The Gautrain control system has triple redundancy to prevent the loss of control should connectivity to each of the stations’ control room fail. Each control room can operate independently of the central control room until connectivity is re-established, says engineering and con- struction company Kentz South Africa electrical engineer Sheldon Frade.

If communication over the 2.5 Gb/s fibre network to the main operational control centre (OCC), in Midrand, is lost, each station’s control centre will issue commands directly to the local programmable logic controllers during a loss of communications or electricity. The systems will resynchronise when connectivity is restored. Stations continuously use geostationary satellites to synchronise under normal operating conditions.

The monitoring systems in the OCC and each control centre monitor in real-time the movement of trains, the train signalling system, electricity supply information, access points, security footage and passenger information, as well as other station and tunnel equipment, says Gautrain operator Bombela Operating Company control centre manager Cornelius Nortje.

The OCC and station con- trol centres use automation specialist Invensys’ Archestra supervisory control and data acquisition suite of systems and its Wonderware InTouch interface system to monitor and manage the 80 km Gautrain system, says Frade.

The Wonderware system provides displays for operators at the OCC that mirror the information received, track trains and stations and automatically generate work orders when defects or faults are detected. Operators can, thus, monitor the complex parameters and systems necessary to keep the trains running, he says.

“We also monitor the power supply and distribution, including the 11 kV and 25 kV connections to the Eskom grid at Rosebank and Midrand, as part of the station and tunnel management system, which includes five electricity sub- stations and our uninterrupted power supply systems,” says Nortje.

The OCC also monitors the 15.4 km of tunnels and can pinpoint the location of a potential fire or fault and instruct people to move to the safest part of the tunnel during an emergency. The tunnel safety system has enough water and space to ensure 1 500 people can safely survive a tunnel emergency.

Maintenance subsidiary Bombela Maintenance Com-pany manager Koos Venter manages the heart of the operations, which is the data centre, and notes that there is scope for additional equipment in the centre should the Gautrain be extended to the West Rand or the southern suburbs of Johannesburg.

The Gautrain system’s triple redundancy ensures that control is maintained even during disaster scenarios, emphasises Frade.

“The flexibility of the Archestra system enabled us to create an extra layer of redundancy, which saved significant costs and engineering time,” concludes Frade.

French public transport operator RATP Dévelopement, which is a main shareholder of the Bombela Operating Com-pany, was involved in the design, commissioning, testing and system acceptance stages and contributed to the system, which was also fine-tuned for operations.