Civil Engineering Reference
In-Depth Information
Landing valve
Dry riser
Hose reel
Less than
50m
Connected to building
water supply
Dry riser inlet
Foam inlet
Foam nozzle
Oil-fired heating appliance
Figure 9.90
Cross-section of a multi-storey building with fi xed installations
or more below ground level must be provided with smoke
outlets. Smoke outlets can be either natural or mechani-
cal. Figure 9.91 shows two ways of achieving natural ven-
tilation from a basement.
If mechanical ventilation is provided for a basement
it must be robust enough to continue to function under
fi re conditions therefore a mechanical system will only
be considered as suffi cient if:
equipment designed to work at voltages in excess of
1000 volts AC or 1500 volts DC if measured between
any two conductors or 600 volts AC or 900 volts DC if
measured between a conductor and earth.
The cut-off switch must be positioned and coloured
or marked to ensure that it is readily recognisable by
and accessible to fi re fi ghters. The local fi re and rescue
authority and the Institution of Electrical Engineers
provide information on such colouring and positioning.
Gas and other service isolations
- many organisa-
tions produce documentation relating to the positioning
and mechanisms of isolation for a variety of services and
processes to assist fi re fi ghters on arrival. Typically these
documents consist of fl oor plans, schematic diagrams
and manufacturers' guidance documents (when available).
On larger sites arrangements are also made for engineer-
ing staff to be on hand to assist the fi re fi ghters to identify
and make safe services and systems to minimise the risks
to the themselves and those they may be rescuing.
➤
The basement is fi tted with a sprinkler system
➤
The system is capable of achieving 10 changes of
air per hour
➤
The system can handle gases at temperatures of
300ºC for at least 1 hour.
Adequate means for isolating services
Fire fi ghters' switches for luminous tube signs, etc.
-
isolations or cut-off switches to protect fi re fi ghters must
be provided for luminous tube signs or other similar
