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Following in a long tunnelling tradition of giving individual names to TBMs, ‘Fionnuala’ was named after the female member of the Children of Lir, one of the legends most closely associated with the Erris region. 

Paul Hughes, Tunnel Construction Manager, is happy with the tunnelling operation so far.  “It is a very challenging project but it is also very exciting.  There was a slow start-up at the initial launch of the TBM as we had to commission the numerous hydraulic and electrical systems on the machine.  This isn’t unusual in a project of this kind and on a TBM of this size but Fionnuala is now fully commissioned, is working well and we are making steady progress.”

BAM/Wayss & Freytag are the joint venture contractor delivering the tunnel and they bring with them the combined expertise of tunnelling specialists from Germany and Irish staff with vast experience of the construction industry here. 

Downtime has been built into the tunnelling schedule.  “On any tunnelling project, the TBM is usually in operation for approximately 65% of the time,” said Paul.  “This is to allow sufficient time for maintenance.  It also allows us to adjust and, if necessary, change the cutter heads at the front of Fionnuala depending on the type of soil or rock.”

Safety is paramount and Paul Hughes says that a simple approach has been adopted to ensure all work is carried out in a safe and secure manner.  “The tunnel is a huge logistical challenge and fully trained operators are working in confined spaces and often in compressed air environments.  It is essential that every measure is put in place to ensure our work is undertaken in a safe way.”

When complete, the tunnel will be the longest tunnel in Ireland and the longest gas tunnel in Europe.

The tunnel – by numbers

  • 4.9kms - length of the Corrib tunnel
  • 4063 – number of concrete rings to be used to line the tunnel
  • 500 tonnes – the weight of ‘Fionnuala’
  • 8 – size of crew working on ‘Fionnuala’ at any one time

Updates on tunnelling will be carried on this section of our website regularly.