Cranes were used in medieval construction sites. The had a treadwheel for 1-2 persons. Due to their weight they were not installed on high framework or on top ofsingle thin walls. Instead they started on the ground at the first building phase and were then placed higher when the next level was built and secured. [5a] : “That way the crane grew and „moved“ with the increasing building so that all medieval cranes that exist today [in Britain] are above the vault and below the roof of medieval church towers because they were not removed after completion of the building to allow the transport of material for repair“.

Principal arch construction (Prinzipalbogenkonstruktion)

 ("Prinzipalbogenkonstruktion") One major advance of the gothic architecture was the increase in efficiency: with the help of the principle arch the stones for the vault could be crafted in advance. The master-builders tried to use as many arches as possible with the same radius so that the masons could manufacture the stones according to sketches on the floor (sometimes those sketches can be found, scraped into the floor somewhere in the church where it is not visible for the visitor). Using the sketches stones could still be crafted when church-building was not possible, e.g. in the winter. In the Romanic period the stones were usually crafted and fit „on demand“.