Reconstruction of the load bearing structure
The construction of Arsenal in Hvar started in the13th century. At first it was a ground-floor structure which served as shed for boat and its equipment. In the course of time it was subject to many changes regarding space usage, but also regarding the size of the structure. The most important issue for the present state is its surroundings, i.e. annexes built on its base volume, on the north, south, and part of the east side. On the north side, in the direction of the Square, the place where low-rises were located earlier was converted for Fontik, with terrace through which entrance to the theatre on the first floor was gained. Along the whole south facade, at the north-eastern corner and on part of the east side, one-storey and two- storey residential buildings were built, adjacent to the Arsenal. Thus, the town block was formed as a separate unit in architectural-structural sense.
Alterations on the Arsenal building were significant regarding volume, as well as interaction of parts of the bearing structure. The most significant is the change resulting from construction of the first floor, when transverse stone arches were built about 5,0 m apart, within the ground floor, between longitudinal walls. Parallel to the longitudinal walls and supported by stone arches, wooden beams were placed about 50 cm apart, as floor beams of the first floor.
The auditorium of the theatre, occupying the eastern half of the first floor of the Arsenal, is partly located in the parquet circle, partly in lodges built on two levels, in parterre and on the first floor. The entire bearing structure of the lodges was constructed of wood posts supported by floor beams, and boards dividing the lodges. The floor of the lodges on the first floor was constructed as a grid of wooden beams, leaning on longitudinal walls of the building, posts between the lodges and queen post trusses that carry the edge of the access gallery to the first floor lodges.
The bearing structure of the stage is a wooden structure, placed about 1,0 m above the parquet circle of the auditorium, leaning on the east wall of the building and the first adjacent stone arch.
The roof is wooden, constructed as purlin roof, with or without collar beams. The western part of the roof had queen post truss with braces that supported the rafters. In later interventions this bearing system of the roof was changed by removing the braces and queen post trusses. The eastern part was constructed as purlin roof, with or without collar beams, but without queen-post trusses. On the part above the stage two double queen-post trusses were constructed, one by the eastern wall and the other above the stage portal, carrying purlins and rafters.
The bearing structure of the attic floor consists of wooden beams placed on every other pair of rafters. Due to this, beams on the walls transfer horizontal force from the pair of rafters without connecting beam to the pair with connecting beam, by bending in horizontal plane. The particularity of the ceiling beams in the attic floor above the theatre lies in the fact that they don't directly lean on longitudinal walls, but below them (at the distance from end walls of the first floor lodges) short beams are placed, leaning on the walls and fixed to the ceiling beams with steel fastenings and screws.
The dimensions of ceiling beams above the theatre are not uniform, but are generally of insufficient cross section, so their sinking is easily observed. The floor level is not the same in the eastern half of the attic floor, the one above the theatre. The part above the auditorium is elevated and the remaining part is lower. The reason for this probably lies in positioning of the bottom beams that lean on the walls, so the ceiling beams had to be placed above them, which resulted in different level of the attic floor.