Looking down on WMATA Metrorail Red Line and CSX/MARC/Amtrak tracks in Silver Spring. Image by Adam Fagen licensed under Creative Commons.

Recently, a reader posed us this question:

Hi folks- I've got this curiosity that I wanted to run by you and see if anyone could shed light on it. I recently moved to Takoma, from Capitol Hill. In this part of the Red Line (between Brookland-CUA and Silver Spring), Metro shares a right-of-way with CSX's Metropolitan Subdivision, formerly B&O's Metropolitan Branch. But the curious thing is that the CSX tracks straddle the Metro tracks. If CSX (or Amtrak or MARC) trains are operating normally, it means the right two tracks are northbound and the left ones are southbound. This is the only place in the Metro system where the tracks are laid out like this, as far as I can tell. Everywhere else — the other end of the Red Line in Montgomery County, the Orange Line in DC/PG County, the Blue Line in Alexandria and Fairfax County — both Metro tracks are on one side, and both (or all) Class I tracks are on the other side. Why do you think this is? I have a few theories: - This is the way Metro prefers it, but in all other parts of the system, the Class I railroad wanted to be able to keep operating during construction. In this part of the Red Line, Metro had to rip up the Class I tracks. - The B&O (or whatever successor was operating it at the time) needed to access customers on both sides of the tracks. If the rights of way were side-by-side, B&O would have to build bridges or flyovers (never great for diesel trains) to get to the other sides. - Somebody was really into aesthetics and found a symmetrical layout pleasing to the eye. Whatever the case, it looks like CSX can't switch trains between tracks for the entire length of the Red Line right-of-way sharing. One fact I found in my research: WMATA owns the land under the entire right-of-way. I'm not sure if that's the case in other places where WMATA is parallel to Class I tracks. Another thing to consider is the possibility that in other places in the system, the Class I railroad may have already owned a right-of-way wide enough to accommodate Metro tracks. As far as I can tell, in the Metropolitan Subdivision, the right-of-way was only wide enough for two tracks. Timothy

Good observation! First, this is *not* the only location in the Metro system where this happens. The Orange Line is straddled by freight railroad tracks from Minnesota Avenue to just north of Cheverly.

In both cases, this was done, as noted in the hypotheticals, to preserve access to customers on either side of the right of way. The Metropolitan Branch runs through an industrial corridor that was built up around the railroad, and those industries relied on local freight switching to get their raw materials and ship their products. Building the Red Line on either the east or west sides of the Metropolitan Branch would have cut off the industries on that side (the idea that flyovers would've been built is unlikely, except for a very major industry). And in the case of a flyover, it woudn't have been B&O (the predecessor to CSX) flying over, it would've been Metro going up and over the spur, which is the case at one location along the Orange Line near Landover (immediately south of the Route 410 overcrossing).

The reason that we don't see more of this is that the lack of separation and a crash wall leaves the Metro tracks susceptible to intrusion by derailed railroad equipment. In later Metro construction (both the Red Line eastern section and the Orange Line eastern section opened in 1978), not only are the freight tracks on one side, but they're also farther away from the Metro tracks, and are sometimes accompanied by a concrete wall.

The other reason it's less of an issue now is that the industry has changed. The freight railroads are less focused on local customers and more on long-haul trains that run between cities. Additionally, many of the industries along the Metropolitan Branch have closed or stopped using their freight sidings. So there's simply less demand to have access on both sides of the corridor.

Finally, the fact that there are no interlockings between the two CSX tracks between Rhode Island Avenue and Georgetown Junction (Silver Spring/16th Street) is not at all abnormal or a strain on CSX. Crossovers along mainline railroads are much farther apart than they are on Metro. Between the interlocking north of Metropolitan Grove and the interlocking just north of the Shady Grove Yard, it's 4.6 miles. The next interlocking is 4.9 miles south, at Twinbrook Metro, and was added recently (paid for by Maryland) to improve MARC reliability. From the crossover at Twinbrook, the next interlocking south is 5.78 miles away at Georgetown Junction (16th Street). The section with Metro inserted between the CSX tracks stretches until the next CSX interlocking, at Rhode Island Avenue. That distance is a comparable 6.1 miles.

I'll also point out that the National Transportation Safety Board (NTSB) hates this arrangement. Back in the late 1970s or early 1980s, there were three closely-spaced incidents in which trains on the B&O caused intrusion into the Red Line right of way. In one case, vandals drove a backhoe onto the freight tracks one night, in the vicinity of Silver Spring Metro. A freight train struck the backhoe and dragged it. While the train did not derail, the incident sprayed debris onto WMATA trains parked in the Silver Spring tail tracks and could have caused injury to WMATA personnel or patrons, had the trains been occupied. The other two incidents were derailments in which freight cars tore through the WMATA perimeter fence and obstructed the Metro tracks.

In neither of those cases were any Metro trains struck or passengers injured. However, had a train been passing, the damage could have been catastrophic, because Metro trains, especially the 1000-series, were not built to withstand collision with railroad equipment (or as we discovered, other Metro equipment). NTSB's recommendation to WMATA was that a holdout rule be created such that whenever a Metropolitan Branch train was transiting the corridor in either direction that all Red Line trains be held prior to the shared corridor. Both WMATA and B&O/CSX found that recommendation to be untenable and did not implement it.

Even before the incidents, WMATA had installed an Intrusion Detection Warning System (IDWS) that is posted along the chain link perimeter fence (this is also the case on the other areas adjacent to freight tracks, like the Green and Blue Lines). The cables are very easy to break, so if anything tears through the fence, or even hits it particularly hard, the cable will detach. The resulting alarm should automatically stop all Metro trains in the vicinity (by sending zero-speed commands through ATP) in addition to alerting the Rail Operations Control Center.

Do you have a question? We regularly post a question to the Greater Greater Washington contributors and post appropriate parts of the discussion. You can suggest questions by emailing ask@ggwash.org. Questions about factual topics are most likely to be chosen.