After the Scaffolds

The roof has been completed, and the windows are all in place. Whilst construction continues on the remaining 10 towers, other workers remove scaffolding from the interior. With them removed, one can begin to see the beautiful ceiling and interior decoration of the church, in addition to the catenary arches. Unlike Romanesque and medieval pointed arches, catenary arches are inherently stable and can therefore stand without any buttresses or flying buttresses to compensate for outward thrusts.

In the basement/crypt, there hangs a model Gaudi built to demonstrate the stresses and thrusts of the church's structure made entirely with strings, weights, and entirely upside down.

This was same exact method used by Saarinen when he designed the Gateway Arch in St. Louis.