Metropolitan Atlanta Rapid Transit Authority

To meet the challenges of a highly specialized application, Quester Tangent redesigned products to integrate a Fault Identification and Monitoring System that substantially enhanced overall operational efficiency and data management capability and supported superior train-to-wayside communication.

Project overview

Project name: MARTA Train Control and SCADA System (“TCSS”) upgrade

Client: Alstom

Type of project: Retrofit

Vehicle application: Metro

Number of vehicles: 318

No. of QT units sold:

  • 318 Fault Monitoring Units (FMU) including Train Network Controller (TNC)
  • 318 Fault Display Units (FDU)
  • 318 Network switches
  • 954 Cable harnesses
  • 2 Bench Test Equipment (BTE)
  • 4 Training Aids

Contract awarded: 2011

In-service date: 2015


  • Train Control and Monitoring System (TCMS)

Location: Atlanta, Georgia

A tailored monitoring system that substantially enhances overall communication

Quester Tangent supplied a Fault Identification and Monitoring System (FIMS) to replace legacy equipment during the midlife refit of Metropolitan Atlanta Rapid Transit Authority’s CQ310, CQ311, and CQ312 series of married pair cars. The new system provided the functionality of existing equipment, plus train-to-wayside communication.

Superior flexibility and functionality

The project is a testament to the adaptability of Quester Tangent’s products to unique vehicle applications. The new Fault Identification and Monitoring System components were delivered to fit within the constricted spaces of vehicle equipment lockers and cab consoles. Quester Tangent’s Train Network Controller was redesigned for inclusion within the Fault Monitoring Unit enclosure, and the size of the Fault Monitoring Unit was reduced to fit sideways in the equipment locker.

Real-time fleet readiness

The retrofit project adds two-way communication capability between the wayside and the train at each station stop and supports plans to include continuous Wi-Fi coverage between stops. The operations center can dynamically control fleet spacing while trains are in service to adjust each train’s schedule.

Restrictions and other information, complete with diagrams, can be sent to the Fault Display Unit (FDU) while trains are underway to provide clear instructions to the train operator, with an acknowledgement of receipt returned to the operations center.

The Fault Identification and Monitoring System performs calculations, based on both on-train data and information from the wayside, that reports train readiness to the operator and to the operations centre. The calculation results are displayed on the Fault Display Unit and indicate train status, including whether the train is healthy or must be taken out of service at the end of the line or immediately.

For easy maintenance scheduling, complete train status and logs can be requested at the end of each run and the end of the service day without requiring physical access to the train cars.

The Fault Monitoring Unit monitors discrete inputs to determine car ID and monitors and controls the car sequencing trainline to determine vehicle sequence within the consist.

Easy access to operational data

During initial design discussions, MARTA witnessed the vast improvement in driver situational awareness at Massachusetts Bay Transportation Authority (MBTA) after their fleet upgrade to the more powerful Quester Tangent interactive display. As a result, MARTA authorized a change order for Quester Tangent to supply Fault Display Units for each car.

The new 12-inch touchscreen FDU features excellent daylight visibility, gloved-hand operation, and an intuitive user interface.

Simplified maintenance

Quester Tangent also supplied fully automated Bench Test Equipment and desktop touchscreen training units, providing MARTA with easy internal maintenance and training support for their new Quester Tangent equipment.

This flexible solution enhanced data management, system integration, operational efficiency, and wayside functionality of MARTA’s metro fleet.