Heathrow Closure

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. 

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 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'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

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 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

I wasn't suggesting that everything needed to be done in one night. There is such a thing as staging over weeks or months. 

What happens when the airport has to close because of bad weather (example Fog).

My wife experienced a situation many years ago when her fight into London was delayed because of bad weather and her plane was diverted into a airport in Scotland for a few hours.

Just think what happens when the local clocks are changed in spring and fall and the airlines are forced to adjust their schedules.

Peter Brooks

Palm Bay FL

No grid substations or DNO substations have back up generation -for an Energy Minister to suggest there was shows the level of engineering knowledge he has.

No one is guaranteed a 100% reliable supply from NG/DNO -if electricity is that important to your site it is then your responsibility to provide back up generation to cover the grid power outage.

I guess at Heathrow the cost of back up generation would be huge, a 40ft container can house 2MVA of standby diesel  generation and are commonly installed on hospital sites.in multiple configurations.- Heathrow could have followed this model.

It is reported the adjacent data centre continued operations - presumably with UPS supplies to cover the short time period while the standby generation ran up and connected.

From comments in the press it appears Heathrow had sufficient standby  capacity to undertake an orderly site shutdown but not sufficient capacity to continue operations.

Bobby123 said:

back up generation

I did see one report (www.youtube.com/watch that suggested there was a potential fire suppression system on-site (just outside the electric fence;-), which may be the source of the 'generation' misunderstanding if it had some form of diesel backup for the fire fighting/suppression aspects. These things can be less reliable than typically hoped, but then again it might not even have been a fire suppression building that was being noted!