Now glass panes shatter at airport, AAI orders probe

CHENNAI: As if things couldn't get worse for the Chennai airport, now glass panes have mysteriously started shattering every so often in its new international and domestic terminals.

The Airports Authority of India (AAI) has roped in experts to investigate the cause of the problem.

An outer glass pane on the mezzanine floor of the international terminal gave way and crumbled on Sunday evening. Nobody was injured even though it was a large pane, around six feet high and five feet wide.

A senior AAI official said the pane was two-sided and outer part shattered. "As several panes have broken in recent months, we have asked consultants to conduct a study," he said.

Sources said AAI has not ruled out the possibility of sabotage. But AAI officials are divided on why the panes are breaking. They have floated several theories: from extreme differences in temperature inside and outside the terminals, to installation errors, faulty manufacture and sabotage.

Engineers involved in the construction of the terminals say it is normal for glass panes to shatter in a large building and the manufacturer had given them a huge quantity of panes in the event replacements were required. They estimate that one glass pane in 1,000 develops fractures.

Creative Group, which designed the buildings, studied the panes and ruled out installation flaws.

The terminals have more than 5,800 glass panes. "The number of fractures are well within the norms for buildings that have so many glass panes. One can expect one pane to break in a building with 1,000 panes, and 10 in a building with 10,000 panes," Saint Gobain Glass India managing director B Santhanam said.

"There could be various reasons for glass to develop cracks or shatter. Nickel sulfide in glass can expand and cause a pane to break," an engineer said, describing a phenomenon that the industry refers to as 'spontaneous glass breakage'.

Another theory is that the two-layered glass is exposed to high temperatures of more than 40oC on the outside while on the inside it is airconditioned and around 20oC. "This difference is temperature can cause glass to shatter," an official said.