christian_wolmar

Crossrail is delayed, but this is not surprising give the complexity of the project – but when it arrives we will all be impressed

 


 

There’s been a lot of fuss about the delay and the extra cost of Crossrail in recent weeks, but overall the project has escaped the sort of negative publicity which such projects often attract. Although 95% or so complete, the project is now appearing rather troubled and certainly there is a lack of clarity about when it will open, the time given ‘next autumn’ is sufficiently vague to cover a long period. Crossrail is in danger of going down as yet another troubled megaproject.

In fact the delay was inevitable. As I was researching my book on Crossrail at the beginning of this year, it became clear to me that the promised opening date of December 9th was never going to be achieved. There was just so much to do and although the big tasks of cutting out the tunnels and stabilising the structures had been achieved, the fitting out of 10 major stations in the centre of London was never going to be easy. Indeed, while the tunnel boring process took just over three years, being completed almost on time in May 2015, the fitting out and completion of the project to create a functioning railway has taken longer.

That is hardly surprising given the range of systems that have to be installed, starting with the track and the overhead catenary. Various bespoke machines had to be constructed to carry out other tasks such as drilling all the holes needed to fit the trays carrying the various electrical wires. This would have been a messy job to do manually and instead a machine with the drilling equipment was programmed with all the information required and slowly taken through the tunnels making eight holes at a time.

There were, inevitably, some mishaps. The worst was the death of René Tkáčik, a Slovakian, and an experienced tunneller, killed in March 2014 by falling concrete, an ever present danger during tunnelling. This led to the prosecution of the contractor, Bam Ferrovial Kier and the payment of a large sum in compensation. Although he was the only fatality – apart from three cyclists and one pedestrian killed by Crossrail lorries – which meant that the project’s safety record was far better than most comparable schemes, the death had a very strong impact on the Crossrail team and still casts a pall over the project today.

In terms of causing delays, an explosion in a transformer on the eastern section of the tunnels was the most significant accident and undoubtedly contributed to the eventual delay in opening.

Two aspects of the scheme made a delay in opening highly likely.

Two aspects of the scheme made a delay in opening highly likely. The first is the sheer complexity of the interplay between the different systems. While each system, such as ventilation, high voltage wiring or tracklaying can be planned out and scheduled, their interaction can lead to unexpected consequences. This was brought home to me by Bill Tucker, a Bechtel man who is in charge of project delivery.

He cited an excellent example of how a change in part of the project can lead to changes in an unrelated section elsewhere. His team had gone through a lengthy process of identifying the precise size of fans and ventilation shafts needed at each station. Various factors such as the aerodynamics of the tunnels had to be taken into account in the design of the shafts which, in turn, had an impact on the architecture of the station.

However, after that work was completed, Howard Smith, who is the operating director, chose Bombardier to supply the trains and the Derby-based company opted for lighter trains than had been envisaged. They occupied a smaller proportion of the tunnel envelope than had been expected and consequently pushed through less air in the piston effect that is the key to ventilation in underground railways.

Tucker explained to me: “That changed the whole calculation. Bombardier’s solution was more economical in terms of maintenance but it meant we needed bigger fans. The fans had to do more because the trains did less, and these bigger fans caused more vibration and noise, and therefore needed more abatement and better insulation from the vibration. So one little change can have a ripple effect on station design, acoustic mitigation and the design of the fan itself.” It is a great response to critics who all too easily blame the Crossrail team or the politicians for delays. There are simply bound to be some unknown unknowns in a £15bn project.

The second factor that made delay almost inevitable was the complexity of the signalling system – or rather systems. Again, critics have been quick to point out that having three different systems for the trains was bound to cause difficulties, and in that respect they have been proved correct. Commissioning the trains to cope with the three systems was the main – but by no means only, as some stations were not complete – factor in deciding to push the opening date ahead by a year.

While it seems unnecessary to have three signalling systems for a relatively short railway – just over 100kms from end to end – ultimately it was unavoidable due to legacy issues.

Howard Smith took me through the lengthy explanation and logic. The need for three systems is a result of European requirements to create an interoperable system throughout the continent. All new railways must now be fitted with a system that is compatible with European Train Control System Level 2 which requires trains to be controlled by radio signals in the cab, obviating the need for lineside signals.

The obvious solution would have been to fit ETCS Level 2 on the Crossrail trains but to continue to use the old TPWS (Train Protection and Warning System) that is fitted throughout the national rail network. However, in the Heathrow tunnels there is an Automatic Train Protection system (devised by British Rail) which, while more sophisticated than TPWS, is not compliant with ETCS Level 2. That left Crossrail with a dilemma. The obvious solution would have been to fit ETCS Level 2 in both the Heathrow and the main tunnels but there were doubts, currently confirmed, that ETCS Level 2 would be sufficiently developed to be available in the long tunnels. That is why a system called Communications Based Train Control was chosen for the main section, as it is sufficiently developed to be reliable over the 21km tunnels. Overlaying CBTC on the main sections was considered too risky, as that had not been done anywhere in the world and was also, for complex technical reasons, considered unsuitable for the Heathrow tunnels. So the ultimate result was that there seemed no alternative but to fit three systems onto the trains, with the consequent complexity which has been the main cause of the delay.

All these difficulties, however, will be forgotten when Londoners first set eyes on the stations and some of the fantastic architecture below the streets, they are bound to be impressed

All these difficulties, however, will be forgotten when Londoners first set eyes on the stations and some of the fantastic architecture below the streets, they are bound to be impressed. Because most of the work has taken place under the ground, hidden from view, all most Londoners know about Crossrail is the huge hoardings hiding the various surface building sites (memo to Crossrail – would be a good idea to take down those which say ‘opening in December 2018’). Moreover, the idea of calling the railway the Elizabeth line as a result of a daft intervention by former mayor Boris Johnson means that many think that it is just another Tube line. Given the tunnels are nearly 50% wider in diameter than the Tube, there are doors on the edge of the platforms which are more than 200 metres long, and that the trains are nine cars with the potential of carrying up to 1,500 people, it is nothing of the sort. It is a huge railway, an amazing addition to London’s infrastructure and it will immediately stimulate demand for more new lines. Its inevitable positive reception will not only ensure all these problems are forgotten but will increase pressure for Crossrail 2.

However, I suspect that it will be a struggle to get a project already costed at more than double the £15bn bill for Crossrail 1 through the political process, not least because of the uncertainty over future passenger numbers. That is the one big concern for the completed scheme. In a way, it has been built too late. While I am sure many people will use it, whether the target of carrying 200 million passengers annually will be met, as hoped for, by the early 2020s, is an open question. If it is not, that will fatally undermine the case for Crossrail 2. Meanwhile, though, Londoners and visitors to the capital should look forward to their first view of what will undoubtedly be perceived as London’s greatest public transport project.

For a signed copy of Christian’s book, The Story of Crossrail, email christian.wolmar@gmail.com
Twitter: @christianwolmar

 

This article appears inside the latest issue of Passenger Transport.

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