salt IMHO and comparing with what the manufacturers have published.
Pete
Well that is pretty rude in my opinion.

What is "wrong" with what I posted in your opinion?

If you take note, I did suggest relying on manufacturer's info at the very start of the post.

The balance is just based on my experience and opinion.

To each their own.
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Old 08-03-2019, 09:29   #11
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Re: Mantus rode

Quote:
Originally Posted by ramblinrod View Post
Well that is pretty rude in my opinion.

What is "wrong" with what I posted in your opinion?

If you take note, I did suggest relying on manufacturer's info at the very start of the post.

The balance is just based on my experience and opinion.

To each their own.
Rude? Pete politely disagreed and is certainly entitled to his opinion as much as you are to yours.

I happen to agree with him. Even anchoring a few times a year in conditions predicted to be mild entails some risk. I have many times experienced thunderstorms and really strong wind gusts when forecasts called for calm. It only takes once to lose a boat.

I also don't think manufacturers recommendations are always correct. Not sure why but I think many recommend smaller anchors than are warranted. Maybe they don't want to scare away customers that see the higher cost for the larger anchor.
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Old 08-03-2019, 10:53   #12
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Re: Mantus rode

]
Quote:
Originally Posted by ramblinrod View Post
What is "wrong" with what I posted in your opinion?
Rod, I disagree with your advice from "Q2 Chain" onwards.

Rule 1. How would someone know if only the chain is lying on the bottom? Wouldn't all chain be safer?

Rule 2. Does catenary play a part in setting an anchor? I tend to start gently building up to reversing hard with with the engine to test the holding, at which point the chain will be taught. The manufactures recommend weight in the anchor not the chain. What evidence do you have that the weight of chain is the number one reason for anchors dragging?

Rule 3. "At least one boat length This has been a long standing rule"
Of what, rode? Who has decided this is a long standing rule? So one boat length is suitable for 30 knots of wind? really?
"heavier conditions, I don't believe this is enough"
Well I have to agree with you there.
"300 ft of all chain rode is not overkill "
You haven't said anything about the size of the boat this refers too, but 100m of chain will be difficult to store on a boat much below say 35ft.
"I recommend a minimum of 2.5 times the LOA in chain"
Ok, you are entitled to your opinion, my concern is since chain is expensive someone might take you at your word. I think you will find most of us carry a lot more and you recommend even more later on as we will see.

Rule 4. "One cannot secure the boat to the ground tackle by chain alone"
Oh I think you can.
"or it could rip the boat apart in a blow""
Okay, does this happen often in your neck of the woods?
"If you use a chain / nylon rode, you can just let out all the chain, with about a boat length of nylon"
Was this one boat length or the X2.5 boat length of chain? is that 35m for a 10m yacht? doesn't the depth play a part in determining the length of rode to use or is it just the boat length?
with about a boat length of nylon, and that will act as a decent shock absorber. Beyond these conditions, or for all chain rode, you will need a snubber.
I don't understand the difference, you have said both less and more than 30kn need chain and a snubber?

Rule 5. "The bitter end should be secured to the boat"
Agreed, you might add that seizing with rope that can be cut in an emergency would be useful, which I have had to do.
"Such that if the boat dragged backwards at hull speed"
Under what circumstances could this happen?
you will also need a chain stopper, to ensure the load on the rode, is not transferred to the windlass"
I think this sentence is excellent advice for those with chain, but I thought you were advocating more rope than chain?

Rule 6. "For the standard rode, this needs to be at least 10 times the maximum depth + bow height, you ever expect to anchor in"
Earlier you said "at least one boat length" and then "x2.5"
Confused now. You then give an example of anchoring in 25ft and using 300ft of rode. Well that will work which is why I said your advice wasn't dangerous, but I wonder how many boats carry 300ft and what happens if they want to anchor in 30ft? You also suggest that 50ft of water needs 550ft or rode. Do you sell rope by chance? do you carry 550ft of anchor rode?
"Some who use all chain rode
I do.
"may claim less is acceptable"
I do.
"Once one reaches a circuit wind velocity vs vessel windage"
Sounds technical, can you explain circuit wind velocity?
"that removes the effective catenary in the chain"
In 20 knots? make that 30 and I will agree with you.
"and does not reduce the importance of total length vs depth any significant amount"
At last, so what was all the stuff about earlier?

"If you take note, I did suggest relying on manufacturer's info at the very start of the post"
So why not quote it or link to it so the reader can form their own opinion?

"The balance is just based on my experience and opinion"
You are perfectly entitled to your opinion and I will respect your opinion. Equally members are entitled to challenge something they don't believe is correct and put their viewpoint on record. If you don't like someone else's viewpoint constantly arguing your point won't endear them to you. In fact the opposite is likely to happen, they will just ignore you posts.

