Excavation of the Airport Link and Northern Busway has got underway with the start on site of the first of 11 roadheaders scheduled to work on the major road project, which will also see two TBMs arrive next year.
The contractor, joint venture of Thiess and John Holland, is due to bring the second Sandvik MT720 (formerly Alpine Tunnel Miner ATM 105) roadheader to the Truro Street site by June. Later, a further three units will work from the site.
The entire fleet of roadheaders will also include four working from the Kedron site and two from Bowen Hills. Driving at depths of up to 35m, the contractor expects each roadheader to advance up 3m-6m per day, depending on ground conditions.
Geology in the area is dominated by the Neranleigh Fernvale Beds, which are regionally metamorphosed rocks, including hardened shales, greywackes and quartzites. For hard rock, the MT720 uses 72 picks, and 57 for soft rock.
The JV is undertaking the design and construct contract for the concessionaire BrisConnections on a fixed-price, fixed term basis contract for completion by 2012. BrisConnections was awarded the 45-year toll link concession by the Government of Queensland. In addition to Thiess and John Holland, members of the consortium include Macquarie Capital Group, Arup and PB.
A pair of 12.48m diameter hard rock Herrenknecht TBMs were ordered last year with contract value of more than Aus$90M (US$64M). The shields are to be delivered to site late this year for launch by mid-2010 (T&TI, October 2008, p12).
The TBMs will drive parallel tubes southbound from Toombul to Bowen Hills for the project’s 5.25km long toll tunnel, which dominates the 6.7km long link. The Airport Link and Northern Busway is part of Brisbane City Council’s TransApex plan.
In total, the link calls for approximately 11.8km of tunnel excavation – the balance mostly bored by roadheader, and there will also be some cut and cover construction. Cross passages spaced at 120m nominal intervals. Roadheaders will also be used for the 3km long road (half in tunnel) between Windsor and Kedron on the Northern Busway.
Separate to the technical progress being made on the major project, BrisConnections continues to have to counter difficulties with an investing body in the unit trusts that provide financial support to the venture. The investor, Australian Style Investments Pty Ltd (ASI), has called on other investors to vote to wind up the two key unit trusts supporting the project, and which are managed by BrisConnections Management Co Ltd.
While making the case that winding up does not relieve unit trust holders of their obligations to progressively provide the balance of financing required by the partly-paid security, or “staple trust”, when called at key stages, the management firm noted a legal setback. The Supreme Court of Victoria did not back its claim of ASI’s move was invalid and that ASI itself should be wound up.
The reasons for the judgement were not immediately available, and the management firm has, consequently, advised unit holders that ASI’s requested extraordinary meetings were set to proceed, on 9 and 14 April. However, it further noted that legal challenges are continuing in Queensland and Victoria.
At the end of March, the venture received note of continued financial and other backing from the Macquarie Group bank, which is both an underwriter and a investor through the unit trusts. It noted further purchase of stapled units, provision of Aus$92.5M (US$66.3M) in a previously agreed bridge facility and that it has initiated legal action to ensure all parties fulfil contractual obligations.
The next call on funding from unit trust holders is scheduled for late April and in January 2010.
