Built at a cost of S$4.6 billion, the North East Line is Asia's first fully automated underground heavy rail System. Construction work started in 1997 and completed five years later at the end of 2002. Its completion marked the LTA's commitment towards building a comprehensive rail network for a connected Singapore. It's the second major MRT line to be built, since the completion of the main MRT network in 1990.
Affectionately known as NEL, this 20-km line links communities living in the North-east of the island, providing service from Punggol in the North to Harbour Front in the South. All sixteen stations, namely Punggol, Senkang, Buangkok, Hougang, Kovan, Serangoon, Woodleigh, Potong Pasir, Boon Keng, Farrer Park, Little India, Dhoby Ghaut, Clarke Quay, China Town, Outram Park and Harbour Front are underground.
CNA designed and implemented the Local Sequential Controller (LSC) System to control the Tunnel Ventilation and Environmental Control Systems. The Local Sequential Controllers design was based on a dual-redundant PLC system with two Local Control Panels and one Programming and Maintenance Terminal. The contract required the PLC control system to be developed in accordance with the standard RIA 23.
System Description
The Tunnel Ventilation System provides an acceptable environment within the tunnel for the operation of trains under normal / congested operation conditions and effective means of controlling smoke flow during emergency condition. Tunnel ventilation shafts and fan system are located at both ends of the tunnel for each of the stations to ensure acceptable operational conditions for the equipment and comfort to the operators.
The Environmental Control System provided by CNA is to provide a comfortable and safe environment for commuters, station personnel and equipment in the station. It serves to provide smoke control during fire emergency and interfaces with the Fire Protection System to shutdown appropriate equipment and operation of Smoke Purge System.
The Smoke Purge System is included as part of Environmental Control System. The system consists of a smoke control panel, smoke purging fans and supply air fans. The smoke purging fans are provided for the station public areas and service corridors at ancillary area. Supply air fans are provided for the smoke stop lobbies and emergency / firemen staircases.
The control system is a three-level intelligent system comprising the Central Computer located at the Operations Command Center (OCC), the Remote Terminal Unit (RTU) and the Local Sequential Controller (LSC) located in the main and sub ECS rooms of every MRT station.
The Central Computer located in the Operations Command Center (OCC) is responsible for monitoring and controlling the equipment at all MRT stations of the North East Line.
The Remote Terminal Unit (RTU) at the station is responsible for the handling of the communication between the OCC and the Local Sequential Controller (LSC).
 |
High-speed robust PLCs were installed throughout the campus to provide round-the-clock monitoring and control of security and alarming functions, indoor comfort and energy conservation. PLCs are linked by high-speed fibre optic network from building to building within the campus.
The integrated solution includes an Information Kiosk System which provides facilities like directional aids to campus guests and bulletins on campus activities.
Local Sequential Controller and Local Control Panel
|
|
