How to salvage a capsized cruising catamaran

[a64pilot]

I have a gut feeling that whatever weather conditions it would take to capsize a cruising Cat would likely continue to essentially tear it apart from a salvage standpoint, that and the fact everything is literally saturated with salt water, I doubt there would be much to salvage.

[Cadence]

Originally Posted by tp12

No need to get shirty; I agree with a lot of what you say. Except your last sentence.

My question was genuine and didn't require your response, so please play nice. None of these things relate to the question I asked you which leaves me doubting that any mast is designed break under wind loading.

The whole thing is hypothetical. I would think, someplace in your thinking the air providing buoyancy would escape prior to righting? The air got capture during turtling which was fast.

[Gmcgyvr]

Originally Posted by tiopirata

I am both a rigger and a salvor, and very occasionally a builder of multihulls.
Those multis that I have righted from inversion I have done so by longitudinal flip, always stern over bow. It is surprising how little energy is needed to achieve this.
It is not true that rigs on production cats are designed to fail on inversion. While the stresses are enormous and failure frequently does occur in such instances there is no design requirement for this.

I presume you mean bow over stern? Using the bridle?

[uncle stinkybob]

Interesting to see it in action.
https://youtu.be/U4UXmre_aoM

[donradcliffe]

Originally Posted by Cotemar

Production Cruising Catamaran Designers give you a Reefing Chart with each boat they design.

At 50 knots you should have NO sails up.

This is why Production Cruising Catamaran Designers pull the Rig at 50 knots with full sails.

As you can see in the pictures below. Its all part of a good Catamaran design.

If you screw up with a Production Cruising Catamaran you will end up in a large white upright floating life raft that will float until someone tows it in or it washes up on a beach.

The boat will most likely be a total loss / insurance claim as it would be much cheaper to buy another boat.

Thanks for posting the reefing chart. I know the chart is required by ISO 12217-2, but this is the first one I've seen. Is the windspeed in the chart apparent or true wind (it appears to be apparent)?? The calculations behind the chart are the same ones for the stability index, and they are based on lifting a hull in flat water under the worst case scenarios (the angle of attack on the sails is assumed to be at maximum lift and the force is assumed to be perpendicular to the axis of the boat) with a 30% gust factor. Under normal conditions the chart is quite conservative, which accounts for several posters saying they can't fly a hull at their stated limits. It would also say that the boat is safe with you down below asleep under autopilot if you follow the reefing chart .

However, in squally conditions with waves it is possible to exceed this design basis. Therefore ISO 12217-2 considers a cat which has to reef at under 25 knots based on their calculations as 'vulnerable to inversion', which means that it must have escape hatches and it has to float inverted without allowance for trapped air and within 10 degrees of its normal waterline.

Makes a modern cat safer, but hard to sink with gunfire.

[JPA Cate]

Which is part of why "Heartlight"'s owners had her crushed by the rescuing ship during the infamous Queen's Birthday storm....it was the only way to sink her.

Ann

[Cadence]

When to reef can only been determined if you are there. I kind of believe if something sudden comes up someone should have been on watch to totally slack the sheets, so the salvage isn't necessary.

[SV DestinyAscen]

Originally Posted by Ann T. Cate

Which is part of why "Heartlight"'s owners had her crushed by the rescuing ship during the infamous Queen's Birthday storm....it was the only way to sink her.

Ann

Thought that boat was actually no longer in distress and there was some new age nonsense about spirits and stuff that led the admiral convincing the freighter to ram it....

