Image: Fire & Emergency rescue an injured worker in a tunnel.
In September last year, the emergency sirens on Watercare’s Central Interceptor project sounded the alert as thick white smoke filled the tunnel constructed beneath Auckland City. As the workers made their escape, it became apparent that three people were missing, possibly injured, and would need rescuing. Mary Searle Bell explains.
Fortunately, the emergency was just a training exercise, albeit a complex one involving a high level of coordination and cooperation between the many parties involved.
First, there was the asset owner, Watercare, for whom the massive tunnel will form its new wastewater pipeline, collecting sewage/stormwater from the existing old combined network and taking it to the Mangere Wastewater Treatment Plant.
Second, the workers from Ghella Abergeldie Joint Venture (GAJV), the tunnelling specialists charged with constructing nearly 20 kilometres of tunnels, more than 17 shafts, a major pump station and substantial wastewater management and network infrastructure works.
And thirdly, an array of emergency services, including Mines Rescue Service, Fire and Emergency, St John, and Police.
GAJV’s site senior executive for the Central Interceptor, Paul Miles, says the project is being constructed under the mining and quarry regulations, which requires a particular level of emergency preparedness.
“Watercare and GAJV are working together to ensure we are well prepared and well-resourced for any incident, although our focus is always on prevention. However, given the specifics of the project – its scale and complexity, its tunnels and shafts – we have to have a certain amount of self-reliance and capability as the traditional rescue organisation Fire & Emergency, has limitations in dealing with an incident in an underground mine or tunnel.
“We worked with Mines Rescue, which is the specialist emergency service to the mining and tunnelling industries, to develop a training plan specifically for the project, including a bespoke First Aid course that had an emphasis on likely scenarios for our work sites, plus rescue from long tunnels using specialist breathing apparatus.”
Paul says an emergency management plan and training were undertaken before any tunnel work began. The training includes routine emergency practice, and Paul says they have undertaken more than 50 exercises per year across the project, with two or three per site (there are 17 along the tunnel route) each year.
Every two or three years, they run a large-scale emergency exercise, with all emergency services working together.
“It took four to six months to prepare for last year’s emergency exercise, starting with what the drill will be, and who will participate, etc. We had a planning group made up of members from each organisation involved.”
The exercise was designed so that each emergency service had a role to play, but the most challenging response would be the one that took place inside the tunnel, and the emergency response here would rely on the expertise of Mines Rescue.
The scenario was to be a fire in the tunnel, and three victims would be unable to evacuate: one trapped deep underground, and two injured during the evacuation in different sections of the tunnel.
“Our challenge was to keep it dynamic, interesting, and challenging for all involved.”
Around 150 people were involved in the exercise, with only a small group of facilitators and observers knowing what was going on, says Paul.
Three St John response vehicles were deployed to the self-evacuation sites, five fire appliances, including a specialist breathing support unit, around five Police, 20 specialists from Mines Rescue, 35 workers in the tunnels, plus more above ground, and various response management teams with eight to ten people in each. WorkSafe was also informed as the drill played out.
Paul says the ‘Level 3’ emergency drill management was based on the Coordinated Incident Management System (CIMS) and was aligned with the Emergency Response Protocol for Underground Mines and Tunnels, albeit modified to suit the Central Interceptor’s construction environment.
The drama played out in the 4.5-metre-diameter main tunnel, which varies from 15 to 110 metres deep along its 16-kilometre length.
As the tunnel filled with a non-toxic white smoke, simulating a fire, and the emergency sirens blared, the workers underground knew what to do, donning breathing apparatus and either self-evacuating to assembly points at the main tunnel access point at May Road in Mt Roskill, or at the tunnel escapeway at Lyon Ave in St Lukes, or taking shelter in one of two refuge chambers in the tunnel boring machine.
These refuge chambers deep in the tunnel provide a safe shelter for up to 36 hours until an emergency is resolved.
Meanwhile, emergency services were called above ground as the incident management team assembled at the May Road operations site to coordinate the response. Cameras in the tunnel provided the team with a live view of locations along the tunnel as the incident played out.
At the same time, an incident support group was assembled at GAJV’s head office in Onehunga, while an incident governance group was assembled at Watercare’s head office to provide support.
It soon becomes apparent that three workers are unaccounted for underground.
Once on the scene, the firefighters quickly prepared to enter the access shaft to locate the first injured worker, who was a short distance into the tunnel, and removed him using a stretcher. Further underground, Mines Rescue located the other two workers – one sheltering inside a fresh air base and the other collapsed beside the tunnel boring machine.
Both were carefully transported from the tunnel by electric locomotive, with the five-kilometre journey taking half an hour.
“The length of the tunnel tested Mines Rescue, their equipment, and how they would respond – the time it took to deploy was particularly challenging,” says Mines Rescue operations manager Paul Moffitt.
Paul Miles says that one of the lessons from the exercise was around alternative entry points, such as entering through the escape route and using a mobile rescue chamber. This means the rescue team doesn’t have to use their personal air while travelling to reach trapped workers, which has been practised and demonstrated in subsequent emergency exercises.
Paul says the exercise was a great learning opportunity for everyone.
“It’s one thing to work it out on paper, another to test it in real life.
“There’s always room for improvement and we tried to pinpoint areas where it is critical that an issue is addressed. For example, understanding the respective capabilities of various services. We were not aware of the full capability each organisation can provide, but now we do, we can find the best response for each situation.
“The other thing we did, which we haven’t before, was to have ‘family members’ and ‘media’ showing up on site to stress test the staff working on the gates at the operations site, as well as providing a side challenge for the emergency management teams.”
As a part of the scenario, several ‘distraught family members’, played by Watercare staff, showed up at the gate after ‘hearing’ about the incident on social media. Paul says they went to town with their roles, convincingly demanding answers around what was happening and access to the site. One ‘family member’ didn’t speak English, adding to the confusion.
A ‘media team’, played by a real journalist and camera operator, also showed up asking question after question, heightening tensions at the gates.
“We wanted to see how staff responded to these visitors during a major emergency and see what lessons could be learned.
“It’s one thing to talk about various scenarios, but to actually have a news crew pushing you to the limits is another,” says camera operator Murray Milne.
“The focus of the emergency needs to be primarily about rescuing people injured or trapped underground, but these incidents associated with the rescue add extra challenges for the incident management team, and that is where the off-site JV and Watercare incident support teams can provide assistance to the site-based team,” Paul says.
It is not often emergency services combine to participate in drills on this scale. Still, Pauls says they all welcomed the opportunity to expose their staff to the challenges of underground rescue.
“The whole exercise was a large undertaking and disrupted the project workflow. We’re appreciative of GAJV for giving us the time to do this.
“We’re also fortunate that Watercare has a really good comms team who captured fantastic videos of the event, and these have been shared with all rescue agencies as well as industry to maximise the learning opportunity from the exercise.
“It was a big effort but definitely worthwhile.”
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