QUEENSLAND TRANSPORT- INB3 ALLIANCE BUSWAY
DESCRIPTION
Queensland Transport and the Brisbane City Council have developed strategies to reduce traffic congestion – a vital component being the construction of a busway network, which will reach across Brisbane. The second busway in the network, the Inner Northern Busway (INB), stretches 4.7km, and links the Brisbane CBD to the Royal Brisbane Hospital.
Consisting of 10 sections, and constructed in stages, section 3 of the INB, involves a two-lane busway between Roma Street and Normanby Fiveways. It includes an underground tunnel of approximately 80m in length and runs beneath the Roma Street railway line. Constructed under an Alliance contract between Thiess, Sinclair Knight Merz and Queensland Transport. The Electrical Contractors for the project, O’Donnell Griffin contracted MPA Engineering to design, program and commission the PLC system, which controls stormwater pumps and lighting, and monitors environmental conditions in the tunnel such as air quality, as well as the power supply to the tunnel. Engineering staff from MPA worked in conjunction with staff from Sinclair Knight Merz and O’Donnell Griffin to develop a 24 hour-a-day continuous control system for the tunnel.
TECHNICAL SPECIFICATIONS
The following environmental conditions and power supply factors are monitored using an Allen-Bradley SLC5/05 PLC:
Stormwater – the stormwater pump station consists of three pumps – duty, standby and storm. The PLC automatically controls each pump via a series of processes that are determined according to the water level detected.
Lighting – there are five levels of lighting within the tunnel, which are designed to maintain the level of lighting to be equivalent to the natural light outside the tunnel. The PLC controls the lighting levels via photometer readings, and adjusts the lighting when the reading falls below a predetermined level, providing bus and emergency vehicle drivers with uninterrupted visibility on entering the tunnel.
