Catamaran Capsizes in Galveston Bay

[markpierce]

It's well known the most expensive way to cruise is fourth class on our private yachts (super-rich excluded). Least expensive is on a cruise ship where your cabin/bed is made up every day, food is good and plenty, live entertainment in several venues (stage shows, piano bars, and so on), etcetera. Still, we put up with it because we want to be in command.

[cal40john]

Late 70's on Lake Washington Seattle a Macgregor 36 was upside down, I didn't see how it got that way. A club member said a big cat was capsized on the Lake so I went out on one of our club's 16' Whalers to offer assistance. They wanted me to try and right it bow over stern, I said my little boat wouldn't have enough power. I offered to take them to shore. They stayed with the boat until the Police arrived, who towed it to a place to anchor upside down for the night since it was windy and choppy. Next day they got some big boat to right it. They towed it to our courtesy dock, it was surprisingly empty of water.

IIRC there was something about more than one person attempting to release the genoa sheet in a gust which didn't get accomplished in time.

John

Originally Posted by clockwork orange

Factor, could you point to actual evidence of a Mac 36 pitchpoling, i ask this because i used to own one and before buying it had researched it pretty extensivly and have a ring binder with every article i could find on their racing exploits from back when they were raced hard in the early to mid 80s and not once did i read of any tendency to pitchpole, in fact as im writing this i have in front of me an article from an old Multihuls magazine where a French guy who used to own the Mcalpine Downie racing cat British oxygen which he lost crossing the Atlantic, he bought a Mac 36 and raced it in the 1979 St Marteens Tradewinds race which was an 800 mile race in heavy weather (where he finished 3rd) and he has high praise for the boat in every way and i quote "i am very suprised to find that the Macgregor handled itself so safely. In the conditions we encounted the boat didnt get overpowered. When we were surfing down the waves it WOULD NOT dive into the next wave, it would come right back up again" end quote. The boat in fact has a fair bit of reserve bouyancy in the bows with the long overhang and stability is the same as any other 36ft x 18ft x 4000 lb cat. In all my research i found NO evedence or suggestion of any Mac having flipped at all anywhere and they were raced hard back then and it was well covered in Multihulls magazine. as i mentioned earlier, i did read in a mag many years ago of one that flipped at anchor in a hurricane in Belize and now this one in Galverston, THATS IT, so if anyone has any actual evidence of any others please post them so i can add them to my list.
Steve.

[downunder]

Originally Posted by s/v Jedi

erhmm.. you can only count volume of materials that are lighter than water and also have to distract that volume's own weight from the calculated displacement figure.

I'm wondering what the volume of balsa or foam in your hull and deck is. I can't believe it will carry the hull, rig and engines without the help from those 50+ sealed compartments.

ciao!
Nick.

Suppose I could add all up

Divinicell foam sheets for 46 ft resin infused cat.

11 sheets 12mm x2174x1200 , 23 sheets 15mmx2174x1221
130 sheets 20mmx2174x1223, 6 sheets 30mmx2174x1224
17 sheets 40mmx2174x1224
Will be some left over clearly but a hell of a lot of buoyancy for vessel which went in water minus only rig/sails at 7 tonnes.

[hummingway]

Originally Posted by 44'cruisingcat

Completely incorrect. The TOTAL volume will displace that amount of water. Doesn't matter what material it is.

ie 10 m3 of lead will displace 10 m3 of water. (it won't float, because it weighs much more than 10m3 of water, but the fact is it still DISPLACES 10m3 of water)

So if all the material in the boat occupies 10m3, and the boat weighs less than 10m3 of water (call it 10 tonnes) - then it can't sink.

The basic material kit for just my hull/deck structure was more than 6m3. (There is quite a bit more material in the final product.) The boat launched, with near full water tanks, engines, batteries some fuel and lots of other gear, but less the rig, at 4800kg.

So even without the 50+ bouyancy compartments, my boat would not, COULD NOT sink.

Which doesn't leave a lot of wiggle room. Say 300 kilos for mast and surely at least 100 in SS wire, another 100 in sails. That leaves 700 kilos for people and beer before equilibrium. Drink up everyone.

[s/v Jedi]

Originally Posted by hummingway

Which doesn't leave a lot of wiggle room. Say 300 kilos for mast and surely at least 100 in SS wire, another 100 in sails. That leaves 700 kilos for people and beer before equilibrium. Drink up everyone.

yes but cruisingcat is right, I made a mistake... you don't need 300kg load carrying capacity for a 300kg mast, because the mast itself also replaces water when submerged... i.e. it weighs less under water. I bet that when just the tri-color masthead light sticks out of the water, this cat-crowd is gonna tell us it ain't sunk yet :-)

He's still going down if not for the enclosed spaces. Just put a big scale on the dock and start clearing out the boat and weigh everything... will be big shock when you add that up :-))

There's often a ton to work with and when you take the weight of crew and their toys you normally go over that already. Heck, I got 4,800kg of tools and parts aboard

When I take in full water and fuel tanks, I gain 4 tons lol.

cheers,
Nick.

[clockwork orange]

Thanks for that John, the reason the Mac had not much water in it after a capsize is that they had an enormous amount of foam in the right places and had a 2" plug in each hull just above the waterline which you removed and the floatation would do its job and drain each hull to the level of the plugs which you then replaced and pumped or bailed the rest, the boat could be sailed with water at the level of the plugs.
Steve.

[catty]

After reading articles like the one linked below, one may be excused for thinking that many capsize related falsehoods are pedaled by the catamaran evangelists amongst us.

Taking note of ...."Most multihulls will not capsize even under intense conditions. A catamaran in extreme conditions will round into the wind, much like a monohull. Thereby in actuality it is not possible for a cruising catamaran to capsize from extreme wind conditions."

