Heathrow Tunnel Partial Closure Monday 10/08

Thames99 · 10 Aug 2026

According to this article

Major disruption to train services between Reading and Heathrow

There is major disruption to train services between Reading and Heathrow this morning (Monday, August 10) due to a tunnel closure

www.readingchronicle.co.uk

the tunnel into Heathrow is partially closed because of a 'water leak'. No Elizabeth line trains are running between Hayes and Harlington and the airport. There is a limited Heathrow Express service.

GWR's website says that there is a good service on all lines, but Paddington departures show curtailed and cancelled services.

Does anyone know exactly what the problem is? The article puts water leak in inverted commas as if they are not sure whether to believe it or not.

RailUK Forums

signed · 10 Aug 2026

On FlyerTalk rumor is that the fire supression system is leaking

FlyerTalk Forums - View Single Post - Heathrow Rail Delays - Aug 10

Post 37877927 - FlyerTalk is a living, growing community where frequent travelers around the world come to exchange knowledge and experiences about everything miles and points related.

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The tunnel fire hydrant system is leaking water apparently.

pokemonsuper9 · 10 Aug 2026

Looking at Traksy the tunnel towards the City from Platform 2 at Heathrow Central) is shut.

Traksy screenshot with signal blocks showing *LB* and SHUT on the line out of Heathrow Central Platform 2

T4 seems to have a very limited service, only a couple Elizabeth Line trains so far today - bit surprised there's no Heathrow Express running as a shuttle, I assume everyone's having to get the Tube or Bus.
Looks like the service that remains is an every 30 minutes Heathrow Express from T5.

rower40 · 10 Aug 2026

Given the number of lineside fires during this year's heatwaves, I'd suggest that an over-eager fire suppression system is a "right-side" failure.

NSEWonderer · 10 Aug 2026

rower40 said:
Given the number of lineside fires during this year's heatwaves, I'd suggest that an over-eager fire suppression system is a "right-side" failure.

Hosepipe ban doesn't seem to apply to them

flymo · 10 Aug 2026

And this evening the Piccadilly line is off due to a signal issue. Madness at Heathrow.

TFN · 10 Aug 2026

Leaving the water to leak can cause water to pool up, affecting track circuits and causing signal failures etc.

Switching off the water supply in that tunnel means I’m guessing there’s regulations that don’t allow trains into a tunnel with no fire suppression available?

This is the second time in recent months that the Up tunnel is closed between T2/3 and Hayes.

OxtedL · 11 Aug 2026

Still going on today.

Looks like the plan they've settled on is half hourly Heathrow express to T5 and half hourly Elizabeth line to T4.

Requires flighting to get 8tph through that tunnel and not looking very punctual so far.

Warrior2852 · 11 Aug 2026

pokemonsuper9 said:
T4 seems to have a very limited service, only a couple Elizabeth Line trains so far today - bit surprised there's no Heathrow Express running as a shuttle, I assume everyone's having to get the Tube or Bus.

Would HEX drivers even have competencies on the T4 branch? There's no HEX services down there these days, not even a Parliamentary, it's all Elizabeth Line.

TFN · 11 Aug 2026

Warrior2852 said:
Would HEX drivers even have competencies on the T4 branch? There's no HEX services down there these days, not even a Parliamentary, it's all Elizabeth Line.

They’re still competent. They can get diverted down to T4 if needs be and HEX run the terminal shuttles on Christmas and Boxing Day.

signed · 11 Aug 2026

Is it the first time HEx only granted acceptance to pre-booked tickets only?

I had never seen this catch when seeing planned acceptance (when EL shut between Ealing Broadway and core in the wee hours of the morning for example.)

RJ · 11 Aug 2026

Taxis will be busy. Fortunately Paddington is quite unique in Central London for being all dual carriageway / motorway to the airport. Even during the day it barely takes 40 minutes to get to T5.

RailWonderer · 11 Aug 2026

RJ said:
Taxis will be busy. Fortunately Paddington is quite unique in Central London for being all dual carriageway / motorway to the airport. Even during the day it barely takes 40 minutes to get to T5.

But the first 20 mins is painful crawling in traffic before you get to the motorway. The driver had to keep promising me and the guy I shared with last year that we would be going a lot faster once we reached the motorway.

Jimini · 11 Aug 2026

Looks like it's reopened now (based on Traksy).

Horizon22 · 11 Aug 2026

Fully reopened now.

The mad thing is this is almost a repeat of an incident that happened a couple of months ago. Not great for major national infrastructure and a railway line connected to one of the world's busiest airports.

== Doublepost prevention - post automatically merged: 11 Aug 2026 ==

signed said:
Is it the first time HEx only granted acceptance to pre-booked tickets only?

I had never seen this catch when seeing planned acceptance (when EL shut between Ealing Broadway and core in the wee hours of the morning for example.)

Definitely not. In fact this is almost always the case because Contactless / Oyster will automatically calculate based on where you tap in / tap out at Paddington which service you have taken and of course the price difference can be substantial. It would be nice if there was a sensible workaround but all parties don't seem to be able to agree what that might be without zero fare being obtained (e.g. being let out of the gateline to tap in elsewhere).

pokemonsuper9 · 11 Aug 2026

Horizon22 said:
The mad thing is this is almost a repeat of an incident that happened a couple of months ago. Not great for major national infrastructure and a railway line connected to one of the world's busiest airports.

