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Tuesday, August 22, 2017

The Axis Invades Baltimore

Some of you may have heard that the Baltimore Metro was installing a new CBTC signaling system in conjunction with its new order of 78 Breda (now owned by Hitachi) railcars.  This might be surprising as such systems tend to only be economically viable when extremely high throughput over 20tph is required.  Baltimore's 6tph service is more than adequately serviced by a traditional block system, but I figured that once again some non-technical administrator was fooled by a signal vendor.  However this weekend I learned that the situation is far worse.  Not only has the Maryland MTA guppied up for CBTC, but they have also opted to adopt a German style axle counter system for backup train detection without any track circuits, even within interlockings.

The Baltimore metro was constructed back in 1983 with a fairly typical audio frequency cab signal system with 6 speed codes.  Apparently they have not very little investment in renewing the system and 30 years later most of the impedance bonds are end of life and getting unreliable so they see an axle counter system as a way to cut costs.  Breda is under the same umbrella as Ansaldo STS, the Italian signaling company that bought US&S and now both operate under Hitachi. This enabled Hitachi to offer both the cars and signal system as a $400 million package deal, and Baltimore found it hard to say no.

Unfortunately use of a German style signal system without positive train detection may result in problems when the German railway culture is not important.  The Baltimore Metro will be blind to broken rails, floods and random vehicles rolling onto the main line.  Track workers will no longer be able to clip in a track circuit shunt to protect themselves.  In Germany the government spends freely on rail maintenance and employees tend to obey orders without question.  In the lower cost United States, it is only a matter of time before this budget system proves deadly.

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