improved for carrying gravity and other loads. The foundation pile was partly replaced. While the initial foundation were only 6 m deep, the new ones with 1,4 m diameter reached a depth of 17 m and reached solid rock. The structural analyses were made with dynamic calculation models using the "TABS" model from Berkely University. All the dimensioning of the elements was done in accordance with European and Yugolsav codes. For the lifting procedures, instruments were placed into the structures to compute the data collected which were analysed by computers. All relevant data was monitored live during the lifting of the heavy assembled elements of the main arches, pendentif and the main dome. Deflection, jack's strokes, leveling of supports, deformations and stresses of main elements were analysed. Lifting of the dome The greatest achievement of the construction process was lifting of the 4,000 ton central dome, which was built on the ground, together with the copper plate and the cross, and later lifted onto the vaulted arches. The lifting, which took 20 days with the specially constructed hydraulic machines, was finished on 26 June 1989. Before the dome could be lifted, the four main arches had to be brought into place. The four arches are the elements linking the bell towers both physically and in terms of communication. All four pairs of arches were very successfully lifted and fixed into position between January and June 1988. On the outer arches, which belong to the wing section, the semi-domes were formed, each consisting of eight curved, reinforced concrete trusses covered with curved slab decking. The assembly of the arches was done on the ground from pre-fabricated slabs, with their weight of 4000 kN each, they were lifted with "chains" to their intended position. The lifting of heavy loads to great heights was remarkably easily achieved, which as an innovation was a completely new system especially designed for the building. The chains were tested against safety factor of overloading between 1.6 and 2.2. As the expansion-joint arch rests "hanging" from chains in the lifted position, its own columns had to be subsequently cast underneath. They were then relaxed and together with the columns, form a framed system in a "portal" configuration. As the arches are major elements in the structural safety of the dome, they were analyzed in detail in all stages of static live, both in terms of stresses and deflections.