EA Networks based in Mid-Canterbury, New
Zealand, is a locally owned electricity network
co-operative which owns and operates the
region’s distribution network. Bordered by the
Southern Alps mountain range on the west and
the South Pacific Ocean on the east, Canterbury
is prone to extreme weather, particular the
powerful nor-west winds that cause havoc for
“Back in 2011, we had a single repeater part way up
the mountains so coverage, particularly on the eastern
seaboard area, was quite poor. In adverse weather
conditions, when you need communications the most, it
became very poor and we just weren’t able to deliver the
kind of service to our customers that we wanted to.
We looked at several options for addressing this. We
implemented a voting system but it was confusing for
people to use and it wasn’t that successful. So we decided
to migrate to digital. We evaluated vendor options and
we have a long-standing and trusted relationship with
Tait so we chose to work with them.
We initially looked at P25 but when DMR Tier 3 became
available we realized that it was a better fit for us. When
we have storms and we’re working in other power
companies’ areas, the ability for us to communicate with
each other is a huge advantage and I believe that DMR
is more likely to become a general purpose standard
here. P25 also had encryption and security features that
we didn’t really need so we made the decision to switch
to DMR Tier 3 and started a Beta trial with Tait.
Initially, we made the decision to have all users
operating on an open channel so that everyone could
hear what was happening during day-to-day operations.
We knew trunking was an option but we couldn’t quite
see the benefits.
In September 2013, we were hit by a severe wind storm.
To give you an idea of the severity, we had a record 251.9
km/h (157mph) wind gust recorded at the summit of
Mt Hutt, our local ski field, and 128km/h (80mph)
gusts in town.
During the windstorms, our radio channel utilization
was virtually 100% for several hours. The continuous
traffic made it challenging to work as efficiently as we
Following that event, we realized that by splitting radio
traffic into multiple channels we could help our people
work more effectively during major events. We now
run multiple groups, all using the same infrastructure.
We have a four channel system – three audio channels
plus one control channel so we can have up to three
simultaneous conversations on different groups or
individual vehicle-to-vehicle conversations. Our
operations channel is an open channel so everyone can
switch to that to hear what’s going on when they need to.
With the DMR Tier 3 solution, we’re seeing much better
“at the summit of Mt Hutt...”
coverage. We’ve now put in five repeaters so we have
complete coverage across our entire network. Like any
digital system it goes and then stops so you don’t get that
grey area where people start making assumptions about
we were hit by a
severe wind storm...
“Gusts in town...”
PUT TO THE TEST
Just four days after commissioning a Tait
DMR Tier 3 system in Canterbury, New
Zealand, the region was hit by a huge
storm. Electricity Ashburton (EA) Networks
Network Manager, Brendon Quinn, tells us
how Tait and EA Networks worked together
to design and implement the Tait DMR Tier
3 solution and how the storm caused him to
rethink his position on trunking.
“DURING THE WINDSTORMS, OUR
RADIO CHANNEL UTILIZATION WAS
VIRTUALLY 100% FOR SEVERAL HOURS.“