Warnings about lightning ignored

PUBLISHED : Tuesday, 26 July, 2011, 12:00am
UPDATED : Tuesday, 26 July, 2011, 12:00am


Transport emergency specialists said yesterday rail authorities ignored their warnings on the risks of lightning and pointed out the country's railway system still had insufficient protection against such strikes.

The railway ministry blamed Saturday night's fatal high-speed train collision on 'equipment failure caused by lightning', said ministry spokesman Wang Yongping , citing an initial investigation.

Tsinghua University professor and National Lightning Protection Technology Standard Committee director He Jinliang said his committee offered to provide suggestions on lightning protection measures to the rail ministry, but was turned down.

Lightning rods on power transmission pylons could significantly reduce the risk of lightning strikes damaging high-speed rail lines by channelling extremely high voltage currents into the ground, He said. The devices were cheap and simple, but to install them on every pylon in China's high-speed rail network required a considerable investment and the rail ministry regarded it as too expensive.

The lack of lightning protection hardware on the mainland's high-speed network led to a high frequency of lightning strike incidents.

There had been at least eight major incidents since 2007, causing massive delays in provinces such as Hebei, Shandong, Fujian and Jiangsu, according to China News Services. The latest accident crippled the Beijing-Shanghai high-speed rail service three days after it began operation this month.

The railway ministry also rejected a request from the country's best lightning experts to fund research on the safety impacts of lightning on the high-speed rail links, He said.

'Our high-speed railways are extremely fragile,' he said. 'A small lightning bolt can wreck a line. I hope that the unnecessary deaths in this accident will make the authorities realise the seriousness of the issue.'

Guan Xiangshi, a senior engineer with the International Electro-technical Commission, told the China Meteorological Administration's news website that the construction standards of China's high-speed rail did not include lightning protection and he believed this omission was the ultimate cause.

Professor Wu Mingli, an expert in high-speed railways at Beijing Jiaotong University's school of engineering, said bullet trains were more vulnerable to lightning strikes than jumbo jets.

He said the metallic hull of a modern passenger jet worked as a near-perfect conductor to bypass electric current and protect passengers and equipment inside while the plane was airborne. But a bullet train was not so well insulated and lightning could pierce a carriage and wreck equipment inside.

'From electric motors to signalling antennae to emergency response systems, any device using electricity may fail,' Wu said.

There are still many questions about Saturday's crash. In particular, authorities have not explained why multiple layers of anti-collision mechanisms on the high-tech bullet trains all failed.

The train from Hangzhou was a CRH1B model based on German technology, while the other train was a CRH2 model using Japanese technology. An anti-collision mechanism called Automatic Train Protection, or ATP, was installed on both trains.

The ATP system automatically slows down or forces a train to a complete halt when it detects any operational abnormality.

This means that if one train lost its signal due to a lightning strike, the ATP on the following train should have been activated and prevented the collision.