AMF canopy upgrade?

[T2x]

T2x, so no testing? .

I never said that, what I question is the value of scale model testing.

I am reminded of a conversation that the late Doug Lewis ( a truly gifted rigger, crew chief, throttleman and engine builder)had with a safety equipment provider. The gist of the conversation was how strong some new cockpit devices were...and Doug scoffed at some of the hardware. The vendor was quoting various lab and test results and Doug was openly dismissive of the mock up display ,

His suggestion was to put all of this hardware on a dummy in a test cockpit...... place it 100 feet from a pool or harbor on land and then hit it at 100+ mph with a dump truck into the body of water......... Then repeat the process until your development reached the point where a human replaced the dummy....... Until that was possible....you had work to do.

I agree with Doug except that with today's 200 mph turbines.....you might want to replace the dump truck with a bullet train.

If reading the above gives you a new perspective on what we are truly dealing with....... I've made my point.

T2x

 

[skaterdave]

I never said that, what I question is the value of scale model testing.

I am reminded of a conversation that the late Doug Lewis ( a truly gifted rigger, crew chief, throttleman and engine builder)had with a safety equipment provider. The gist of the conversation was how strong some new cockpit devices were...and Doug scoffed at some of the hardware. The vendor was quoting various lab and test results and Doug was openly dismissive of the mock up display ,

His suggestion was to put all of this hardware on a dummy in a test cockpit...... place it 100 feet from a pool or harbor on land and then hit it at 100+ mph with a dump truck into the body of water......... Then repeat the process until your development reached the point where a human replaced the dummy....... Until that was possible....you had work to do.

I agree with Doug except that with today's 200 mph turbines.....you might want to replace the dump truck with a bullet train.

If reading the above gives you a new perspective on what we are truly dealing with....... I've made my point.

T2x

underatood on the scale model.

i'm with 100%, i just don't see anyone taking those necassary steps. And at this time only the hydro and drag guys have proven to have a reliable safety program.

 

[2ros]

Even trucks and trains are designed w/in a CAE.

http://www.cd-adapco.com/media/videos/6dof/boat.swf

http://www.cd-adapco.com/media/videos/6dof/tanker-front.swf

http://www.cd-adapco.com/events/webinars/2009/marine.html


ps:You will have to register, watch the free webinar Engineering Simulation for the Design of Maritime Structures - May 21, 2009

 

[Scotty B]

One driver lighter boats, big difference. You just cannot test a cockpit the way it needs to so we have to rely on past experience, mathmatics and tapping into the smartest engineering and racing minds we can find

 

[skaterdave]

what about going back to the old-school twin canopy design? either tow hydro or drag designs?

atleast that has been proven. especial since almost all the current center pods have shown weakness and thats at supercat/class1 speeds. add another 50-60 mph to that for the turbines.

 

[2ros]

I know nothing:leaving:

 

[Steve Miklos]

The one thing we can all agree on (I hope) is that the canopy needs to be as strong as the bottom of the boat.
Steve

 

[Offshore Ginger]

The one thing we can all agree on (I hope) is that the canopy needs to be as strong as the bottom of the boat.
Steve

No , stronger without a doubt .

 

[Dr Speed]

I can't see how you would scale down weight, inertia, cockpit air/water pressure or the human body and its organs.

Weight, inertia, water pressure can be scaled. Accelerations in waves are tested all the time. A model and be built and tested to test the accelerations on the canopy from various angles. Phots from various angles can determine the interaction and a 6 axis force gauge can get you all the pressures you could want.
The best purpose of tank testing would be to test the hydrodynamic effects of the mods which can be tested and changed quickly then tested again to compare results. This is done often with strakes. I've done it with steps as well.
Here is an underwater photo of twin step variation of a cat lite running at 105 mph scale speed

 

[Madpoodle]

what about going back to the old-school twin canopy design? either tow hydro or drag designs?

atleast that has been proven. especial since almost all the current center pods have shown weakness and thats at supercat/class1 speeds. add another 50-60 mph to that for the turbines.

Would two smaller pods be stronger than one large one?

 

[Steve Miklos]

Weight, inertia, water pressure can be scaled. Accelerations in waves are tested all the time. A model and be built and tested to test the accelerations on the canopy from various angles. Phots from various angles can determine the interaction and a 6 axis force gauge can get you all the pressures you could want.
The best purpose of tank testing would be to test the hydrodynamic effects of the mods which can be tested and changed quickly then tested again to compare results. This is done often with strakes. I've done it with steps as well.
Here is an underwater photo of twin step variation of a cat lite running at 105 mph scale speed

Very cool! Anymore pictures?
Thanks
Steve

 

[T2x]

Weight, inertia, water pressure can be scaled. Accelerations in waves are tested all the time. A model and be built and tested to test the accelerations on the canopy from various angles. Phots from various angles can determine the interaction and a 6 axis force gauge can get you all the pressures you could want.
The best purpose of tank testing would be to test the hydrodynamic effects of the mods which can be tested and changed quickly then tested again to compare results. This is done often with strakes. I've done it with steps as well.
Here is an underwater photo of twin step variation of a cat lite running at 105 mph scale speed

Gee, you make it sound so easy......... It's amazing that a tunnel boat builder named Hodges in England had to drop a full scale safety canopy repeatedly from a helicopter in the late 80's after scaled tank testing failed to replicate the conditions involved in a crash scenario........

Must have been the wrong tank............

