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Old 08-02-2008, 20:00   #1
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preparing cats for problems:inversions

There was a bit of a thread drift and I thought I'd dedicate a thread for reference for people, such as me, who are looking for good advice for preparing the boat for long trips and the ever present possibility of flipping.

I truely doubt a catamaran lying to a sea anchor in survival conditions could flip, and in my mind that would be the rule, keep sailing until the gusts start going above 40 knots and then put out the sea anchor and sit tight.

But should you flip because something happened lets talk about what should be prepared ahead of time:

1) Food. We in the past had put our food in water proof air tight containers to thwart bugs, seems double effective as it would prevent salt water intrusion. Also people I know use water tight tupperware for their refrigerators and freezers as it helps prevent all of the cold air from leaking out when they open the refrigerator and also helps keep most humid air out and the refrig and freezer dry. Again, it makes even more sense when thinking of it in an inversion as top loading chest type freezers would spill their contents pretty quickly in an inversion.

2) Water. Most water tanks have vents in the top which would cause all of the water to spill out when inverted. So jerry cans would make a lot of sense. Perhaps putting some sort of valve on the vent hose which would allow the air to leave but prevent the water from flowing out. I'd really like to know I could keep the water in my keel mounted water tanks, I'd think that the pressurized line and fittings would be fine regardless of an inversion...

3) Mounted, permanent jack lines underneath, maybe even nonskid on the underside of the bridgedeck.

4) Permanently mounted inverted strobe that ala Catana. Great idea.

5) glow in the dark paint I'd think would be the best type of paint as Africancats uses.

6) epirb mounted in a very retrievable location would be great, ideas? It sounds like catana has a cockpit locker that has underneath it a large water tight access port. In that locker you'd keep the water proof bags with signal flares, epirb, hand held VHF, flashlight...

7) Ventilation and entry and exit into the boat. Sorry, I've got no ideas there. Lavranos mentioned that keeping the escape hatches open would allow the boat to continue to sink down till the escape hatch was under water and the air was again trapped. Sooo, you rig up a jackline? And ventilation?

8) We scuba dive, but I'd think the wetsuits would be the choice gear if living inverted for a while to guard against heat loss.

9) Keep the batteries very secured. Hopefully if a large ship comes along and you can rig a line up to pull the boat upright again you could use the bilge pumps.

10) Medical kit should be in water tight container. Never really thought of a good reason why until now.

Go ahead and add more items to this list of things you think would be good.
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Old 08-02-2008, 22:01   #2
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Quote:
Originally Posted by schoonerdog View Post
2) Water. Most water tanks have vents in the top which would cause all of the water to spill out when inverted. So jerry cans would make a lot of sense. Perhaps putting some sort of valve on the vent hose which would allow the air to leave but prevent the water from flowing out. I'd really like to know I could keep the water in my keel mounted water tanks, I'd think that the pressurized line and fittings would be fine regardless of an inversion...
I doubt that all the water would escape as it is sealed apart from the vent, a vaccumn would build up and stop the flow. If inverted just cut the vent and clamp it to stop more comming out then remove the pickup to allow air to enter.

Mike
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Old 08-02-2008, 22:14   #3
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I know there are few reliable statistics...

There are few stories of crew surviving a flipped cat.

Same as crew surviving a catastrophic failure in a monohull.

Most pilots don't wear parachutes as using them is more dangerous than not using them.

I would suspect that the same is true for an upturned cat or rapidly sinking mono in the middle of the ocean.

That is, put your energy into not having a problem in the first place. Triple check all key items, get good weather forecasts, use conservative planning, no "getthereitis".
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Old 09-02-2008, 03:22   #4
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[quote=Boracay;132791]There are few stories of crew surviving a flipped cat.

Same as crew surviving a catastrophic failure in a monohull.

I would suspect that the same is true for an upturned cat or rapidly sinking mono in the middle of the ocean.

G'day,
There are few stories because there are so few cruising cat capsizes. Race boats that capsize, the crew almost always survives. All the suggestions so far are good ones, but the escape hatch has to be above the inverted waterline, assuming a cat with positive buoyancy when flipped. Cats heavy enough to sink when inverted probably won't capsize.

