Stow Anchors

[Fore and Aft]

Don’t forget Vito Dumas, EL Pinguino, I wonder if he stowed his anchor?
Cheers

[Gdog6]

Originally Posted by Russ

Does anyone leave their anchors stowed and secured on the bow pulpit during long offshore voyage??
OR do you stowe them below in the bilge or whatever?

Ditto your outboard motors.

Russ

Hi Russ, unlike most others on here, I stowed my bow anchor below, and pulled my chain further aft in the bilge. Also stowed my outboard in the lazeret.
I like my deck as clear as I can keep it for offshore passages, so no jerrycans canoes dingys etc on deck either.
I did have an anchor and rode tied to the stern rails that could be deployed in seconds.
I felt happy this way, so each to there own.

[El Pinguino]

Originally Posted by Fore and Aft

Don’t forget Vito Dumas, EL Pinguino, I wonder if he stowed his anchor?
Cheers

Ah.. my mate Vito... always with me..

If I was a worrying man.. I would worry about the 3 other anchors I have stowed below obeying the law of gravity when push turns to shove... but I'm not..

[CassidyNZ]

If my boat started to hobby-horse just because of where the anchor is stowed, I’d be looking for another boat.

But everyone has their plan . . . .

Having an anchor stowed in the accommodation Down below in a rough sea is an injury waiting to happen. How many people on this thread have bilges big enough to stow their ground tackle? How many people on this thread have locks on the hatches in their cabin sole? Another requirement for CAT1 in NZ.

[a64pilot]

Well, I did worry about it. I have 67 kg of anchors hanging off of a bow sprit and 100 meters of chain right under them.
Plus I have likely 400 lbs of dinghy, motor, anchor, fuel, davits and solar panels hanging off behind my stern.
I could see how that much weight hanging off beyond the hull on both ends could easily be enough inertia to get her going.
But for some reason, luckily it hasn’t. But I do remember seeing one boat in particular hobby horsing madly and I don’t know why, it was under sail going the other way, just watching it was uncomfortable.

[Fore and Aft]

El Pinguino, Vito's book is a great yarn and see we both have the same copy of his book. Did you go visit his yacht in the naval museum?
Cheers

[Alan Mighty]

Originally Posted by Fore and Aft

Alan Mighty I understand what you are saying but I am no fancy sailor and every time my boy and I (150kg) are on the bow relaxing while sailing the boat does not suddenly start hobby horsing or going wild she just keeps plodding along. Is this “keep the weight out of the ends” another thing that has gone along with the sextant?

I must be slipping in my writin' ability. Ain't got me message across.

Lemme try 'gain:

Suppose you've got your barnacle-encrusted bundle of joy in yer quiet water marina berth. And you've got it laden in a known state (e.g. departure condition; or maybe arrival condition; or racing lightship) n you and Jonah-who-wants-to-go-in-a-whale are in the cockpit in your usual sailing positions. So you coo-ee to the Guy- or Gal-from-Glenwood who is idling on the dock, calls him/her over, and tells her/him to (1) loosen the docklines a tad; (2) start pumping the bow up and down; and (3) use her/his stopwatch to time the pitch frequency while you and Jonah sits on yer asses and smokes yer camels in the promised land of yer cockpit.

Say, for the sake of argumentation, that the Guy/Gal records an average of x seconds (having counted 10 pitch cycles of your barnacle-encrusted one).

Now, let's try again, this time with you and Jonah's balls of muscle and lard amounting to 150 kg as for'ard as you can go.

I'd be ready to shout the bar at the Glenwood pub if the pitch frequency with your ball of lard up for'ard is not x + m seconds. Meaning the pitch frequency is longer (da opposite of shorter).

Why? Well because the Pitching Moment of Inertia of the bundles of lard up for'ard in the cockpit case will be 105 kg * 9.8 * (distance from CG to your cockpit)^2.

And the PMI when the bundles of lard are for'ard will be 105 * 9.8 * (about 4.9 * 4.9) [you'll note that I'm guessing that your CG is about amidships of a 9.9 m long LOA; and I'm also guessing that your cockpit is a lot closer to the CG than the pointy end is.]

So putting the tubs on lard on the bow should slow your pitching down, not speed it up.

