Fire protection specialist Wormald, a Tyco Business, has installed comprehensive fire protection solutions in both the Mount Victoria Tunnel and the Terrace Tunnel in Wellington/NZ, as part of upgrade work undertaken by the Wellington Tunnels Alliance. The Wellington Tunnel Alliance incorporates the New Zealand Transport Agency, Leighton Contractors Pty Ltd, Aecom and Sinclair Knight Merz (SKM).
The tunnel works included upgrading fire fighting, lighting, ventilation and drainage systems, building new tunnel control buildings and some earthquake safety improvements. Wormald was chosen to supply and install the fire suppression systems and equipment. The upgrades aim to ensure that the tunnels continue to operate effectively and meet modern safety standards.
The Mount Victoria Tunnel opened in 1931 and connects Hataitai and the eastern suburbs with the inner city suburbs of Wellington. The 623 m long tunnel has a traffic flow of approximately 40,000 cars per day. The Terrace Tunnel was built in 1978 and is recognised as the gateway to Wellington with its connection between the State Highway 1 motorway and the Inner City Bypass. The 460 m long tunnel has in excess of 1,000 vehicles travelling through it every hour during peak times.
According to Dave Hipkins, National Technical Manager with Wormald, “Modern tunnels must be able to suppress a fire quickly and prevent it from spreading. Typically, fire suppression systems release water from the tunnel ceiling and require a combination of components, such as water supply, nozzles, pipes and drainage, to work seamlessly together.” In addition to having the correct fire protection equipment in place, staff members, particularly those assigned to a company’s fire safety team, should be fully briefed and trained what to do in the event of a fire. Hipkins also advises that regular servicing and maintenance of fire equipment and fire protection systems helps ensure that they will work appropriately if and when required. „Well-maintained fire systems can help to save lives and property“, he says.
At the Mount Victoria tunnel, Wormald was involved in supplying and installing the fire protection solution on site. The project included a 21 zone deluge system using a Tyco deluge valve with a remote resetting trim. The system is easy to operate as the diaphragm-style design allows for external resetting; simply re-pressurising the diaphragm chamber resets the valve.
Wormald also supplied 2,000 m of pipe work for the job and installed 260 sprinkler nozzles and fire rated cabinets to house the deluge valve sets.
At the Terrace Tunnel (Fig.), the Wormald team supplied and installed the specified fire system and equipment, including an 18 zone deluge system. Wormald installed 160 nozzles to the deluge system and worked with the sister company, Tyco Water, to supply pipe work for the essential water connections. Nine double-outlet fire hydrants were installed in the tunnel along with nine fire hose reels. In addition, a double outlet fire hydrant was fitted outside each entrance to the tunnel. A total of 1,000 m of pre-fabricated pipework was required for the project.
The pipework for both tunnels was pre-fabricated in Auckland by a Tyco company and then transported to the Wellington sites. The pre-fabrication resulted in much faster installation in each tunnel. Construction of the upgrade was scheduled to take place overnight to minimise traffic disruptions. Thorough preparations were essential for the night work, including making sure tools and machinery was in good working order and that all material and equipment to be installed was in the right place at the right time to enable the team to keep on schedule.
The installations team created a mock-up deluge cabinet prior to installation to ensure there were no sizing difficulties onsite and that the installation went smoothly. Wormald completed the fire protection systems on schedule and without a hitch.