NGE - Episodes 03 to 06 - More on Platform Architecture

In the third and fourth episodes of Neon Genesis Evangelion ("A Transfer" and "Hedgehog's Dilemma"), Shinji continues to learn more about what it means to be an Eva pilot, for better or for worse. When the fourth Angel, Shamshel, appears in Tokyo-3, Shinji has to make some tough decisions and rely heavily on his new training to overcome the threat. In doing so, he begins to question whether he is really cut out for the task of piloting an Eva.

In the fifth and six episodes ("Rei I" and "Rei II"), Shinji begins to learn more about his fellow Eva pilot, Rei Ayanami. This mysterious girl began the series with crippling injuries after a synchronization test underwent complications. Now returned to active duty, both Rei and Shinji have to work together to defeat the toughest Angel yet: Ramiel.

 Ramiel is a very powerful Angel, with both short-range and mid-range counter-weapons. Ramiel's sole purpose is to use a shield drill to pierce the 22 layers of plating which separate the city surface from the core of Tokyo-3, also known as the Geofront. Each of the 22 layers uses a thick metal plate suspended under additional gaps of soil and rock.

This places the Geofront roughly a kilometer below the surface of the city. While the surface and subsurface levels of Tokyo-3 are connected by a monorail system, there are additional vertical shafts designed into the plate armor, through which foot travel into the Geofront is possible. This becomes very important during Episode 11 ("The Day Tokyo-3 Stood Still"). Finally, there are a multitude of lift tunnels for the Evangelions to be launched through.

The metal plates are one and a half kilometers in diameter, thus they also serve as support structures to prevent the Geofront from caving in on itself when Tokyo-3's buildings are being pushed and pulled into place. While Evangelion has the perks of hand-waving the details (being a work of fiction after all), the design elements from the series are all very plausible.

When it comes to load-bearing, the distribution of mass is essential. Putting too much mass, and thus too much force, on a single point runs the risk of fracturing or tearing it apart. But if the force of the object's mass is distributed evenly, then the risk of collapse is mitigated significantly.

Have you ever seen someone lay back on a bed of nails, and wondered why none of the nails pierced their skin? A lot of it has to do with the number of nails used. If there are only five nails, then the person's mass is distributed evenly on all five. The person exhibits a high degree of force on the nails, and the nails exhibit an equal force, which is great enough to skewer the skin. Now instead of five nails, have there be 250. The force on each nail, and thus the force each nail exerts, is reduced by a factor of fifty, enough to prevent any of the nails from piercing the skin.

We can apply the same principle to engineering and often do. So whether it be a floating city or a subterranean one, remembering to support the structure with a large base (or ceiling) area is vital.