What having mass, such as tubs of muscle and lard or chunks of ironmongery, on the bow does is slow the bow from lifting. For one, you're more likely to play temporary submarine if your hard on the wind into a swell (and then Jonah might get his wish to slip right down the gullet of da whale). And of course that's why no skipper in her/his right mind lets tubs of lard stand on the bow when you're beating hard to weather in significant ocean swell or a large wind wave.

So the deal of stowing with respect to the rules of (1) keeping the ends of the boat light; and (2) knowing the PMI of the large mobile gear so that - for instance - if you're heading off soundings for a week or three of deep water/blue water cruising, then you move the ironmongery closer to the CG or pitch point of the boat, is twofold.

For one, a light bow (and a light stern) lifts to a passing wave. That's relevant in most any situation - whether you're close hauled, close reaching, beam reaching, broad reaching, etc.

For two, you want to know what your vessel's "natural" pitch frequency is so you can avoid a situation such that the pitch frequency of the vessel does not resonate or match the frequency of meeting waves. That's really only relevant when you're going to weather, either close hauled or close reaching.

And if you followed my hint to discover who had authored that quote about hobby horsing and how it loses drive power from the sails etc, you'll have discovered it was from Pierre deSaix, who was part of a small team called in as consultants to one of the America's Cup boats in '74. That AC boat knew that races are won or lost on the win'ard leg. And the boat that hobby horses spills pressure from its sails and creates drag from its hull and fin. DeSaix's team did present a short paper at a conference. But apart from that short paper and the article in Boating, the research and findings were considered commercial in confidence and never published. The article in Boating is well worth reading. It suggests that light hulls (aluminium in the case of the AC boat) could do well with fore-and-aft mobile ballast so they could change the PMI of a section of hull and so change the pitch frequency; or perhaps for (in the case of a light hull) not concentrating the ballast just in one place (which has been the accepted practice for a long time).

Going back to your (F&A) situation: you is right lucky that your state govt has invested in a couple-three WaveRider buoys that report on the period of the ocean swell.

You'll see a graphic of where those WaveRiders are at: https://www.qld.gov.au/environment/c...ng/waves-sites

And a menu so you can look at the data at: https://apps.des.qld.gov.au/waves/

The data is close to live (meaning it's a tad delayed). Take a look for now:

Off Caloundra: https://www.qld.gov.au/environment/c...ites/caloundra

Off Mooloolaba: https://www.qld.gov.au/environment/c...tes/mooloolaba

Off Bribie Is: https://www.qld.gov.au/environment/c...th-moreton-bay

See the periods: wave period mostly in the range of 6 - 7 seconds, right?

See the swell height: pumping 4 - 5 metres over the weekend; a few patches of 6+ metres off Mooloolaba; (and if you look down at the WaveRider buoy off N Straddie, you'll see it registered two 8 m peaks but still around the 7 second wave period during the time when lifesavers on the Gold Coast were closing the beaches: https://www.qld.gov.au/environment/c...sites/brisbane)

So now ... what were the pitch frequencies that the Glenwood Gal timed for you? How close were they to 6 - 7 seconds?

Of course, you're sailing at a positive angle to the True Wind. And you're making progress to win'ard when you're sailing. So you don't meet the swell at the 6 or 7 seconds that the WaveRider buoy does. You might be meeting them more quickly, or less quickly.

A racing skipper supposedly only cares about winning (and survival) on a windward leg.

A cruising skipper sailing to windward can bear off (increasing the frequency of meeting waves) for comfort and for less stress on the hull and rig (and for survival as well as keeping Jonah from diving into the whale's gullet).

Both skippers should care about keeping the ends of the boat light and take regard for avoiding the situation in which the natural pitch frequency of their vessel resonates with the frequency of meeting waves. And paying attention to stowage, having a stowage plan, keeping the ends of the boat light, and so on.

For the tl;dr crowd:

* putting a tub of lard and muscle on the bow slows the "natural" pitch frequency of the vessel;
* removing chunks of ironmongery from the bow and putting them close to the CG or pitch point of the vessel (which can be on deck, not necessarily below - an anchor on deck can be launched by motivated crew only a few seconds later than one that is sitting lashed in a bow roller) reduces the "natural' pitch frequency;
* having light ends of the boat is almost always a good thing;
* hobby-horsing occurs when going to windward and when the "natural" pitch frequency of the vessel resonates with the frequency of meeting a wave;
* WaveRider buoys are a good source of information of the expected wave period;
* hobby-horsing slows a boat by spilling pressure from the sails and spilling hydrodynamic pressure from your keel;
* if you let Jonah stand on the bow when you're driving hard on the wind in a developed sea state, then I reckon you're going to be culpable if Jonah fulfills his spiritual fate.

