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 as 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 have been done 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, 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. 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
impacted 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 a
relatively short railway – just over 100kms from
end to end – having three signalling systems,
ultimately it was unavoidable due to legacy
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. 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, 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 such lines. Its inevitable positive
reception will not only ensure all these
problems are forgotten but will increase
pressure for Crossrail 2.