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To chain or not to chain

Posted in Seamanship, Shanti's Adventures  by Gary Felton on March 19th, 2010

 

First, for reference: go to Tuning an anchor rode by Al Frasse and take a read, or after you read this blog. It is the best article I have ever seen on using chain, line or chain/line for anchoring. He gives some GREAT mathematical scenarios for the use of chain and/or line for anchoring. All of my samples in this article are derived from running the spreed sheets he provides on the site.

Ok…ladies and gentlemen, grab a cup of joe and listen to my reasoning regarding too much weight in your bow. You may not agree which is fine. In the end you are responsible for the safety of your vessel and those who sail with you. So what you do is up to you. I will not fault anyone for that. This is all my theory and I’m stickin’ to it mainly because it has worked well for me. Isn’t that the way it usually works in the end?

Let’s start with a situation and a realization.
My wife (then) and I were on a cruise from L.A. to the Sea of Cortez. This is aboard Angelsea, our 22’engineless Falmouth Cutter. We had been anchored in Cabo San Lucas and departed for La Paz which is about 150 miles up into the Sea of Cortez. Our first leg was to a bay called Los Frailes about 50 miles up the coast. The last 30 miles into the anchorage we were headed on a course that is pretty much due north. The sail started out a pleasant one…close reaching in about 12 kts of wind. But that was soon to change. We had a tail wind and a current at about 1 kt to help us along. Everything was cool, or so it seemed. Now about 15 miles from the anchorage it looked like we would make it in by night fall. Then the wind started to pick up out of the north, and blowing contrary to the current that was helping us along.
North winds this time of year in the Cortez happen and usually can be quite strong. Well, this was a doozey of a norther. By nightfall it was blowing 35-40 against the current. We were reefed down to the 3rd in the main and the first or second in the staysail, depending on the state of the wind. The seas were square. At the time we were carrying a 65lb ABI windlass and 200′ of 5/16 BBB right up in the bow. This was 310 pounds total w/anchor or like having 2 average sized men sitting right on the bow. This proved to be too much weight for Angelsea. She would nose dive into the oncoming swells and almost come to a stop. Of course because of our course to destination and the direction of the wind we were beating. (I then realized why they called it beating).
We beat off Los Frailes for 3 days and made 5 miles to weather. Finally we turned tail and sailed back to Cabo. We promptly went ashore to have an ice cream cone  8-)

Now to the analysis:
Not only is anchoring and the gear to do it important for one’s safety, but a vessel MUST also be able to beat off a lee shore in most circumstances. Sure, there are times when things go so bad it’s “bring out the sea anchor!”, and hopefully you have enough sea room through prudent planning to survive. So weight in the bow is an important consideration balanced with the gear to keep you put in one place. It’s not an easy decision really.

So what did I change on Angelsea?
I took the ABI bronze windlass off and went to 100′ of 1/4″ HT and ½” multi-plait line. That took 200 lbs out of my bow. Angelsea now sailed like a witch to weather easily lifting her bow over the seas. It was an entirely different boat. This setup for my primary working anchor worked well for over 10 years in the Caribbean.

Let’s look at trade offs, specifications and scenarios for going lighter with the anchor gear. After all we all want to sleep well at anchor.

¼ G4 is rated at 2600lbs. WLL (working load limit) with a safety factor of 3 giving us a breaking strength of 7800lbs

5/16 G3 is rated at 1900lbs WLL with a safety factor of 4 giving us a breaking strength of 7600lbs.

I have no idea what the reasoning is for the different safety factors used for the different materials.

So as far as strength goes we can use either ¼ G4 (HT) or 5/16 G3 (BBB).

