In 1951, the line received two, and later three, Class 87 multiple units.
The line received new 81-714/717 trains upon its opening in 1983.
In the year since it was created, the hot line has received more than 20,000 calls.
The line still exists today and has received over 2.5 million calls since its inception.
By the end of last week, newspaper surveys said, the hot lines had received 460,000 calls.
The city's 311 line received more than 175,000 calls.
It was at this time that the line received its current name.
As of 2010 the line has received a major upgrade.
On 10 November 1994, the line received automatic train control.
So far the hot line has received more than 6,300 calls.
