Speed to survive container colision?

[fcftampa]

On a common charter type catamaran (lagoon, FP, etc) assuming it has a sealed compartment at the bow (yes some aren't sealed and some don't even have them; but lets assume there's a sealed volume up front).

What would be the fastest it could hit a submerged container and limp its way home?

Thanks for entertaining the idea and try to be flexible and stay on topic

[CaptsWife]

I forget where I read it, but I read that it's a myth that a container will be "slightly submerged", so with a lookout, in theory, it should never be a problem. There will always be a portion above water level or it will have sunk.

Not sure of the accuracy of the statement.

[Franziska]

Add a bit of swell and bad visibility and that portion above water becomes quickly invisible within few waves distance.

Containers have been struck, and not just in movies...

Regarding the OP question, lots of variables here, laminate built up, angle of collision, location of collision....

So hard to say. Crash boxes below the water lines can surely increase your chances.
Kevlar reinforcing them might increase your chances further.

[S/V Illusion]

Originally Posted by fcftampa

What would be the fastest it could hit a submerged container and limp its way home?

:

Any reliable answer would necessarily have to derive from testing, experimentation, repetitive trials, etc...
Absent that, the answer is "x". Actually, "x minus 1".

Debating suppositions might be fun but pointless.

[billknny]

Sounds like a job for Crash Test Dummies!

But seriously... How fast would you have to go to crush the bow back past the collision bulkhead? Who knows?

Why limit to cats? There are monohulls with watertight bulkheads... Heck, between the main saloon and the bow, I have two... Six all together...

[Snowpetrel]

I'd be far more worried about logs than containers. Far more likely to hit one of them drifting about in oceans than a container.

Or prehaps an unlit drifting yacht abandoned at night, lots of them floating about, or even a meteor hitting your boat. Might be worth reinforcing the cabintop to deal with this danger!

[danielamartindm]

Originally Posted by fcftampa

On a common charter type catamaran (lagoon, FP, etc) assuming it has a sealed compartment at the bow (yes some aren't sealed and some don't even have them; but lets assume there's a sealed volume up front).

What would be the fastest it could hit a submerged container and limp its way home?

Thanks for entertaining the idea and try to be flexible and stay on topic

If you think there are a thousand and one ways to go crazy, there are.

[landsend]

We almost hit a semi submerged industrial freezer in the keys traveling at 16 knots!!
So yes they can be invisible. Missed it by about 10 feet.

[fcftampa]

Charter cats was 1 assumption, another one was that they HAD watertight bulkheads.
With one of the important criteria -for me- when picking a cat being speed, I thought picking on this issue would weigh in to make speed less important. In addition to the fact that a cruising cat can only sail so fast before becoming a chore to sail it for long.

[Sojourner]

Originally Posted by billknny

Sounds like a job for Crash Test Dummies!
There are monohulls with watertight bulkheads... Heck, between the main saloon and the bow, I have two... Six all together...

By that description alone, I can bet you got what I got...

[valhalla360]

Why too many variables to give a fixed answer.

A hit that only opens a small hole may shake the crash box bulkheads lose so they drain into the main hull.

[atlantical]

I was in the Merchant Navy, and I wouldn't even know how many miles I sailed, but twenty years at an average of ten knots, that's a lot of miles, and none of the ships I was on every hit a floating container, no one on any ship I was on, even seen, or had seen a floating container. I did once see a dead Orca whale floating, we called that in as a hazard to navigation, I also saw twice a whole tree floating, again called in, saw various other floatsome and jetsome, like buoys fish boxes, rope, oil, plastics of every kind, but never a container, I think its a bit of a myth. There seems to be all those floating containers, that never wash up on any beach. Also the complete nonsense, that they float a couple of feet bellow the water, it would either float above the water, or it would sink, I would be more worried about hitting a whale, or a log.

[rabbi]

I remember I followed the blog of a german family who built their own cat to sail the world.
They were afraid of hitting something underway. They included multiple crash compartments into the build. The complete bilge was constructed as multiple individuallly sealed compartments to ensure floatation.
They even added a forward facing sonar (which turned out to be useless)

guess what: A few month into the journey they left the Cap Verde Islands to do the Atlantic passage. Afte just a few hours they hit something (they believed a container) and badly damage one hull.
They made it back to the islands.

No clue what happened afterwrds, I just remember the cat had a strange name.

Morale: Don't think too much about this problem or it will get you!



Edit: Found it! Hermann Heinrich

[john61ct]

The Law of Attraction has been denigrated in recent years, but I'm still a believer

[goat]

7 knots.