DC power and the Christchurch earthquakes

In September 2010, Christchurch, a city of 400,000 in New Zealand, was hit by a magnitude 7.1 earthquake 38 km away. The city sustained moderate damage with no loss of life. Nearly six months later, a shallow magnitude 6.3 aftershock close to the city centre caused serious damage and significant loss of life. Infrastructure was (and remains) severely damaged. Underground power cables were destroyed, and substations damaged. Most of the city lost power for periods ranging from hours to weeks. Despite this, communications held up well. Most people were able to use mobile and fixed telephones to call for help or contact family members. This paper shows the strategies the telecom operators managed to maintain service, focussing on the role of DC power. It also shows what lessons have been learned for DC power equipment.