Page 126 - Offshore Electrical Engineering Manual

Alternating Current Supplies 113

Secure DC and AC (battery-backed) power supplies are required to maintain
power for the following:

A1 An installation alarm system – an acoustic alarm that is audible throughout
the installation, to warn of danger, signal assembly at muster stations or to
prepare for evacuation.
A2 A PA system – to enable those managing the emergency to broadcast mes-
sages to all personnel onboard, to warn of hazards, to issue instructions and to
inform of incident status.
A3 Muster station communications – to provide communications between muster
stations and the emergency control centre (ECC)/emergency control point (ECP).
A4 Emergency response/support teams communications – to provide communica-
tions between members of emergency response teams and with the ECC/ECP
from all areas of the installation.
A5 Other communications – the provision of other communications for the
purpose of emergency response, between persons on the installation, as
identified by the prevention of fire and explosion, and emergency response
(PFEER) regulation 5 assessment.
Objectives for external communications include the following:
A6 Ongoing operations – to enable the ECC/ECP to communicate with any ongoing
associated operations, e.g., pipeline, heavy lifts, supply or diving operations.
A7 Onshore emergency services and support – to enable the ECC/ECP to inform
or call for external assistance or support.
A8 Nearby offshore installations – to enable the ECC/ECP to communicate with
nearby offshore installations that may be able to provide assistance or to
advise of changes in pipeline status that could have an effect on the safety of
their operations.
A9 Vessels in vicinity – to enable the ECC/ECP to alert and communicate with
any ships in the vicinity, including standby boats or any other vessels, that
may be able to provide assistance during an emergency.
A10 Aircraft communications – to enable the ECC/ECP and Helicopter Landing Officer
to communicate with helicopters involved in evacuation and rescue operations.
Note that battery-backed helideck lighting and a directional navigation beacon
will also be required (see CAP437 in Bibliography).
A11 TEMPSC (totally enclosed motor propelled survival craft) communications –
to enable persons in survival craft to communicate with ships and helicopters
in the vicinity.

ALTERNATING CURRENT SUPPLIES
The uninterruptible power supply units are required where process controls, instru-
mentation, telemetry and telecommunications equipment require a secure source of
AC power to avoid disruption of remote control, blank sections in logging records or
loss of voice communication with the shore base.