Heathrow Closure

Heathrow had enough power to avoid shutdown, says National Grid | The Independent

National Grid CEO John Pettigrew told the Financial Times: “There was no lack of capacity from the substations. Each substation individually can provide enough power to Heathrow.”

Heathrow’s management acknowledged on Friday that: "the site was served by two other substations", but claimed that, "in order for these to be used, the power supply to all terminals needed to be re-engineered."

A Heathrow spokesperson said: "It would not have been possible for Heathrow to operate uninterrupted. Hundreds of critical systems across the airport were required to be safely powered down and then safely and systematically rebooted."

It sounds like some manual reconfiguration of the in-feeds was required to reroute the supply. I find it hard to believe that automatic transfer switches were not installed for the HV distribution system. Even if manual switching was required, I'm amazed that it would have taken longer that the UPS autonomy time from critical systems.

Lots of questions. Will we ever find out the real causes?

Will we ever find out the real causes?

Well maybe, though there seems to be enough high level interest to trigger an inquiry.

It does seem pointless to have multiple in-feeds at HV if there is no  mechanism for performing the change-over faster than the hold-up time of the emergency power.
As above it sounds like the suitably qualified folk to make the technical decisions and pull the right  levers, perhaps even literally,  were not available - which is remarkable in an organization that size, even if the battle plan for such an event had to involve losing supplies to non-essential areas.

After there are plenty of other places with dual HV feeds and HV rings with zone isolation switching and so on, - consider for example that  most large hospital campuses manage this sort of thing as a matter of routine and even manage to rehearse on a semi-regular basis as well as during planned maintenance. It ought not to be that hard to have someone who understands the systems available at short notice.

Mike.

If it were up to me, I wouldn't even allow microprocessor relays without an electromechanical relay backup for the critical feeders. Putting all your trust in a microprocessor that can be programmed to burn itself up at a moments notice (or predefined future time) seems foolhardy to me - maybe I'm just paranoid.  Then again, we're constantly being told to expect cyber attacks from state actors, so why the disparity?

If it were up to me, I wouldn't even allow microprocessor relays without an electromechanical relay backup for the critical feeders. Putting all your trust in a microprocessor that can be programmed to burn itself up at a moments notice (or predefined future time) seems foolhardy to me - maybe I'm just paranoid.  Then again, we're constantly being told to expect cyber attacks from state actors, so why the disparity?