Now to shackles to hook this all up with. Shackles have been a weak link in the past for ¼” chain, as equivalent strength has not been available. Most shackles with equivalent strength will not fit 1/4″ chain. So we have a weak link so to speak. But there are shackles out there that do. Look up Van Beest shackles from Holland. They are sold here in the US. Their 9mm shackle looks like it will fit  ¼” chain. It is rated at 1500lbs WLL, but that is with a safety factor of 6. Again no idea why this safety factor, but they are the Dutch and the government may require a higher safety factor. So the breaking load is at 9000lbs. If we use the same safety factor as the HT chain, that would be a WLL of 3000lbs. If anybody knows the reasoning for the different safety factors, please speak up,

Now for some sample scenarios I ran with the excel sheets from France.

Lyle Hess 26′ Falmouth Cutter (12000Lbs). Inspired by a forum post at the Bristol Channel Cutter forum for a 26′ Falmouth Cutter.

Scenarios:

Anchored in 22′ of water and freeboard of 3′ = 25′ total

All chain 5/16 G3 (BBB) – Labeled 5G3
100′ of 1/4″ G4 chain w/1/2 nylon line – Labeled 4G4

Working load limit for 5/16 BBB is 1900 lbs,
WLL for 1/4 HT is 2600 lbs

Wind 20 knots, gusting to 25 knots – over 30kts I deploy a second anchor.
Force of wind calculated for 30′ boat, as a safety factor and to take into account the extra rigging and spars of a Lyle Hess design.

Force of wind at 20kts 163 lbs, Force of wind at 25kts 741 lbs (gusts) w/ boat at 30 degrees yaw

Note: we do not want to exceed a 10 degree pulling angle at the anchor. After that point we will lose way too much holding power.

20-25 kts of wind

4G4 100′ chain and 25′ line (5 to 1) – Angle ranges from 0 to 8.8 in the gusts with a max dynamic force of 1096 lbs

5G3 with 125′ chain (5 to 1) – Angle ranges from 0 to 9.9 in the gusts with a max dynamic force of 2568 lbs

Now we increase our scope by 25′ with either chain or line to 150′ (6-1)

4G4 – Angle ranges from 0 to 6.3 in the gusts with a max dynamic force of 1033 lbs

5G3 – Angle ranges from 0 to 7.7 in the gusts with a max dynamic force of 2433 lbs

Lastly, go to http://alain.fraysse.free.fr/sail/rode/rode_b.htm and run some of your own scenarios through the spread sheets there. It’s a good exercise and very informative.

Last year anchored in Charlotte Amalie Harbor I experienced one of my wildest times at anchor, even worse than riding out a Cat 4 hurricane in the mangroves. I was anchored in 30’ of water with my 100’ of chain and 50’ of line out (5-1). The wind was blowing 10-50 knots (confirmed by some Mega yachts close by at the marina). The large range of wind speed was what caused all the problems. After a major gust, and the chain and line had been stretched out, the boat would spring forward then go beam to the wind because the rode was so slack. So when one of the 40-50kt gusts hit it was right on the beam. A couple of times I was knocked down to about 40 degrees, or visually my side decks were underwater. Stuff flying all over my cabin below. IT WAS WILD!
I would normally have put out a second anchor, but I was clear astern and wanted to see how well the system would hold. The bottom was excellent holding by the way. This wind condition went on most of the day. I didn’t budge an inch.

Chafe!
Now to last last and final argument in the chain line debate, chafe. One of the reasons I use 100′ for the first part of my rode is for the chafe factor. Here in the Caribbean we have coral rubble bottoms and coral heads that the rode can chafe against. Although I try not to anchor to close to coral heads. First, you don’t want to damage the coral. Second if you do get close and the wind shifts, you can wrap the chain around the head. This makes for a bad situation if you get something bad in the night. With the chain effectively shortened you can easily have a shock load when the load comes up short on the chain. This can easily break the chain.

With the chain/line combo, you get the best of both worlds. In most cases when you are anchoring close to coral heads it is fairly shallow. So you can use all chain at 5 to 1 in 20′ of water. Oh, and put out 6 or7 feet of line instead of using a snubber. In 30 feet of water you can deploy all your chain and 20′ of line to give 4 to 1, or 50′ of line if it is going to be blowy. With the wind blowing and the angle of the rode, the line is still fairly shallow and not even near the bottom. In 25 years of sailing the Caribbean this has always worked well for me.

