YOLO wrote:I am now noticing violent vibrations between EFC and McLean on the ground level tracks on the toll road, I wonder what changed.
I notice this many days on my ride to work out to Wiehle too; both EFC-McLean and Spring Hill-Wiehle have some sections which seem to produce very noticeable vibration. I've had it happen on both 7Ks and legacy cars, although it seems to predominantly occur around 40-50mph from my experience. The sections that it occurs over are a few hundred to a couple thousand feet in length.
WMATA seems to be aware of the issue, although I don't think they've figured out the cause yet. I was on a train a few weeks back along with an ERT group performing riding inspections between Wiehle and Spring Hill, and overnight on the 27th-28th a track crew performed a few riding inspections and then a lengthy track walk from McLean most of the way to EFC (to the N91 yard lead). They reported rough vibrations between N2 550 and N2 600 during that inspection.
I wonder if the cement ties have anything to do with it?