Tests on Metro’s Silver Line show that while a new tunnel in Tysons Corner has settled by about an inch, there is enough room for a train to fit, despite concerns from watchdogs and workers involved in the building of the first phase of the $5.6 billion rail line.
A report by two contractors working for Bechtel found that despite the settling in a segment of the tunnel that runs from Route 123 to Route 7, there is the necessary clearance for a Metro train to pass. Bechtel is building the first phase of the rail line, which runs from East Falls Church to Wiehle Avenue.
The report, completed March 6, also said that no additional settling has occurred since the problem was first noted last year.
The findings will be reviewed in coming weeks by Metro and engineers at the Metropolitan Washington Airports Authority, which is overseeing the construction.
“At this point in time, right now, it looks all right,” said Pat Nowakowski, chief construction manger on the Silver Line for MWAA. “It was built in accordance with the requirements.”
The first phase of the rail line, one of the largest public transportation projects underway in the country, is expected to open to riders this year.
The settlement problem came to light in February 2012, Nowakowski said, when Bechtel engineers “noticed movement in the floor of the tunnel” when they were back-filling part of the tunnel with dirt.
But in recent months, new concerns surfaced about movement in the tunnel, and the airports authority decided to expedite planned testing. Bechtel hired two firms to measure clearances in the tunnel. The testing was done last month.
There have been other hiccups on the Silver Line.
MWAA ran specially outfitted Metro test trains along the Silver Line and through the tunnel in December, and the train struck several items along the route, including a handrail and boxes containing emergency cutoff switches. Nowakowski said the handrail and boxes were “installed in the wrong place.”
Nowakowski said the test cars “didn’t hit the roof of the tunnel” and “did not hit the sides of the tunnel.”
A second test train that was run two weeks ago in another section also hit several items.
Metro General Manager Richard Sarles said Thursday Metro would “not accept” the Silver Line until “we’re satisfied it is ready for operation.”