How many cats have flipped ?

[thomm225]

Originally Posted by redneckrob

Is it possible that most cat's flip end over end rather than to the side given the massive force necessary to get them to 90 degrees?

Racing, lighter weight catamarans pitchpole many times while flying the spinnaker because a tired skipper steers the wrong way to save it when a big gust hits.

Rather than heading down they will head up causing a very fast pitchpole

[44'cruisingcat]

The answer to the question is: not many.

The vast majority of cruising cats never have and never will.

[David M]

Originally Posted by smj

Statistically you have about the same chance of flipping a cruising cat as you do sinking a cruising monohull, pick your poison.

Do you have a link to those statistics? I'm curious.

[smj]

Originally Posted by David M

Do you have a link to those statistics? I'm curious.

No, as stated above it was a conversation I had with a Lloyd’s of London insurance rep.

[mikedefieslife]

Originally Posted by David M

...On the other side of the debate, catamarans have a greater initial righting moment and less beam per hull providing a speed advantage allowing them to dodge low pressure areas more readily. If you have the ability to reduce the chance of getting into a bad situation in the first place then that is a distinct advantage.

Don't cold fronts usually move around 20knts? Very few cruising catamarans will get anything like that in sustained speeds, to 'get away' from the weather unless they have days of warning.

Originally Posted by tomfl

There is really no such thing as a generic cat...

There have been some lighter cats getting capsized due to a microburst getting under the bridge deck and flipping at anchor; but that is rare.

When I was anchored in Vliho bay in Greece I met another Prout owner. He had a 37 Elite. When I told him where I was anchored, he replied "oh I wouldn't stay there for long." He went on to tell me about 100mph winds that flipped an anchored Prout Snowgoose 37. Helped I think by a genoa coming partly unfurled. With the chaos in the anchorage a couple of people lost their lives that day.

[Fore and Aft]

I know of three that have flipped. The first was a 40’ foot Wharram in Wellington Harbour. The guy had way to much sail up and when he left the lee of our yard the first few gusts just flipped him.
The second was a 40’ cat on the Wide Bay Bar, bad timing I believe and he got flipped crossing at night.
The third cat was a 32’ Fast Back, racing in Moreton bay. Flipped while pushing her to hard.
Cheers

[Svan]

I capsized my first multihull on the first day I owned it. Granted it was a hobie 18. We buried the lee bow and it didn’t come back. Nearly every capsize video I’ve seen goes this way.

If you can picture the forces at work it is easy to see how a full sail will pitch the boat over the rail/bow as it plows underwater. So most storm tactics are aimed at keeping the speed down and boat motion easier on the rig.

[David M]

Originally Posted by mikedefieslife

Don't cold fronts usually move around 20knts? Very few cruising catamarans will get anything like that in sustained speeds, to 'get away' from the weather unless they have days of warning.

The idea is to dodge them laterally...not run in the same direction as they are moving. Lows and their predicted path can be determined a few days out.

[Bean Counter]

I do not recall reading of any cruising factory boats (Lagoon, Leopard, FP) that has capsized or pitch poled only by force of wind /waves other than in Hurricane force winds, there has always been some other factor to cause the inversion, eg hitting whale, busted escape hatch etc.

[a64pilot]

Originally Posted by KC375

This is a well worn topic. That tends to attract trolls and passionate mono and multihull enthusiasts.
Be skeptical of those making assertions without links to credible fact bases or sources. I won’t pretend I have any of those.
The monohull missionaries will point to a number of multihull inversions and discuss the dangers of boats with stability curves that disappear as you approach 90 degrees.
Multihull advocates will acknowledge that multihulls tend to have two stable positions upright and fully inverted. They will then make the case that it’s better to up side down in or on something with positive flotation even when flooded as compared to monohulls that may be self righting but typically don’t have positive flotation when flooded (as may happen with a knock down, through hull failure, or hull breach). Its worth noting that some of the “unsinkable” multihulls have proven their ability to sink but the absence of a ballasted keel makes it easier to have a truly unsinkable boat. Many multihulls are designed (including Atlantics) to have crew living/shelter arrangements in the event of an inversion.
The multihull enthusiasts will point out that monohullls have two stable positions – on the surface when not flooded, and on the bottom when flooded. That leads to the next point – an inverted multihull is more likely to make the news get good photo coverage than the monohull on the bottom as the later is less photogenic and more likely to disappear without a follow up story from survivors.
Some of the older multihulls were more prone to capsize. In particular higher performance multis are more prone to capsize (Atlantics would fit in the higher performance bucket). The more condomaran charter boats tend to have more conservative rigs.
Most modern bridge deck catamarans sailed by competent appropriately cautious crews have a low risk of capsize (and a decent likely hood of maintaining shelter if a capsize occurs). However the combination of poor crew judgement (reef early and often) and sever/surprising weather can invert almost any boat.
There has been quite a lot of work particularly for ultra high performance multis on systems to prevent inversions – probably the best known/most advance would be upsideup by Ocean Data Systems

I tend to agree with every thing you have said and only thing I might add is that due to the Cat’s current popularity that the guy with a big checkbook and ego but little experience may be more likely to buy a big, new Cat than a Mono.

[44'cruisingcat]

Originally Posted by Fore and Aft

I know of three that have flipped. The first was a 40’ foot Wharram in Wellington Harbour. The guy had way to much sail up and when he left the lee of our yard the first few gusts just flipped him.
The second was a 40’ cat on the Wide Bay Bar, bad timing I believe and he got flipped crossing at night.
The third cat was a 32’ Fast Back, racing in Moreton bay. Flipped while pushing her to hard.
Cheers

The second one wasn't actually crossing the bar. He was using what's known as the "fisherman's gutter", a shorter but much shallower route.

At night, at low tide. According to his report, a breaking wave caused his bows to hit bottom.

[Factor]

Originally Posted by smj

Statistically you have about the same chance of flipping a cruising cat as you do sinking a cruising monohull, pick your poison.

You are being charitable to the monos

[Factor]

Originally Posted by 44'cruisingcat

The second one wasn't actually crossing the bar. He was using what's known as the "fisherman's gutter", a shorter but much shallower route.

At night, at low tide. According to his report, a breaking wave caused his bows to hit bottom.

And that boat went on to sail extensively blue water after that without further incident.

[JPA Cate]

Originally Posted by Factor

And that boat went on to sail extensively blue water after that without further incident.

It certainly did, but it did require some repairs and re-masting.

Ann

[fxykty]

Originally Posted by KC375

... In particular higher performance multis are more prone to capsize (Atlantics would fit in the higher performance bucket). The more condomaran charter boats tend to have more conservative rigs...

Not necessarily true. Our 54 foot performance cruising catamaran has a white sail area of 115 sq m. Many condomaran type catamarans have higher sail areas than us even with smaller size (e.g. Lagoon 450 = 130 sq m, Leopard 43 = 120 sq m) and similar SA/D ratios. Higher performance cruising catamarans can have less sails in the same wind, with the difference increasing with wind speed. Sounds safer to me.

However, there may be a higher likelihood of capsize due to lower displacement for a given size. There have been other threads that have discussed stability factors for catamarans.

Final note, don’t conflate capsize statistics for cruising catamarans with those for catamarans that are racing. The vast majority of large (not beach) catamarans that capsize are racing. Nothing to do with cruising.

Oh, and Ran Tan ll losing her keel recently shows that a monohull can lose her keel and stay upright.