199408 – Wallace – Inner City Quadruplication Project – An Overview of the Project and Current Status

The hub of the Brisbane Suburban network, Central Station, is constrained in capacity due to the two-track tunnels on either side leading to Roma Street and Brunswick Street. Currently, this is limited for technical reasons to 25 trains per hour in both directions (up and down). With the increase in traffic, including the planned Gold Coast traffic, the system as it presently stands will not be able to cope. This has resulted in the upgrade project called inner City Quadruplication (ICQ).

The “Inner City” is defined as extending from Bowen Hills to Roma Street together with the connections to Mayne Yard, Northgate, South Brisbane, Milton and the Normanby. Essentially, the project will provide four tracks from Bowen Hills to Roma Street. This includes construction of new tunnels on either side of Central, new platforms at Bowen Hills, Central and Roma Street and civil works, trackwork, overhead, signals and communications systems to suit.

Construction has commenced with the most obvious element being the two single track tunnels between Central and Brunswick Street with breakthrough being achieved on the first tunnel in March 1993 and the second in June 1993 and the Roma Street Tunnels which had breakthrough in June/July 1994. The total project is currently being planned for completion in mid 1996. The new Long Distance Platform will be opened in mid 1995.

The total cost of construction is estimated to be $141.8m in outlay dollars.

When the project is complete, the total system will be capable of handling 45 trains per hour in both directions which will be sufficient capacity well into the next century.