See......Fact from Fiction: Catamaran Myths Busted

Regards

[downunder]

Originally Posted by catty

After reading articles like the one linked below, one may be excused for thinking that many capsize related falsehoods are pedaled by the catamaran evangelists amongst us.

Taking note of ...."Most multihulls will not capsize even under intense conditions. A catamaran in extreme conditions will round into the wind, much like a monohull. Thereby in actuality it is not possible for a cruising catamaran to capsize from extreme wind conditions."

See......Fact from Fiction: Catamaran Myths Busted

Regards

Reading anything on the web one has to be able to sort the wheat from the chaff.

[44'cruisingcat]

Originally Posted by hummingway

Which doesn't leave a lot of wiggle room. Say 300 kilos for mast and surely at least 100 in SS wire, another 100 in sails. That leaves 700 kilos for people and beer before equilibrium. Drink up everyone.

Except for the fact that as I said, considerably more material went into the finished boat, much of it bouyant. At least another cubic metre. Oh and then there's the 50+ sealed comartments. Didn't I mention those?

[44'cruisingcat]

Originally Posted by s/v Jedi

yes but cruisingcat is right, I made a mistake... you don't need 300kg load carrying capacity for a 300kg mast, because the mast itself also replaces water when submerged... i.e. it weighs less under water. I bet that when just the tri-color masthead light sticks out of the water, this cat-crowd is gonna tell us it ain't sunk yet :-)

He's still going down if not for the enclosed spaces. Just put a big scale on the dock and start clearing out the boat and weigh everything... will be big shock when you add that up :-))

There's often a ton to work with and when you take the weight of crew and their toys you normally go over that already. Heck, I got 4,800kg of tools and parts aboard

When I take in full water and fuel tanks, I gain 4 tons lol.

cheers,
Nick.

As I said, the boat was weighed with about 95% full water and quite a lot of food, clothes, tools and other gear already aboard. (Much easier to load the boat up while it's sitting in the backyard.) In fact I've taken off quite a few of the power tools, which were basically left aboard from the building process just in case they were needed.

Funny, but I'd have thought I would know more about what's on my boat than you do, but I guess monohull owners know everything... so I suppose you can tell me how a boat that weighs less than the water it displaces is "going down"?

And did I mention the 50+ sealed compartments?

[44'cruisingcat]

Originally Posted by downunder

Suppose I could add all up

Divinicell foam sheets for 46 ft resin infused cat.

11 sheets 12mm x2174x1200 , 23 sheets 15mmx2174x1221
130 sheets 20mmx2174x1223, 6 sheets 30mmx2174x1224
17 sheets 40mmx2174x1224
Will be some left over clearly but a hell of a lot of buoyancy for vessel which went in water minus only rig/sails at 7 tonnes.

Each cubic metre of foam adds about 920kg of bouyancy.

[44'cruisingcat]

This really has been an enlightening thread. I now know that boats carrying several tonnes of lead under them NEVER sink, yet boats which have positive bouyancy always do.

And I have several tonnes of gear on my boat that I never knew about.

Even though it's floating just under it's design waterline for 5200kg displacement....

[44'cruisingcat]

Originally Posted by 44'cruisingcat

Except for the fact that as I said, considerably more material went into the finished boat, much of it bouyant. At least another cubic metre. Oh and then there's the 50+ sealed comartments. Didn't I mention those?

On reflection, probably closer to 2 or 3 cubic metres of extra material went into the boat - I widened the beam by 300mm and increased the sheer height by 180mm, the materials for which were not included in the first delivery. Then there's the internal furniture, paint, bog, timber trim etc etc...

So we have well over 8, probably over 9 cubic metres of material in a boat that weighs not much over 6 tonnes fully loaded. Yet it will surely sink. If I somehow manage to hole 50+ sealed compartments. Many of which are well above the waterline.

Yeah, right.

[44'cruisingcat]

Originally Posted by s/v Jedi

Soooo.... cats don't sink? My eyes must have deceived me then because I have seen a Prout and a Voyage 440 go down down down.

cheers,
Nick.

You actually watched them sink? To be perfectly frank, I don't believe you.

[AussieGeoff]

Originally Posted by Mark1977

Don't even get started on ferro.......

Hey, if we try hard, we can get the cat v mono x ferro v the rest in some kind of reciprocating mud slinging match here.

FWIW, I'm not keen on cats personally, but it's not religion. Under the right (wrong) conditions you can reliably flip them. (Quartering sea, drive a hull into a swell just right, so it digs in, over she goes.) Takes the right combination of sea, wind, speed and stupidity of course. The worst part of that however is that if you do flip a good sized cat, it's darn near impossible to get it right way up without a skyhook.
Monos can get knocked down by extreme seas, but unless something breaks they will usually come back up.
I guess my point is that no system is perfect, no hull combination, no construction material (I'm a ferro owner, I'm not religious about that either, but some of the rabid anti-ferro rants I've seen are truly mind boggling.) so we need to just accept that there are horse for courses and this applies to various types, styles, sizes and construction of boats as well as to, well, horses. You wouldn't put a Percheron on a racetrack, or a Shire in a trotting jinker, or try ploughing a field with a thorougbred. Boats are no different, the various designs, sizes, shapes and construction materials all have their advantages and disadvantages. Your choice of a boat is due to many things, not least of which is the size of your wallet. Now, I'd really like to own half a mills worth of steel hulled, 70 foot topsail schooner, but I can just about afford my $14k 35' ferro ketch. Yes, it's a compromise, but it's half a loaf or no boat, so guess which I prefer. Ditto for cats. They're good boats in some areas and no so good in others. Like monos.

AussieGeoff