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inventions have had as a revolutionary
effect on her society as the advent of
the steam engine
this machine allowed the automation of
production creating thousands of new
jobs in our cities and drawing humans
from our farmland existence to an ever
more metropolitan life the population of
London doubled in the first half of the
19th century as people flooded from the
country sites in to London's Kings Cross
on the very engine that spurred the new
trend of urbanization and
industrialization with few options for
transport within the city beyond horse
and carriage these new city dwellers had
little choice but to live in crowded
slums near their places of work areas
like Whitechapel and Spitalfields that
were once home to the prosperous
Victorians and French Huguenots became
disease and crime infested homes to the
working-class these areas had one thing
in common they were within walking
distance of Kings Cross the supply line
of the city's new factory workers London
needed a new transport system to allow
these workers to spread out and prevent
overcrowding bored little space above
ground for an urban rail system northern
city planners needed a novel approach
and so the world's first underground
rail system was born our ancestors have
probably been digging burrows and
tunnels since they climbed down from the
trees but the earliest tunnels we know
of existed as far back as 2003 most
tunnels were created for mining or
military engineering often through
stable rock and over short distances in
fact the word for mining and mine used
for an explosive device are closely
linked for exactly this reason
as early tunnel technology was developed
in order to approach fortification walls
undetected to place an explosive charge
one of the primary reasons moats became
popular was because ground water mixed
with soft porous soil was one technical
problem these early engineers had no
solution for constructing tunnels was
and still is dangerous work tunneling
accidents were common whether it be from
flooding tunnel collapse due to
inadequate reinforcements or explosions
the fear of collapse was always on the
mind of these workers who dug these
tunnels with simple tools like pickaxes
and shovels in dark claustrophobic
environments despite the constant risk
civil engineering made huge strides in
total building techniques
over the course of the 19th century
starting with the world's first
underground railways in London but the
development of the London Underground
was made vastly easier thanks to the
London clay which the city is built upon
although the soil today makes it
difficult to build skyscrapers as it
cannot support their weight it is ideal
for tunnelling being soft yet relatively
stable London's first underground
railway line the Metropolitan line began
in 1863 and was mostly built using the
cut and cover technique a trench would
be dug walls and a supporting roof
structure built and then buried again a
safer and easier tunneling technique but
it resulted in the demolition of streets
or whole city blocks even today the
remnants of this construction technique
can be found with hollow buildings
hiding the skies of London's past the
Metro in Paris was largely constructed
this way and in 1970s absurdum the use
of these cut and cover techniques led to
the Newmarket riots and even an
attempted bombing at one of the new
metro stations the new 3.5 kilometre
line forced a destruction of numerous
homes in a time when absurdum was
struggling with a housing crisis the
plans for a complete Amsterdam
underground were abandoned as a result
no new subway line would be built
through the city centre until 2003 with
the help of a tunnel boring machine
which began life in London in 1825 Marek
Isambard Brunel together with a son
Isambard Kingdom Brunel invented a
technique to make tunneling somewhat
safer and less invasive the tunneling
shield this shield was a scaffold like
wrought iron structure with 36 chambers
each containing a single workmen these
chambers were further broken down by
polling boards which were horizontal
planks of wood that the workers removed
individually to hew out the tunnel wall
to a predetermined depth before
replacing the board and moving on to the
next section separating the tunnelling
face like this compartmentalized the
constant risk of tunnel collapse
reducing the chance of a small collapse
in the face cascading and causing a
total collapse burying every worker in
the area once each worker had finished
their work the entire shield would
advance while bricklayers rushed to
finish supporting brickwork behind the
shield this early concept laid the
foundation for all future tunnel boring
machines but much was left to be
improved construction of burnell's
Thames tunnel was fraught with problems
despite this new tool water constantly
seeped into the tunnel which was a
nuisance wild pumps were operational and
a disaster when the pumps failed in the
summer of 1826
the tunnel floating up to 12 feet would
polluted tames river water this combined
with poor ventilation made working
conditions horrendous temperatures rose
and plunged with no warning and workers
complained of illness ranging from
headaches and diarrhea to temporary
blindness and one worker died from his
illness this was just one of many
problems that Brunel encountered and we
would need an entire video to document
it all but the team persevered and 16
years later with the painfully slow
progress of just four inches a day the
tunnel opened a pedestrian traffic in
1843 the project tested the technology
of the time and provided vital lessons
for future projects in 1869 a second
passage was dug under the Thames from
great Tower Hill to pickle herring
stairs it was built with a much improved
version of the tunnelling shield by
Peter William Barlow parallel made one
crucial change to the design instead of
a rectangular cross section he made the
shield circular improving its ability to
support the surrounding soil and the
swelling of the Thames River above it
this passage under the Thames was fitted
with a narrow gauge railway and a cable
hauled wooden carriage carried
passengers back and forth this proved to
be on economic and the company went
bankrupt within a year the tunnel was
then converted for pedestrian use and
became known as the tower subway it was
relatively cheap to cross the Thames
this way however when the toll-free
Tower Bridge was opened the so boys
income dropped and was sold in 1896
currently it's in use as a utility
tunnel for water mains Barlow's design
was further improved upon by James Henry
great head when constructing the city
and South London railway nowadays part
of the northern line using compressed
air tunnelling below the ground water
table became safer as the pressurized
air prevented water inflow into the
tunnel workmen would enter and exit the
excavation through an airlock this
together with a circular shield and cast
iron rings to line the tunnel walls made
for a much safer and efficient job this
is how many of the deep-level tube lines
were built and travellers on the
underground could still see the cast
iron rings lining the tunnel walls in
certain places the circular shape of the
tunnels this method created inspired the
London Underground's name the tube to
this day most tunnelling shields are
loosely based on the great head shield
modern day tunnels like the Royal Oak to
Farringdon tube line are built using
TBMs or tunnel boring machines and these
long machines consists of several
sections and essentially form an
automated assembly line for tunnel
boring the front section of the machine
is a
version of the tunneling shield however
nowadays it features a rotating cutter
head these rotating heads can be
equipped with different tools depending
on the type of soil as the head rotates
the loosened soil enters the mixing
chamber directly behind the cutters
where a screw conveyor transports the
soil out of the cutter head and onto a
conveyor belt this conveyor belt then
transports it out of the tunnel while
the machine automatically installs
reinforcements as it progresses these
new machines allowed the London
Underground to expand even further with
minimal disruption to life on the
surface with possible future
improvements decreasing the cost and
time needed through endeavors like Elon
Musk's boring company our societies
could be in for more radical change with
ever-growing city populations empowering
people's movement can and will increase
our quality of life just as these early
engineers facilitated a radical societal
change for the working class in cities
like London you can create your own
radical social change by learning a new
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