Anchor Chain Noise

[firehoser75]

Thanks to All

First, thanks Evan for the great info. So the bridle setup you use is purchased as a unit from Mantus. Thanks for the link.

Nepidae, Sorry, but that's why I started this thread. I have been using a 2 legged nylon bridle (snubber) taking all of the weight of the anchoring system off of the windlass and cleating off onto the 2 bow cleats (with a fairly good "loop" in the chain below the water line) and still have experienced quite loud "anchor noise". I have even been putting a small piece (1 foot long) of "opened up" rubber hose laid flat under the chain where it first contacts the bow roller. Still noise.
So that is why I have been continuing to ask these questions. I appreciate all input and ideas that everyone has put forward. I am quite hopeful that next year, I will be able to at least reduce the noise.
Regards,
Tom

 

[eheffa]

The Mantus Bridle is very well made but possibly just a bit too skookum, in that, under tension (and yes with no tension at all on the bow roller), it was still transmitting the anchor chain grinding sounds all too faithfully into the forward stateroom. I think a slightly lighter three strand nylon could be more elastic and more absorptive of the sound energy. With the 5/8" rope of the Mantus, it's probably analogous to the old string telephone.


The Mantus chain hook is excellent and if I were to do it again, might consider buying the hook alone and making up my own three strand bridle of slightly lighter 3 strand nylon. OTOH, the Mantus bridle is very well made and is quite strong.



The shockle inserted between the bridle and the hook has pretty much eliminated the chain grinding. (Since adding the shockle to the system last Spring, we have anchored out more than 60 nights and have heard the chain noise on perhaps 2 occasions... both times relatively shallow, rocky anchorages with lively winds.)


-evan

 

[eheffa]

It would seem to me that those who are experiencing 'chain noise' have 1 thing in common....the chain is on the roller and has tension on it.

In other words, the anchor with chain rode is deployed from the windlass, set on the bottom and then people go get a Sundowner.

IF that is the case, then that is why you are getting chain noise.

As I and others have said, the chain needs to be snubbed by a bridle or if your windlass is like the 1 in Evan's post, it looks like a Lofrans Tigress, then a single line with a hook, Mantus makes a nice 1 but I use a big box store hook, you can tie off to that.

IF you take the strain off of the chain with 1 of these items, no more chain noise.

The technique has been explained previously in this thread so I won't reiterate it again.

Suffice it to say, take the strain off the chain, no more noise.

I agree that you have to take the strain off the chain / anchor roller; but if the bridle is too rigid and inflexible, it can also and very effectively transmit the same chain grinding sounds to the hull - in STEREO, no less .


We first used our forward dock line with a chain hook to create a bridle but it was still very good at transmitting the chain grinding; despite there being full slack at the bow roller. We then bought a Mantus Bridle and found that it was a little quieter but still noisy enough to mess up our sleep.



Adding more elasticity and sound absorption to the setup seemed to be a possible answer and so I tried inserting a heavy duty Shockle between the Mantus Bridle and the Mantus hook. This has made all the difference.


The same thing could probably be accomplished by using lighter gauge 3 strand nylon rope with more stretch in the system. The key feature would be having enough elasticity in the setup to absorb rather than transmit the noise.


-evan

 

[Nepidae]

Well then I guess I stand corrected.

I guess if you are using some form of nylon, 3 strand or braid, as a bridle, and you are still getting chain noise, taking the strain off of the chain, then it must be the boat.;>

We have @ 160' of chain in front of 250' of 8 plait and have yet to get to the plait when we anchor.

When we anchor, with our 40K# boat we don't seem to get any chain noise.

Our windlass is on a pulpit which is suspended between 2 Samson post and attached to the toe rail at the bow. There is a full backing plate under the windlass on the underside of the pulpit.

IF I am using a single line bridle I connect the line to the cleat on the top of our Lofrans Tigress windlass. IF I need to use my custom made Y shape bridle, 3/4" 3 strand with 30' long legs and 10' short leg, which I will connect to the Samson post, the long lines are brought up thru the hawse and tied to the Samson posts with hitches. Again no chain noise.

Therefore, for everyone else, with chain noise, who is utilizing the aforementioned steps in their anchoring procedures, and are still getting chain noise, the only thing left, is the boat.

I think you can buy rubber coated chain.

BTW, just to be on the safe side I asked my wife if she has heard chain noise. Having had to learn to sleep on an aircraft carrier, I generally don't hear much of anything when I sleep, she on the other hand could hear a Heron fart across the river.

She says, no chain noise.

Good luck to all those with chain noise. Wish my comment would have helped.

