Lyttelton Harbour Information
20 Oxford Street

Monday to Friday
10.00am to 4.00pm

    10.00am to 4.00pm

      11.00am to 3.00pm

        Phone: 03 328 9093
        Email: infocentre@lyttelton.net.nz

          Find us on Facebook
          Home Earthquake Earthquake News Lyttelton Tunnel
          Lyttelton Tunnel PDF Print E-mail
          Thursday, 29 September 2011 14:15

          lyttelton_tunnelSpread the Word the Tunnel is Safe.  In response to the concerns raised by many residents, the Lyttelton Harbour  Information  Centre and the Lyttelton Residents Association have written to the New Zealand Transport Agency for clarification on the safety, and excessive dust issues, for the Lyttelton Road Tunnel.


          Response Addressing Safety Concerns:

          Over the last few months while the strong earthquakes and aftershocks have been centred on Lyttelton, NZTA has been focused on keeping the tunnel safe and ensuring that it is in good operational condition for users.  NZTA appreciate the tunnel’s role as a key artery in the city and is happy to reassure road users that the tunnel is structurally sound and safe to use.

          Following the 22nd February earthquake the tunnel was closed for 3 days while a structural inspection was undertaken.  A few additional cracks had appeared in the tunnel walls however none of these were assessed to be of concern.  Above the tunnel road-space area there is a concrete roof slab and wall separating the ventilation shafts and these were also inspected and no damage was found.  The explanation for the lack of damage is because the tunnel is essentially a hole carved through a very tough volcanic rock which has a thick reinforced concrete lining.  When the shaking from the earthquakes occurs the whole tunnel moves as one with the hillside, therefore because the individual components within the tunnel are not moving at a different rate the whole mass moves together and the potential for structural damage is minimal.  Fissures in the rock have opened slightly and created new pathways for water  ingress into the tunnel and three of the water hydrants within the tunnel walls are now also leaking which explains the additional water seepage but this in no way  affects its structural integrity.

          The tunnel was further inspected after the 13th June after shocks and again with the same result.  Contractors have worked in conjunction with NZTA to also ensure that the damaged tunnel control building and canopy (which was demolished within 2 days of the Feb quake due to its unsafe condition) were properly addressed.  Control systems for the tunnel have now been fully reinstated and in addition rock-fall protection measures have been implemented around the Heathcote tunnel portal to protect both tunnel staff and road users.   NZTA remains committed to the tunnel, particularly with the closure of Evans Pass which has placed even more pressure upon the tunnel.  Despite these current  constraints NZTA will continue to manage the tunnel to provide a high standard of safety and a quality link between Lyttelton and the city.

          Response Addressing Excessive Dust

          NZTA is aware of the problem as a result of the earthquake. The increase in dust within the tunnel is not only linked to the cartage of demolition material but to the cartage of aggregate and other materials being transported to Lyttelton.

          In the short term we have increased the roadway cleaning frequency to every second night to minimise the debris on the roadway. We are also working with the Port Company to install "truck showers" to suppress the dust on the trucks at both Heathcote and Lyttelton prior to entering the Tunnel. These are currently being fabricated for installation as soon as possible. At Heathcote these will be installed in the escort bay now that rock protection work has been completed to allow removal of the shipping containers. They will be installed on Port land at Lyttelton.