This unconventional mode of construction was chosen because Spanish steel mills were unable to produce massive steel carriers at the time, and importing such carriers was impossible in Francoist Spain.
Ova nekonvencionalna konstrukcija je izabrana jer španjolske čeličane nisu bile u mogućnosti proizvesti široke čelične nosače u vrijeme kada se gradilo ove stupove, a uvoz takvih nosača je bio onemogućen zbog Francova režima.