Why your trains run slower in heat
Amtrak and SEPTA slowed down their trains due to the extreme heat. Here's why.
If your Regional Rail train seemed pokier than usual Wednesday, blame the extreme heat gripping the Eastern Seaboard.
When the temperature tops 90 degrees, SEPTA imposes speed restrictions on all of its rail services.
Railroad tracks warp when baked in the sun. The overhead catenary wires that feed electricity to trains and trolleys sometimes sag on extra hot days.
“Traveling at higher speeds increases the chance of putting stress on the tracks and wires,” SEPTA spokesperson Andrew Busch said. The speed limit is cut by 5 to 10 mph, he said.
That can cause delays, but transit officials say the slower speeds help prevent a major breakdown that would knock a line out of service.
“Things are more prone to go wrong in excessive heat,” Busch said. For instance, sagging catenary wires can get snagged in the power equipment on top of commuter trains and trolleys, he said.
Heat also can affect switches and signals.
SEPTA deploys extra track inspectors to check for potential problems and has repairs crews on standby during heat waves, Busch said.
During the early part of the morning rush Wednesday, SEPTA issued advisories warning passengers of delays on some Regional Rail lines.
Amtrak throttled its trains to between 80 and 100 mph on the Northeast Corridor, which includes the Keystone line between Philadelphia and Harrisburg.
The intercity trains can reach 150 mph depending on location. Amtrak’s slowdown was leading to delays from 15 minutes to more than an hour.
Other forms of transportation feel the heat, too. The roadway on two sections of I-287 buckled Tuesday afternoon, requiring emergency repairs.
PATCO reported its trains were running on or close to schedule Wednesday afternoon. Like subways, PATCO trains are powered by an electrified third rail.