Pylons bolstered to cope with super typhoons

PUBLISHED : Friday, 20 April, 2012, 12:00am
UPDATED : Friday, 20 April, 2012, 12:00am


The city's ageing electricity pylons will not withstand super typhoons that are increasingly likely to strike the city amid climate change, according to CLP, which yesterday briefed the media on measures to strengthen the structures.

The city's largest power company said it was strengthening 151 pylons, each more than 30 years old, that are more prone to destruction by strong winds, and enforcing the slopes surrounding them. Most of the work will be completed in two years.

CLP's director of power systems Chow Tang-fai said the electricity network was designed in the late 1970s and early 1980s and the facilities were made to withstand winds no stronger than 240 km/h .

But he said: 'In recent years, we have seen super typhoons in other countries with winds as strong as 300km/h,' he said. 'Hong Kong is lucky that no such typhoons have struck the city in the past few years, but we must prepare for them.'

Chow said typhoon Megi, one of the most intense typhoons ever recorded - and which killed dozens of people in Philippines and Taiwan in 2010 - was a sign that the city was becoming more prone to super typhoons, as Hong Kong lay directly in its path at one point.

There are more than 700 high-voltage pylons in CLP's network, of which 151 are susceptible to strong winds, according to CLP. These will be reinforced with steel and the company is studying 74 surrounding slopes to see if they too need reinforcement. The company has also bought three temporary pylons that could swiftly replace a damaged one.

Workers are installing automatic switches on overhead cables, so fewer consumers will be affected if power lines are damaged.

The time needed for repairs could also be shortened from a few hours to one or two minutes.

Chow expects 80 per cent of the work will be finished by 2014.

He said Hong Kong's electricity supply network was 'quite comprehensive' and there was little chance the whole city would be affected by a power outage. He said the company started looking in 2005 into measures to prevent destruction from super typhoons after Hurricane Katrina hit New Orleans in the US, killing more than 1,800 and destroying thousands of homes. More than one million were left without power for days.

Five of the typhoons that have hit Hong Kong since 1960 have produced gusts of more than 240km/h.

Typhoon Wanda, in 1962, the most intense typhoon in the city's history, killed 434 people and left 72,000 homeless.

In 2009 and 2011, thousands of villagers in the northern New Territories lost their power in four separate typhoons, CLP said. Two pylons were wrecked by Typhoon Ellen in 1983.