Silver Line construction by Stephen Barna licensed under Creative Commons.

Over 11% of the concrete panels installed at five of the six new stations on the Silver Line extension to Dulles have cracks in them, according to a new report published by the Metro Office of Inspector General. The OIG wants the panels replaced, but laid out nine steps which must happen before the WMATA Board accepts responsibility for and opens the new extension.

Construction on the Silver Line Phase 2 began in 2014, and aims to extend the line west from the current terminal, Wiehle-Reston East, to Dulles Airport and Ashburn. Metro at this point is hoping to open the line in July 2021, but that date is still uncertain.

A whistleblower complaint in 2016 alleged that one of the concrete suppliers on the Silver Line, Universal Concrete Products (UCP), failed to perform quality control checks and passed off deficient concrete panels to Capital Rail Constructors (CRC), the group building the Silver Line Phase 2 project.

Metro’s OIG initiated an external audit in January of 2020 and hired a contractor, DCE, to identify how many panels have cracks and how big those cracks are. The OIG’s office later hired Structural Services, Inc. (SSI) to evaluate the cracking issues further. Cracks could impact the structural integrity of the panels and potentially result in a more serious safety issue in the future.

Image from SSI report.

Of the 1,600 concrete panels installed on five of the six new stations (this type of panel wasn’t installed at the Dulles Airport station), the OIG’s contractors found 342 cracks in 184 panels. SSI, the contractor, says 145 of those panels have cracks larger than 0.005 inches, which CRC is contractually obligated to fix.

“These panels must be repaired prior to acceptance by WMATA,” states the Metro OIG in its report.

The distribution of the cracked panels is fairly even, affecting all five stations inspected - Ashburn, Loudoun Gateway, Innovation Center, Herndon, and Reston Town Center - about 10% at each.

The Metro OIG consultant noted in its report that a number of precast concrete panels were replaced during Silver Line Phase II construction, before the consultant was brought onboard. At the Reston station, for instance, the OIG consultant report notes 32 panels were replaced earlier on, and they inspected the remaining 342. At the Ashburn station, 33 panels were replaced earlier in construction.

UCP, the panel manufacturer, has suggested that WMATA can use a sealing solution and apply it on the concrete panels every 10 years or so, which they believe would mitigate the cracking problem. Metro’s OIG office and its contractor (SSI) say that sealant would need to be reapplied every 5 to 7 years, and that four coats would need to be used instead of the two that UCP suggested, which would increase maintenance costs. The OIG calls the periodic re-sealing “not a perfect solution,” but says it would be “sufficient” if done properly.

The OIG previously suggested the cracking might require inspections as often as every three months, and inspections could impact rail service and cause trains to be delayed with single-tracking to give inspectors access. The OIG’s contractor spent about three days at each station inspecting panels and the OIG says follow-on inspections should be just as thorough, so train service would potentially be impacted for numerous weekends each year.

Minor additional cracking was found on some panels in the new rail yard being built next to Dulles Airport, but the OIG’s contractor says those are “of no structural consequence.”

Image from WMATA OIG.

Metro can proceed, if it wants, under these conditions

Metro’s OIG says its recommendation is for Metro to instruct that all the concrete panels be replaced. “Based on the information known today,” the OIG report says, “WMATA [should] not accept the application of the silane solution, or any other measures short of complete replacement…”

If Metro doesn’t require that all the panels be replaced, the OIG laid out a list of nine things the agency needs to do or ensure before taking responsibility of the line. Among the OIG’s recommendations are obtaining a list of detailed documentation from MWAA, CRC, and UCP, ensuring that all cracks over 0.005 inches in size are repaired (and documented, so Metro knows what that repair was), and that MWAA and/or CRC put more money than earlier estimated into an escrow account which Metro would be able to use for future maintenance needs.

If Metro accepts the line as-is, the OIG says inspections should begin a year after acceptance. After that, inspections should occur every three to five years, according to SSI, and the OIG says sealant will need to be reapplied every five to seven years, “provided proper inspections are done periodically.”

All cracks greater than 0.005” must be repaired before Metro accepts the line, as well. The OIG report cites the technical specifications of the Silver Line Phase 2 project which notes that CRC is already required to do this.

The cost of reapplying sealant to the panels every five to seven years is greater than what CRC had estimated and presented to MWAA/WMAA. Per the OIG, “The initial proposal by…CRC…are based on the cost of the original sealer application of two coats of product. Since testing by EVONIK has shown that four coats of Protectosil® CIT are required to protect reinforcing at locations where there are no cracks, it would appear to SSI that the use of the original cost as a basis for calculations is flawed.”

A crack identified at the Ashburn station by OIG contractor DeSimone. Image via Metro OIG.

CRC had calculated costs based on just two coats of the sealer. The calculations also did “not appear to anticipate the cost of regular visual inspections or identify and remediate panels that have begun to corrode,” which would increase Metro’s costs. The OIG’s recommendations suggest more money needs to be set aside by CRC/MWAA to allow for future inspections and repair - that is, if Metro accepts the line as-is.

Earlier quality control checks failed

The OIG report and its contracted SSI identify several areas where quality control checks failed on the project by UCP, CRC, and MWAA.

“…UCP failed to consistently manufacture these precast concrete elements in accordance with the project’s required industry standard quality control practices and specifications,” says SSI in its report to Metro’s OIG. “The deficiencies that have been identified are individually, and collectively, known to be detrimental to the service life (durability) of precast concrete, particularly given the conditions of exposure to which they will be subjected.”

After initial concerns with the concrete produced by UCP were raised, CRC hired a quality assurance engineer and placed them on-site at the factory. But according to SSI, that didn’t help: “The increased scrutiny provided by one additional full-time QA person at the job site failed to reduce the frequency of [Non-Conformance Reports] or to impact in any significant way the types of fabrication drawing/production errors that were experienced prior to that date.”

SSI’s report to the Metro OIG also notes that UCP had no checks in place to ensure the fabrication drawings they were given were “without error.” This may have contributed to differences in the expected vs actual product creation from the factory and “suggest that that part of the checklist did not receive proper scrutiny.”

In conclusion, SSI reported to the OIG that “The measures taken by UCP, CRC, and MWAA to improve the quality of the precast panels fabricated by UCP after February 23, 2017 were generally ineffective.”

MWAA, in charge of building the new stations, still needs to shepherd construction of the new stations through to completion, at which point they’ll be able to present it to Metro for acceptance.

Metro, for its part, will need to negotiate a resolution of the concrete issue with MWAA and CRC which it feels comfortable with. The Metrorail Safety Oversight Commission, whose permission is needed in order to run trains with passengers onboard the new line, has made it clear that they too need to be satisfied with the resolution.

And for riders wanting to take that trip on a train to Dulles Airport? It may be a while longer.

Stephen Repetski is a Virginia native and has lived in the Fairfax area for over 20 years. He has a BS in Applied Networking and Systems Administration from Rochester Institute of Technology and works in Information Technology. Learning about, discussing, and analyzing transit (especially planes and trains) is a hobby he enjoys.