Good morning and welcome to central London. Holborn underground station to
be exact. Thirty four million people every year use this station, riding up
and down one of the four escalators probably not thinking a thing about it.
But what happens if you have to take one of those escalators out of action? Well
we've come to find out
So the man in front to me, that's Adam Thompson. He's in charge of all this
today. So talk about where we're heading at the minute Adam? We're heading to the UMC, which is the Upper Machine Chamber
On escalators four to seven. There's two machine chambers on an escalator.
An Upper Machine Chamber and a Lower Machine Chamber, and in between there's the incline
which the escalator runs down.
and can hear you why it's called a machine chamber. Because there's quite a few machines in here.
so whereabouts in the station are we right now like if you're walking in
and out of Holborn station, where are we? We're right below the ticket hall now. So this space is
basically the same size as the ticket hall. The sizes of machine chambers vary in different stations
In Holborn it's the whole width of the ticket hall.
and these are the drive machines for escalators four to seven. The long escalators at Holborn.
Do they ever stop or are they continuously running?
They're designed to stop for four hours in engineering hours although that's now
changed because we have night tube. So on Friday and Saturday night they run constantly.
These machines have all had the motors replaced, the brakes replaced and the gearboxes replaced.
To actually get between the escalators to where they're actually doing the work
we have to walk between the motors and then underneath the top of the escalator
luckily I didn't look up because it was pretty grotty the amount of hair hanging
down above me it's difficult to see though when we show it on the camera
This is underneath the top of the escalator. You can see all that hair hanging down.
That's the dirt off the escalator.
We finished this about six months ago so that's 6
months hair. Gives you an idea of how much dirt.
It's a pretty narrow gap right, as you kind of would expect i suppose.
We're standing here between the escalator. There's not very much between people standing on
the steps and a moving machine. In fact they are standing on a moving machine.
and generally if you think about it where you have moving machinery you have guarding to
stop people touching it. Escalators are different you stand on the steps
for that to be safe these rails which are called the tracks, have to be very
accurately aligned, so there are no gaps above that people can put their fingers
in or get caught in or anything like that or the steps get undue
stress. When we work on an escalator the first thing we do is take all the steps and the chain out
and then we go and do what they call scoping, which is to establish what condition the tracks are in
When the tube was built, the Bakerloo line, the Northern line
Central line. The big expansion of the tube in the early 20th century, they
all had lifts and in fact there were lifts at Holborn. There is actually
a lift shaft still here at Holborn and that sometimes creates us problems
because we have lift shafts that sort of appear underneath escalator works which
you then have to bridge over if you're replacing the escalators
What's the most common reason for the escalator to kind of like
malfunction? Is it someone dropping something? The most common thing is
coins and things getting dropped on on the steps and then they they hit the what
they call the cone plate which is the teeth at the bottom.
You were asking me earlier about where does the dust from all the steps go
the answer is on trays like this. It gets caught as it comes around the steps and drops down to where
your coins and all that sort of stuff that might drop through the steps it comes down
onto these dust catchers. Have you found anything unique? There's a lot of stories. gold rings and gold coins
but I've never seen them myself. So the lower chamber also houses the
water pumps. Now they're continuously running to remove water from the network
and although it's noisy down here it's not completely unbearable. So we leave the
lower chamber up this narrow staircase and behind us is Nancy carrying the
tripod that I did ask her to carry we didn't end up using it, sorry about that Nancy
but she did a grand job nonetheless. Now having seen the works from underneath we
are now getting the chance to take a look behind the blue hoarding from above
nice hat
so this is the bottom of the escalator this is called the idler shaft
it's the smaller of two shafts. A driveshaft and ider shaft and the chain
runs between the two sets of shafts so there's a big chain that runs in these
sprockets and then the steps are attached to those big chains. In Holborn
there's 34 million people go through this station a year.
on a weekday that means there's a hundred thousand people going in and out
of the station on any given week day. As a comparison
Gatwick airport takes about the same number of people but over a much bigger area so
it just gives you an idea of the intensity
Adam takes us back to the top of the escalator to explain the differences
between the two ends. The top shaft drives the machine so what we saw downstairs that
the gearbox and the motor there's a chain that goes from the gearbox
to this sprocket here
which turns the steps. This was the escalator that was in the worst condition in the
station so there's been a number of issues that we've encountered with the condition of the machine.
but yeah if I can get the step chain and the steps back in beginning of the year I'll be happy
When are you back again? 15/20 years time? 15/20 years yeah. We've already started a Charing
Cross. This team will go to St. Pauls next. So there you go, a peek into the work of Adam
and his team. Keeping the escalators on the tube network in tip-top condition