31 October 2011

Breakthrough gives Victoria Park Tunnel dangerous goods rating

The partial opening of the new Victoria Park Tunnel in Auckland (29 October) has opened the door on a new era of sophistication for the fire-safety industry in New Zealand.

Innovative systems from a specialist Auckland company have provided the world-class solution that enabled the new Victoria Park Tunnel to surpass the stringent fire safety standards to become New Zealand’s first and only dangerous goods rated tunnel.

Penrose-based CSD Sealing Systems NZ worked with the VPT consortium building the 450-metre tunnel after qualifying from a global sourcing mission by international consulting engineer Parsons Brinckerhoff to find the right fire-sealing products to meet the onerous fire-safety standards.

“There was no other system suitable that could meet the specifications and warranties required to meet this demanding fire rating,” says Frank Wiseman, director of CSD Sealing Systems in NZ and Beele Australasia. “This is a first as no other tunnel in New Zealand is open to vehicles carrying various classifications of dangerous goods in bulk.

“The tunnel is designed with an escape corridor along one side and it is crucial that the fire seals protecting this corridor function correctly to ensure that motorists caught up in any conflagration inside the tunnel can escape the flames and toxic smoke by using the protected escape route.”

To further complicate matters, the tunnel is a cut-and-cover design – not drilled. This required a flexible jointing system to deal with continuous expansion and contraction as well as movement from varying load factors to ensure the structural integrity of the tunnel as part of a state highway that must remain open at all times.

This has been achieved using concrete panels that line both sides of the structure and form the escape route along one side. In addition to the precise joint seals between each panel, there were also hundreds of service penetrations through the walls to duct cabling, pipes, electric lighting, CCTV, alarm cabling, sensors, and fire sprinklers that had to be sealed to meet the stringent fire-safety ratings.

Beele Engineering, the Netherlands-based principal developer and manufacturer of the solutions used by CSD Sealing Systems, performed extensive additional testing of the system for the consortium, specific to the tunnel’s fire design and construction, and Forman Group worked closely with CSD Sealing Systems during the construction process, co-ordinating logistics and installation of the systems.

The Victoria Park Tunnel takes north-bound Harbour Bridge traffic only, freeing the existing viaduct to take all south-bound traffic on four lanes. For this reason, there would be no practical alternative route for dangerous goods carriers using the bridge, such as petrol tankers.

“In the event of a fire in the tunnel, our fire stop sealants must be able to stop the progress of the flames through vents, walls and cabling ducts,” explains Mr Wiseman. “The special fire-rated systems not only ensure the fire integrity of the flexible joints between those panels, but also expand to replace any voids created from piping or cabling that is destroyed in the fire, thereby maintaining a barrier seal against gas, smoke, water and fire.

“If there’s an inferno inside the tunnel, anyone who makes it safely into the escape corridor must expect to be able to flee the scene without impediment. We also use similar fire-stop sealing systems in buildings such as hotels and hospitals and on commercial sites.”

The fire-stop and sealing work recently completed by CSD Sealing Systems in the Tauranga Hospital east wing extension, for example, set the construction industry alight with its precision and certification standards. Every single one of the 2750 holes made through the walls, floors and ceilings for services such as plumbing, electricity and heating was sealed against fire, smoke, gas and water – and the precise location of each was recorded in a searchable computer database.

“We worked with some of the same consortium members, such as Fletchers, on the Tauranga Hospital and Victoria Park Tunnel,” says CSD co-director Greg Hand, “and we will be seeking to continue this relationship when construction starts on the 4.5km Waterview tunnel. Fire-stop sealing is a vital sector of the building and construction industry in New Zealand, and will become even more so as insurance companies tighten up their safety requirements.

“We know there are many dangerous buildings across New Zealand that don’t meet the required passive fire-stop safety standards, and the industry has now recognised that this is the next major issue for building owners, following on from leaky buildings and earthquake-prone buildings.”

ENDS

© Scoop Media