Heathrow Closure

I think flights stop taking off at arund midnight or just before and incoming flights start arriving at 4ish so not a huge window of opportunity.  Maybe the required programme for such works would push the costs beyond the realms of what was deemed palatable - especially if the cost of an enforced outage to reconfigure the supplies in a big-bang moment is only £20m

chrisbryant said:

Heathrow has grown organically

A common feature of a failure trajectory.

See [1] for accident trajectory diagram (fig 6.3, p149) showing how we bounce along the boundaries of acceptability and safety.

I'm not sure if any of the other 'regional' airports have such a spread of terminals and mixed on-site infrastructure all focussed around the common 'runway' purpose, with the 'human crowd control, at scale', back story.

I'd guess that once the full story and enquiry reports that there will be disjoins in the whole-system FMEA, obvious, apparently, in hindsight. There will be a lot of 'normalisation of deviancy'.

The Grid-Airport interface has already moved from the hand-shake to the fist-bump stage

I understand that the Heathrow airport effectively shuts down (planes stop taking off or landing at night) so with careful planning changing the power feeds could be done with minimum disruption.

From a historical perspective I took my first plane flight out of Heathrow in 1958.

Peter Brooks

Palm Bay 

I have seen reports of the cost to Heathrow airport for the incident being in the region of £20m - with costs to the wider industry and economy boutne by others.  Given that Heathrow has grown organically with demand being added over decades, i wonder how much of the situation arose because the problem became too big to solve. 

All supplies to the site were connected to a single feeder - my initial thought was to wonder why the load was not distributed across the avialble feeders, but if it would have taken half a day to reconfigure the supplies, with multiple system shut downs required then perhaps a reconfiguration was deeemed not feasible or not palatable.

Looking at the cost - If there are wide spread loads (critical and non-critcal) that are not generator backed across the site, then a project to cover these with generators would cost tens of millions - probably in excess of the quoted £20m loss to 'Hetahrow Airport Limited'.  Perhaps there was always an awareness of the risk but a conscious decision not to mitigate 

I wonder if other airports in the UK like Standstead, Luton, Gatwick, Birmingham and Manchester are looking at how they are powered and what redundancies and contingencies they have in place.  Another thing that hopefully people/organisations are looking at is a run time schedule/checklist or reboot list or procedure list.  The name is irrelevant it is the process of turning things back on in the correct order with the correct dependancies (do not forget Inrush Current).  Eg there is no point turning on a monitoring system before the actual system it monitors is fully up and running. 

That was a nice picture of the quoted IET expert!

Peter Brooks

Palm Bay FL 

The various New York shutdowns (e.g. 1977, 2003, etc.) have similar cascades, and other less well know European ones..

Seen the DPA news feed https://www.dpaonthenet.net/article/214558/What-really-happened-at-Heathrow--Experts-explain.aspx#

At least someone picked it up.

There's always a point of failure :Big-Smiley: [Hollywood movies various]

It's the errors of omission not commission (never saw it coming) that make for the big disasters.

What we haven't seen (yet) is the 'shutdown the airport' cascade of guidance and how that got overloaded. We've had major delays at Heathrow before, but electricity is becoming an essential to life aspect.