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30-06-2010, 04:32
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#1
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Registered User
Join Date: Jun 2010
Posts: 3
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Maximum Carrying Capacity
I'm not sure if this is the right place to start this thread, but I'm wondering how to calculate how much weight in provisions and equipment a yacht can carry without seriously harming the stability. The situation I have in mind is an atlantic crossing with four people in a 27ft albin vega. I'm estimating that we'll require something on the order of 2000lbs of equipment and provisions. Cramped living conditions are fine, but I have no idea how much this boat can safely carry and don't know how to calculate it from readily available information on the net. Any help would be greatly appreciated! Jan
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30-06-2010, 05:45
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#2
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Marine Service Provider
Join Date: Apr 2009
Location: Devon, UK
Boat: Sailing vessels up to 200 tons
Posts: 388
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I think you will be pushing the limits - where are you going to put it all? 27', 4 people and their gear, a lot of bulky stuff like bottles water and food and likely a slow crossing...................
Good luck!
__________________
Regards, Ed
Delivering boats for a living - no more!
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30-06-2010, 05:56
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#3
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Senior Cruiser
Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,139
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Greetings and welcome aboard the CF, Jan.
Ted Brewer explains PPI & MTI and more:
➥ Ted Brewer Yacht Design
Check out the Pounds/Inch (& more) for your boat (& others) here:
➥ Sail Calculator Pro v3.53 - 2000+ boats
POUNDS PER INCH IMMERSION (PPI)
MOMENT TO TRIM 1 INCH (MTI)
According to Carl’s SailCalc, the Albin Vega will immerse ± 1" with every 657 pounds of additional weight. Hence, two thousand pounds of stores will raise the waterline about 3".
I wouldn't undertake a trans-Atlantic with 4 people aboard an Albin Vega.
Excerpted from John Vigor’s review of the Albin Vega
➥ Albin Vega Cruising Yacht Review
➥ Albin Vega 27 - A Review | VAGB - The Vega Association of Great Britain
“It's the Vega's comparatively narrow beam of exactly 8 feet 0 inches that makes for snugness down below, of course. Nevertheless, the accommodations are comfortable for two adults on a long trip, and perhaps even for two adults and two children on a shorter vacation trip.”
“... it would be a mistake to plan on long ocean crossings with four adults.”
See the original Vega Handbook
➥ http://www.albinvega.co.uk/pdf/vegahandbook.pdf
And more ➥ Albin Vega 27 - A true classic | VAGB - The Vega Association of Great Britain
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"
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30-06-2010, 07:10
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#4
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Registered User
Join Date: Jun 2010
Posts: 3
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Thanks for the responses Ed and Gord, especially the sailcalculator website, which is really cool. I have read the review of the vega that says it would be comfortable for four adults and possibly four adults and two kids on a short trip, but I always understood that passage to be strictly about comfort and not saftey issues. Is this incorrect? raising the waterline by 3 inches doesn't sound aweful, but then I'm not sure of the effect on stability. Thanks again, Jan
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30-06-2010, 07:27
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#5
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CF Adviser
Join Date: Oct 2007
Boat: Van Helleman Schooner 65ft StarGazer
Posts: 10,280
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Welcome to CF Jan.
There is more to a safe passage than just stability. In heavy weather there is also the consideration of recovery, which is a function of reserve buoyancy (especially at the ends)
In other words coming down a wave and then getting the bow up before the next wave hits is quite critical.
Otherwise the sheer stresses of heavy water clearing the decks will become more than what the Albin was designed for
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30-06-2010, 07:37
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#6
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Registered User
Join Date: Jun 2007
Location: Northern California
Boat: finally a catamaran dive boat...
Posts: 505
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27' huh?
I always thought of myself as a competent, paying attention to details, macho, take a risk or two in the ineterst of the adventure kinda guy but I have to admit, you got me beat.
I'd be skeptical of taking a loaded down 27 footer from Florida to the Caribbean. LoL Good luck to ya mate.
__________________
the perfect dive boat is one you're on...
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30-06-2010, 07:41
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#7
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Registered User
Join Date: Jun 2010
Posts: 3
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I definitely wouldn't describe myself as the macho take unnecessary risks type. I subscribe more to the adage that there are bold sailors and old sailors, but not many old and bold sailors
I'm just trying to see what the risk is like.There seem to be lots of blogs and stories of Scandinavians who have done that sort of trip with at least 3 people and been fine. Of course it still may have been crazy to try in the first place, that's just what I want to figure out
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30-06-2010, 07:52
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#8
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CF Adviser
Join Date: Dec 2008
Location: sausalito
Boat: 14 meter sloop
Posts: 7,260
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The Albin Vega 27 only displaces 5,000 lbs dry, 2,000 of which is ballast. If you add cargo equal to the total weight of ballast, you will compromise stability--not to mention destroy performance. That poor boat will roll horribly in a seaway, will recover slowly, and will respond agonizingly.
When that boat begins to roll, I shudder to imagine what it will be down below with four adults after the first of them becomes seasick.