On my present boat, Shanti, which is a 15000 lb 28’ Bristol Channel Cutter I use 100’ of 5/16 HT, hooked up to 200’ 5/8 multi-plait nylon. This is handled by an all bronze manual ABI windlass. The windlass is located about 8’ aft of the bow and dumps the chain in the bilge right in front of the mast. I use a 22’ Delta anchor, which as far as I can figure equals the holding power of a 35lb CQR. And as you can see with line in the equation I have a lot less dynamic load on the anchor.

Now I’m going to go get some sleep!

Gary

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Sailing from South Florida

Posted in Shanti's Adventures  by Gary Felton on October 3rd, 2009

I have just received notification that my standing rigging is at the post office. Once it clears customs (and that could take years and cost thousands of lives) I will be able to start the next phase of Shanti’s rigging.

Mean while I have a story. This was prompted by another BCC owner who is headed south from New England and is going all the way to South Florida before jumping off to the Caribbean. I wish him well. Anyway here is my experience with that journey. And it is a journey and not just a trip.

I have twice made the trip to the islands from south Florida. The first time in Angelsea (an engineless Falmouth Cutter, the little sister to the Bristol Channel Cutter) in 1990. That trip was not bad….just LONG. I figured I would wait for a front to make my easting out to 65w then turn right for the islands. We waited and waited for a front to come through. No luck. Wind was East, then east some more. We were hanging out at Green Turtle Cay in the Bahamas waiting while it blew east, east, east….god if it blows ANY direction except east I’m leaving I told myself. Oh, did I tell you the winds were east? We waited for 2 weeks. Finally the wind went SE, so we left on a starboard tack. A few days later the wind went E again and we tacked to the SE at about the latitude of Jacksonville (we departed from Ft. Lauderdale). So we continued tacking and tacking until we finally reached 65w. Boy was I looking forward to a little reaching, as we would be heading due south towards St. Thomas. Well guess what???? The wind went south on us! GRRRRR! So we tacked all the way to St. Thomas. Mind you we never saw more than 22-24kts and the average was around 15kts on the trip. So the sailing was easy. But it was a 21 day sail (we average 100 miles/day) from our departure from Green Turtle Cay. Total time from departure from Ft. Lauderdale was around 6 weeks. Went into emergency rations and were using country time lemonade to mix with our warm rum. Glad I threw on a couple of bags of beans and rice!

 

Ok that was the first trip. I think I remember swearing I would never make that trip again. There is a reason they call it the thorny path. But I’m getting old and my memory is failing, So what do I do? I make the trip again with Shanti in November of 2007 from Palm Beach.

Ok, forget about making easting…I have an engine now. Ha! Lots of good that did us. So my plan this time was to draw a rhumb line from S. Florida to St. Thomas and bounce off that to the east each time we were taken back down to the rhumb line. The pilot charts show mostly NE winds in November at an average of 15kts. (remember that’s an average, so it has to blow harder to make up for the light days). Well our course to STT was going to be basically ESE to STT. So hey, maybe we will get lucky, it will blow NE and we will have some close reaching and not much tacking. Jeeez am I getting stupid in my old age. But with the memory of my first trip lingering in the back of my mind I even considered just sailing up to Bermuda, then head south. Fortunately I had hired 2 guys from STT to make the trip with me (insurance required it), but I’m glad I did.

One must realize that just a little south of Ft. Lauderdales latitude you start picking up the Trades. These winds blow ALL the way from Africa. They build up some pretty good seas that you have to tack into. Ugly business!

Ok, so we left from Palm Beach across the gulf stream with light NE winds. Tacking towards the east to transit the Northwest Providence Channel through the Bahamas then out into the Atlantic. At least that was the plan. We made it into the channel late into the second day. That night we played dodge ball with a continuous line of cruise ships(they stretched from horizon to horizon), while tacking into 20kts of wind. It was a scary sight with all these huge ships steaming through the channel. I was going to put a radar reflector on, but one of my crew reminded me that a working radar was one of the best solutions for ships to see us. Well we lost our radar that night. Tense!!!!

