Getting Chain Out of the Bow

[Dockhead]

Originally Posted by boden36

From another angle, I have made a device to pull chain from the chain locker in the bow, horizontally under the sole and deposit it in the middle bilge.
The device consists of a gypsy driven by a 12 volt motor through a hydrostatic clutch from a car's cooling fan. This means that the gypsy can be stalled with the motor still running and that the gypsy freewheels when the motor is not running. There is about a 10 lb drag on the chain. The drag can be adjusted by adding extra oil to the clutch.
It will be wired to operate when the windlass is working.
I have run it in the workshop and it operates fine. Remains to see how it will work on the boat but it should be OK.

Regards,
Richard.

If I ever build myself a new boat, it will definitely have a naval pipe from the bow back to a chain locker low and midships -- like on the Dashews' Sundeers. That is the perfect solution to this whole problem. But I am definitely not going to chop up my boat to try to imitate it here -- I have a watertight bulkhead between forepeak and main hull volume which I'm not going to compromise, plus there's no room to install a proper naval pipe. It would be a huge project with doubtful results, adding complexity, too. No, whatever I do will have to be without structural modifications to the boat.

[Dockhead]

Originally Posted by TeddyDiver

In my build the windlass comes right in front of the main mast and the chainwell down below it in the bilge. This is 11' from the bow which is quite good considering the LOD of 35'.

I'm not familiar with the term "chainwell", but that sounds like a very good solution.

[accomplice]

As a potential zero cost solution, how often do you use your secondary anchor? Could you move its rode, and even the anchor itself?

[Dockhead]

Originally Posted by carstenb

Dockhead,

Nigel has a good point and you should consider leaving this problem alone until you have solved your dinghy issues. If you get rid of your divats and move the dinghy onto your back deck, you'll be moving the entire weight of the dinghy (and when there are no divats, the weight of the divats), closer to the center of the boat.

This will in turn, give you less of a see-saw effect in heavy sea, albeit your bows will drop a bit.

Were it me, i would solve my dinghy issue, see how the boat handles when that weight is moved and then proceed to solve the bow weight issue

Well, except that the problem will be worse with the dinghy moved forward onto the deck!! This line of thought was actually stimulated by the idea that I'm going to do something about the dinghy, and the green water will be even worse!

I think I'll do it the other way around.

[Dockhead]

Originally Posted by accomplice

As a potential zero cost solution, how often do you use your secondary anchor? Could you move its rode, and even the anchor itself?

I use my kedge a fair amount, usually off the stern. I am, actually, planning to have a bracket made for it like the Baltic sailors have, and keep it on the pushpit. But this won't help with trim, because it's an alu Fortress with 150 meters of rope rode (polyester double braid), so negligible in terms of weight on the bow.

[Dockhead]

Originally Posted by noelex 77

I think your best solution is go with 10mm G7 chain. The only change you will need is a new gypsy and the weight savings are considerable.

Steve Dashew uses 3/8 (9.6 mm) G7 and a 110 kg Rocna on his 83 foot FPB. This has a 39T displacement. As you know, he likes large reserves of safety especially in anchoring gear. The general thought is that it is safe to re-galvanise once, but replacement is probably sensible as you get to larger boats.

Now that's really interesting -- a key data point. I didn't know. If Dashew is happy with 10mm chain for a 38 ton boat, then surely it will be enough for my 25 ton one. It must be.

OK, then I guess that's the solution. I'll do that over the winter. The next question is how much of it -- do I stay with 100 meters? Or reduce it to -- what, 60? 70? And then add rope?

Originally Posted by noelex 77

When you finally get around to building your custom 65 footer you can move the chain storage much further back by installing a large locker for fenders etc in the bow, followed by the chain storage. As an alternative it is possible to move the chain all the way back to the mast, if you prefer, or even back to the mast and under the waterline (the 66 yacht with the complicated electrics that I posted a photo of had this system). All these options do have some compromises, but the nice thing is you get to pick which compromises you would prefer.

Now we're back in fantasy land But a very pleasant fantasy

I would think that a sloping naval pipe would do it without any additional mechanical means of moving the chain. It works on ships, after all!

