ANDY CADMAN, senior contracts manager at NG Bailey, talks about the challenges of redeveloping Tottenham Court Road Tube station

Tottenham Court Road is one of the busiest Tube stations in London and, with the introduction of Crossrail in 2018, demand is likely to increase by around 30 per cent.

Originally built as two separate stations over 100 years ago, Tottenham Court Road was simply not designed to cope with such high demand from passengers. The station entrances were frequently congested, often leading to temporary closures during peak periods of the day to prevent overcrowding in the station.

To eliminate this congestion, Crossrail and Transport for London (TfL) are redeveloping Tottenham Court Road and constructing a separate Crossrail station, the length of three football pitches four storeys underground, with a total investment of £1 billion – the biggest investment in the West End for decades.

The scheme is part of the wider transport developments taking place across London, where TfL is investing in projects that will improve travel for people who work and live in the city.

The existing Tottenham Court Road Underground station has been running over capacity for with around 150,000 passengers per day, but when the project is complete it will cater for more than 200,000.

A new public plaza outside the adjacent Centre Point building is being created, with wider pavements, better cycling facilities and improvements to bus services.

Modernisation begins
The redevelopment of the 100-year old Tube station began in 2009 and is expected to be completed in 2016. NG Bailey’s Rail division was contracted by Taylor Woodrow/BAM Nuttall Joint Venture to modernise the existing operational Tube station.

The first phase of the £27.9 million contract began in 2010 and was completed in January 2015. It covered the design and installation of all electrical, mechanical, fire detection/suppression and communication systems.

One of the most exciting elements has been installing a high-definition digital IP CCTV system, which is linked to the existing station infrastructure. It offers improved security and can record images to a much higher standard than any other monitors, by using fibre optic and CAT6 cabling infrastructure.

Keeping the underground running
The key challenge on the project has been keeping the existing station areas operational as, due to the constraints of the programme for the phase two civils section, the old systems such as lighting, CCTV, PA/VA and fire detection had to be immediately shut down and removed.

To overcome this, NG Bailey installed new systems alongside the existing ones, particularly on the Northern line platforms, that required seamless operations for trains. These systems were installed and commissioned back to both the new station communications equipment room (CER) and station operations room (SOR), meaning that two parts of the project _ the modernisation and the new build station _ were required to be completed and commissioned simultaneously without fail. The high voltage and low voltage supplies were also migrated to new power supplies via a series of changeovers across a three-month period.

To make the process successful, identification of critical areas of the existing station were made and coordination of the new installations implemented in and around many of the old assets. These were already considerably congested through the ‘back of house’ areas and public passageways and required a series of enabling works. At the same time, close coordination with the architectural team was required, to ensure the finishes could be effectively implemented at a later date in areas which were to be modernised.

This process was planned and implemented over the full six-year project period, in line with progress on civils and tunnelling works.

Looking ahead
We’re now in the second phase, in which we’re building on our ‘one team’ ethos _ where all contactors take a collaborative approach _ to progress mechanical, electrical and plumbing (MEP) services in the next section of the new ticket hall, where the two new glass plaza entrances near Centre Point will be built.

The ability to provide a combined MEP and station communications installation has achieved considerable project management savings over the life of the project. Meanwhile, work has begun on the modernisation of some existing areas of the station, including passageways and escalators, and the newly installed electrical and communications systems.

The old ticket hall will be demolished, re-constructed and completely fitted out, matching the new ticket hall.

December 2015 will see the re-opening of the Central line, following an 11-month closure. NG Bailey has modernised the existing passageways and escalator areas in preparation for this, as well as some temporary installations due to the sequence of architectural and civil works taking place.