Reply With QuoteThat was epic.
After the 2nd or 3rd time it got kind of tragic.
The one landing in the trees was tough...
http://img.consumating.com/photos/24...rge/135553.jpg
...but with the way cats are designed to get "out of the water" and with as light as they are becoming, is anyone worried about what happens if they get airborne?
I picture it flipping like the famous benz at le mans...
http://img.consumating.com/photos/24...rge/135553.jpg
Or wait! If it was on a treadmill....
That was epic.
After the 2nd or 3rd time it got kind of tragic.
The one landing in the trees was tough...
http://img.consumating.com/photos/24...rge/135553.jpg
That was epic.
After the 2nd or 3rd time it got kind of tragic.
The one landing in the trees was tough...
http://img.consumating.com/photos/24...rge/135553.jpg
Seriously. I keep can't gett his image of little kids getting launched out of a deck boat. They keep getting faster and lighter...
Seriously. I keep can't gett his image of little kids getting launched out of a deck boat. They keep getting faster and lighter...
I couldn't either. Which is a huge reason we went away from the cat/air entrapment hull and into a hydro. They don't create any of that style "impact lift" and will under no circumstance blow over.
It is obviously a huge concern to us, since we are the ones primarily getting faster and lighter. After seeing how successful the hydro is, I am having a difficult time imagining why anyone would design a new boat as an air entrapment hull short of an F1 outboard.
Well I was gonna let Wes answer in on all of this, but I'll give you the readers digest version..
The weight of a boat and the stabillity of a boat aren't in direct correlation to each other.
For example, you can have a very light hull that works entirely on hydrodynamic lift and it's exceptionally stable. Or you can have a heavier hull that uses alot of aerodynamic lift, and tunnel compression and it'll be less stable, but in some cases actually be faster then the light boat.
The vast majority of air entrapment boats tend to use a kinda combination of both. In a certain hull They use a shitload of tunnel compression to get the boat up and out of the water. I don't have a bottom pic handy, but if you look at it, basically it's a large tunnel, that then has a V shape in the center of it at the transom. Air enters the tunnel at a rate (say 60mph) and is then "squeezed" into a smaller area producing a pressure. That pressure then pushes the boat up. That same boat tends to have a reputation for ending up bottom side up.
In any event, the second portion and argued by some the largest factor in this is actually the bow section of the boat and the deck. By that meaning the boat is basically becoming a wing.. As the boat is running, it's in some trim angle (bow being slightly higher then the transom). The air is being deflected down into the tunnel (causing lift) but is also being diverted up and over the boat.. Well since the boat is at an angle there is a large vacuum on the top side of the boat until the air re-attaches itself to the hull.. Think of a wing and how it creates lift.. By making the air travel further across the top it's actually creating a vacuum "pulling" the wing up.. Same thing with a boat. This is the reason why again bottom side up guys made this kind of "wing shaped" bow.
In any event, most tunnel decks are all based off the same Bottom.. That particular bottom has alot of hydrodynamic lift, and incorporates some aerodynamic lift, but not as much as say the High Turn over Machine that was afore mentioned. The aerodynamic lift boat in "most" cases will out run the more stable boat HP to HP. Not by alot, but enough to make it worth it in some peoples eyes.
Wes's new bottom is a reverse Hydro (3 point design) with the 3rd point being fairly wide and is ridiculously stable as well and uses zero aerodynamic lift (to my knowledge). The unique thing about his deck is that it's ridiculously stable, but the bottom is also really "efficient" at creating lift hydrodynamically with very little drag. Previous bottoms that used only hydrodynamic lift (like a V bottom) aren't nearly as efficient. I hate to swell his ego even more then it is, but it is kinda revolutionary (no pun intended) from the aspect of having complete stabillity with a very light weight package, that is out performing even the more flighty cats that were known for there ridiculously low HP to high speed ratios.
In other words, no worries on the deckboat Brian..
The Magic, Conquest, Eliminator, Shockwave, American Offshore, and just about damn near everyone else on the market has a Talon bottom or a derivative of.. Not sure about the Cobra as I think they tooled there's from scratch, but I'd bet if you look at it, it's similar to a Talon..
Pretty much the only one out there that's really different is Wes's in terms of mainstream tunnel decks.. I think Hallett has their own bottom as well, but not sure..
