Sound systems are normally associated with venues or sites, but occasionally for public safety this can expand to a need for a system which covers whole cities and regions. Such is the case with Marghera City, in the province of Venice, Italy, which has recently had an audio warning system installed utilizing Community loudspeakers.
Marghera is situated on the area of dry land facing Venice. It arose in its present form in the early 20th century to provide Venice with an industrial area and port, essential for competing with the other centers of the Mediterranean. The project was crowned by the building of a residential district inspired by the city-garden model, to merge life, work and the natural environment.
Port Marghera was bombed in World War II which stopped its operation, but after the war it resumed activities and development throughout the 1950’s to become one of the best known industrial hubs of Italy. In the 1960’s it experienced its greatest expansion, reaching an impressive number of production activities including chemical and aluminum, naval shipyard, petroleum refinery, metallurgy, electricity and the commerce of petroleum products.
The proximity of the industrial port Marghera to the residential Marghera City has been a subject of concern and even legal action for decades. Inside the industrial facility there are different types of warnings and alarms, both acoustic and non-acoustic, for employees and visitors in the event of any problem, typically the leakage of toxic and harmful chemical material from the processing and storage plants.
The Servizio di Protezione Civile of the City of Venice has now wisely implemented the provision of an acoustic alarm system for the residents of the neighboring city, to warn them quickly of toxic pollutants in the air and allow residents and the relevant authorities to operate pre-planned actions and counter-measures.
The Consorzio Venezia Ricerche (CVR, Venice Research Consortium) was charged with the design of the system and defining and managing the various installation stages. Having recently completed the large scale audio warning system that forms part of the flood defense system for Venice, all of the experience the project would demand was available to tackle the new project.
The CVR established a Marghera Acoustical Warning System Task Force, consisting of internal staff and specialized professionals. The installation was managed by Sofitel from Treviso, while the acoustic simulation activities were carried out in full within the CVR. The Task Force included Marco Ferrari for the architecture of the communication system and Gianluca Sorbara for the electrical aspects, coordinated by the acoustic and electro-acoustic expert Umberto Nicolao, who also managed the overall design.
The system designed by Nicolao utilized the water tower of Marghera, one of the highest buildings available, as a central ‘acoustic lighthouse’. The tower is fitted with thirty Community PC1542M loudspeakers with M4 drivers, covering a precise 220 degrees horizontal.
Critical coverage angles were calculated and implemented to avoid nearby ‘Cita skyscrapers’ from excessive SPL. In addition to the central tower, and to create an acoustic umbrella of typically higher than 75 dB-A over the city, Nicolao designed five additional sub-locations each using four Community RSH462 loudspeakers.
A Biamp Vocia system VA8600 system controls the audio network and automated monitoring, while AM600C power modules drive the Community loudspeaker systems.
Building on and adapting the extensive acoustic transmission and perception work carried out on the Venice system, the warning tones of the system have been finely tuned to give appropriate warnings without creating undue alarm.
The sophisticated warning system combined with the appropriate counter-measures has given the residents of Marghera City the level of security they have sought for many decades.
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