[Jim Cate]

Alan, seems to me that avoiding resonance between pitch frequncy and wave interval is what you are advocating (wisely). Should such resonance occur, you could break it by changing your pitch frequency... either up or down. So it is easy to see that simply lightening the bow isn't necessarily gonna improve your HH likelihood.

And btw, in your example above, doesn't falling off a bit decrease the wave impact frequency rather than increasing it? Besides decreasing the frequency, it also reduces the vertical acceleration rate imparted by the wave, perhaps a more significant change in comfort and in tendency for HH.

Finally, the analogies between old 12 meter race boats and modern cruising boats are pretty stretched iMO. Totally different hull shapes, weight distributions of fixed objects and in purpose. Apples and persimmons IMO.

Jim

[Fore and Aft]

Alan Mighty your writing ability is excellent, I could find no reference to goats and sheep in Skenes but that’s another story
Yes light ends are good and you have the maths to support it but I just struggle to get my head around two items that weighs less than 2% of our barnacle encrusted bundle of joy effecting her performance that much? No doubt it does but I am not an America’s cup skipper,so my psyche is just not that finely tuned to notice the slightly better sailing.
If what Desaix’s team discovered is hugely beneficial then why do race yachts not have moveable fore and aft ballast on tracks? It would not be hard to have a movable box that you could fill with a couple of tons of seawater? A computer program could then tell the sailor the position and when to fill the tank?
Now as to Jonah’s fate, say we are off soundings, what’s to say we capsize and my 20kg Lewmar Delta and 60 meters of anchor chain fly around the cabin? Jonah and his sister Pippi should be tucked in their quarter berths and fine. But Tina and I will probably bounce around the cabin with the chain and anchor that’s not going to be pretty. We literally have only a small sump for a bilge so all that chain extra would have to be flaked out on the floor ( spread the weight sir) and the anchor lashed to the stove ( close to amidships). That’s the issue that no maths can ever fix, no storage space in the bilge. Which funny as it seems has gone the way of that saying “keep the weight out of the ends”. Most modern boats I survey have very small bilges.
Cheers

[Alan Mighty]

Originally Posted by Fore and Aft

Yes light ends are good and you have the maths to support it but I just struggle to get my head around two items that weighs less than 2% of our barnacle encrusted bundle of joy effecting her performance that much?

It's all got to do with that multiplier: (distance from CG/pitch point to the centre of mass)^2

If the distance to the mass is big, that multiplier is big. PMI varies with the square of the distance to the pitch point. Squaring 2 makes 4, squaring 3 makes 9. And once a multiplier is close to 10, we're talking an order of magnitude.

If what Desaix’s team discovered is hugely beneficial then why do race yachts not have moveable fore and aft ballast on tracks? It would not be hard to have a movable box that you could fill with a couple of tons of seawater? A computer program could then tell the sailor the position and when to fill the tank?

Yes. I wonder that same.

And have done so since 1974. De Saix and team were looking at light hulls (remember that in America's Cup racing, owners and skippers have been quite happy should the boat sink after crossing the finish line - suggesting that AC owners consider the boats to be disposable).

Could it be that De Saix's finding is not applicable to anything that has more displacement than a thin light hull?

To repeat myself, apart from his article in Boating in 1974 and the conference paper, that research has never been published or repeated as far as I know.

But it makes me think of great grandfather, who had a boat with rocks and things for ballast. He'd take the ballast out every now and then to maintain the boat. And then insist that he and only he was in charge of re-placing the ballast. The ballast was distributed along the available bilge, but concentrated in the middle 1/3 of that bilge in a particular way.

Contrast that with every boatbuilder I known since the 1970s (you've had more years of direct experience than I have). They've all insisted that a boat (but all have been hulls built to last, so there's displacement/mass in those hulls) has ballast that is best concentrated in one small location.

Now as to Jonah’s fate, say we are off soundings, what’s to say we capsize and my 20kg Lewmar Delta and 60 meters of anchor chain fly around the cabin?

I agree with you.

I do not advocate (1) putting any large mass below deck that is not secured such that it will not stay in place in a capsize; (2) taking all anchors off the deck.

