Powering the streetcars, part 1: The dilemma
In 1962, Washington, D.C. closed the last of its streetcar lines. Today, the District is working to resurrect its streetcar system. A starter line is already under construction in Anacostia, and H Street and Benning Road, NE have rails in the ground in anticipation of a future line. One of the most significant obstacles to planning a new streetcar system is the question of how to power the vehicles.
Most streetcar systems use overhead catenary wires for power. However, a very old law prohibits wires of any kind in the L'Enfant City, generally bounded by the Potomac and Anacostia Rivers, Rock Creek, and Florida Avenue. The pre-1962 system had a network of vaults under the road. Wires ran in the road, and a device called a "plow" connected to the streetcar reached under the roadbed and contacted the wires. Streetcars switched back and forth between the in-ground system and overhead wires at the edges of the L'Enfant City. This system was prone to breakdowns and difficult to maintain. Also, once DC shut its system down, the specific technology ceased to exist.
Some systems do use similar systems today. Bordeaux, France, has an in-ground system manufactured by Alstom. Unfortunately, they, too, have had many maintenance issues. Any system that's not used widely and only made by one company is inevitably less reliable and more expensive than a more widespread system. Bordeaux also gets much less snow than Washington. Further, Alstom has insisted, at least in the past, that a city using its technology buy all of its vehicles and equipment from them, including the overhead wire portion, removing the opportunity for the city to negotiate for better prices.
Bombardier developed an alternative power systems, called PRIMOVE. It uses magnetic induction to convey power from an underground wire to a streetcar through the roadway without requiring an actual, physical connection. This is the same scientific concept behind electric toothbrushes. Magnetic induction is not very efficient, but it could work over short distances. This technology hasn't yet been deployed anywhere, and being the guinea pig for any new technology invariably means working through bugs, reliability problems, and inevitable cost overruns.
Paris is testing another alternative, Alstom's STEEM. This uses supercapacitors mounted on the vehicles, which charge when the train brakes and when vehicles are stopped in stations. These vehicles can switch back and forth between battery and overhead wires. However, Paris's trams don't run air conditioning, which is a must in muggy DC.
The bottom line: A new streetcar system will almost surely cost far more and break down more often if DDOT has to use a new technology throughout the L'Enfant City instead of the tried-and-true wires. Councilmember Tommy Wells' staff have been researching the legal issues around the ban. As he told us in a recent chat, they believe the DC Council could legally modify or overturn it. However, the National Capital Planning Commission, the federal board that oversees many aspects of planning in and around DC, strongly opposes wires. Even if Wells is right about the law, NCPC could push Congress to overturn it. Therefore, DC faces a much easier road if they can work out a deal with NCPC.
Next: Are wires really that bad?
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