CRL – Operational Configuration – OC 2.1

The purpose of OC 2.1 construction stage of City Rail Link was to facilitate the removal of the Down Main to enable pilling works for dive structures and the ultimate realignment of the Down Main on the North Auckland Line (NAL). This infrastructure change subsequently increases the Earth Potential Rise and Earth Resistance under operational circumstances. To address this issue, earth stakes were connected to the Earth Wire along with additional cross bonding to reduce the traction return resistance.

The key works scope being undertaken by Alpha Rail includes:

• Installation of an auxiliary feeder wire
• Removal of the Down Main Wire
• Installation of 8 new OLE structures
• Removal of 34 OLE Masts
• Transfer the Up Main wire from existing infrastructure to new support structures
• Re-grading the NAL Up Main and Aerial Feeder Wire to support the installation of 2 new Overbridges.
• Multiple Earth electrode installation at Kingsland Station.