And yes I realize that certain points of this post can be argued for days... but like I said "readers digest" version. I'm not trying to type out any more of a Novel here then I already have.
RD
Well I was gonna let Wes answer in on all of this, but I'll give you the readers digest version..
The weight of a boat and the stabillity of a boat aren't in direct correlation to each other.
For example, you can have a very light hull that works entirely on hydrodynamic lift and it's exceptionally stable. Or you can have a heavier hull that uses alot of aerodynamic lift, and tunnel compression and it'll be less stable, but in some cases actually be faster then the light boat.
The vast majority of air entrapment boats tend to use a kinda combination of both. In a certain hull They use a shitload of tunnel compression to get the boat up and out of the water. I don't have a bottom pic handy, but if you look at it, basically it's a large tunnel, that then has a V shape in the center of it at the transom. Air enters the tunnel at a rate (say 60mph) and is then "squeezed" into a smaller area producing a pressure. That pressure then pushes the boat up. That same boat tends to have a reputation for ending up bottom side up.
In any event, the second portion and argued by some the largest factor in this is actually the bow section of the boat and the deck. By that meaning the boat is basically becoming a wing.. As the boat is running, it's in some trim angle (bow being slightly higher then the transom). The air is being deflected down into the tunnel (causing lift) but is also being diverted up and over the boat.. Well since the boat is at an angle there is a large vacuum on the top side of the boat until the air re-attaches itself to the hull.. Think of a wing and how it creates lift.. By making the air travel further across the top it's actually creating a vacuum "pulling" the wing up.. Same thing with a boat. This is the reason why again bottom side up guys made this kind of "wing shaped" bow.
In any event, most tunnel decks are all based off the same Bottom.. That particular bottom has alot of hydrodynamic lift, and incorporates some aerodynamic lift, but not as much as say the High Turn over Machine that was afore mentioned. The aerodynamic lift boat in "most" cases will out run the more stable boat HP to HP. Not by alot, but enough to make it worth it in some peoples eyes.
Wes's new bottom is a reverse Hydro (3 point design) with the 3rd point being fairly wide and is ridiculously stable as well and uses zero aerodynamic lift (to my knowledge). The unique thing about his deck is that it's ridiculously stable, but the bottom is also really "efficient" at creating lift hydrodynamically with very little drag. Previous bottoms that used only hydrodynamic lift (like a V bottom) aren't nearly as efficient. I hate to swell his ego even more then it is, but it is kinda revolutionary (no pun intended) from the aspect of having complete stabillity with a very light weight package, that is out performing even the more flighty cats that were known for there ridiculously low HP to high speed ratios.
In other words, no worries on the deckboat Brian..
The Magic, Conquest, Eliminator, Shockwave, American Offshore, and just about damn near everyone else on the market has a Talon bottom or a derivative of.. Not sure about the Cobra as I think they tooled there's from scratch, but I'd bet if you look at it, it's similar to a Talon..
Pretty much the only one out there that's really different is Wes's in terms of mainstream tunnel decks.. I think Hallett has their own bottom as well, but not sure..
And yes I realize that certain points of this post can be argued for days... but like I said "readers digest" version. I'm not trying to type out any more of a Novel here then I already have.
RD
I'm not reading that.hahaha no really though...thanks dave.
Dave,
I honestly couldn't say that better myself. I think you actually are getting a grasp on the physics of it all.
Took me a while, that's for sure.
V bottom, no worries.
apparently Trident/Wes nailed it, and nailed it perfect with >2 mpg at 80-90mph. I'm still in awe over this one. I never heard of an i/o with this kind of efficiency.
V bottom, no worries.
Especially if you don't know what "chine walking" is...
There are positives and negatives about all hull designs. V-botoms are much more prone to roll over at high speeds if they take a sudden turn. They don't have as much lateral stability, and the single fulcrum point increases the impact against chop greatly.
A "V" bottom however would be technically the fastest hull if stability wasn't a factor. The long, thin profile of a 40' V is just the ticket for reducing drag. Problem is, that by the time you get really, really fast... the inherent stability isn't enough to allow you to continue running it faster. The cat hull retains stability as you go faster, thus allowing it to go faster, though less efficiently.
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