Bunks that can be used inverted are a good idea, and somewhere that can be kept dry. Turn the plans upside down, ask the designer where the inverted waterline will be and plan accordingly. Water surge is a killer. It will suck everything not firmly bolted down out of the boat very quickly and make living inside impossible. Lockable bulkhead doors and compartments that can be bailed dry will prevent this. With decent epirbs, long stretches of living inverted have become rarer, but epirbs can be lost and occasionally fail.
However, the cold and wind will get to you very quickly, so access to the interior is critical, as is access to the exterior if trapped inside. Anybody who puts to sea in a multi without an escape/access hatch is crazy.

regards,

Rob
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Old 09-02-2008, 05:09   #5
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For bunks, some rolled-up hammocks stowed away and some good attachment points. Diesel tanks should have leak-prevention measures as well. A manual watermaker might be a good idea. Kelsall mentions having a dedicated dry area - that is an area with water-tight doors and pumping arrangements. He has more ideas in the attached article, including a righting method.

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Old 09-02-2008, 06:36   #6
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There was a bit of a thread drift and I thought I'd dedicate a thread for reference for people, such as me, who are looking for good advice for preparing the boat for long trips and the ever present possibility of flipping.
Reef early
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Old 09-02-2008, 08:42   #7
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Originally Posted by schoonerdog View Post
I truely doubt a catamaran lying to a sea anchor in survival conditions could flip, and in my mind that would be the rule, keep sailing until the gusts start going above 40 knots and then put out the sea anchor and sit tight.
I believe 40 knot gusts is a bit too early to stop sailing depending on the boat and other conditions. We've managed OK with 45 across the deck with main double reefed and just enough jib to balance the helm. Even the AP was happy. We still have a third reef to go. That said, each skipper/boat combination has to pick their threshold.

Using sea anchors can be a hot debate. Conventional wisdom among Catana owners is use one ONLY if you can't claw your way away from a lee shore. Otherwise, run like hell and drag something to slow down.

Quote:
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6) epirb mounted in a very retrievable location would be great, ideas? It sounds like catana has a cockpit locker that has underneath it a large water tight access port. In that locker you'd keep the water proof bags with signal flares, epirb, hand held VHF, flashlight...
Catana does not have what you describe - at least not the boats I'm familiar with. I apologize if something I said earlier gave this impression.

BUT - everyone should have a ditch bag with all this obvious stuff in it. We keep our ditch bag not too far from an escape hatch.

Dave
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Old 09-02-2008, 11:20   #8
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Have survival stores in separate watertight containers lashed somewhere in the boat where they are safe. Do not rely on your food supply that is stored in the usual places like cabinets and lockers unless they have substantial locks/latches. The action of water in the upturned hull will eventually suck everything out of the boat and possibly break open cabinets/lockers. Consider any of your normal stores that survive a gift. Same goes for water, have a few 5 gallon jerricans lashed in somewhere and a manual watermaker. A trimaran will rely on airlock in the amas to keep it floating high and this allows you access the main hull thru a hatch or hole cut in the hull. In a cat you lose any airlock in the hulls thru the hatch or hole cut in the hull so you need to be sure your cat has adequate foam/watertight flotation compartments. Many cats seem to have this safety hatch but if yours does not make sure you have access to tools to cut an access hole in the upturned hull. Strongpoints for attatching jacklines on the underside of the bridgedeck or hulls as well as nonskid paint would be a good idea.
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Old 11-02-2008, 04:51   #9
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There are few stories of crew surviving a flipped cat. Same as crew surviving a catastrophic failure in a monohull..
Rubbish

Dancing emu and rontagjuuu both went over in the gladstone race, all crew survived happily. Thats 10 safe sailors in the last year. Then there is john glennie in rose noelle.

Winston chruchill got rolled in the sydney hobart - sunk, three of the crew died in the life raft.

In fact point me to one story where the crew havent survived an inversion in a multi - I am sure there is one, I just cant think of it at the moment.
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Old 11-02-2008, 05:51   #10
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When we did the survey on our St. Francis, it was a weird feeling to see that the underside of the bridgedeck was painted International Orange and it already had jacklines rigged and in place!

Those jacklines will come in handy for cleaning -- I certainly hope I never need them for their intended purpose, though.

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Old 11-02-2008, 22:27   #11
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velcro tabs to hold mattresses in place, and if possible, a mattress that doesn't hold water when wet; washboards to seal off bits of the hull when upside down to provide separate areas to prevent surge and ability to bail out to make a dry upside down area; some sort of inflatable device to lift the bridgedeck. Could be incorporated in the roof of the bridgedeck. Sufficeint bouyancy in the crossbeams to support the the boat to the level of the crossbeams when immersed;
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