Standard for Fire Safety in Rapid Transit Systems - Singapore Civil ...

(e) Where the supply air duct serving the exit staircase has
to penetrate the staircase enclosure, the portion of the
duct where it traverses outside the staircase shall be
enclosed in masonry construction or drywall
complying with Cl.2.3.8.7(c) of at least the same fire
resistance as the elements of structure and it shall not
be fitted with fire dampers.
(f) Where duct risers are required to be enclosed in
protected shafts, the protected shafts shall be enclosed
in masonry construction or drywall complying with
Cl.2.3.8.7(c).
(g) Battery rooms shall be ventilated to maintain the
average hydrogen concentration by volume in the room
below 2%.
(h) Magnetic (short circuit) trips are permitted for use in
motor circuits of essential mechanical ventilation
systems and equipment. Moulded Case Circuit
Breakers (MCCBs) with magnetic release only are
permitted for use in lieu of High Rupturing Capacity
(HRC) fuses.
2.6.2.3 Fire dampers shall not be fitted in the following locations:
(a) Openings for ducts of emergency ventilation systems
in walls of ventilation shaft.
(b) Anywhere in an air pressurising system.
2.6.2.4 Vent Openings in Lift Hoistway
(a) The protected lift shaft shall be vented in accordance
with SS 550 Code of Practice for Installation,
Operation and Maintenance of Electric Passenger and
Goods Lifts. The vents shall be so arranged as to
induce exhaust ventilation of the shaft. Where vents
could not be provided because of the location of the
lift shaft, ventilation duct protected by drywall
complying with Cl.2.3.8.8(b) serving as ventilation of
the shaft may be provided instead. If the duct is not to
be fire rated, fire dampers shall be provided to the duct
at the wall of the lift shaft, provided such relaxation
shall not apply to shaft containing fire lift.
Prohibition of
fire dampers
Hoistway
ventilation
Standard for Fire Safety in Rapid Transit Systems 112