I instead advocate and practise (for my boat, for its design, and for its setup) removing big chunks of ironmongery from the bow and stowing them in a secure way on deck amidships and also minimising the mass in the pointy end by hauling as much of my anchor chain (I've 100 metres of it) aft so it sits nearer to the CG. There's no significant delay in anchoring.

And that's not even taking the question of outboard engines etc into account.

What any owner can do depends on their boat, how it has been designed, how they have set it up.

If someone has an anchor that can be disassembled and has a place to secure it below decks, good for them. If someone has a boat so bereft of alternatives that any bower has to sit on the tip of their pointy bit, so be it.

But if someone has alternatives and is going to be off soundings for a considerable time, why not use those alternative if they deliver an advantage?

What I think is strange are sheep, including some who are older hands at cruising than myself and therefore should be smart goats, declaring to one and all that because their boat has no bilge and they don't reduce mass in the ends of their boats when they are voyaging off soundings for a significant time that therefore considering stowage with respect to the pitching moment of inertia is a fool's errand and that anyone who does it is a fool.

Or sheep saying that they respect their boat and their body to the point that they would rather pitch to the point of hobby-horsing, losing drive from their sail and creating drag, than to consider what options they might have.

[Alan Mighty]

Originally Posted by Fore and Aft

my 20kg Lewmar Delta

I've used genuine CQR, genuine Danforth, Rocna, Delta, an unbranded plough anchor, an unbranded danforth copy.

I do agree that a Delta is a tad superior to a CQR. I do accept that in the sand bottoms of SE QLD, a CQR will hold nicely. Most of the time. And a Delta will do better.

Last boat (a Hanse that came new with a Delta - you know why? the boat builder gets them inexpensively in bulk order) I crewed on that used a Delta as its best bower, I did spend time arguing to the owner that Rocna, SARCA, Manson Supreme, etc of the same mass as the Delta were superior to the point of justifying a change from the Delta.

YMMV

[CassidyNZ]

Originally Posted by Alan Mighty

I instead advocate and practise (for my boat, for its design, and for its setup) removing big chunks of ironmongery from the bow and stowing them in a secure way on deck amidships and also minimising the mass in the pointy end by hauling as much of my anchor chain (I've 100 metres of it) aft so it sits nearer to the CG. There's no significant delay in anchoring.

Perhaps in your ramblings above you have shared the size of your boat but I don’t have the interest to decipher them. If it’s a 20ft boat with 6mm chain I will have an easier time understanding. But if it’s 45ft with 10mm chain, please help me understand how you practically move 100m of chain from your anchor locker to mid ships and secure it there. This is not a sarcastic response, I think of my boat and even just 40m of chain and can’t figure it out, I really don’t know how you would do it.

If the chain is that light that you move it with ease and with no significant delay in anchoring, why bother moving it. My chain relative to my strength is bloody heavy and not easy to haul aft without doing substantial damage to my decks. And I simply can’t figure out how you would secure chain that is lying along your deck.

Originally Posted by Alan Mighty

Or sheep saying that they respect their boat and their body to the point that they would rather pitch to the point of hobby-horsing, losing drive from their sail and creating drag, than to consider what options they might have.

What about sailors (neither sheep nor goats) who have a boat that routinely achieves hull speed, does not hobby-horse and never has anchors and chains relocated to midships. It would seem that the science you apparently share with us is according to you the only solution and everything else is just plain garbage.

I have considered my options, the best one is to leave the stuff where the naval architect who designed the boat intended it to be.

[El Pinguino]

Originally Posted by Fore and Aft

El Pinguino, Vito's book is a great yarn and see we both have the same copy of his book. Did you go visit his yacht in the naval museum?
Cheers

Up at Tigre? Certainly did.... one of the high points of my time in BA.

No sign of an anchor but most likely being a fisherman it stows flat and tidy on deck.... up the front....

[Fore and Aft]

Awesome EL Pinguino, I love visiting maritime museums in foreign countries.
Alan Mighty I enjoy being a sheep, it’s easier on my back and the yachts paintwork.
Funny you mention Hanse and a Delta plow. I brought mine brand new of Gumtree for $150. It was from a guy who just purchased a European yacht and did not even want to try it. Seems to work so far for our local cruising grounds.
Cheers

[charliehows]

by the way, I'm a kiwi, and theres a bit of a rumour that we quite like sheep...