Project Description

Henderson Substation

The existing 33kV switchyard was replaced with indoor gas insulated switchgear housed in a new ODID building.

• Construction of a new 33kV switchroom building
• Construct cable stand foundations
• Excavate/backfill feeder cable trenches
• Manufacture and install Connell’s precast concrete troughs
• Install stormwater drainage scheme
• Demolish existing 33kV bank
• Re-metal existing switchyard yard

The two storey building is constructed of concrete blocks with insulated roof panels. Midfloor was cast in situ to accommodate the new switchgear panels. Cable entry was through penetrations in the basement. All structural steel was coated with intumescent paint for fire protection.

Connells manufactured and installed precast concrete troughs for cable access. Cable stand foundations were cast in situ and connected to the existing transformer bank.

Extensive cable trenches were formed through the existing switchyard where many high voltage cables and earth straps had to be negotiated – none were damaged. TPCR40 was laid through the construction zone to complete the yard works.

A stormwater drainage scheme was installed to accommodate the new building roof catchment including the basement pumps. The project was completed on time and budget with no serious harm incidents reported.