Sydney T2 Blackout

[Ash W]

Phillip, both points you make are exactly how it works in the real world. In relation to your first point where you take the single point is all based on risk and cost.

Hence high availability data centres you will find equipment with dual power supplies, feed from completely different sources with appropriate UPS and generator systems.

In a building like Sydney airport you will probably find it is more like what Greg was suggesting above where they have some circuits connected to a UPS, which in turn is feed from mains and a back-up generator. With the UPS being there just to hold the equipment whilst the generator fires up, stabilises and switches over. On an auto generator this could take 30 seconds to a minute.

[Greg Hyde]

Only "mission critical" systems need to be supported by UPS/Gen sets. Equipment that takes some time to restart.

On new builds (on request) you can have two main power feeds from two discrete power supplies that never pass through the same sub-stations.

It can be retro-fitted, at a cost.

[Philip Argy]

Not sure in what scenario T2 is not mission critical - ask the passengers and staff who were there last Friday ...

[Ash W]

Philip sometimes even with a mission critical design the "you know what" can happen.

A good example was Calvary Hospital in Canberra where it suffered a black-out early last year. This was a result of a heavy rain storm that flooded the room where the mains come in, and also flooded the feed from the back-up generator. The hospital also had UPS, but that only lasted so long, think it was about in hour in the case of the hospital.

Without knowing the design of Sydney airports power feeds, nor what the issue was, it is a tad unfair to go around pointing fingers of blame as others in this thread have done.

[Bradley Porter]

I'll bet the car park pay machines worked just fine throughout the whole ordeal !

[Hugh Jarse]

Apart from the shops, practically everything in a terminal is mission critical. From the heavily-relied upon 2-way comms to the power driving aerobridges and NIGS systems. Then there's the computer and network systems upon which the airlines depend for checkin, dispatch etc.