CLEM7 construction facts and figures | Brisbane City Council

CLEM7 construction facts and figures

The Clem Jones Tunnel (CLEM7) tunnel includes 308,000 tonnes of concrete tiles, 192 kilometres of electrical cable, 120 jet fans, 166 emergency phones and about 2000 lights. Other interesting facts and figures include:

  • the tunnel's deepest point is 60 metres underground
  • the speed limit is 80 kilometres per hour (this is variable and can be lowered if required)
  • mobile phones and radios work in the tunnel
  • the road surface is concrete, not bitumen
  • white side panels reflect all light
  • there is one tunnel northbound and one tunnel southbound, with two lanes per tunnel.


Construction on CLEM7 commenced in September 2006 and finished in March 2010. 

CLEM7 was a 'public-private partnership', with Rivercity Motorway Group (RCM) building the project. In 2013 Queensland Motorways took over the operation and maintenance of the CLEM7. Queensland Motorways have the right to toll the tunnel for a 38-year concession period. After this time, it will be transferred to Brisbane City Council. 


Two tunnel boring machines (TBMs), named Matilda and Florence, and several smaller roadheader machines, created the tunnel. Digging the southbound tunnel, Florence completed her journey from Bowen Hills to Woolloongabba on 16 April 2009. Approximately six weeks later on 26 May 2009, Matilda 'broke through' into the access shaft at Gibbon Street Woolloongabba. This signalled the end of tunnelling for the project.

Matilda and Florence were the largest of their type in the world and excavated 75% of the tunnel. The TBMs operated like a moving factory - excavating the rock, erecting the concrete tunnel lining and placing the road base as they went.

The excavated rock was removed from the tunnel via an enclosed conveyor and stored in large silos before it was loaded into trucks and transported off-site.

Upon completion of tunnelling, the TBMs were dismantled and removed from the CLEM7 construction site to allow crews to focus on the mechanical and electrical fit out of the tunnel.

Bridge construction and road widening

The more visible components of the project included the construction of 18 bridges connecting surface roads to the tunnel.

Major road widening work is continuing at the northern, eastern and southern entrances to the tunnel and is nearing completion. This work will ensure motorists enjoy fast, safe and reliable access as they enter and exit the tunnel.

Other facts and figures


Length 4.8 kilometre twin, two-lane tunnels
Rock to be excavated 3.5 million tonnes
Tunnel lining segments 38,000
Concrete 280,000 cubic metres

 Tunnel boring machines

Cost                $50 million per machine
Diameter 12.4 metres
Length 253 metres
Weight 4,000 tonne
Cutters 78 tungsten carbide tipped 19 inch disc cutters
Manufacturer Herrenknecht (Germany)
Progress Up to 20 metres per day
Crew 22 people per shift


Number of bridges    18
Number of beams 350 Super T bridge beams
Length of beams 25 kilometres if placed end-to-end
Number of decks 1,100
Biggest beam 39 metres in length and 75 tonne in weight


14 March 2019