By the next morning we were roughly 2/3 of the way through the channel and had been sailing hard on the wind for 2 days. But we had problems. Of course the radar was down. We had also lost the self-steering. Our water and fuel were contaminated. Things were going to hell in a hand basket. So the decision was made to put into Nassau. We had already put in 2 1/2 days beating to weather, so we turned south for rest, repairs and some gambling. We arrived in Nassau in the early afternoon. We picked up a fresh load of water and fuel, Then looked for a place to stay for the night. We decided to get a slip at Atlantis, since none of us had ever been there. It’s a very nice marina geared for Mega yachts. It was quite the sight, little Shanti tied up amongst 25+ million dollar yachts. We had foulies and stuff hanging all over the place drying. We had fresh showers and hit the slot machines that night. Next morning we left to cross the Exuma Banks and breakout into the Atlantic at a little place called Highbourne Cay. Winds were still on the nose, but reasonable. We actually had a nice sail. But we could not make it across in one day. So we anchored on the banks that night. It was only 10-15 feet deep. Very strange feeling anchored out in the middle of the ocean with no land around…all by yourself. At around 2am that night I heard …Gary…Gary…you better come up here! Under a full moon we watched an old gaffer sailing towards us. It was quit a beautiful sight in the moonlight actually, but stories of pirates played through our minds and we were ready to repel borders. The old gaffer sailed up to us, then headed off towards Nassau. Whew! the next morning we awoke to find the wind right on our nose again. Imagine that. So we motored into it and arrived at Highbourne Cay on Thanksgiving day. That afternoon we broke out a bottle of wine and popped some Marie Calender Turkey diners in the oven. It was a beautiful Thanksgiving day. It was to be the last nice day for the next 2 1/2 weeks.

The next morning we awoke to a very nice sunny day for our transit of the pass at Highbourne Cay. The tide was ebbing so we had a 10k flow going with us through the pass. We broke out into the Atlantic about 11 am that morning with the wind blowing about 15kts. Soon it was back up to 20 and we were hard on the wind in 6-8ft seas. The next few days we were hard on the wind, tacking in 25kts of wind, making very little progress. Day and night living with the rail buried and getting drenched from punching into large seas. We lived in our foul weather gear and ate very little. Some days it was so hard to get around we didn’t eat at all. So for the next 7-8 days we tacked and tacked. Bouncing off our rhumb line. Wind was averaging 25+ knots and the seas were upwards of 6-8 ft. Finally the NE winds started to fill in and we were able to lay a course for STT. But, we were still hard on the wind. Still had our rail buried. Still getting soaked! One night we encountered up to 40kts of wind and 14ft seas. After Shanti fell off the backside of a particularly large wave and my crew levitated off the deck by 3 ft, we decided to heave to. We slept hard that night, for we knew what the morning would bring. You guessed it, what was your first clue? More 25kt winds on the NOSE. Ah, but we were at least laying our course. Towards the end of the trip we were pushed a little SW of our rhumb line and ended up off the east end of Puerto Rico. The morning brought squally weather with winds ranging from 0-25kts. Soon these squalls past and we turned on the motor in flat calm seas. Motoring for the remainder of the day we reached St. Thomas a 9pm that night.

What a relief! Hot showers (I think we all took 2 actually), big cheese burgers and this strange clear kinda square things floating in our drinks.

 

This trip was HELL. My worst trip in 40 years of voyaging. I implore anyone coming from the NE U.S. to jump off at Annapolis at least. The best would have been to go straight to Bermuda, then south. Reaching with a BCC (or any boat) you will make great time to more than make up for the extra distance.

Well at least I now have a BCC by the name of Shanti here in the Caribbean and life is GOOD!

Cheers,

Gary

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