AMF canopy upgrade?

[T2x]

More thoughts to ponder......................

I spoke to Linder last night and reviewed this thread.......

He asks..... If scale model testing is valid, why do car companies and testing labs spend tens of millions of dollars on full scale crash tests?

One added point to follow, but first let me ask if any of you know the maximum speed of a falling object at sea level?

T2x

 

[imco offshore]

two seperate man pod was removed because ,,your partner is your first responder,,in the case of a problem a person sitting next to you ,that is ok,, can help,, like put an air hose in your mouth,,seperate pods your waiting for someone to come and help and that might be too late,

 

[phragle]

More thoughts to ponder......................

I spoke to Linder last night and reviewed this thread.......

He asks..... If scale model testing is valid, why do car companies and testing labs spend tens of millions of dollars on full scale crash tests?

One added point to follow, but first let me ask if any of you know the maximum speed of a falling object at sea level?

T2x

If your going to ask that and ask for a definitive answer, your going to have to provide the variables. Gravity is only one factor. Drag coefficient etc...

 

[skaterdave]

two seperate man pod was removed because ,,your partner is your first responder,,in the case of a problem a person sitting next to you ,that is ok,, can help,, like put an air hose in your mouth,,seperate pods your waiting for someone to come and help and that might be too late,

what good is that, if the guy your counting on to help is unable because the canopy failed

 

[2TR]

Ok, I know this may sound dumb but a V-Bottom hull seems to hold up and cut the water at most any angle, why not design a v-bottom deck/canopy?

It might look ugly but it would be safe ???

Maybe I'm still drunk :ack2: Just thinking out loud...

 

[T2x]

If your going to ask that and ask for a definitive answer, your going to have to provide the variables. Gravity is only one factor. Drag coefficient etc...

I believe you can slow an object down with drag.....but I don't think you can speed it up....... hence my question....the maximum speed of a falling object at sea level?

 

[T2x]

Ok, I know this may sound dumb but a V-Bottom hull seems to hold up and cut the water at most any angle, why not design a v-bottom deck/canopy?..

Vee bottoms don't cut the water when they are moving sideways.

 

[2TR]

Vee bottoms don't cut the water when they are moving sideways.

Have you ever seen Dean (Wahoo) drive? :willy_nilly:











Thanks, Point taken.

 

[T2x]

Okay...let's cut to the chase..... an average object accelerates in free fall at 15ft/sec/sec and a human body maxes out at approximately 120 mph at or near sea level... (faster in higher altitudes and lighter air). It seems to me that what we are attempting to do with cockpit design is essentially make a dead stall light weight plane crash survivable for boat speeds up to about 150mph. Above that you are dealing with forces that can increase exponentially.
Taking all that into consideration there must be some kind of "crush zone" around the occupant(s) in all directions. This can be pneumatic, rubber or foam but it must be there. Aside from Statement's suspended cockpit, which is an update on Bob Nordskog's 1966 suspended racing seat design I have seen little development in this area. What is needed is an "egg within an egg" cockpit with a crushable/flexible substance between the inner and outer shells. The thickness of this layer is strictly dependent upon the maximum forces at play and the deceleration reduction needed between those forces and the limits which the human body can sustain without external...or internal injury(s).

There is also a dynamic that I'm unsure how to approach. A rotational or spinning moment at over 200 mph can generate centrifugal force strong enough to rip your insides apart without any contact, collision, or intrusion into the cockpit.....

We can leave that to a later discussion.

T2x

 

[Maximus]

. What is needed is an "egg within an egg" cockpit with a crushable/flexible substance between the inner and outer shells. The thickness of this layer is strictly dependent upon the maximum forces at play and the deceleration reduction needed between those forces and the limits which the human body can sustain without external...or internal injury(s).

There is also a dynamic that I'm unsure how to approach. A rotational or spinning moment at over 200 mph can generate centrifugal force strong enough to rip your insides apart without any contact, collision, or intrusion into the cockpit.....


T2x

Interesting Rich,

Almost ...word for word/design what the Lockheed guys have come to us with and are working on designs for. Inside the egg a wall of air bags (like a car). They believe that this is actually quite simple. The pod will be able to remove the top half for full servicing and will be sealed with fly by wire controls and instrumentation.

 

[shifter]

After the pod is sealed thoughts of I should not have had that bran muffin this morning.... or the bowl of chili.

Do not trust Gary he is British.

pat W

 

[phragle]

Im not getting the airbag concept. In a car you a minimally restrained with a lap/shoulder belt so you can move quite abit.. hence airbags. In a raceboat with a 5 or 6 point belt system and a hans your torso isnt going anywhere and your head should stay put with the hans and seat cradle headrest. your limbs are another story but good design and padding should take care of that.