With all due respect...there have been a myriad of "experts" called on between the APBA, the UIM, Fabio Buzzi and the Arab racers to delve into boat racing accident dynamics. At this moment Bob Wartinger a respected APBA/UIM boat racer and aircraft engineer is probably heading up the best effort, but he has a long way to go....... George Linder,one of the pioneers of Offshore cat design, also an Aircraft and Marine Engineer has been working on these issues since the mid 80's and probably has more knowledge regarding this subject than anyone on the planet......At the very least he understands most of the questions. The challenge is to coordinate all of the historical data and build from there and not as I said earlier to waste time re-inventing the wheel (or the sponson in this case). The best way to attack this is a combination of historical accident data, engineering, experience, and common sense. I seriously doubt that a computer program, a slide rule and a test tank will solve this problem in a silo without the other ingredients.

T2x

 

[T2x]

Would two smaller pods be stronger than one large one?

Abso-friggin-lutely!!!!!

 

[Dr Speed]

Gee, you make it sound so easy......... It's amazing that a tunnel boat builder named Hodges in England had to drop a full scale safety canopy repeatedly from a helicopter in the late 80's after scaled tank testing failed to replicate the conditions involved in a crash scenario........

Must have been the wrong tank............

With all due respect...there have been a myriad of "experts" called on between the APBA, the UIM, Fabio Buzzi and the Arab racers to delve into boat racing accident dynamics. At this moment Bob Wartinger a respected APBA/UIM boat racer and aircraft engineer is probably heading up the best effort, but he has a long way to go....... George Linder,one of the pioneers of Offshore cat design, also an Aircraft and Marine Engineer has been working on these issues since the mid 80's and probably has more knowledge regarding this subject than anyone on the planet......At the very least he understands most of the questions. The challenge is to coordinate all of the historical data and build from there and not as I said earlier to waste time re-inventing the wheel (or the sponson in this case). The best way to attack this is a combination of historical accident data, engineering, experience, and common sense. I seriously doubt that a computer program, a slide rule and a test tank will solve this problem in a silo without the other ingredients.

T2x

Of course the complete project will not be easy. I was wondering why they, or someone supposedly connected to this project, considered tank testing and then opted against it. Tank testing is not the be all end all, but it can provide a lot of good data for a lot less money then prototyping something and dropping it from a helicopter. Also, when designing ribs to "pierce" the water in the event of a roll over, tank tests on a variety of designs can determine which is best for various situations.

If you and AMF think that forces cannot be accuratly scaled enough to rely on the results, then that is the answer to my original question, although I disagree. You could always build full size prototypes, RC them and crash them.

 

[phragle]

or hang a mystic from a 747 like the space shuttle and drop it from 50' into the ocean at 300 mph. there's ideas and practicle ideas...

 

[Bobcat]

Why not lose the canopy/module on these 200 MPH beasts . Driver and throttleman could sit down farther into the boat, and have a video monitors instead of windows. something similar to a flight simulator (fighter) .

 

[T2x]

Of course the complete project will not be easy. I was wondering why they, or someone supposedly connected to this project, considered tank testing and then opted against it. Tank testing is not the be all end all, but it can provide a lot of good data for a lot less money then prototyping something and dropping it from a helicopter. Also, when designing ribs to "pierce" the water in the event of a roll over, tank tests on a variety of designs can determine which is best for various situations.

If you and AMF think that forces cannot be accuratly scaled enough to rely on the results, then that is the answer to my original question, although I disagree. You could always build full size prototypes, RC them and crash them.

Good questions...... The issue as I recall was that scaled down boats...even RC race boats behave quite differently than full sized versions. In fact the most successful RC racing designs don't work at all as full sized race boats. The English tests failed to create the dynamics present in full scale accidents, hence the helicopter testing. I can follow up if needed, but this is old news.

I am interested in your "piercing" concepts. While I understand the piercing concept (currently used in a wide variety of semi planing hulls), I don't see how you could align the blade(s) with an almost infinite number of attack angles. On the other hand we have been working with air management on tractor trailers and small deflectors are having a significant impact on drag characteristics.....perhaps a dimpled, deflective surface design has merit?

Like I said this will take the efforts of a lot of people....some of whom may actually have something to contribute...

T2x

 

[Maximus]

what about going back to the old-school twin canopy design? either tow hydro or drag designs?

atleast that has been proven. especial since almost all the current center pods have shown weakness and thats at supercat/class1 speeds. add another 50-60 mph to that for the turbines.

That was the most obvious solution and our first initiave as we looked at this challange, we are still weighing this as an option. The main builder of these units has sent us the drawings as well as a two man design as well. We still believe that a pod can be built that better fits our purposes.

Bottom line is even the most basic "lessons learned" are not being implimented on many race boats. As Rich commented these wheels have already been invented. Safety pods for the "big boats" are getting there and most smart teams are taking it seriously.


Hmmm "dimples"....I ' Like it a lot!!!

 

[Offshore Ginger]

Abso-friggin-lutely!!!!!

I hate to say this put there will always be those people who will try to use or modifided there canopies because they just to not feel confortable with the way they are set up for them and Jack Carmondy of the old Carlos N Charlies X-treme is a prime example of this .

 

[skaterdave]

That was the most obvious solution and our first initiave as we looked at this challange, we are still weighing this as an option. The main builder of these units has sent us the drawings as well as a two man design as well. We still believe that a pod can be built that better fits our purposes.

Bottom line is even the most basic "lessons learned" are not being implimented on many race boats. As Rich commented these wheels have already been invented. Safety pods for the "big boats" are getting there and most smart teams are taking it seriously.


Hmmm "dimples"....I ' Like it a lot!!!

can you give description of the two man pod and how it would vary from your current Mystic setup?