[rich_sasha]

Literally just guessing: that substation is on the train route to central London, which is the main public transport connection in and out of Heathrow. Indeed the Elizabeth tube line is suspended on the Heathrow branch.

So perhaps the core issue isn't inability of the airport to operate, but of people to get in and out.

[Symbiote]

I think it's likely the Elizabeth Line branch is suspended because the stations are closed, and the stations are closed because there's no power to the buildings.

[seabass-labrax]

The Elizabeth line is fully electrified, so why wouldn't the issue be power to the trains themselves rather than the stations?

[Symbiote]

Other trains are running on the main line through the area. It's 25kV electrification, there's plenty of distance between feeder substations.

National Rail say [1] "An unadvertised shuttle service is running from Heathrow Terminals to London Paddington to ensure customers and colleagues can leave the airport" so trains can and are running, they just don't want flight passengers to go to the airport.

[1] https://www.nationalrail.co.uk/service-disruptions/heathrow-...

[seabass-labrax]

Ah, thanks, that makes sense.

[ajb]

I doubt they would suspend flights for that. Heathrow is used by people from all over South England, not just London, so a good proportion of customers come by car. Not to mention the people doing transits. Also TFL has a stock of buses which they use if a rail line goes down.

[fredoralive]

The Piccadilly line isn't noted as suspended, presumably it has its own electricity feed, so there are even still trains you could get.

[gambiting]

Also it's not like Heathrow is on an island, in the worst case you could get everyone out by buses.

[supernova87a]

Lights are out in the terminals at LHR. https://www.bbc.com/news/live/cly24zvvwxlt