In 1994 Jackson’s Otago & Southland Branch Manager Howard Healey prepared a report on the underground powerhouse ventilation systems for the powerstation’s then-owner ECNZ. In 2010, current owner Meridian Energy engaged Healey to provide a condition assessment of station’s ventilation systems as part of the powerstation’s half-life upgrade (it was built in 1971).
The resulting Manapouri Power Station Ventilation Upgrade and Refurbishment Feasibility Report released in 2011 recommended new supply and exhaust air systems fans be installed in a new building adjacent to the control building and powerhouse lift shaft. It also recommended a full replacement of the ventilation systems’ ducting down the 200m lift shaft.
The report also covered fire safety and protection systems associated with the station’s half-life upgrade works and which impacted on the proposed ventilation systems works. The plan included a refuge area in the powerhouse where staff and visitors can assemble and progressively be evacuated to the surface via the lift.
The new main outdoor supply and exhaust air fans’ duties are 12.7m3/s at 2,800Pa. with several smaller-capacity fans providing powerhouse refuge, foul air and lift machine-room ventilation.
A new ventilation PLC was included in the project – this is housed in a dedicated room in the control building’s carpark.
Developed design was completed and the project was tendered in 2013. The contract was awarded to E-Type Engineering Ltd who commenced physical construction works on site in 2014.
The physical construction works are now almost complete and commissioning has commenced, with Jacksons providing technical assistance and quality assurance. Contract completion is programmed for late 2016.