Ballast, concrete panels add to Silver Line extension problems

Two memos from Metro’s inspector general show concern over issues with concrete panels and the ballast for the Silver Line’s Phase 2.

The memos are management alerts from Metro Inspector General Geoffrey A. Cherrington that were sent to General Manager Paul Wiedefeld.

The memo, dated Aug. 16, said that a subcontractor used “unapproved aggregate” in the concrete of some 1,500 panels. This will result in moisture getting into the panels from the surface, which causes a reaction between the materials in the concrete that will ultimately cause damage.

Testing of samples of the concrete panels found that some 70% have sufficient sealant, 10% are “on the border” and 20% are “not sufficient and require additional sealant for the warranty to stand.”

Cherrington recommended that Metro not accept the panels without the warranty, saying that “20% failure rate suggested by these test results is of great concern.”

Another memo, issued by Cherrington’s office three days later on Aug. 19, said that tests identified that the ballast in the rail yard is contaminated by materials that are of “inappropriate size and consistency.”

The ballast are the rocks that support the tracks upon which railroad ties are laid; they also facilitate water drainage.

The inspector general’s office believes that there is “significant deficiency in the composition of the ballast that will impact safety and cost.” It is recommending a complete survey and testing of the entire ballast of the rail yard.

The Silver Line to Dulles International Airport and Loudoun County, Virginia, is scheduled to open on or about July 2020, at least if everything goes according to plan, Metropolitan Washington Airports Authority said.

The problems with the concrete panels and the ballast are the latest in a number of snags the construction has hit along the way, which include switches that do not line up, insulated joints that have failed testing and issues with rail ties.

WTOP’s Max Smith contributed to this report. 

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