Heathrow Closure

Technically they could still accept flights as a lot of the kit in the apron runway area have back up and such the issue is they do not have backup and contingency power in the main buildings so they can not deal with the people in the terminal buildings. Poor Planning (PPP) or lack of contingency?

The other thing that people are NOT discussing is the possibility of sabotage from the the USSR.  Someone may have asked for a large spanner to be Putin the works, so to speak.

I would expect Heathrow to be mostly fed at 33kV from Longford while the fire was at North Hyde. The common feed to both is the National Grid switching site at Iver. Perhaps all output circuits from Iver tripped rather than Iver-Hyde 1/2 275kV circuits.  

I also wondered that Andy - but the lack of ability to accept inbound flights makes me wonder what would could possibly have failed to prevent flights from landing.  I would have anticipated back-up generators as part of the airport's infrastructure and completely independant from the DNO supply.  I can think of lots of examples of less important sites in the UK that have onsite power generation independant of the national grid. 

As you mention, i can't envisage that the functionality and resilience would not be distributed around the site/area.  The statement from he Energy Minister that the fire has taken out back-up generators also seems to add more doubt in my mind.  

Faults on the power system and fires in the locality of the airport should have been well within the bounds of contingency planning.  I can understand liminted or no departures, but inbound diversions and turnarounds seems like a failure of engineering, failure of contingency planning or something else more malicious

I wonder if the disruption was larger than the actual fault? - e.g. having to shut down the entire site to make it safe for the fire crews to enter. Some reports say 60,000 odd customers were affected at one point, falling to less than 10,000 now. There are also reports of the fire taking out a backup generator at the same time (which might suggest some lack of detailed planning).

   - Andy.

Well it looks pretty serious. The question I suppose, given odd things happening around the world at the moment,  is was this a natural maintenance  avoidable failure or was it pushed? The fundamental problem with Heathrow of course is that it is too big, and really the functionality should have been distributed over a no of smaller sites

I understand it is North Hyde   www.ssen.co.uk/.../north-hyde-grid-supply-point---strategic-development-plan---for-consultation.pdf

I.

Mike