Greene Fire provided FireMaster Concertina and vertical fire curtains as fire protection for the PWC Barangaroo Tower 1 project in NSW.
Greene Fire’s solution ensured the architectural design of the building was not compromised to meet fire safety compliance regulations.
Some areas of the Barangaroo Tower 1 building did not comply with the DTS provisions of the BCA. A performance-based fire safety engineering approach developed alternative solutions, which included vertical fire curtains on Levels 14-17, around the stair voids and through the centre of the office space on Level 15, in lieu of fire walls achieving an FRL of not less than -/120/120. To ensure safe evacuation of people in fire mode, these areas were required to be fire separated from the remainder of the fire compartment.
The stair voids on each level had been architecturally designed with multi-shape glass balustrades surrounding the stair/landing on Levels 15 and 16. The steel stair construction on Level 14 transformed into a timber stair and landing before re-joining the floor level. A custom-made fire curtain would ensure that it surrounded each staircase and landing taking into account the different shapes including varying amounts of corners.
To facilitate occupant evacuation, the FireMaster Concertina curtains would need to drop to a height of 2 metres and hold at this position for 30 seconds before completely deploying in the closed position within 60 seconds from the time of the general fire alarm being activated. To avoid occupants getting trapped, clearly marked push buttons would have to be provided on the inside of the fire curtains with signage on each curtain to notify the occupant of the location.
Greene Fire provided multisided FireMaster Concertina curtains on Levels 14, 15 and 16 with a vertical FireMaster wide single roller curtain used on Level 15.
To meet the requirements for occupant escape, the FireMaster Concertina curtains on activation, deploy to 2,000mm AFFL and hold for 30 seconds (SDD – Split Drop Delay). After the 30-second hold has expired, the curtain will continue to deploy to FFL.
Emergency retract buttons can be pressed in a fire event to lift the vertical curtains to 2,000mm AFFL and hold for 20 seconds before deploying again. However, Greene Fire expressed their concerns about incorporating the emergency retract function in the Concertina product. For instance, the whole perimeter of the curtain would need to be raised, removing the compartmentation around a very large area. Secondly, retracting the fire curtain against the large forces exerted on it from the zone pressurisation system may not be possible. Also, the curtain may not be able to redeploy against the air movement created from the zone pressurisation system.
The need to be able to create a safe environment and account for the possibility of someone being trapped inside the stair meant that emergency retract was required in this instance. Extensive meetings were held between Greene Fire, Buildcorp, Defire and NDY to outline the specific requirements of the fire curtain, fire detection and mechanical systems within the building. This meant that all systems were installed and commissioned together to work correctly the first time.
Red light warning strobes located on both sides of the curtains were incorporated to notify occupants of the deployment of the fire curtains. Obstruction sensors are used in conjunction with a voice warning system to notify occupants of any obstructions in the way of the curtain as well as inform them when the curtain is dropping.
Benefits of Greene Fire’s fire curtains
The curtains have been built into the ceilings and so the architectural design did not have to be compromised to create the required fire separation. The multi-shape design also ensured that the architectural intent did not have to change as each FireMaster Concertina curtain has been installed on the perimeter of the stair/landing.
The concealed control panels are at a lower level, simplifying the monthly testing as well as for future servicing requirements.
The inclusion of emergency retract buttons and split drop delay adheres to the Fire Engineers’ evacuation requirements in fire mode.