__________________
cruising is entirely about showing up--in boat shoes.
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30-06-2010, 08:13
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#9
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Long Range Cruiser
Join Date: Dec 2007
Location: Australian living on "Sea Life" currently in England.
Boat: Beneteau 393 "Sea Life"
Posts: 12,822
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Any person crackers enough to do a passage in a 27 footer with 4 people will find the space for the food.
The only constructive comment I can give you is that we *must* have learned somthing because we used to over provisoned by a huge amount. You don't need too much food and junk and extra junk and crap and goods and extra cargo and things you dont need and gifts for mid-atlantic whales.
Mark
PS pack a shoe horn.
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30-06-2010, 11:56
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#10
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Registered User
Join Date: Jun 2010
Posts: 27
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How much experience do you have? Crossing the ocean in a small boat requires a lot of really good seamanship and experience. I wonder, if you are asking a basic question like this, if you realize how dangerous this is.
Reading stories seems to make it a nothingburger. It certainly can be sometimes. It can also mean requiring very expensive lifesaving effort on the part of many people. Or four people just disappearing forever. So fly Delta, its a cheaper and safer way to get to Europe.
If you have lots of offshore small boat handling then never mind. Ken on Satori
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30-06-2010, 12:29
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#11
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Registered User
Join Date: Mar 2007
Location: Lakeland, FL
Posts: 1,296
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Quote:
Originally Posted by MarkJ
The only constructive comment I can give you is that we *must* have learned somthing because we used to over provisoned by a huge amount.
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Echo that. It took us about 2 weeks in the Bahamas to realize that we had way way too much food (obviously we read the wrong books). We wound up bartering or just plain giving most of it away. In the Bahamas/Caribbean most cruising boats are overloaded. We raised our waterline 3 inches when we left, and raised more it than an inch more on our next bottom job in VZ. I don't think this is a big deal for carefully planned, glorified daysails around the Caribbean. But, crossing an ocean in a 27 footer with 4 people is very different, and I would take this boat's capability and capacity very seriously..
__________________
"There's nothing . . . absolutely nothing . . . half so much worth doing as simply messing around in boats."
Kenneth Grahame, The Wind in the Willows (River Rat to Mole)
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30-06-2010, 15:21
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#12
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cruiser
Join Date: Sep 2007
Location: Tampa to New York
Boat: Morgan 33 OutIsland, Magic and 33' offshore scott design "Cutting Edge"
Posts: 1,594
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How the boat is loaded would be the key. If you packed the dense weight part of the provisions low and centered, accessible and secure, I can see it happening. I've done plenty of things in a 23' boat that many thought I was crazy for doing. Would definately be careful about who was included in the four people. I've seen tough guys totally incapacitated huddling in the fetal position after a couple of days of big seas in a small boat.
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30-06-2010, 18:55
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#13
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Registered User
Join Date: Feb 2010
Posts: 250
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Interesting that when you use the sail calculator and use all of the specs for the Albin Vega but increase the displacement to 7000 lbs that the capsize ratio and comfort ratio actually improves while, predictably, the disp/length ratio and sa/disp ratio drop.
Gentoo, If you already own the Albin you have nothing to lose by loading it like you would for the ocean passage, ask your friends to coordinate their vacation time and go out and spend some time coastal cruising and see for yourself how the boat behaves. ( make sure and do some sailing when the weather is less than cooperative) Might be an eye opener for how little room there is for 4 adults too.
Cruising boats being down on their lines is certainly not that unusual - especially in this day and age where everyone wants to take all the comforts of home with them. Space may be more of an issue than stability, especially with only 8 ft of beam and 23 ft of waterline.
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12-02-2019, 06:15
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#15
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Registered User
Join Date: Mar 2011
Location: Southport CT
Boat: Sabre 402
Posts: 2,712
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Re: Maximum Carrying Capacity
Going from Tenerife to the Caribbean with the trades is not the same as riding the Gulf Stream across the Grand Banks towards Ireland. And it's not always downwind. While this thread is 10 years old, the story in your link is 40 years old. Weather predicting has improved a lot in the last 40 years. This is a good thing, because weather has become considerably more volatile (read:nasty) in the interim.
The (previously) last post mentions that using the sail calculator and increasing the Albin displacement to 7000 pounds improves the capsize and comfort ratios. This makes some sense: heavier boats are more seakindly and have a slower, more comfortable motion in waves. To improve the "capsize ratio", how does the sail calculator take into account WHERE the added displacement is, however? Supplies and equipment four people for a long passage (it took us more than three weeks on a 38' boat) can't be added to the keel, where they would help stabilize the boat. Stowing things in the bilges or on the cabin sole will end up with them getting damaged and/or wet. Some stuff will have to be above the waterline, and room for crew to rest needs to be included in there too. This is a tall order for a 27' boat. People do manage to take risks and get away with things. It appears that the guys in the '70's link made it under relatively pleasant conditions. We don't know what happened with the OP. Maybe they tried, maybe they didn't. Maybe they made it. Maybe they didn't.
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