NBN Co replacing 10,000 FTTC modems after damage by lightning in NSW’s Blue Mountains region

There’s been a growing chorus of NBN users reporting that their NBN modems have been damaged during lightning events, such that NBN Co has now agreed to replace some 10,000 Fibre to the Curb (FTTC) modems in New South Wales’ Blue Mountains region.

The move comes after recent electrical storms in the area caused widespread outages and faults, with most affected users reporting that their modems simply didn’t work anymore after there had been heavy thunderstorm activity.

The mechanism of the damage is quite curious. It seems that lightning strikes in the area have caused sufficient dissipation in the surrounding earth to reach the Fibre to the Curb Distribution Points (FttCDP), which then transfer the surge of power up the copper lines to people’s houses, and into their FTTC modems.

The Guardian reports that NBN Co will now be replacing around 10,000 of these modems (either those damaged or prone to damage), explaining that NBN Co had found issues in areas with sandstone ground composition. To counter this, it has produced a more resilient FTTC modem which is designed to withstanding these kinds of faults without failing, but NBN Co notes that excessive surge could still damage the devices, which are designed to fail safe (i.e. not burn down people’s houses).

Ultimately, though, this fault highlights just another concern with NBN’s multi-technology mix. Relying on copper conductors for the last few meters of a connection just telegraphs electrical faults into users’ homes, which wouldn’t have been an issue with the original fibre-only design. Electricity can’t flow up optical fibres (but if it struck power lines in the area, that could cause a fair amount of damage anyway).

Some users in the Blue Mountains have reportedly been through three or four FTTC modems in recent times, with some users in particularly prone areas left with a spare modem that they can swap in themselves in the event of their current modem being damaged.

While NBN Co struggles to come up with a workable long term fix, the solution just might be one that the broadband network operator doesn’t want to examine – with FTTC bringing fibre so close to people’s homes already, it might just be easier (and cheaper in the long run) to upgrade those premises to full fibre and do away with the FTTC infrastructure.