AC40

enigmatically2

Super Anarchist
3,884
1,989
Earth
It seems like the only storm around the crash of the AC40 is in this tiny sailing anarchy tea cup.
And the few other outlets that give a shit about the AC at all. So yes, most of the media and social media don't care, but unless an entry by the Yacht Club of Jupiter, helmed by Elvis, wins, I doubt they will (excluding national/local media of any country winning)
 

nroose

Super Anarchist
5,307
328
Berkeley
Not sure I think that it is at all appropriate to compare deceleration of a boat that is about 12 meters long with a boat that is about 23 meters long. Since they are 3 dimensional objects, the frontal area is related to the square of the length and the mass is related to the cube of the length, so that smaller boat will have much more area to present to the water per amount of mass, but the inertia will be directly proportional to the mass. In the case of the 40 vs the 75, the ratio of the lengths is about 1.875, so the impact on the 40 per unit of frontal area will be about 1.875 times the impact on the 75. So almost 2x the acceleration even if the speed is the same and the shapes and everything else are to scale.
 

smackdaddy

Super Anarchist
6,213
610
SmackDab, Middle
Not sure I think that it is at all appropriate to compare deceleration of a boat that is about 12 meters long with a boat that is about 23 meters long. Since they are 3 dimensional objects, the frontal area is related to the square of the length and the mass is related to the cube of the length, so that smaller boat will have much more area to present to the water per amount of mass, but the inertia will be directly proportional to the mass. In the case of the 40 vs the 75, the ratio of the lengths is about 1.875, so the impact on the 40 per unit of frontal area will be about 1.875 times the impact on the 75. So almost 2x the acceleration even if the speed is the same and the shapes and everything else are to scale.

Now, now - you’re just complicating things with silly constructs such as math and logic. Didn’t you see that chart that’s being bandied about? That clearly absolves the AC40 designers. How could they possibly have foreseen such forces - even as seasoned design professionals - even looking at countless examples of this same crash mode - who even had a nonsensical chart at the ready in case this happened?

Such would have required math and logic.
 
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david r

Anarchist
595
55
pond
Here are some screenshots from that youtube vid. The graphs of their 2 crashes, the rudder broken free, the boat all the way into the lower middle of the forestay, the boat popping back out. The boat does't look like it gybes, it just dives in and po Screen Shot 2022-11-28 at 3.09.57 PM.png Screen Shot 2022-11-28 at 3.10.12 PM.png Screen Shot 2022-11-28 at 3.10.20 PM.png ps out. Speculation of a possible smaller rudder foil that day.

Screen Shot 2022-11-28 at 3.10.37 PM.png
 

Schakel

Dayboat sailor
What about the crew? It's almost a instant standstill at 40 knots.
They are hidden in their trenches. Were there any injuries?
In the video it looks like no one is hurt.
Do they wear safety belts?
Nose dive 2.jpg
 

yoyo

Anarchist
761
318
Safety belts ... no
Airbags... Can you f'ng believe it...
Sprinkler systems setup in the back. Can you f'ng believe it....
 

johnstarks

Member
55
27
USA
AM sunk because a battery wasn't tied down properly or broke the tie down and shot through the hull bottom, different than this. The AC40 broke because they didn't carry the deck beams forward far enough. The deck panel that buckled looks pretty big and flat and is surprising that they stop all the longitudinal structure at the watertight bulkhead
 
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smackdaddy

Super Anarchist
6,213
610
SmackDab, Middle
well you could argue that having a crushable bow reduces crew impact. maby its a feature not a bug!

ETNZ clearly doesn’t care about crew safety. Just look at the design of this shart-in-a-tux of a boat.

“Women? Children? Let them eat carbon - and/or drown under the twin foreskin sail. Just look at our technology that you too can have for only $2M!” - The Kiwizis

PS - You’re welcome breezie. I finally acknowledged your pathetic existence. At least take lessons from Four on how to troll. You’re not very good.
 
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porthos

Super Anarchist
1,090
419
Michigan, USA
AM sunk because a battery wasn't tied down properly or broke the tie down and shot through the hull bottom, different than this. The AC40 broke because they didn't carry the deck beams forward far enough. The deck panel that buckled looks pretty big and flat and is surprising that they stop all the longitudinal structure at the watertight bulkhead
The AM battery didn't go anywhere. The internal structure of the boat was designed to take the force on the keel. When AM reentered after launching itself, it did so on its side rather than the keel, and the internal structures blew out a portion of the side hull panel. In other words, the AM designers and engineers either never contemplated those side forces, or contemplated them and discarded the need to address that possibility as too remote.
 

The_Alchemist

Super Anarchist
2,952
1,609
USA
AM sunk because a battery wasn't tied down properly or broke the tie down and shot through the hull bottom, different than this. The AC40 broke because they didn't carry the deck beams forward far enough. The deck panel that buckled looks pretty big and flat and is surprising that they stop all the longitudinal structure at the watertight bulkhead
foil.gif
 

smackdaddy

Super Anarchist
6,213
610
SmackDab, Middle
Comparing the AC4Skin to ANY 75 is just stupid. They are simply not comparable. It’s like comparing an oil tanker to a Boston Whaler in a rough cut. Hence the stupid graphic.

THE FREAKIN BOW BROKE OFF THIS BOAT, PEOPLE. In a crash we’ve seen countless times!!!!

It‘s stupid enough that the Kiwizi ”designers” didn’t foresee this through common math. They failed spectacularly and should all be fired forthwith. (When you can’t even blame Chinese manufacturing you know you’re in trouble.)

The fact that clueless fanbois here are humping that same cold, dead pegleg? Please. Have some dignity.
 
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johnstarks

Member
55
27
USA
The AM battery didn't go anywhere. The internal structure of the boat was designed to take the force on the keel. When AM reentered after launching itself, it did so on its side rather than the keel, and the internal structures blew out a portion of the side hull panel. In other words, the AM designers and engineers either never contemplated those side forces, or contemplated them and discarded the need to address that possibility as too remote.
Had to go back through articles and your right it wasn’t the battery.

67D716C9-8B5B-4C58-9E02-6F363B29DCC2.png
 
Comparing the AC4Skin to ANY 75 is just stupid. They are simply not comparable. It’s like comparing an oil tanker to a Boston Whaler in a rough cut. Hence the stupid graphic.

THE FREAKIN BOW BROKE OFF THIS BOAT, PEOPLE. In a crash we’ve seen countless times!!!!

It‘s stupid enough that the Kiwizi ”designers” didn’t foresee this through common math. They failed spectacularly and should all be fired forthwith. (When you can’t even blame Chinese manufacturing you know you’re in trouble.)

The fact that clueless fanbois here are humping that same cold, dead pegleg? Please. Have some dignity.
Every now and again, and I mean it was a pretty rare event, you had a point, but man, you really don't this time and it's sooooooo boring to read you say the same thing 20 different times.

yawn....
 




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