Hard Rock Tunneling Machines
In 2013 CREG acquired the Intellectual Property rights, including all drawings, details and records of experience of WIRTH Rock tunnelling machines from Aker.
With this knowledge and experience CREG is able to offer suitable tunnelling machines for hard rock tunnels
WIRTH Tunnelling machines.
Wirth started developing tunnelling equipment for Rock tunnels in 1967, designing and supplying over 300 machines for hard rock tunnels.
In 1996 they supplied the largest (at that time) Double shield TBM for hard rock at 11.8 m diam.
In 1999 they supplied the largest (at that time) TBM for hard rock at 12.5 m diam.
Hard rock tunnelling.
Machines are generally divided into two categories
1. Double shield – or Telescopic Shield
These machines are uswed in less stable, broken rock conditions. The forward shield provides the ecutterhead support and means of excavation, whilst the rear, or gripper shield provides an anchorage from which the forward shield can be thrust forward. Ground supports in the form of rock bolts, arches shotcrete or other means are installed at the rear of the gripper shield.
Typical example is this 5.39 metre diameter machine supplied for the Lesotho project in South Africa.
This machine was fitted with 1500 kW of power to the cutterhead drive, which could rtate at up to 8.6 revs/min, and a thrust of 30,000 kN.
2. Open or Gripper type TBM’s
This type of machine is used in very hard stable ground which needs a minimum of support after excavation. The cutterhead for this type of machine is supported on a central beam – or kelly, which is in turn supported by two sets of grippers functioning as indicated in this diagram. Head rotation speeds will usually be faster than in soft ground, - typical data for rock TBMs is as indicated in this table. But all situations must be examined on their own merits.
The indicated data are approx. values. Exact and detailed data depend on project and machine design. Other diameters upon request
|Machine Type||Diameter Range||Cutterhead Drive||Torque||Thrust||Stroke|
|TB220/280||2.20 - 2.80||440||250||3500||0.8|
|TB260/320||2.60 - 3.20||540||320||4300||1.0|
|TB280/350||2.80 - 3.50||800||550||6200||1.2|
|TB320/400||3.20 - 4.00||1200||870||8300||1.6|
|TB350/450||3.50 - 4.50||1320||1200||8800||1.6|
|TB420/520||4.20 - 5.20||1500||1700||10500||1.6|
|TB440/580||4.40 - 5.80||1800||2100||12000||1.6|
|TB520/680||5.20 - 6.80||2100||2900||15000||1.6|
|TB640/820||6.40 - 8.20||2600||4200||18000||1.6|
|TB750/920||7.50 - 9.20||3000||5300||21000||1.8|
|TB880/1100||8.80 - 11.00||3500||7500||25000||2.0|
|TB1050/1300||10.50 - 13.00||4000||10500||30000||2.4|