A connection between tunnels and a new Bank tube station entrance on Canon Street was made last week as construction workers broke through the final layer of concrete.

Edited Dragados video of the breakthrough

The new Cannon Street entrance will have a set of escalators taking passengers directly down to an enlarged Northern line concourse, and via a second set of escalators straight down to the DLR platforms.

The breakthough point you are looking at is at the bottom of the new escalator shaft up to street level, so this is the very place people will pass through on their commute when the upgrade is completed.

The new entrance will also add a lift giving step-free access down to the Northern line and DLR.

The breakthrough now creates the link from the Northern line level to the new entrance, which will also make further construction work easier as they gain an addition route from street level down into the tunnels.

The connection is part of a substantial upgrade of Bank station, which will see the Northern line platforms enlarged and a travolator connecting the Northern and Central lines.

All the tunnels have been excavated using two diggers as the confined tunnel space prevented the use of a tunnel boring machine. In some instances, tunnelling has been undertaken by hand, using traditional mining techniques used on the Tube for over 100 years.

The project to upgrade Bank Tube station, which is being delivered alongside contractor Dragados, will increase capacity at the station by 40 percent when it is completed in 2022.

An in-depth look at the Bank station upgrade is here.

Stuart Harvey, Transport for London’s Director of Major Projects, said: “Bank Tube station is one of the busiest and most important stations on the network. The area around the station has a high concentration of important infrastructure both above and below ground, including a number of historic, significant buildings in the local area, making the upgrade work incredibly complex. The hard work done by the project team will result in real improvements in the journeys of hundreds of thousands of customers every day.”

The interchange between Bank and Monument Tube station is one of the busiest on the Tube network; each weekday morning around 120,000 customers use the stations, of which over 50,000 are changing lines. Demand has risen by around a quarter since 2008 and its complex network of pedestrian tunnels and escalators between the Central, Northern, District, Circle and Waterloo & City lines, as well as the DLR, regularly causes congestion and delays to customer journeys.

There will be a closure of the Bank branch of the Northern line between Kennington and Moorgate in 2021 to allow the tunnelling to be completed, as the new Northern line southbound tunnel is connected to the existing railway.