Muni Experts Troubleshoot Obsolete Control System to Keep Trains Running By Dan Howard Two weeks ago, we experienced yet another subway train control system failure caused by aging equipment. A failure like this is certain to impact everyone working on or riding Muni. What’s not widely known is that the ingenuity and skill of Muni’s technical staff makes the difference between these failures crippling the system for weeks or for just a few hours. On March 3, a control computer failed that governs part of the underground network of tracks and switches between Embarcadero Station and the surface, where most Muni Metro trains turn around. When our Signal Maintenance team is called to address a problem like this, all they start out knowing is that there are a bunch of “disturbed” switches and track segments. The Automatic Train Control System, or ATCS, constantly watches over the system’s track and switches, and reports them as “disturbed” when it gets a peculiar reading, or when a sys...