 

[Dr Speed]

More thoughts to ponder......................

I spoke to Linder last night and reviewed this thread.......

He asks..... If scale model testing is valid, why do car companies and testing labs spend tens of millions of dollars on full scale crash tests?

One added point to follow, but first let me ask if any of you know the maximum speed of a falling object at sea level?

T2x

NHTSA Regulations. There is a difference between knowing the forces, and proving that the design works. Car companies also speed millions on CFD before building a prototype and millions on wind tunnel testing before creating the final design. Solids are also better understood then fluids.

Falling object speed is not the problem. The boats arent high enough to reach terminal velocity in a freefall. The boat flipping and hitting the canopy at an angle is. If a boat is going 100mph in the horizotal direction, flips and is traveling at 10fps verticle, the resultant vector speed that the canopy hits the water is 100.23mph.

We could always just control the boats from the safety of the support truck like an unmanned surface craft or a drone.

 

[stainless]

More thoughts to ponder......................

I spoke to Linder last night and reviewed this thread.......

He asks..... If scale model testing is valid, why do car companies and testing labs spend tens of millions of dollars on full scale crash tests?

One added point to follow, but first let me ask if any of you know the maximum speed of a falling object at sea level?

T2x

.From 5000 feet: 122 MPH
From 10,000 feet: 550 MPH
From 20,000 feet: 770 MPH
From 5000 meters: 1127 km / hourThe above are for falling in a vacuum.

 

[T2x]

.From 5000 feet: 122 MPH
From 10,000 feet: 550 MPH
From 20,000 feet: 770 MPH
From 5000 meters: 1127 km / hourThe above are for falling in a vacuum.

See my post # 86 above.....

T2x

 

[T2x]

Falling object speed is not the problem. The boats arent high enough to reach terminal velocity in a freefall.
.

My point was not about dropping from a great height it was about designing technology capable of allowing people to survive a plane crash...... Point being.....the forces are similar.

 

[T2x]

Im not getting the airbag concept. In a car you a minimally restrained with a lap/shoulder belt so you can move quite abit.. hence airbags. In a raceboat with a 5 or 6 point belt system and a hans your torso isnt going anywhere and your head should stay put with the hans and seat cradle headrest. your limbs are another story but good design and padding should take care of that.

I am not referring to airbags...this is about a deceleration cushion for the entire cockpit...... The human body cannot withstand a dead on deceleration to zero from 60 mph (much less 200) without some flexibility in the impacted structure. The amount of flexibility is directly related to the amount of speed reduction in the scenario.......so if a 2 inch foam cushion of a particular density will suffice for 100 mph crashes perhaps a 6 inch cushion is needed for 150 mph....etc......

 

[T2x]

Interesting Rich,

Almost ...word for word/design what the Lockheed guys have come to us with and are working on designs for. Inside the egg a wall of air bags (like a car). They believe that this is actually quite simple. The pod will be able to remove the top half for full servicing and will be sealed with fly by wire controls and instrumentation.

Great minds think alike......... I'll help out for half their fee......

 

[C_Spray]

The basic principle is to keep all the components of the body in alignment (hence the advent of head restraints like the HANS and seats with extensive head surrounds), and then slow the entire body as progressively as possible. Immense G-forces are survivable if they are applied slowly enough. Rapid changes in acceleration ("jerk") is the killer. The other important factor is to eliminate any rebound effects. Any energy-absorbing mechanism should not launch the person back in the other direction once the impact is over. Introduce rotational acclerations (spins, barrel rolls, trips, etc.) and things get really complicated. The crack-the-whip effect can kill a person without leaving a mark on them (see "basal skull fractures").


Any padding/deceleration damping mechanism would have to take into account the likely G-forces expected in any particular direction. Where boats are different from a car hitting a wall is that the boats orientation at impact will affect the deceration loads. For example, a boat submarining will slow down much more progressively that one that lands sideways on the face of an oncoming wave with its hullside forward. The fact that a boat can dig into the water makes the issue far more complex that what car racers face. Race tracks have recently gone through great efforts to provide smooth (often paved) run-off areas so errant race cars don't start tumbling. Boat racing does not provide this luxury.

The boat drag capsule design makes a lot of sense in many ways. The capsule is designed to break away from all the heavy and pointy parts of the hull, and is designed to skip over the water, rather than dig in.

 

[phragle]

Aside from the basal skull fracture, another occurance that is not often thought about but that I have seen first hand a few times is the Aorta tearing as the heart moves inside the chest. According to the calculatons we made after one incdent this occured at a speed under 62 mph on a dead stop impact.