The Times - UK (2022-04-30)

18 Saturday April 30 2022 | the times

News

London can breathe a little easier —
animals, fish, birds and pets as well as
people.
Digging has been completed for the
city’s “super sewer”, the 16-mile
Thames Tideway Tunnel running
under the river from Acton in the west
to the Abbey Mills pumping station in
the east, six years after construction
began and more than 20 years after the
project was first mooted.
Sir Neville Simms, chairman of the
Tideway group, said: “London is a giant
leap further towards a cleaner River
Thames.”
The six huge tunnelling machines —
named after pioneering London
women — will be dismantled. The shaft
will be given its secondary lining before
it is brought into operation in 2025, a
few months behind schedule, thanks to
Covid. The work will relieve pressure
on a sewer system that has essentially
remained unchanged since Sir Joseph
Bazalgette built it in the middle of the
Victorian era, prompted by the Great
Stink in the summer of 1858.
To celebrate the end of tunnelling
this week, probably the most surreal
musical event of the year was held. A
work specially written by Rob Lewis, a
cellist and composer based in London,
was performed on a live stream and is
still available on YouTube. Lewis played

buses driven down it side by side, should

anyone wish.

Yet when the capital is hit by a big

storm, creating a surge of rainwater, the

entire system could be filled in a few

hours. In that case the entry shafts

would act as storage tanks, preventing

the Beckton treatment works from

After more than 20 years, city’s

super sewer is breath of fresh air

Richard Morrison the cello in the vault-like acoustics of
the tunnel, managing to include in his
ten-minute piece the sounds of the river
and the construction, as well as more
melodious elements.
To reach this unique performance,
more than 200ft below the Thames just
east of Tower Bridge, a venturer must
make a journey not to be recommended
to anyone prone to vertigo or claustro-
phobia.
With an emergency oxygen supply,
the explorer descends in a metal cage
down a vast concrete shaft as wide as
the dome of St Paul’s Cathedral.
Once down in the tunnel one starts to
understand why the sewer is reckoned
to be the largest infrastructure project
in Europe. A subterranean building site
of massive dimensions appears, each
tunnel equipped with miles of pipes and
cables and railway tracks on which
trucks carry away the 5 million tonnes
of chalk slurry and clay that have been
excavated. All that will be cleared away
in two years and the tunnel sealed to
everything except sewage.
The passage slopes imperceptibly
downwards at a gentle gradient of 1:70,
giving London’s monstrous flow of
effluence just enough gravitational
nudge to move eastwards towards the
sewage treatment works at Beckton, in
Newham.
The excavation is on a huge scale —
wide enough to fit three double-decker

How it works

Overflow

Heavy rainfall

and sewage spill

into newly

constructed

shafts

2

3

4

5

1

Central Thames tunnel

Sewage travels beneath

the Thames until it

reaches pumping

stations

Up to 30m wide

Up to

65m deep

Shad

Thames

Heathwall

Abbey Mills

Acton storm

tanks

Greenwich

River Thames

CHICHICHIHSWSWISWIWCKCK CHECHELSELSESESAA

LAMLAMMBETBETBETETHH One mile

BATBATBATATERTERTERSEASEASEAA

River Thames

Current

sewer

system

Hammersmith

Pumping

station

Deep shafts

Sewage travels

down into deep

shafts located

along the

Thames

Sewer connections

Sewage fills the shaft

and feeds via

connecting pipes to the

central Thames tunnel

Source: Tideway

London bus

to scale

7.2m wide

main tunnel

Deep underground

Rob Lewis plays his

composition to mark

the end of digging for

the Tideway Tunnel