If you don’t have power, or if the phone lines are cut, the network won’t function.
During Cyclone Gabrielle we saw both those things happen on a scale we’ve never seen before across the entire upper North Island and for many people that meant being left without the ability to call for help or to check in on family and friends.
The cyclone knocked out the Redclyffe substation, causing a massive region-wide blackout affecting more than 200,000 people across Hawke’s Bay and Gisborne and taking down mains power supply to hundreds of telecommunication facilities including cellphone towers, roadside cabinets and exchanges.
The actual damage to these sites was limited, but the loss of power was immediately felt.
These installations have backup power – batteries for short-term immediate use, and generators for longer-term outages – and they immediately kicked in.
Batteries don’t last very long because the power draw from a facility like a cellphone tower is immense.
Typically we would expect four to eight hours’ worth of power out of a battery – more if we restrict the service to voice and text only.
That’s enough to keep the service going while electrical engineers fix things and to provide our technicians time to deploy generators and fuel where needed.
Each year the telcos refresh these batteries, and each generation of battery is better than the ones that came before, but there are regulations that limit the size of the equipment we can deploy.
The national standards are being updated and we hope will allow for larger facilities to be rolled out in future.
Having such a widespread loss of power alone would have been a major problem, but on top of that there was extensive damage to roads and bridges in the region, and that in turn destroyed a lot of the fibre networks that connect telco facilities together.
Cellphone towers are connected to the rest of the world typically by fibre optic cables, and they’re extremely robust.
Fibre works even if it’s bent, buried in mud or submerged in water and is relatively easy to repair. The old copper lines were brittle by comparison, tend to short out when exposed to water or mud and take a lot longer to repair.
Cyclone Gabrielle saw more than 80 bridges destroyed across the region and in each case the fibre network attached to the bridges was cut to pieces with some gaps of more than a kilometre in length.
Even cellphone towers with power couldn’t connect to the outside world.
As an industry we have reviewed how we build and run our networks as a result of the cyclone.
We work with the lifeline utilities groups around the country, NEMA and Civil Defence and our partners in the electricity sector to see what we can do to ensure supply in the future.
The answer isn’t as simple as anyone would like. We can’t just buy a new battery or move the fibre network to another place because that won’t reduce the risks. Weather isn’t the only issue we have to consider. We have earthquakes, volcanoes, tsunamis and other issues like cyber attacks to consider when building networks. The next event might be a cyclone or it could be another pandemic and have a totally different set of requirements.
We will continue to partner with the Hawke’s Bay Regional Economic Development Agency and the council’s lifelines team to see what else we can do to prepare for the next big event, and we continue to invest heavily in redundant systems, new software that remotely manages sites more effectively, in diversity of routes and alternate new technologies like satellite as well as new batteries all of which are designed to improve our ability to respond quickly to major events and to keep you connected.
We don’t know what the next event will be but we are preparing for it nonetheless.
