Nuremberg Wall Security Monitoring
As the Nuremberg city wall grows in length, it loses more and more stability. Due to the fact that the building was constructed in the 14th century, it mostly consists of sandstone. In the 14th century, stresses and strains were not yet taken into account; e.g. vibrations of heavy load and tramway traffic. Off-sets of several cm can be found. In some places prominent cracks were noticed.
To make sure that the people who are in close proximity are out of danger, LGA in cooperation with Civil Engineering Office had the important places of the wall online 24 h a day monitored. A total of 52 displacement sensors were inserted into the wall, to register areas of least displacements. The signals were recorded with the data logger IDL 101, which continuous the actual values with the set points compared and the data via modem to the PCs of LGA and Civil Engineering Office transmit. When the limit values were exceeded, an alarm activated at the monitoring system and a SMS automatically transmitted to the mobile phones of the Civil Engineering Office.