Sinking Cats

[Dragon Lady]

Is there anymore info on this cat I'm supprised FP don't use it in their promotional material!

[Eleven]

It also reminds me of the advice to Cat travellers to link the dinghy and liferaft securely to the Cat. If it is necessary to leave the Cat, and the surge within is tremendous when the cabins are flooded, then there will still be recoverable stores, navigation, and maybe even a recoverable boat once the storm dies down. Mid Ocean is no place to be in a dinghy/liferaft when the sun comes out. A vital point is that the domestic batteries MUST be sealed units AND with Solar Charging all securely mounted. Moving them to start the engine won't be easy but they should survive full immersion will destroy standard batteries, (which are necessary for the high amps needed to crank a diesel).
Just another thing we all hope to never need, but plan for the worst, hope for the best.

[Dragon Lady]

Sounds like good advice, is there any stories of this happening with a happy ending?
There are stories of yachts being abandoned then being found still floating after the storm has passed.
As they say never step down into a life raft only ever step up into one.

[schoonerdog]

The boat with the scuba divers is a lagoon. Many of them have the double disadvantage of being very heavy and having very little structural bouyancy. FP would be harder, yes, as would privilege. And from South Africa, gunboat, SF 50 and 44, Admiral I think as well, and Africancats has also done a great job of designing an unsinkable boat.
Dolphin and PDQ are also excellent and made in South America.

Originally Posted by Cotemar

YIKES! It had no mast, the salon door was open; it was swamped. Clearly a Fontaine Pajot, French-built cat in the upper thirty to lower forty foot range. You don’t see this everyday!

I inquired around the island the next day to learn the cat was abandoned in terrible weather somewhere near the Bahamas and was left dismasted to its own devices. It had just been found the day before, seventeen miles north of San Andres in the open sea, drifting westward in the currents and trade winds.

However disturbing the scene, the incident is a testament to the “unsinkable” rating of European-built catamarans. Brands such as Lagoon, Fontaine Pajot, and Catana utilize watertight bulkheads, foam sandwich construction, and other buoyant materials that actually qualify their cats to be certified unsinkable.

When you think about it, that’s pretty darn nifty! Not all cats are created equal and some catamaran brands are not certified to meet unsinkable standards and will not remain floating if totally swamped. Those “Brand X” cats will plummet to the bottom if they take on too much water. It’s a good question to ask when shopping for a cruising catamaran.

And the proof is in the pudding. The Fontaine Pajot full of water drifted across the WILD and rough central and western Caribbean and there she sits, still on the surface.

[fastcat435]

Hallo Eleven , I like your positive thinking but if a battery is submerged sealed or not it short circuits and is destroyed no matter what. salt water is very conductive.
The only solution would be keeping them in a water tight compartment but they need some form of cooling so that is also very hard.
The best way to stay afloat in any boat is keeping the boat as light weight as possible and put in a lots of buoyancy in the form of foam or balsa and have buoyancy chambers in front, center and rear that have the capacity to keep the boat evenly afloat in loaded condition.
A example of a cat with a loaded weight of 10 tons metric
Build in structural buoyancy in form of foam wood of at least 5 tons ( this is easy in case of a composite hull with a foam or balsa core.
Seal off all possible buoyancy chambers that are not used for storage and make sure this space has at least 8000 liters of air capacity and make these chambers true out the boat.
It is useless to only have the chambers in front since most of the weight is in the rear so 2 bows will stick out into the air.
Placing the boat on 4 load cells will tell you where to put in the buoyancy.
Having the CE A certificate does not mean that she will stay afloat evenly, only that there is enough buoyancy to keep her on top no matter in what way.

Greetings

Gideon

[Therapy]

Originally Posted by fastcat435

Having the CE A certificate does not mean that she will stay afloat evenly, only that there is enough buoyancy to keep her on top no matter in what way.

Greetings

Gideon

CE A means it is guaranteed not to sink?????

[fastcat435]

for multihulls a formula is used adding up all floating materials and the weight of the boat including the max load

[Therapy]

Originally Posted by fastcat435

for multihulls a formula is used adding up all floating materials and the weight of the boat including the max load

What are you saying?

