Beijing buildings prone to lightning strikes
Over 20,000 lightning strikes hit Beijing every year, but the majority of buildings in the Chinese capital are not properly protected from lightning.world Updated: Jul 16, 2010 12:22 IST
Over 20,000 lightning strikes hit Beijing every year, but the majority of buildings in the Chinese capital are not properly protected from lightning.
There is an average of two to three lightning strikes every 1,000 square metres during the peak summer season, according to the Beijing Meteorological Station.
Although most of the buildings have lightning rods, these are insufficient to protect against strikes that are increasingly occurring due to the presence of video surveillance systems on roof-tops, officials from the test centre for safety of lightning protection devices said.
The officials came to the conclusion after inspecting over 8,000 buildings in the Chinese capital, Global Times reported.
Video surveillance systems, buzzer systems and walkie-talkies had sparked more than 80 percent of lightning accidents, centre director Zhang Lei was quoted as saying by the Beijing Evening News.
"Those systems need special protection like magnetic shields, but in reality lots of buildings don't have any protection," he said.
The sides of tall buildings are also vulnerable to lightning strikes, he warned. Metal window frames and metal brackets linking glass walls are the main reasons.
"Often they don't have proper earth grounding, which is extremely dangerous," Zhang said.
Shanghai's signature landmark Oriental Pearl Tower was struck by lightning April 13, setting the top antenna on fire - despite the fact that the 468-metre-high building already had a lightning rod. An investigation found the lightning was attracted by a cable on the antenna, according to a report in the Legal Mirror.
Beijing has 58 skyscrapers over 100 metres tall. Any building taller than 45 metres is required to install proper lightning protection devices. Those that refuse to install rods are subject to fines ranging from 20,000 to 30,000 yuan ($2,592 to $4,428).