A system-wide computer problem stalled four South Shore Line trains at their stations between 20 and 45 minutes Tuesday afternoon.
The issue was with Positive Train Control, the computer-operated system that’s a backup for train operators.
When the PTC system goes down, South Shore Line President Michael Noland said, a train operator can’t initialize — log onto the system — before the train has started its service from Chicago, Gary, Michigan City or South Bend.
“If a train has not started service that day, that train does not move,” Noland said of a PTC outage. “If a train has initialized, it can return to its home base under reduced speed conditions.”
All railroads have been required by the Federal Railroad Administration to install PTC in case a train operator doesn’t, or can’t, obey the signals that control train operations.
Noland said the South Shore Line has been updating its PTC system because of the new infrastructure – the tracks, bridges and stations built for the Double Track project between Michigan City and Gary – that has been added to the railroad. PTC has to know where everything on the railroad is.
“As we were updating the system, we hit a snag,” Noland said.
He said a similar problem occurred a couple of weeks ago when the PTC system on Metra, the Chicago-area commuter rail system, went down for a while. Because the South Shore Line uses Metra tracks and stations in Chicago, it also was affected.
“I’d like to say it will never happen again,” Noland said. “But any railroad that tells you that is making it up. It’s a computer system.”
Tim Zorn is a freelance reporter for the Post-Tribune.