 

[eheffa]

Well then I guess I stand corrected.

I guess if you are using some form of nylon, 3 strand or braid, as a bridle, and you are still getting chain noise, taking the strain off of the chain, then it must be the boat.;>

We have @ 160' of chain in front of 250' of 8 plait and have yet to get to the plait when we anchor.

When we anchor, with our 40K# boat we don't seem to get any chain noise.

Our windlass is on a pulpit which is suspended between 2 Samson post and attached to the toe rail at the bow. There is a full backing plate under the windlass on the underside of the pulpit.

IF I am using a single line bridle I connect the line to the cleat on the top of our Lofrans Tigress windlass. IF I need to use my custom made Y shape bridle, 3/4" 3 strand with 30' long legs and 10' short leg, which I will connect to the Samson post, the long lines are brought up thru the hawse and tied to the Samson posts with hitches. Again no chain noise.

Therefore, for everyone else, with chain noise, who is utilizing the aforementioned steps in their anchoring procedures, and are still getting chain noise, the only thing left, is the boat.

I think you can buy rubber coated chain.

BTW, just to be on the safe side I asked my wife if she has heard chain noise. Having had to learn to sleep on an aircraft carrier, I generally don't hear much of anything when I sleep, she on the other hand could hear a Heron fart across the river.

She says, no chain noise.

Good luck to all those with chain noise. Wish my comment would have helped.

It may well be the Boat.



The OP, Tom, has the same vessel as we do - a Nordic Tug 37. They are great boats but have at least one well described weakness: The main stateroom is in the bow and suffers from a significant amount of noise from either Chain Growl or Chine slap or both.


We modified our chines and eventually solved the chain grinding, resulting in a much quieter stateroom. According to my good wife, the only thing left to fix is my snoring.


-evan

 

[dhays]

The Mantus Bridle is very well made but possibly just a bit too skookum, in that, under tension (and yes with no tension at all on the bow roller), it was still transmitting the anchor chain grinding sounds all too faithfully into the forward stateroom. I think a slightly lighter three strand nylon could be more elastic and more absorptive of the sound energy. With the 5/8" rope of the Mantus, it's probably analogous to the old string telephone.


The Mantus chain hook is excellent and if I were to do it again, might consider buying the hook alone and making up my own three strand bridle of slightly lighter 3 strand nylon. OTOH, the Mantus bridle is very well made and is quite strong.



The shockle inserted between the bridle and the hook has pretty much eliminated the chain grinding. (Since adding the shockle to the system last Spring, we have anchored out more than 60 nights and have heard the chain noise on perhaps 2 occasions... both times relatively shallow, rocky anchorages with lively winds.)


-evan

I made my own bridle using 1/2" 3-strand. Each leg of the bridle is about 25'. One advantage of the Mantus bridle is the chafe guard. That is also a disadvantage as well. I often won't use the full length of the bridle and it is easy by just cleating each leg at the length I want. Hard to do with the chafe guard. I also can easily make the bridle asymmetric. I purposely didn't join the two legs. Each is its own length of line with a thimble spliced into the end. I can attach the thimbles to the chain with a line grabber and soft shackle, or I can use a short length of double-braid that I have which has a thimble at one end. Just use a soft shackle to connect the three thimbles and a rolling hitch to connect it to the chain.


I generally have settled on using the line grabber and soft shackle to connect the legs to the chain. Very easy to setup and all the pieces I made myself for very cheap. The 3 strand is cheap ebay anchor line. You can pick it for almost nothing (ie $30 for 200'). The line is strong and stretchy and if the line starts to chafe or get too dirty, you just make up another pair.

 

[C lectric]

I am another that has chain noise from dragging the chain on the bottom.
I do use a snubber line that also has a rubber snubber/shock absorber installed.
I let out a big loop of chain once the snubber is in place so NO there is no tension on the chain.
I also have an aluminum wheel as part of the anchor roller bracket which itself is bolted solidly to the hull.

One thing I will try next time is to place a thick ,softer, rubber pad between the wheel/roller and the chain or a heavy old towel folded to help isolate the chain.
I'm sure some noise will come through but hopefully not so much.

Noise can transmit regardless of whether or not there is tension on the chain.
No tension helps but as long as the links are in contact with each other noise will transmit and they are still in contact, loop or not. If we could effectively break the link to link contact then noise should become far less of a nuisance, my guesswork.

Take a look at the roller. A hard plastic such as nylon or delrin or a metal wheel will transmit more noise than one of the soft urethane rollers. There are hard urethanes though so you would need to watch what you use.