Drill and blast excavation commenced at Bowen Hills, construction of cut and cover structure at Toombul (Kalinga Park) commences March 2009 - First roadheader commenced tunnelling at Truro Street site (mid tunnel point) in Windsor April 2009 - Roadheader tunnelling commenced at Federation Street site in Bowen Hills May 2009 - 24-hour tunnelling operations commence across the project June 2009 - Roadheader tunnelling commences in Kedron November 2009 - First Tunnel boring machine (TBM) arrives from Germany for assembly March 2010 - Completion of both cut and cover structure and Tunnel Boring Machine (TBM) launch box at Toombul, of tunnels were already dug and 13 roadheader machines (each 18.2 m in diameter and weigh ) in use on tunnels. In the months that followed this rose to 16 roadheader machines. 18 June 2010 - First mined tunnel breakthrough between Bowen Hills and Lutwyche. Transport Minister Rachael Nolan witnessed the occasion. Mid 2010 - First TBM commences tunnelling from Toombul while second TBM arrives from Germany Mid 2010 - Second TBM commences tunnelling from Toombul heading west toward Lutwyche Early 2011 - Northern Busway tunnelling complete Early 2011 - TBMs removed from tunnel shaft at Chalk Street in Lutwyche Late 2011 - Airport Roundabout Upgrade complete 15 July 2012 - Construction complete and public preview walk 24 July 2012, 11.55 pm - Airport Link opens to public after final safety certification History On 17 June 2009, CNI requested that the Coordinator-General evaluate a proposed change to the Airport Link project under section 35C of the State Development and Public Works Organisation Act 1971. Due to the discovery during the first half of 2009 of less than favourable ground conditions in the vicinity of the Kedron ramps, BrisConnections proposed the establishment of a new worksite on vacant land at Rose Street, Wooloowin, between Kent and Park Roads to facilitate improved construction access to the mainline tunnels. A shaft 15 metres in diameter and 42 metres deep would be constructed to launch two of the project’s ‘roadheader’ excavation machines. It is anticipated that the worksite would be in use for up to 29 months, including backfilling and rehabilitation. In August 2009 the main earthmoving contractor TF Group went into receivership, owing subcontractors as much as $2.8 million. A group of these subcontractors threatened to blockade the project until their outstanding debts were paid. On 15 July 2012, the tunnel was opened to registered