Greene Fire installed vertical and horizontal fire curtains at the Lend Lease tenancy in the Barangaroo Tower 3 building to ensure fire separation of internal voids.
The internal voids including the inter-tenancy stairs within the Lend Lease tenancy on levels 8-14 and 16-19 of the Barangaroo NSW office building had to be fire separated from the remainder of the fire compartment. The fire separation of the internal voids had to be continuous between the fire rated floor slabs including the ceiling spaces and access floor voids.
In lieu of 120/120/120 fire rated construction, the separation may utilise:
A) -/120/- horizontal fire curtains to provide fire separation of the voids at every second level, i.e. levels 11 and 18. The horizontal fire curtains must automatically close upon smoke detector or sprinkler activation within the two fire compartments that the fire curtains are separating.
B) Combination of -/120/120 fire walls and -/120/- fire rated glazing to provide separation of inter-tenancy stairs at every level. Where vertical fire curtains are proposed, the following requirements are applicable:
i. All vertical fire curtains on levels 8 to 13 must automatically close upon smoke detector or sprinkler activation within any of those levels.
ii. All vertical fire curtains on levels 16 and 19 must automatically close upon smoke detector or sprinkler activation within any of those levels.
iii. The curtains must comply with the requirements for split drop delays and push buttons on the stair side.
Greene Fire’s solution:
Vertical fire curtains
The Lend Lease tenancy comprises of floors connected via open circulation stairs on levels 9-12 and 16-19. The interconnection of these levels created a single fire compartment.
The open circulation stairs on levels 9-12 and 16-19 were fire separated with vertical fire curtains.
Once activated, the vertical curtains will deploy to 2000mm Above Finished Floor Level (AFFL) and hold for 30 seconds. This function is known as Split Drop Delay (SDD). After the 30-second hold has expired, the curtain will continue to deploy until it is fully closed.
The retract buttons can be pressed in a fire event to lift the vertical curtains. As a special functionality, the curtains retract to 2000mm AFFL and hold for 20 seconds before deploying again. Standard retract function would be to retract the curtain completely to the headbox, facilitating the evacuation of anyone who did not make it out of the internal stair area when the curtain was deploying.
The red light warning strobes located on both sides of the curtains will activate until the curtain is in the fully deployed position and will continue to operate until the curtain is reset. A voice warning ‘fire curtain descending’ will be heard whenever the curtains are deploying.
The Obstruction Warning System notifies of obstructions that are left underneath the curtains for more than 10 minutes. The voice warning is also used to notify of any obstructions, announcing ‘Warning, please remove obstruction’.
The curtains will remain in fire mode (ZCP on the front of the control panel will show solid red light at ‘Alarm’) until the alarm signal is restored at which time the curtains will be auto retracted.
Horizontal fire curtains
The voids on levels 11 and 18 were separated with horizontal fire curtains.
Curtains deploy on fire alarm activation (GFA) as per the FER strategy. The mechanical systems are delayed in these areas to allow the curtains to fully close.
The curtains will remain in fire mode (ZCP shows solid red light at ‘Alarm’) until the alarm signal is restored at which time the curtains will be auto retracted.
Greene Fire’s fire curtains delivered several benefits to the Lend Lease office installation. Since the curtains were built into the walls and ceilings, the architectural design did not have to be compromised to create the required fire separation.
The concealed control panels have been placed at a lower level to simplify the monthly testing.
The use of emergency retract buttons and split drop delay adheres to the Fire Engineers evacuation requirements in fire mode.