[robbievardon]

Assuming you are deepsea, what flipped the boat? if you HIT A FLOATING OBJECT then chances are that one hull (on a cat) is going to be partially/totally submerged depending on how much air has remained trapped in that hull. So if you wish to recover the boat start by keeping the air in there and the undamaged hull. I have done this in one salvage opperation using sails to act as open bottomed air lift bags.step 2 is to try to close all hatches/openings because do not forget if you manage to right the hull every opening is a potential exit point for the air that is keeping your boat afloat.The idea of an air bag on the mast is not new,there was a time when cats (some) were fitted with a rigid float at masthead to try to stop full rollover.I can*t say if they worked as I have never been a fan or follower of multihulls. From here on there is no best way. My opinion is that unless you have a large supply of industrial air bags you are not going to right the boat. with mast tip on surface the one floating hull will not lift your hauling rope high enough above the surface and will not roll the boat but merely drag it sideways.It will also try so submerge the upper hull.As we are in the realms of fantasy we can go through the routine for small salvage vessel as you are unlikely to want to spend perhaps a million dollars a day for a barge and crane. set anchors on casualty and tug/salvage boat, 1 construct A frame on casualty run cable from A frame base under floating hull, under submerged hull and up to masthead,tie off then continue cable over top of A frame to winch. Brace and pad out all changes of direction. 2 attach airbags to damaged hull. 3 inflate airbags/haul on winch. 1 could be left out if airbags can lift sunken hull. 4 temp patch to damaged hull. 5 pump out hulls and tow to nearest crane. This asssumes calm weather. Head over heels has been used in past where you need to ballast down good hull, but when it is floating like a bottle there is a pretty delicate bit of work to get it back down right way up. if hulls are in tact dont try to right it, remove mast and tow as is to port for crane lift. Unless you are a big sponsor there is little point in long distance recovery. to remove mast take 3 to 4 ft of cortex,1 safety fuse for mast and bolt cutters for rigging.

[DerekKelsall]

Cruising cat capsizes are rare. 2-3 a year I guess, which means this is a serious subject and everyone sailing a cat should consider. Every owner would choose to lose his rig rather than capsize. In my experience when a rig is lost the question is always asked what went wrong and who made the mistake. No one ever asks, was this a capsize saved. Rigs are designed with sufficient strength to capsize the cat if driven hard. The Spar makers use the stability to size the rig.

40+ years ago, I did a capsize test of a self righting system, on a 36 footer on a lake. I will not go into details here but a lot can be done, with relatively little cost to provide a survival compartment and prepare to self right. Usually this would be F and A, bow down, which was the way we did it on the Lake. I was somewhat surprised to see a Lagoon floating with transoms way under. I would want to see more built in buoyancy aft.

I point to consider, a fully waterlogged cat has very little stability.

I have capsized a proa offshore but not a cat.

Happy boating,

Derek.

[KJThomas]

In the early days of multihulls in Auckland there were a few capsizes. Mostly racer cruisers like GBE's.
Righting bow over stern with a bridle from the bow was decided on as the best method. After a few unscheduled experiments.
Flooding the stern compartment if necessary.
All those boats are still sailing as far as i know.
Requires much less energy than a transverse righting. It is conceivable that the large outboard RIB's, most cruising cats carry these days, could have enough pull.
Though, energy, is not really a problem when the rescuer is a container ship.

[donradcliffe]

The video was worth 1000 words:

The mast either came off or was taken off.
Pulling sideways did not work.
Pulling backwards did not work.
Last seen the boat was towed in upside down, presumably for a date with a crane.

[CdS2 Roland]

Hello,
When I was younger ... 30 years ago . Il was working in a rescue squad . We tried to turn a capsized 40 foot racing cat. We dived to take off sails (mast was in place with no visible damages). We put a lift bag 60ft down on top of the mast and inflated it partialy to bring the mast on surface. We pulled slowly from one side with a power boat. Sudenly the mast broke at half high, just before the top of the mast came on surface. I think load on the mast came to high once one hull was in the air with some water in the hulls . Other problem, the other hull was draging on the surface during towing and we could not pass the vertical. End of the story.

[django37]

A capsized cruising cat. Attatch Lines to bow, pull the boat slowly backwise. A cat half full of water has very low longitud. stability. Never over the Beam.

[Franziska]

Agree with the latter.

Free surface effect of water in hull greatly reduces longitudinal stability.

Bow over stern with long bridle.

The cat in the video floated very high.
Little water in hull, so still fairly stable in inverted position.
Partial flooding before end over end would have helped.