Finally, were do these rules come from? are they Rods rules, or are they written down somewhere, or even accepted practise?

Pete
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Old 08-03-2019, 11:18   #13
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Re: Mantus rode

RYA course rules from the 90's: (not sure if they are still used):

Chain only: 4 x (depth plus height of freeboard)
Chain and rope: 2 x (depth plus height of freeboard) as chain plus 4 x (depth plus height of freeboard) as rope.

Having said that, there was the recommendation to let out more when the weather gets really nasty. Also, the recommendation was for Nylon as rope as it absorbs shocks nicely and thus reduces peak loads on the anchor and the boat.

I am still going by these rules, they are simple and easy to remember. So - by these rules, if you want to be able to anchor in 50 ft of (depth plus freeboard) and want to keep the boat light, that would be 100 ft of chain plus 200 ft of rope plus something to let out in really bad weather. With the 100 ft of chain, you could also anchor chain only in 25 ft of (depth plus freeboard).
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Old 08-03-2019, 15:52   #14
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Re: Mantus rode

Quote:
Originally Posted by TommmD View Post
So, I have a 35 lb Mantus on a rode 5/8" x 200' 8-strand spliced to 3/8"x15' d4 chain. This was built for my present 36 Hunter, 12,000 lbs + crew + gear.
Trading up to a 40' , 18,000 lbs + crew + gear.

This anchor felt oversized for the 36, so I'd like to think its more appropriate for the new boat. Plan on replacing the present 15'of chain with a longer length, somewhere between 50 & 100', but this is guesswork.

I'm in New England, if I anchor in 40' thats a lot, and 200 nylon+100 chain is over 7:1. That sounds like quite a bit. 100' of chain is 140 lbs + 35 lbs, all on the nose. 50 ft of chain cuts thats down to 105 lbs, but I'm thinking I should split the difference.

Is my thought process prioritizing the wrong thing here? How out of whack is all this? I just spoke to a friend with a 42' 24,000 lb boat (+ +) & he's carrying 300' of chain!

Thx for the thoughts,
Hello, TommmD,

We have a 60 lb. Manson Supreme, backed by about 275 ft of chain. The boat is 46 ft. overall and displaces about 12 tonnes. This has still dragged, although rarely, both times in soft mud. Both instances occurred when a vigorous frontal passage, and sustained over 50 knots, but they DID occur.

By your suggested standards, we should have a 45 lb. anchor, but we ditched it because it just couldn't hold the boat.

One "rule of thumb" that is sometimes used is to buy at least one size larger than the manufacturer's recommendation.

I think your choice will depend on how familiar you are with the bottoms you anchor in. If you're just going to stay around new England, and count on never getting caught out, nor have any more extreme than planned conditions, then MAYbe you could get away with the manufacturer's recommendation. It's your boat, your choice.

PS. My credentials are that I have lived the majority of the last 30 years at anchor.
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Old 09-03-2019, 07:22   #15
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Re: Mantus rode

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Originally Posted by skipmac View Post
Rude? Pete politely disagreed and is certainly entitled to his opinion as much as you are to yours.
Yes "RUDE!"

I agree we are all entitled to our opinions.

In my opinion, and I hope shared by others, it is absolutely OK for someone to state disagreement with another on a forum.

That is what makes forums so great; when two or more disagree and they "justify their position. This then makes the reasoning behind the position apparent, and others can determine if the contradiction is "correct" or "incorrect" or somewhere in between (conditionally "correct" or "incorrect").

It is when some get rude, when they feel they cannot adequately support their stated position, that it breaks down into offensive name calling, personal attacks, etc. that are so disruptive.

So I was definitely not offended that Pete disagreed with my post.

It was how he did it, that was so offensive to me.

Some people tend to immediately become rude when their post (or belief) is challenged.

In this case, I believe that my post challenged Pete's belief about how chain should be used for ground tackle, and rather than stating disagreement with reasoning to support it, he stated disagreement with the recommendation that others pay no attention to the post he was disagreeing with, without any basis for his position.

I believe that it is common courtesy, when disagreeing with another in a public forum, to express the reason.

This allows others to evaluate the contradiction based on its merit, rather than due to the implied authoritarian position, "Because I said so!"

It also affords the originator the opportunity to defend their post against claims of lack of merit, which may be a completely baseless opinion.

Anyone can disagree on this matter or not, because this too, like everything else posted on a forum, is based on opinion.

I personally believe that this is especially unbecoming of someone who I feel should know better.

(BTW Pete, thank you for posting you reasoning for the disagreement; that is far more civilized and respectful to myself, and the forum in general, in my opinion.)

So that out of the way, if I get time soon, I will respond "in kind" to Pete's stated reasoning for his posted disagreement, and claim that my original post lacked merit.
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