Regional Direction for the Cultural and Landscape Heritage of Puglia - Progress Report
THE HISTORICAL VALUATIONS ON BELL TOWER OF TRANI'S CATHEDRAL
The bell tower was built in two phases. Base, first and second floors have been built in the first half of the thirteenth century and the first half of the fourteenth century.
The other floors and the spire were erected in the second half of the fourteenth century. The inscription in stone indicates the name of the first architect “Nicolaus sacerdos et protomagister me fecit”.
The holy visit of june 19, 1633 verifies for the first time the tower’s structural problems. We know that in 1786 the niches of the base were closed.
In 1884, it was proposed, without success, to demolish the top three floors of the tower and spire to improve tower's stability of bell tower of Trani’s cathedral.
In these images we can see the consolidation project made by the civil engineering boureau in 1886 (genio civile): the structure of the struts is wood. Then other minor restoration works were made in 1891 and
1893, while in 1892 a bell fell down.
In the bell tower’s measurements realized by Sarlo in 1893 we can see that the bell tower was inclinated because of important structural problem at the base's arch.
In 1902 the bell tower was completely restored by engineer Francesco Sarlo, in particular he substituted all deteriorated elements like stone ashlars where was old cracks, but also columns, capitals and plinths. The most important reinforced was at the arch of base of the bell tower. In a picture of 1933 we can see the reinforced arch realized by Sarlo under the original one. In this way Sarlo intended to increase the
resistent base and to improve the stability of tower. The foundation, the masonry’s core at the base and at the first floor was realized in reinforced concrete.
In the first time the reconstruction project intended rebuilt the bell tower skeleton in reenforced concrete. Finally the project was modified and the skeleton was limited to the base up to first order.
The phase of demolition was realized with this method: every stone was signed with a number to identify the position into the wall for facility the reconstruction.
In July, 1953 the demolition of spire is completed. The elements of spire were ordinated in the square under the tower.
In the priced bill of quantities we can read that only the 60% of original stones was use to rebuilt.
In the other images of rebuilding we can see the skeleton in reenforced concrete with the round rods on the top and the stone masonry. But attention: in this way the wall had lost the original load
bearing function and now it is only a cladding.
Today we can see the same situation that in the 1959. We can observe two different treatment of stone surface: gradine and bushhammered surface.