Monday, December 2, 2019

1904 Long Bridge over Potomoc River at Washington, DC

(Bridge HunterHistoric BridgesSatellite)

The B&O first used a bridge at this crossing. But a Pennsy subsididary, Baltimore & Potomac, won control of it in the 1870s. CSX now owns it and Amtrak and Virginia Railway Express (commuter trains) also use it. [AmtrakDCNRHS]

DDOT via ggwash
dkeg via Amtrak

DDOT via Executive Summary via DIES via LongBridgeProject
This bridge was rehabilitated in 1942-43 by replacing the truss spans with girder spans except for the swing truss.
National Photo Company collection, Library of Congress via Bridge Hunter
Passenger train crossing Potomac [Long Bridge] July 2, 1925
When I-395 was built upstream, it blocked the swing span from opening. So it was last used March 3, 1969. I noticed that the Charles R. Fenwick Bridge is now even closer. It is for Metrorail's Yellow Line.

The two tracks on this bridge are at capacity. Not only would CSX, Amtrak and VRE like to add more trains, NS and MARC would also like to run trains between DC and Virginia.
Image by DDOT
CSX rehabilitated this bridge in 2016. So the proposed solution is to build another two-track bridge just upstream of this one. And also build a trail (pedestrian and bike) bridge upstream of that one. The new RR bridge is expected to be a steel girder bridge and cost $1.3 to $1.6 billion and take five years to build. The cost for the trail bridge is expected to be significantly lower.
Image by DDOT
The trail bridge is mitigation. While trying to figure out what problems the trail bridge is mitigating, I think I figured out why this bridge would cost over a billion dollars. They have to expand the right-of-way on the DC side from two tracks to four tracks. This requires replacing all of the overpasses between the river and Maryland Avenue. But then the four tracks funnel down to three tracks between there and E St SW+2nd St SW where the passenger and freight lines separate. There does appear to be four tracks on the Virginia side. The red dots in the following diagram show the replacement overpasses that have to be built as part of this project.
Project Study Area
The trail bridge mitigates "direct property impacts to Long Bridge Park, GWMP, and East Potomac Park" [Executive Summary via DEIS]

The estimated cost has already risen to $1.9 billion. [WashingtonPost] Hopefully, that would be because the cost now includes the cost of the trail bridge.

No comments:

Post a Comment