As part of the project to comply with the requirements stated in Article 22 of the Regulation on Minimum Safety Conditions for Tunnels, which mandates the installation of speakers for providing information in evacuation paths and other areas where tunnel users wait for evacuation, we have equipped 9 tunnels on the A1 Zagreb-Split-Dubrovnik highway with a public address system.
The following tunnels have been equipped with the public address system: Brinje, Plasina, Grič, Ledenik, Bristovac, Dubrave, Bisko, Stražina, and Kobiljača. The following works have been carried out in the tunnels and control centers:
- Installation of the central sound station at the Brinje CNUP, Plasina Fire Station, Sveti Rok CNUP, and Zagvozd CNUP
- Installation of sub-centers for sound distribution in the tunnels
- Mounting of speakers and sound columns in the tunnels
- Cable laying in the installation ducts within the tunnels
- Adjustments, testing, measurements, and commissioning
- Preparation of documentation on the as-built condition
- User training for operation and maintenance of the system
The public address system is designed to sectorally distribute sound to areas where passengers are expected to gather in case of an incident in the tunnel. These areas include tunnel entrances and cross passages. The Honeywell Variodyn D1 system was selected, which fully complies with the HRN EN 54 standard for alarm sound systems.
Sound columns have been installed at tunnel entrances, immediately after each cross passage, and behind emergency niches, facing away from the traffic direction, towards the users.
For direct access to the public address system from each tunnel sub-center, a microphone console with a keypad for selecting zones has been provided in the sound cabinet located in the tunnel cross passages.