Karapiro Dam Substation Upgrade

The civil and structural scope of work within the live switchyard, in a 13 stage sequence of works included the following:

• Removal of existing top soil within Switchyard, and replacement with crushed rock;

• Modify and make good the existing stormwater drainage and water reticulation to

• Install new nib wall outside the switchyard fence, and install crushed rock;

• Strengthen existing eastern and western gantry foundations;

• Demolish all the old ring busbar, equipment, support structures and foundations

• Demolish unused foundations

• Install new primary equipment foundations;

• Install new cable trenches

• For new foundations, undercut an additional 500mm and restore with compacted layer

• of engineered fill material

• Supply and install new equipment stands;

• Relocate and install existing VT4 equipment and stands;

• Level the new foundations to top of existing cable trenches;

• Remove redundant valve pits

• Install bollards (to restrict vehicles access ways)