Would I be correct in saying Heathrow own the tunnels?
If so I'm sure they'll be having some interesting conversations about what happened given I would expect them to care more about customer experience than most TOCs.

signed · 11 Aug 2026

pokemonsuper9 said:
Would I be correct in saying Heathrow own the tunnels?

Heathrow does own the tunnels

Horizon22 · 11 Aug 2026

pokemonsuper9 said:
Would I be correct in saying Heathrow own the tunnels?
If so I'm sure they'll be having some interesting conversations about what happened given I would expect them to care more about customer experience than most TOCs.

Indeed - all owned by Heathrow Airport Limited (HAL). Although NR often come to assist them on infrastructure issues.

stuving · 11 Aug 2026

Horizon22 said:
Indeed - all owned by Heathrow Airport Limited (HAL). Although NR often come to assist them on infrastructure issues.

According to the HAL Network Statement, Network Rail are Asset Manager, Infrastructure Manager, and Operator for the track, railway communications, signalling, and overhead lines. HAL have the same full responsibility for ventilation, non-railway communications, stations, and the control room. For tunnel structures HAL is AM and NR is IM.

In the description of the two tunnels (covering the whole HAL network) there is this:

Intervention shafts are provided at locations allowing egress and access for emergency services.
Intervention points also exist at the tunnel portals and at the stations. Cross passages link the
twin tunnels. All the tunnels have emergency walkways, at track level for emergency services
and at platform level for passengers. A tunnel ventilation system provides a supply of fresh air
that removes stale air and enables the direction of air flow to be controlled. The ventilation is
controlled from the HRCR.

A wet fire main is provided throughout the running tunnels to provide the emergency services
with a water supply for firefighting purposes should a fire break out on a train. This is
supplemented by a forced ventilation system to ensure that passenger escape routes and access
routes for emergency services are kept clear of smoke.

The W&W Sectional Appendix clarifies that the Heathrow Rail Control Room does control fire monitoring and protection, and access to the tunnels, so this is all HAL's responsibility. So while it is not explicit that HAL are responsible for the fire suppression system itself, it does sound as though they are.

Horizon22 · 11 Aug 2026

stuving said:
According to the HAL Network Statement, Network Rail are Asset Manager, Infrastructure Manager, and Operator for the track, railway communications, signalling, and overhead lines. HAL have the same full responsibility for ventilation, non-railway communications, stations, and the control room. For tunnel structures HAL is AM and NR is IM.

In the description of the two tunnels (covering the whole HAL network) there is this:

The W&W Sectional Appendix clarifies that the Heathrow Rail Control Room does control fire monitoring and protection, and access to the tunnels, so this is all HAL's responsibility. So while it is not explicit that HAL are responsible for the fire suppression system itself, it does sound as though they are.

Good overview of the network responsibility. Yes, I am pretty sure HAL are the fire suppression system managers and maintainers.

The issues that have caused prolonged disruption in recent months have mostly been around the fire suppression issues and leaking hydrants and looking up who is responsible gives some context as to why it seems to take so long to resolve.

zwk500 · 11 Aug 2026

Horizon22 said:
Fully reopened now.

Looks like the Elizabeth line got the full service back to both Terminals 4 and 5 just after 5pm. HEX have advertised the cancellation for the half-hourly service, presumably there's a fairly low chance of them reinstating them and they'll stick with half-hourly to the end of service.

Horizon22 · 11 Aug 2026

zwk500 said:
Looks like the Elizabeth line got the full service back to both Terminals 4 and 5 just after 5pm. HEX have advertised the cancellation for the half-hourly service, presumably there's a fairly low chance of them reinstating them and they'll stick with half-hourly to the end of service.

It is a little easier for the Elizabeth line - instead of terminating at Hayes / West Drayton / Paddington the trains just run through so very easy to reinstate. HEX shouldn't be too hard but if they've sent trains off to West Ealing sidings it's a little bit more of a faff to reintroduce.

zwk500 · 11 Aug 2026

Horizon22 said:
It is a little easier for the Elizabeth line - instead of terminating at Hayes / West Drayton / Paddington the trains just run through so very easy to reinstate.

Indeed. They also didn't cancel the services too far in advance, so it's less work to reinstate them (just ask the driver to phone control and tell them they're going on to Heathrow)

Horizon22 said:
HEX shouldn't be too hard but if they've sent trains off to West Ealing sidings it's a little bit more of a faff to reintroduce.

By the looks of RTT they never took the units of Reading TCD this morning.

Horizon22 · 11 Aug 2026

zwk500 said:
By the looks of RTT they never took the units of Reading TCD this morning.

Even more hassle then! Guess they need to find a driver who signs the 387-Air units (ETCS trained).

hwl · 15 Aug 2026

And today the water main in the road tunnel to the CTA (T2 and T3) has burst so Heathrow are advising all passengers to use rail or tube to get to / from T2+3.
Luckily the 2 sets of problems didn't happen at the same time!

Heathrow Airport pipe leak causes flood disruption

Water in the central terminal area means passengers cannot use roads to the airport.

www.bbc.co.uk

Horizon22 · 15 Aug 2026

It is worrying just how many issues they appear to have with water mains / hydrants / fire supression systems; it can't all be coincidence but appears to be taking their eye off the ball for maintenance.

Looks like its reopened now.

Heathrow Tunnel Partial Closure Monday 10/08

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