It’s hot outside.
At 3:00 p.m. Tuesday the National Weather Service was reporting 87 degrees at Dulles Airport, 88 in Manassas and 90 in Leesburg.
That heat is affecting train schedules on VRE’s Fredericksburg line. Heat restrictions were imposed at 1:00 p.m. and that means slower trains.
According to VRE, trains begin their trips on time then heat-related delays accumulate over the course of the trip. So, the farther you go the longer the delay becomes. If your destination is Franconia/Springfield, you will likely not notice the two-minute delay. However, if you travel all the way to Spotsylvania the delay will be about 14 minutes.
What are “heat restrictions?”
Here’s how VRE’s website explains it:
Just as automobiles are sometimes requested to lower speeds for various road and weather conditions, trains are subject to similar restrictions. Heat restrictions are orders given to railroad engineers to reduce their speed over a given section of track.
Steel rails slowly expand and contract as temperatures rise and fall. Careful engineering measures are taken when rail is installed to account for rail expansion and contraction. The ties, rock ballast, and rail anchors, which hold the rail longitudinally, must be strong enough to keep the rail solidly in place instead of expanding or contracting. Under extreme heat, the rail, on rare occasions, will experience a “sun kink,” which causes the track to shift laterally causing a curve in the track.
When a “kink” or high tension is found in the track, the track is taken out of service, repaired, and then put back in service. That is why there are times that we are limited to one track during the summer as repairs are made.
Heavy rain may also be on the way
The National Weather Service expects a front to stall over the DC area Tuesday afternoon and evening. That could kick off thunderstorms over Fairfax County this evening. The forecast calls for 1 to 3 inches of rain and a Flash Flood Watch is in effect through the evening.