Are you saying that CE A certification means that formula is used and it has to have a number that ends up meaning the cat is unsinkable at "max load"?

It is a simple question - the original one.

[Eleven]

Fastcat435 commented "Hallo Eleven , I like your positive thinking but if a battery is submerged sealed or not it short circuits and is destroyed no matter what. salt water is very conductive.
The only solution would be keeping them in a water tight compartment but they need some form of cooling so that is also very hard."
These are solvable. A tight aluminium enclosure flooded with a vegie oil would seal against water protecting the terminals and connections reasonably. Bearing in mind these are usually installed below the sole, so are now in an air pocket, and well protected. A bigger issue is having the general cabling survive flooding without shorting or degrading.
I hope all your batteries, gas bottles etc are secured in position and not going to become mobile should the worst ever happen.
Do bear in mind that seawater plus battery acid produces chlorine gas (submarine style) making the interior a death chamber so 'sealed' batteries make a lot of sense.
Domestic batteries shouldn't see high amperage rates so aren't going to heat up much.

[fastcat435]

That is correct, I have found the original calculation of the Fastcat 435 and it is posted below , since these weight sheets were made we have added air volume in buoyancy chambers from the original of 4400 to a volume of 7600 kg , , this 3200 was added in the rear of the cat to compensate the heavy weight of electric motors , batteries and generator Greetings
Gideon

[schoonerdog]

Therapy,

In response to your question, from my limited understanding the answer to the Question of does CE class A rating mean that it is guarenteed not to sink is "NO". The CE class A rating means that the boat is constructed to certain norms, such as the hatches and vessel is capable of withstanding 4 meter waves and force 8 winds. This rating for recreational vessels was based upon an agreement made between EU countries and manufacturers. What we as catamaran consumers should ask for is a much higher standard than CE class A ratings provide. Catamarans can be constructed to the standards of the Safe Return to Port Rules of the Maritime Safety Committee. Simply put, these rules state that a vessel should be able to return to port under its own primary propulsion in event of flooding of any single water tight compartment. For sailing vessels primary propulsion is considered to be engines as wind force and direction is always uncertain. This simple rule sounds like a perfectly reasonable request of a catamaran buyer.

It might not make you feel very safe, but just this simple rule is applied now only to passenger vessels greater than 120 meters, only goes into effect his year, only applies to new construction and frankly few existing passenger ferries meet it because they have their engines co-located in the same compartment.

Contrast that with an African Cats design or PDQ (and there are a few others). It's engines are in seperate water tight compartments with seperate fuel systems. Should even a mid hull breach occur, that particular hull would flood only I believe 18 inches or so for the PDQ (I don't know the specs for the African Cat) but the boat would still be able to return to port using its other engine. In other words, a 40 ft catamaran designed with safety as its first aim, can provide the potential safety of a 120 meter plus passenger liner. I think that's the true bottom line that we as consumers should be asking for. Some boat builders are leading the way in this design, and an educated public rewarding that sort of design specification through their dollars I think would justly reward those designers. After all, these designers have obviously sacrificed their ability to provide charter boats with massive amounts of births and offer instead safer designs for private owners with fewer births and greater structural bouyancy and larger water tight compartments.

You will never see the Safe Return to Port rule applied by the CE to regular recreational vessels because only a few people die when a recreational vessel sinks and almost no monohull could ever be constructed with seperate engines in seperate water tight compartments. But we can hold catamaran manufacturers to a higher standard as its possible, its currently being done, and frankly its the best choice for an owner venturing into blue water with his family aboard.

[Therapy]

Schoonerdog,
Thank you for the information.

[Little Otter]

Thank you schoonerdog i always have wondered what exactly that rating meant.

[RayG]

Atlantic 46 up on Rocks in 2008

http://www.sailinganarchy.com/article.php?get=1439
“Port hull is totally gone. House empty. Starboard hull floating and dry.”

I’ll leave it up to your opinion if it “Sank”.
It is fair to note that this was a plywood/composite boat and not the current generation of foam cored Atlantic Catamarans.

RayG

[Palarran]

I always thought the definition of "Sank" was underwater. So my opinion is that it didn't.