In 1946, construction of the Ali Baba movie theater in the Boulak district of Cairo.
The thin reinforced concrete vault, which acts as a roof and covers the huge interior space of the cinema, is first poured on the ground on a vault-shaped earth mould.
Once the concrete has hardened, the vault is slowly raised to its final position by a system of jacks.
Here the vault is halfway up to its final position..
In this photo, the vault has been raised to three-quarters of its final position.
Note the five peripheral columns, which alone will support this slender vault of reinforced concrete with an area of 800 square meters (8,600 square feet).
In this photo, taken from a different angle, we see the vault almost in its final position.
Very complex calculations were required to establish a three-dimensional shape that allows the weight of the vault to be redirected towards the peripheral support columns.
View of the interior of the movie theater hall covered with the large vault.