The works carried out by Teulère were performed within a tight time-frame: three campaigns limited to when the weather was good (six months, at best) between 1788 and 1790. When it came to logistics, Teulère had to deal with the same problems that Louis de Foix had faced: sending supplies to the site was dependent on the vagaries of the weather and transport from Royan in a fleet of small boats, the site's seventy workers, all of whom had to be ferried from the coast, needed to be fed and housed in a very small space, difficulties with handling materials, etc. The architectural challenges were particularly complex. Demolition of the upper section, followed by the construction of the new tower on top of the old walls, required painstaking work and calculations to make the new structure as light as possible. It was a real technological achievement. Teulère, who lived at the site, provided an excellent description of the technical problems with which he was confronted: "Foundations to be built 75 pieds up, a vault to hold up with the load that it must bear, demolition to be carried out at 130 pieds, connections between older sections that must be preserved in several places in order to link them with the new section – all of this means that I must take extra precautions so that nothing goes wrong, and that everything is well connected…" It was a real balancing act, a job for a jeweller in which "we have only very limited room to manoeuver" and one in which the architect worried that "the least act of carelessness could ruin our work and cost the lives of twenty workers…", particularly for the top section and for the lantern, where the "rotating mechanism" and the reflectors were installed.