J.F. White was contracted to provide all the material and equipment required for the replacement of the existing “Haymarket North” signal system. Each instrument house has a geographically designated area of track to monitor and, in an emergency, to control locally. Each house is also connected via fiber optic cable (in innerduct) to the control tower at Wellington Circle in Medford and to the OCC on High Street, Boston. The interconnecting signal fiber reports the real-time speed and position of all trains in its area, plus other functions such as track switch position, signal indications and trip-stop status. A parallel communications fiber reports the status of all station conditions to OCC, including fire and/or smoke alarms, intrusion alarms, and elevator/escalator status. All vital reporting systems have dual supply energy plus battery power back-up.
The application of the new signal control system will be transparent to the “T” ridership. Installation, testing and final cutover will be completed during non-revenue time periods.