Yes, the holy grail is to get the chain locker below the water line. Then the chain is ballast -- yeah! Then you could even go to 14mm, or even something like 16mm stud link chain. That would make some mongo ground tackle. Then a jumbo horizontal windlass with warping drum, something like this: Lighthouse Manufacturing USA . . . . Sorry, this is going over to porn here.


One of the problems we have is that yacht design, with the small chain lockers up in the very bows, evolved when sailors were using rope rodes, or piddly 30 or 40 meter lengths of chain, at most. The prevalence of long chain rodes on cruising sailboats is a fairly recent development, and the rather different configuration needed to suit them has still not been absorbed by yacht designers.

[El Pinguino]

Hmmm , I have 70metres of 'tiny' 8mm chain in the chain locker up the front of the boat....
I also have another 70 metres of chain ( just in case I lose the bit up the front ) under my bunk down the back... complete with a spare anchor.. seems to sort of balance things out.

[DoubleWhisky]

Originally Posted by Dockhead

Decisions, decision. Hmmmm.

Many depend on the internal layout of Your boat and i do not know it really.
Do You have available space to move part of the chain into the bilge not disconnecting it? If so, the system to convey it surely can be designed.
Are other masses You can move back? The battery bank for bow thruster, for example? I bet it is heavy and placed well forward?

We are (almost) all assuming You do carry G 40 chain at present - is it right?

You surely can regalvanize the G 70 several times. The effects of heat do not accumulate - the good news.
Regalvanizing must be done at experienced at very reliable workshop - any overheating in process can be disastrous, and You really need to have specification of the galvanization process made on new chain from manufacturer, to assure the temperature will be not exceeded at regalvanization - rather bad news.

I know there is an product - zinc spray - You can use. As far as I'm informed U.S. made. I saw it once in use on another boat. They told me You need to respray once a year if You do anchor all the time around and that they tried several products before finding the reliable one. Of course I noted the name of the product, but I was stupid enough to make this note in the phone, which was subsequently stolen, so I do not know the brand, but it may be worth some research.

Cheers,

Tomasz

[DoubleWhisky]

Oh, oh, oh,

You created a hot thread (as usual) and You are typing faaaaast, so I'm long after You in my posting

[thinwater]

ABYC calls for a storm anchor working strength of ~ 3500 pounds. G70 would have you covered at 5/16" (4700# SWL), saving 61% of the weight. Shorten to 70M, perhaps, and you are less than 1/2. In fact, even 5/16" G43 (3900 SWL) would have you covered, though I would chose the G70 if I routinely anchored in challenging conditions, and with the greater safety margin, if will last longer. I've never understood low-strength chain for anything other than moorings.



No, transport chain is not brittle or it would not be used banging down the road, jerking.

If you want to reduce the load, use a nice long (30') snubber to damp the waves. I've used all-chain with and with-out a long snubber, and the difference is huge when waves are a factor (if waves are not a factor you don't have a problem).

Re-galvinizing can't represent that much of a cost savings. As for the wear allowance, since the G70 chain is the same strength and it will wear in proportion to the strength of the steel, why would we think it would wear as fast soft steel? Doesn't a good knife hold an edge? You will find the life expectancy is roughly the same if the same safety factor is specified.

This isn't complicated.

----

I remember when Spectra and Dyneema first came to the world of climbing, the guys were scared to trust their lives to something so insubstantial looking; they trusted nylon rope more because it was fat. I think it is the same with fat chain. The strength numbers are either right, or they are not.

[Panope]

Originally Posted by Dockhead

I would think that a sloping naval pipe would do it without any additional mechanical means of moving the chain. It works on ships, after all!

Dockhead,

I have found that sloping naval pipes work very poorly on smal craft.

Prior to my rebuild, Panope's entire anchor system (roller, windlass, chain pipe) was off center because a large, traditionaly mounted bowsprit was fitted.

This off center arrangement caused the chain pile to "climb" up the side of the chainlocker (hull). For years and years we fiddled around with sloped pipes and ramps designed to get the pile just a few inches inboard. Chain would frequently hang up causing a crew person to go down below to "knock down" the chain pile so there was enough "free fall" to overcome the friction of the ramp/slope.

This very serious problem was corrected once and for all by moving the windlass directly over the desired chain pile location.

