T h e . l e c t u r e s . o f . J a c k . J i t t e r s
 

The ideal balloon
This is an abridged version of an Occupied Images lecture from the series:
"Aesthetics vs. efficiency":

 

 


 

 Theorists will probably tell you a sphere is a very efficient shape. A solid figure or its surface, with every point on its surface equidistant from its center. There is a minimum of friction between a ball and the ground floor it rolls on. There are absolutely no superfluous corners or irregularities to discover in spherical shapes.
The world would be a better place if it was spherical.

Well: I seriously disagree with these opinions.

Spherical shapes have got the tedious quality that they refuse to co-operate with mankind. I would like to put my thesis on solid ground on the basis of air-balloons.


Before taking-off a balloon commander has to consider whether he wants to ascent with a full or a flat balloon.

 
 


 
Aesthetics will probably prefer to see a full balloon rise, but flight-technique cannot reckon with aesthetic ideals.

A full balloon ascents slower than a flat one. The climbing-speed of the flat balloon is twice as fast as a full balloon which is a great convenience when ascending from a built up area or near high-tension cables.  Besides these advantages there are also considerable savings on gas.

 
My first conclusion therefore must be: the aesthetic ideal is expensive and takes all of your precious time.

 
I would like to introduce you to Prof. August Piccard, a Swiss scientist who was also a supreme balloonist.  His goal was to reach for the stratosphere.
 		 August Piccard on ballooning:
"The free ballon serves freedom, adventure, observation, investigation and the flight of the soul into higher spheres.
Isn't that enough?
Who condemns the sewing- machine for not being able to make coffee?"

The cabin had a diameter of 1.20 meters. Just big enough for 2 observers and the necessary instruments.		 In passing he achieved the highest altitude reached by man.

He was also the first balloonist who used a closed spherical shaped cabin.
From his own writings we can see that Prof. Piccard is mesmerized by spherical shapes:

 
Ir. Kipfer (Piccards partner on his second trip) testing the shape of the ideal balloon.
 "The free balloon relies on the laws of Archimedes: a spherical shaped wrapping of impenetrable material contains light gas.

The spherical shape has become the standard model for balloons because the surface and the weight of the wrapping are as little as possible compared to its content."

 
"If the total weight of the material is lighter than the amount of air the balloon is able to displace, it will lift. The balloon will then reach layers of air where the compression is lighter than the gas in the wrapping. The filling gas will consequently expand.
This is only possible when the balloon isn't yet prall (which means: totally filled with gas). At a certain height the expanded gas will fill up the balloon completely.
At this point we speak about a prall balloon."

"If the full spherical shaped balloon would be shut, a disaster could occur. Further rising of the balloon would cause an overpressure in the wrapping. Very soon the balloon will explode. To avert this disaster a tube shaped appendix is attached in the opening at the bottom of the wrapping. The further remainders of the filling gas will leave the balloon through the appendix."

 

 A nearly prall balloon.
 
My second conclusion is that the spherical shaped ('prall') balloon is not only inadequate but also very dangerous.

 
T h e . i d e a l . b a l l o o n
((( P a r t . T w o : A e s t h e t i c s )))