Chennai Metro commuters have had inconveniences in the past due to technical glitches. For a change, a glitch at one of the ticket vending machines at the Chennai Central Metro station gave many travellers an unexpected windfall for six months.

It turned out that if they had recharged their travel card for ₹500, they ended up getting a bonus of another ₹1,000 on their card.

In every station, a passenger can recharge the travel card — either through a ticket vending machine or head straight to the counter where an operator will recharge the card using a machine.

Many passengers, who recharged at the counter in the Central station, got excess money credited to their card, sources said.

Confused lot

For six months, the Metro officials were confused as accounts were not tallying at the end of the day as they used to fall short by a few thousand rupees.

“We were short [of a few thousand rupees] every now and then but were unable to spot the reason. Recently, one of the operators found the error in the ticket vending machine, which was immediately rectified,” said an official.

During the top-up of the travel card at the ticket counters, the process failed due to communication error or damaged chip inside the card at times. When this happened, there would be a pop up on the computer screen wherein the operator had to choose ‘Retry’ or ‘Cancel’ option, officials said.

“If the operator chooses ‘Retry’ option, then the card is properly re-written. Instead, if he/she selects ‘Cancel’, the process is cancelled. It means, though the money is added, it won’t show up correctly. So the operator retries the top-up process and hence he will inadvertently add twice the value,” an official explained.

Now, the officials have got the contractor to clean it up. The lucky commuters never complained though. They just walked home, smiling.