a two-way communication system without a central switchboard, usually limited to a single vehicle, building, or plant area
Hea teada
In its early form, the intercom system was usually a privately owned installation used solely for internal voice communications. Although such systems still exist, later developments have brought about integrated systems combining these with normal telephones as an option in fixed locations, or with the radio facilities in mobile (land, air or marine) applications.
Except in open vessels, it must be located outside the engine room and must, in all cases, be so arranged as to ensure in the event of fire or other failure of the main electrical installation, simultaneous functioning for at least three hours of: ... - the internal communication system, fire detectors and emergency signals ...
