WMATA: Dulles Corridor Metrorail Project progress update e-mail 01 17 2017
DC to Dulles and Beyond: Metrorail on Track
Silver Line Progress Steady
Construction of Phase 2 of the Silver Line is moving steadily along, according to rail project officials.
In recent weeks, Capital Rail Constructors, the project's design-build contractor, has reported significant progress on the aerial guideways that will carry the tracks through Washington Dulles International Airport.
DCMP crews set the 495th girder out of 622 girders that comprise the aerial guideway for Phase 2 of the Silver Line over the eastbound Dulles Greenway.
(Photo by Jennifer Thomas Alcott/Capital Rail Contructors)
According to John Kearney, project manager/construction manager of the rail project for the Metropolitan Washington Airports Authority which is building the Silver line, the girders to support the future rail station at the airport are being put in along with station framing precast. And only 47 of the girders to support the aerial tracks are still to be made. Construction of the future Ashburn Station, at the end of the Phase 2 alignment, has ramped up. For example, excavations have been completed and a large tower crane, like those now in place along Dulles Toll Road at the Reston and Herndon stations, has been erected, creating a visual landmark for drivers along the Dulles Greenway, Kearney said. In addition, a huge straddle bent required to carry the rail line across wide stretches where central columns cannot be placed has been installed over the eastbound lanes of the Greenway and the first girders set.
Along both the aerial and ground level stretches of Phase 2, tracks are being laid.
In February, girder erection crews will move to the east side of the future Dulles Airport Station to begin setting girders. In addition, Traction Power Substation 13, one of many facilities required to power the rail line along the alignment, is expected to be delivered and erected just south of the new Herndon Station in early February.
Gaining Traction: Silver Line Phase 2 Moves Forward with Anticipated Track Work
Dulles Corridor Metrorail Project crews recently marked a big day for Phase 2 of Metro's Silver Line when they began installing track along sections of the Phase 2 alignment.
"Beginning the at-grade track work is a very important milestone," said Director of Project Engineering Stephen Barna. "It signifies the completion of all below-grade utility work and trackway walls required to place ballast stone, ties and rails. It is an exciting time for the project."
Two kinds of track are needed for the project: one type for the at-grade sections and another for the aerial guideway through Dulles International Airport.
Approximately 8 miles of ballasted track will be used to complete the at-grade (ground level) sections, while direct fixation track will be used for the remaining 3.5 miles of aerial track, said Nikolas Hunter, the track project manager with Capital Rail Constructors, the contractor MWAA tasked with building the rail line.
Construction of ballasted track along Dulles International Airport Access Highway
during Phase 1 construction.
(Photo by Stephen Barna/Dulles Corridor Metrorail Project)
Dulles Airport Station is the only Phase 2 station along the aerial guideway; Reston Town Center, Herndon, Innovation Center, Loudoun Gateway and Ashburn are all ground level stations accessed by pedestrian walkways to be constructed over the Dulles Toll Road, Dulles International Airport Access Highway and Dulles Greenway.
Nearly 1,400 workers support the project which extends the Silver Line from the Wiehle-Reston East Station westward through Dulles International Airport and to Ashburn. All electrical power, train control and communication duct banks, as well as track storm drain pipes and structures, must be installed prior to track construction.
According to Hunter, fifty workers will be constructing the ballasted tracks, a quicker process than direct fixation track installation.
To construct ballasted track, workers first must bring the track road bed to the correct elevation before placing and compacting finely crushed stone along the at-grade sections of the alignment to create the subballast, Barna explained. Then, a 12-inch layer of larger crushed stone is placed to create the ballast to support the precast concrete ties that are set in place next. Sections of rail are then fastened to the concrete ties with steel plates and rail clips. Finally, a specialized machine places additional crushed rock between the ties and corrects the final alignment and grade.
Thirty workers are installing the direct fixation track along AutoPilot Drive at the Airport, Hunter said. That process requires the use of concrete plinths, which are cast-in-place concrete structures that support the rail. Ninety-foot sections of rail are delivered by truck and then welded together into 'sticks' of nearly 1,000-foot lengths and fasted to the concrete plinths with steel plates and bolts, Barna said. The final line and grade work for direct fixation track is done by hand.
Phase 2 workers install direct fixation track along aerial guideway at Dulles Airport.
(Photo by Nikolas Hunter/Capital Rail Constructors)
"Our whole purpose is to build a transit railroad for the public's use," Barna said. "After nearly four years of very difficult design and construction work, we are beginning the challenging phase of installing the track and all of the systems that will allow us to begin testing with rail cars in 2018."
Phase 1 direct fixation track and switch construction on Route 7 aerial guideway
west of the Springhill Station.
(Photo by Stephen Barna/Dulles Corridor Metrorail Project)
The Metropolitan Washington Airports Authority, the entity tasked with managing the project, will turn it over to the Washington Metropolitan Area Transit Authority upon completion, which will operate it as part of Washington's regional rail system.
Sunrise Valley Drive Improvement Work Begins
As Construction of Phase 2 of the Silver Line continues, work along Sunrise Valley Drive will impact commuters.
In early January, Dulles Rail construction crews began preliminary work, including clearing and grading on Sunrise Valley to make way for improvements to access the pavilion and parking for the new station being built in the median of the Dulles Airport Access Highway/Dulles Toll Road.
Initial activities include installing erosion and sediment controls, clearing trees along westbound Sunrise Valley Drive and near the existing parking garage as well as utility relocations, widening of the westbound lanes of Sunrise Valley Drive and construction of a new West Entrance Road to the existing parking garage.
Additional construction activities will follow, continuing through 2018.
The work will require:
- Lane closures on Sunrise Valley Drive will occur between 9:30 a.m. and 3 p.m.
- Closure of the sidewalk on the north (westbound) side of Sunrise Valley Drive between the Arboretum and Thunder Chase Drive. A temporary crosswalk at the intersection of Milburn Lane will be installed for safety, and pedestrians will be redirected to the sidewalk on the south (eastbound) side.
- Narrowing of entrances to facilities along Sunrise Valley Drive for utility work.
Further updates will be provided as the work progresses. Drivers should exercise caution, pay attention to barriers and signage, and obey all flagger instructions.
Letters detailing the work to be done were sent to residents of the area in early January.
###
This newsletter confirms the assumption I made about the track laying on the elevated along Autopilot Drive during my observation in the post above.
Link to PDF version at
Dulles Corridor Metrorail Project web site.