Crossrail wait will be worth it

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.

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