Page 446 - Offshore Electrical Engineering Manual

Preparation and Use of Performance Standards 433

(A)

INSTALLATION: PERFORMANCE STANDARD: INTERNAL COMMUNICATIONS
The emergency role of the communications system installed on the Installation is to provide the necessar y facilities to control the emergency by:
a) Enabling messages and alarms to be broadcast throughout the installation
b) Communicating with nearby or physically linked installations
c) Communicating with vessels nearby working on activities related to the installation, and the standby vessel.
System description
An emergency hot line telephone provides communications between:
1) the control rooms of the nearby installations
2) the radio rooms of the nearby or physically linked installations [if any]
3) the installation’s OIM and the OIMs of nearby installations
A UHF (FM) radio repeater system is usually installed to enhance full duplex radio communications between personnelusing hand
portables. In the event of failure, the hand portables are equipped with simplex channels to allow communications, hand portable to
hand portable, between personnel on the facility.
A radio paging system with facility for sending verbal messages that may be accessed from the installation telephone systems
enables key personnel to be paged.
A duplicated, Public Address/General Alarm (PA/GA) system, fully certified for use in hazardous areas is provided to advise
personnel of an emergency and the actions to be taken. Each system can be accessed from the control room, radio room, helideck
and lifeboat stations. The PA/GA system carries routine and emergency speech and alarm on both halves of the system
simultaneously. In an emergency, the PA system can broadcast a tone indicating the nature of the emergency (muster and prepare to
evacuate) and to issue instructions to all areas where personnel may be present, including lifeboat and muster stations.
The Emergency Intercom system is designed for use in hazardous areas. The system is installed in a ring, and provides
communication between control points and muster areas even if any one of the cables interconnecting two stations is severed, or the
platform 240V- ac power supply is not available. The system provides; two channel communications (one channel each for Control
points and Muster points) with the option of “All Call” simultaneous transmission both channels, full battery back-upfor each
outstation, full line monitoring featuring outstation health and audio line continuity.
Telephones are located at strategic points throughout the operati ng and accommodation areas. In hazardous areas, weatherproof and
intrinsically safe telephone sets are used.
Functions Element Assurance
1 To provide clear signals a) Two emergency signals are provided through the PA/GA Telecommunications
to identify emergencies system. The PA system is used to broadcast a tone maintenance instructions
on the installation. indicating the nature of the emergency. Reference maintenance
b) Instructions can be issued to all areas where personnel may procedure XXXXX.
be present.
The communications system has been designed such that the parts
essential to the safety of the Installation personnel will continue to
function in any emergency including shutdown situations.
The visual and audible alarms are in accordance with the
requirements of PFEER: SI 743 (1995).
2 To ensure that under gas a. Radio equipment is designed to limit radio frequency See Ignition Prevention
escape conditions propagation to a safe level and prevent ignition. Performance Standard
emergency b. The public address system is fully certified for use
communications are in hazardous areas. Also by design
maintained and no spark c. Telephones located external to the control room or
ignition is possible due temporary refuge areas are certified for use in
to their use hazardous areas that remain operational in an ESD
situation.
d. Portable systems are all intrinsically safe.
e. All flashing beacons and loudspeakers used as part of
the PA/GA systems are certified for use in hazardous
areas, even when installed in areas normally classified
as non-hazardous.
f. PD CLC/TR 50427:2006 Assessment of inadvertent
ignition of flammable atmospheres by radio-frequency
radiation. Guide.
FIGURE 9.2.1
(A) Typical internal communications performance standard (based on a floating produc-
tion, storage and offloading (FPSO) with central turret, aft engine room and forward
accommodation). (B) Typical fire and gas system performance standard for an FPSO. (C)
Typical emergency shutdown (ESD) system performance standard for an FPSO. HLG, high
level gas; HVAC, heating, ventilation and air conditioning; LEL, lower explosive limit; LLG,
low level gas; UPS, uninterruptible power supply.