Steve

[barnakiel]

Bow down is not necessarily such a bad thing when you think of upwind performance. IMOCAs used to have a water tank in the bows, I used to slide forward upwind in my Optis and OKs...

Back to the topic then, I would definitely try to keep the amt of chain you want and limit weight by going for equally strong but lighter chain (Dashew's way as you put it).

b.

[Dockhead]

Originally Posted by DoubleWhisky

Many depend on the internal layout of Your boat and i do not know it really.
Do You have available space to move part of the chain into the bilge not disconnecting it? If so, the system to convey it surely can be designed.
Are other masses You can move back? The battery bank for bow thruster, for example? I bet it is heavy and placed well forward?

We are (almost) all assuming You do carry G 40 chain at present - is it right?

You surely can regalvanize the G 70 several times. The effects of heat do not accumulate - the good news.
Regalvanizing must be done at experienced at very reliable workshop - any overheating in process can be disastrous, and You really need to have specification of the galvanization process made on new chain from manufacturer, to assure the temperature will be not exceeded at regalvanization - rather bad news.

I know there is an product - zinc spray - You can use. As far as I'm informed U.S. made. I saw it once in use on another boat. They told me You need to respray once a year if You do anchor all the time around and that they tried several products before finding the reliable one. Of course I noted the name of the product, but I was stupid enough to make this note in the phone, which was subsequently stolen, so I do not know the brand, but it may be worth some research.

Cheers,

Tomasz

Yes, I now have 12mm G40 chain which weighs 330 kg/ 100 meters. It's proof tested with more than 2 tons SWL, and nearly 10 tons breaking strength. I sleep pretty well at night lying to it.

I have now heard pretty persuasive arguments about G70 chain, so I think I'm going to go with that, in 10mm (same or even a bit higher SWL and breaking strength). The only question is how much of it? And how much, if any, rope? I'm thinking maybe 70 meters, with another 70 meters of polyester octo. 70 meters of 10mm G70 weighs 165 kilos, almost exactly half of my present chain.

Another not inconsiderable benefit of going this route is that the chain takes up much less volume than the present one. I flake my present chain with my foot to keep it evenly distributed in the locker, a minor PITA. And the necessity of this also means that I can't haul the chain without being at the bow. The 10mm chain will have such a small volume that I bet it won't be capable of forming a pile reaching to the top of the locker.

There's nothing else I can do for getting weight out of the bow. The thruster bank (now combined with the main bank) is amidships, under the salon floor.

I'm not going to try to rig a naval pipe -- I'm don't have space for it, and I'm not going to pierce my watertight bulkhead, which is a serious safety feature of my boat.

[Dockhead]

Originally Posted by barnakiel

Bow down is not necessarily such a bad thing when you think of upwind performance. IMOCAs used to have a water tank in the bows, I used to slide forward upwind in my Optis and OKs...


b.

That is contrary to my understanding. I have always been taught that weight in the bow kills pointing ability. If I'm wrong, I would be glad to be enlightened.

[Dockhead]

Originally Posted by Panope

Dockhead,

I have found that sloping naval pipes work very poorly on smal craft.

Prior to my rebuild, Panope's entire anchor system (roller, windlass, chain pipe) was off center because a large, traditionaly mounted bowsprit was fitted.

This off center arrangement caused the chain pile to "climb" up the side of the chainlocker (hull). For years and years we fiddled around with sloped pipes and ramps designed to get the pile just a few inches inboard. Chain would frequently hang up causing a crew person to go down below to "knock down" the chain pile so there was enough "free fall" to overcome the friction of the ramp/slope.

This very serious problem was corrected once and for all by moving the windlass directly over the desired chain pile location.

Steve

I always heard that sloping naval pipes work fine as long as the locker is also sloping. If you expect the chain to drop vertically, then naturally it will pile up and jam. It's also crucial that the locker be deep enough, which can be a design challenge.

But certainly, you don't want the windlass to be further away, in the horizontal plane, than absolutely necessary, from the chain locker. I think the Sundeer arrangement is supposed to work perfectly; I would just imitate that, I think.

Here is, by the way, a really interesting thread on the subject:

http://www.cruisersforum.com/forums/...on-100758.html