Town & Country

Yesterday’s twin dramas, a massive power failure in Auckland and a solid dump of snow in the South Island, highlight the great divide between town and country.

There are some excellent lessons to be learnt by every New Zealander from both incidents, but it seems likely that they’ll be lost in the acrimonious debate that is already evident as business, politicians and the usual anti-Auckland lobby fire up.

Auckland’s woes began at about 8:30 a.m. when an earth conductor which protects the high voltage pylon line from lightning strikes collapsed into the Otahuhu sub-station in south Auckland. The area had experienced high winds which may have caused the conductor to sever, even though the wind speed had not exceeded the conductor’s rating.

Suddenly, much of the Auckland area lost power on a cold business day dropping the usual load of about 2 megawatts (MW) to somewhat under 1 MW. About 700,000 people were affected.

The nightmare for electricity workers was that the conductor was still in contact with the pylon and the fallen span had draped itself across equipment in the sub-station that supplies lower voltage distribution circuits derived from the main 110,000 volt feeder.

Meanwhile, many people in the South Island were experiencing the disruption caused by an early snowfall that was more extensive than Metservice predicted. They too, experienced power failures caused by the more obvious effects of snow loading power lines and poles beyond their specification and the visually obvious breaks caused by trees collapsing onto power lines under their load of snow.

Weather conditions aside, the result was the same. People who usually rely on electricity for everyday activity had to make alternative arrangements. Workers in both locations suddenly found they had time on their hands and thoughts turned to food and a nice warm drink.

In Auckland, infamous for its traffic problems and driving style, drivers generally behaved courteously when negotiating the 300-odd intersections without traffic lights, and many people headed home. Some were able to make use of gas cookers, barbecues or wood burners to make hot drinks and meals while they waited for the power to be restored. Others were caught short for lack of planning.

The Auckland power crisis of 1998 had been forgotten by many, and even those who had made contingencies probably didn’t factor in one major difference – the 1998 crisis occurred in summer. Yesterday was colder and darker. Stairwells where the emergency lighting had failed required navigation by torchlight – although some innovative people found that the back-lighting from a modern cellphone could suffice in a pinch.

In the smaller communities in the south people were better prepared, being more accustomed to getting by without electricity. They also benefitted from being more likely to live in a self-contained house with a woodburner.

Not surprisingly, the just-in-time mentality that has crossed from the business sector into the domestic lives of us city folk was more apparent in Auckland. With the power off, food outlets were unable to supply hot food and drinks to people who got to work or returned home to find the cupboards a bit bare.

It was a timely reminder to do a little bit more than storing up a bit of water in a cupboard somewhere. Emergency planning has to cater for more than the immediate effects of an emergency. Torches and radios need batteries. Food needs to be on hand and will require heating, especially in cold weather.

Yesterday’s dramas were a timely reminder to review our emergency planning. We were fortunate that both events were short-lived and didn’t push us into having to shift for ourselves for the 3 or more days that we will have to survive on our own resources in a real emergency.

The unsung heroes yesterday were the guys working at the Otahuhu sub-station and only glimpsed for a second or two on TV1’s News. Already under pressure from the knowledge that a lot of people were inconvenienced by the outage, they had to negotiate a dangerous environment to effect repairs. Removal of the broken conductor was necessary before other restorative work could commence.

Even after a transmission line is isolated, there is always the chance of a backfeed from elsewhere in the network. And even when that risk is eliminated, these long lines conduct electricity generated by the Earth’s magnetic field. I’ve seen it myself at the Haywards control centre where the planet’s fluctuating magnetic field was generating large currents in the Cook Strait cable when it was off-line.

I marvelled at the guys wielding those long insulated grappling poles to remove the broken conductor at Otahuhu yesterday. That was heroic.

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