We're out on the Bakerloo Line
just about to arrive at and get out at Paddington Station
where we're going to check out the Crossrail construction site
and have a look at something, that has piqued my interest
here, down on the platforms of the Bakerloo line
So we're at Paddington, where Cros Eliz Purp line is being built!
Slowly ... it'll get there
I want to point out this blue hoarding here
you can see above, there's a little bit of purple
that is where a new contuction tunnel is being built
let's go and look at the main construction, outside!
So we've come outside at Paddington
last year during 2018, when we all thought
Cross Eliz Purp was gonna open
i started to do a whole series of videos about the exits and entrances, to all the new Crossrail stations
and I never got to where Paddington was, because ... i just didn't get to it!
And now it's gonna open on time
it's gonne open late, it's worth seeing right here
oh wow! it's come on loads, look
So, over my shoulder
what we've got when i did the series in 2018 about
enrances and exits
i showed you where they all were, so I just want to explain that here at Paddington
there'll be three ways in
the first one, is here from the street level
that'll take you in through this building here
and you'll then go down to a mezannine level
that's where the ticket concourse is, and then escalators down, to actual track level
if you're in the main, the Paddington mainline station
there'll be a side entrance there, about where Paddington Bear is right now
they'll have to move him, and his pot of marmalde
and there'll be escalators and steps down
to that same mezannine level, and then they'll get down into there
the THIRD way in
is the one we just saw coming off the tube train just now, is that at the Bakerloo line
there's steps down and a corridor that will take you underneath
the main Paddington station, and then bring you up
into the Crossrail station, and as you will recall a few minutes ago we saw
some of those intruiging ... reflectory yellow discs
gadget thins - which is it's official name!
and THIS is what this video
is chiefly about because it's at this point ...
a man is gonna appear just ... like magic! - WOW!
you were waiting there the whole time! - I was
this is Steve, Steve who are you?
so i'm Steve, i make science videos
and these little reflectors, they're called Retro Reflectors
the way thay work is amazing, what's relly cool is
as Paddington, there's about one thousand, eight hundred of them
all dotted all over the palce, so we're gonna take a look at one
down in the station - We're gonna go back down
have you counted them? how do you know there's 1800?
Oh i read a thing - That's a lot of reflectors
Ok. shall we go down? - Let's have a look
Ok, so here's one of the reflectors down here
there's another one ... up there
if you look all the way along, there's load of them dotted along
there's loads of them dotted along on the walls here
and thee wall there, now - they all point to something
so if you follow, as if it's an eye, where's it looking
it's lokoing up to that cradle there, now there would normally be
something that looks like a robot there for some annoying reason, they've taken them all down
it's called a TOTAL station
it's like a theodolite, have you ever seen
someone doing surveying?
you know they've got a tripod there and a device on top
that's a theodolite, it's tiny angles, so ...
up and down angle, left and right angle
but a TOTAL station is like a theodolite
that has - extra powers!
So, it can also tell distance and it does it by
down to the reflector, it bounces back and it measures
the time difference, these TOTALstations are quite special
they're auotmated motorised TOTALstations
motorissed because they can move around and they can look at all of these different
reflectors that are all over, and automated because, it doens't require an operator
some of them, have this feature where
you can just add a new reflector wherever you want
and it will periodically scan for new reflectors
turns out the reason they took all the Robots away at Paddington
is because they've finished doing all the digging
so, they don't need them there. so we've come to Bank
where they're doing the Capacity Upgrade
and err, there it is!
there's one of the
TOTAL stations, we should see it move!
we've, come back outside
the construction continue behind us
and Steve, all you've down now is just
made me see the reflectors, like ... everywhere
there's one, there's one! there's another one
so i've now become a reflector spotter
*laughs* they haven't got numbers on them though
you know i don't write down numbers, but i'm now gonna
Think about this though, these little reflectors
they're ... not just mirrors
imagine if it was just a mirror, and the
little robot is shining a laser at the mirror
and it's bouncing off the mirror, if you didn't line up that mirror exactly, if it was slightly off
the laser would end up, pointing in the wrong direction
the Robot wouldn't be able to pick up the reflection
so instead - it's not a mirror!
it's a special kind of reflector
and if you like at the
lines in there, the six little lines in there
they all converge on the centre, that's because of the way these things work
you can orient it, anyway you like and it will still send the laser light
back where it came from
and actually, when you start seeing these things, they're called
retro reflectors, they're ... everywhere!
and honestly the science behind, well maybe the maths actually
about how they work, is really cool
and does the software automatically send back something once a day if there's something wrong
does it require manual input, someone to go down
and check a screen, how does it alert, the person?
So Crossrail construction at Paddington has
about fifty of those robot thingsm but a hundred and eight
so one-thousand, eight hundred of the reflectors and it's one integrated software system
so it's constantly reporting back to a central hub
and that central hub, is building a 3D model of ... Paddington
it's amazing, the accuracy is in the order of like one or two millimetres
in terms of distance - So you're allowed a little bit of ...
there's a little bit of give
yeah and if there seems to be movement beyond that
then, a human is alerted
and then some manual measurements take place, to see what the problem is
so there's an alert system, that then requires
manual inspection? - Yes there is
I feel like we should get people to watch your video
Watch Steve's video! - To find out how those reflectors work
but also, a whole load of other stuff, about
why you see these kinds of reflectors
all over the place, but why you won't see
a right angle, anywhere on a stealth aeroplane
and other amazing, nerdy, science stuff ...
click, and watch this happy man
are you putting the thumbnail over my face?
there'll be things on the screen, right now
have you enjoyed your day out? we've basically just hung out at Paddington
yeah, do you know what? i always thought
it would be really dangerous to hang out with a Transport nerd
because ... they would turn me into a Transport nerd
you know, we've found out a lot of interesting things
and i feel like, i'm teetering on the edge ...
of really wanting to find out the finer details of railway construction
so i'm a bit nervous to be honest - It's no bad thing!
alright, watch Steves video subscribe to his channel
do all the click, bell, notifcations things
- Don't forget to like and subcribe! *laughs*
SMACK THAT BELL!
do you ever do that? i don't do that
no, i did it once or twice for when i wanted people to
watch the follow up video!
watch Steve's great video on the science behind
the reflectors, thank you very much!
Steve Mould! - Bye