The hugely overcrowded Holborn tube station is set for a major upgrade to ease congestion, especially for people who use it to swap between the Central and Piccadilly lines.
At the moment, the station suffers from a lack of capacity that often sees people crowding outside in the evening peak hours, and restricted access in the mornings.
There has been talk of an upgrade at the station since at least 2013, but there were delays due to funding being reportedly diverted to other stations.
At the moment though, they are at the design stage, with public consultations starting late this year.
The proposed upgrade includes a new station entrance and enhanced access and interchange including step free access to all platforms.
To help fund it, there would be the usual requirement to redevelop the over-site buildings. That is conditional on being able to buy some additional buildings in the area though.
A new station entrance
A recent survey found that more than half the people using the current station entrance head eastwards along High Holborn — so a new entrance further to the east would reduce walking distances while also increasing capacity for the station.
The new entrance is proposed to be on a side street that links up with the North side of High Holborn. It’ll occupy part of the pavement and the road, reducing the road width slightly.
Direct connection with the far end of the Central line tunnels would be added, and a new bank of escalators down to the Piccadilly line.
Construction of a project this size will always be disruptive, and the lack of space to store equipment and people is a serious constraint in central London. However, here at Holborn there are likely to be two useful bits of old tunnel that should help reduce the problem.
Running near the Piccadilly line is the old spur down to Aldwych station which is no longer in use. A presentation to the London Underground Railway Society suggested that they hope to use the disused Piccadilly line tunnel to bring in heavy deliveries.
The disused Aldwych branch platform would be converted into a new corridor space that then lets people swap between the Central and Piccadilly lines without having to use the existing narrow corridor and escalator. With around 40% of passengers using the station just to swap lines, the new interchange should substantially reduce overcrowding in the middle level where people currently cross over.
The new passage will be linked to both Central Line platforms by escalators and inclined lifts in parallel shafts and to the Piccadilly Line platforms by escalators and also by a further lift.
Another bonus for the construction team is that the old Kingsway tram tunnel just happens to run directly above the likely site of the new connection between the two tube lines. While working inside a tunnel is rarely ideal, the Kingsway tunnel is much larger than most and drilling down inside the tram tunnel has been done by Crossrail before.
As part of the upgrade, there may be an upgrade to the existing electricity sub-station to support increased train frequency on the Central line. The trigeneration facility will make us of heat from the tunnels to generate power, some of which will be used to cool the platforms as part of the cooling the tube project.
If approved, then when complete in 2026 (four years later than originally expected), the upgrade would relieve congestion such that operational controls are not required at the station during normal operations.
Depending on funding and other difficulties, there is some indication that the deep level interchange could still be delivered even if the new station entrance is delayed for some reason.