Ever since the Elizabeth line opened, there’s been a simmering question about the long-term future of the premium Heathrow Express service, and TfL is eying up the route.
Elizabeth line trains at Old Oak Common (c) ianVisits
In a submission on transport options for an expanded Heathrow Airport, Transport for London (TfL) argues that more needs to be done to improve public transport options in the area if the roads are to avoid being gridlocked by the extra passengers and freight coming through the airport.
The airport already has plans and requirements to reduce road traffic and increase public transport use to and from the airport, but TfL argues it will not be able to meet its targets without upgrades to public transport.
TfL’s submission to the Airports National Policy Statement (ANPS) review cites a number of areas where increased passenger numbers would require increased capacity on public transport to cope with demand. Some will be easier to deliver, such as increased provision of cycling and bus services around the airport for workers, but also upgrades to the Piccadilly line, and possibly taking over the Heathrow Express.
Piccadilly line
One proposed upgrade was the signalling upgrade for the Piccadilly line, which is currently on hold.
The Piccadilly line is the original connection between the airport and central London, opening in 1977, and still uses the same trains that were in service when Heathrow tube station first opened. The new fleet of trains, due later this year or early next year, will finally replace them and also increase capacity on the Piccadilly line. And subject to fixing a possible signalling capacity pinch point around King’s Cross, they will eventually increase the number of trains through central London from 24 to 27 an hour.
However, the Piccadilly Line Upgrade Project included a full line signalling upgrade, which would have increased capacity to 33 trains per hour during peak hours. The signalling upgrade was essentially put on hold during the pandemic, and although it will be needed anyway as the old equipment becomes worn out, the funding is still not available.
The signalling upgrade would also support a future increase to 36 trains per hour, but at that point, it would put pressure on some key stations, which might not be able to handle the passenger numbers without upgrades of their own.
Heathrow Express
Much sooner though could be a decision about the Heathrow Express service, which links the airport to Paddington station.
Heathrow Airport built its own railway tunnel and stations linking the airport to the Great Western Main Line. Although the airport owns the tunnel, in 2018 it handed over the operation of the train service to GWR under an agreement that runs until 2028. As confirmed in its financial accounts, Heathrow Express’s current track access license to use the Network Rail tracks between its tunnel and Paddington also expires in 2028 unless renewed.
Pandemic effects notwithstanding, the service has seen a steady decline in passenger numbers since the Elizabeth line trains were introduced.
Heathrow Express passenger numbers
- 2015-16: 5.8 million
- 2016-17: 6.1 million
- 2018-19: 6.2 million
- 2019-20: 5.8 million
- 2020-21: 0.3 million
- 2021-22: 1.8 million
- 2022-23: 4.7 million
- 2023-24: 4.5 million
- 2024-25: 4.3 million
(Source: Office of Rail and Road)
In response to this, TfL says that the review should “reconsider whether this service is the best use of these valuable train paths into Paddington.”
The Heathrow Express is a premium service that uses trains better suited to lots of luggage and offers a faster connection to central London. However, it carries, on average, around 80 passengers per train, compared to its potential capacity of 374.
At the moment, the Elizabeth line operates 6 trains per hour to Heathrow Airport stations (6tph to T2&3, 4tph to T4, & 2tph to T5), plus there are four trains per hour from the Heathrow Express (4 tph to T2&3 and 5).
If the Elizabeth line took over the four slots occupied by the Heathrow Express, it would increase capacity by around 5,600 passengers per hour.
(6,000 passengers per hour minus the circa 400 who currently use the Heathrow Express)
A TfL takeover would also likely benefit the mainline stations along the route to/from Paddington, which could see an additional 4 trains per hour calling at them.
Although replacing the fast Heathrow Express service with a slower, stopping Elizabeth line service would be a downgrade for passengers who prefer the faster service, it would be offset by the wider benefits of running a more frequent Elizabeth line service.
Heathrow Airport might not be entirely out of pocket, as it would be expected to retain ownership of the tunnel and stations, which generate revenue from track access charges and in-station advertising.
Heathrow Airport may also argue that, if it agrees to the Elizabeth line replacing its Heathrow Express service, TfL should reset the fares premium they introduced in 2022 for travel to the airport, although they might argue that, as the Elizabeth line is cheaper (if slower) than the Heathrow Express, then customers would already be saving money.
(That assumes you pay on the day, as Heathrow Express offers cheaper tickets if you book a month in advance)
The Elizabeth line will be able to replace the 12 GWR-supplied trains without cannibalising its existing fleet, as they have 10 more Class 345 trains on order. Initially, those will be used to maintain services while the existing fleet undergoes a mid-life overhaul, but that should be completed by the time they have the option to replace the Heathrow Express.
As the new trains were ordered in part to cope with capacity at Old Oak Common when HS2 opens, as that station is between the airport and Paddington, an increase in Heathrow services would fit neatly into the service upgrade plan.
Closing the Heathrow Express would not just free up more capacity on the mainline tracks in/out of Paddington, it would also free up two platforms in the station. That’s assuming all Elizabeth line trains run through to central London, as there’s always a possibility that the Elizabeth line could run some services as a shuttle between Heathrow and Paddington, as they already do first thing in the morning. That would mean regularly crossing from Network Rail’s “relief” lines used by the Elizabeth line over to the faster main line, which could complicate matters, but is not insurmountable.
Whatever the decision, the lead-up to 2028 will be very interesting to watch.
Much further down the line, there is also the tantalising possibility that the Elizabeth line trains could run from Heathrow to Reading via the proposed Western Link, and out to Staines via the proposed Southern Rail Link.
Hypothetical Elizabeth line map with Heathrow extensions
