It’s just over a year until Crossrail embarks upon its first journey, when its 73 miles of track will cut through central London to connect Reading in the west with Abbey Wood and Shenfield in the east. Making this journey possible through one of the most congested cities in the world has required a monumental effort, with 10 brand-new stations built and a twin-bore, 13-mile tunnel dug that will eventually increase central London’s transport capacity by an impressive 10%.
For good reason those stations and tunnels have received a huge amount of attention, but they have also taken the focus off some equally impressive feats of engineering that underpin the entire network. Addressing the balance for this month’s Work in Progress, SmartRail World’s Dave Songer gives some overdue coverage to three major aspects of Crossrail deserving of the front page.
A powerful transformation.
A fleet of 66, 200m-long trains will eventually run on the east-west train line when full capacity is reached, requiring an awful lot of power and a great deal of cabling – 400kV and 932 miles to be precise. The contract to install the systems powering Crossrail’s infrastructure was awarded in 2012 to a joint venture between Alstom Transport and Costain that would involve the construction of supply points and autotransformer feeder stations at each end of the railway.
Following conversion of those 900kV down to 25kV, the cables – which are linked with overhead catenary systems – will give the rolling stock, lighting and ventilation systems along the network the power they need. The voltage will be maintained with four transformer stations located across the route: Westbourne Park, Stepney Green, Custom House and Plumstead.
The network’s signalling, radio and communications and control systems are also powered by the 25kV power lines. To power such essential rail infrastructure in the most efficient way possible, which has been a big focus of Crossrail’s remit, lightweight energy efficient trains as well as LED lighting in stations, tunnels and trains have been developed. During the construction of Europe’s largest infrastructure project, it’s those kind of initiatives have enabled Crossrail it to lower its CO2 emissions by 11%, equating to a saving of around 52,000 tonnes of CO2.
From street-level to platform.
When up and running, each of the trains will be capable of carrying up to 1,500 – that's 72,000 people an hour. It’s therefore imperative that passengers are able to swiftly enter and exit the stations, and this is achieved by using the best escalators available on the market. Crossrail is in the process of installing 81 at nine stations, which if put end to end would add up to more than 1.8 miles. The £190m contract for this was awarded to Otis Lifts just over five years ago, and the manufacturer made a key commitment to improve the reliability of its escalators by 60%. Helping achieve that figure, Otis will install a new breed of escalator that’s been specifically designed to operate at a range of speeds as required – keeping costs and wear and tear down.
Having reached the halfway point in August, the longest of the escalators will be at the central London station that has undergone an almost total reconstruction following integration with its existing Underground station – Bond Street. The 60-metre escalator will take passengers directly to the platform level 25 metres below street level. Gareth Powell, London Underground (LU) director of strategy, said the deal was “one of the biggest orders ever placed in the UK for station escalators” and would increase capacity by more than 30% over the next 10 years.
The coolest platforms.
Taking the lead from LU’s Jubilee stations, all eight of Crossrail’s below-ground stations are to be fitted with platform screen doors that create a barrier between platform and train. Though not intrinsic to the running of the network, what they do offer is a safe environment for passengers by preventing them from accessing the tracks.
More than just a physical barrier, the doors play an intrinsic part in the line’s air extraction system that – in the event of a fire – keeps air running through the station and extracts smoke from the platform. Thanks to the extraction system, the stations’ air conditioning systems operate more efficiently because cool air isn’t lost down the tunnel – and the platforms stay cleaner due to dust and debris not being deposited onto the platforms.
Knorr-Bremse won the contract to supply nearly 2.5 miles of barriers, and the German company brought in SCX to install them with its innovative bespoke automated system. SCX’s installation system uses the tracks to carry the fully-built doors to the platform edge, where upon arrival it manoeuvres the units exactly into place. Designed to work in all environments, the heavy lifting system holding the platform doors is able to precisely tilt as required to fit into tight spaces inhibited by structural gantries and columns, as shown in the accompanying video.
The next Work in Progress is due to be published on Thursday 14 December. If you would like to suggest a project, please contact firstname.lastname@example.org
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