(IV-7-3) General Safety

Rules IV Industrial Services
Part 7 Offshore Technology
Chapter 3 General Safety
Section 9
Fire and Gas Detection Alarm Systems
• It shall be possible to transmit the undistorted and clearly audible alarm signal at all times. Other simultaneous
transmissions must be automatically interrupted.
• It shall be possible to operate all loudspeakers at the same time.
• The loudspeaker system shall be designed under observance of the minimum required sound level.
• Announcement via microphone shall be free of acoustical feedback and other disturbances.
D.1.3 The installation of a public address system may be dispensed for normally unmanned OSS. In
such case, the operator is responsible to provide suitable communication equipment to the crew for internal
communication during the temporary attendance on the installation, e.g. wireless radio.
Please refer also to GL Rules for Instrumentation (IV-7-6), Section 2.
D.2 General alarm system
D.2.1 On all units or installations an alarm system shall be provided to alert the crew or to call them
to the assembly points. It shall be possible to release the alarm from the central control station and also
from strategically important locations.
D.2.2 Generally, the following alarms shall be established:
• general emergency alarm
• fire alarm
• gas alarm, if required according to A.2.1and A.2.2
• abandon unit/installation
The alarms shall be defined in an alarm philosophy document, which shall be submitted for certification.
D.2.3 The elements of the alarm system have to be designed independently, but shall be connected
by a bus system. The use of a common control panel is permitted.
D.2.4 Means for announcement shall be provided in a sufficient number to ensure that all persons
inside the installation/unit and on deck are alerted. In noisy rooms, additional visual means of alarm may
be necessary.
D.2.5 Once released, the alarm shall sound continuously until it is switched off manually or is temporarily
interrupted for an announcement through the public address system.
D.2.6 Cables for general emergency alarm installations and for loudspeaker systems shall be fireresistant
according to IEC 60331.
D.2.7 If the main electrical power source fails, the general emergency alarm system shall be fed by
the emergency power source (uninterruptible power supply fed by the emergency generator).
Edition 2013 Germanischer Lloyd Page 9–4