Original subtitles

In Australia, Sydney is on a mission.

There's still a huge amount of work that we need to do. To relieve chronic

traffic congestion.

Sydney's traffic problems are incredibly difficult to solve.

By building a new state -of -the -art metro system right through the heart of

the city.

But can it all be built underneath five million busy people? Huge logistical

nightmare. Without bringing them to a standstill. A lot of things have to go

right. in sequence so an expert team of men and women from around

the world quite scary there's a lot that can go wrong are stepping up to this

challenge with some pleasure oh wow this is amazing and pain

along the way that's my station here that's what we built

Deep underneath the crowded streets of Sydney, engineers have embarked on a

-shaping mission to build a revolutionary new metro system for the

and beyond.

It's a really gruelling stage of the project right now. It's all happening

ground, behind the hoardings. People can't see it. Thousands of people on the

ground. Just that constant fight to keep the TBMs moving. It's about getting the

job done.

South of the CBD, two tunnel boring machines.

or TBMs, are driving north towards the city.

On Sydney's lower north shore, two are digging south, downhill to the harbour's

edge. And near the harbour bridge, deep under the surface of Sydney Harbour, the

highly pressurised TBM Kathleen is making a second perilous journey to

Point.

TBM Kathleen has recently completed the risky journey across Sydney Harbour by

barge and arrived safely at Barangaroo.

Her massive front shield and cutterhead were driven onto dry land and she's been

reassembled underground and successfully relaunched

right next to her first completed tunnel.

Making his way to work on this machine, tunnel ship boss Adam Griffiths is happy

with progress so far.

Overall, we're pretty much on time and apart from a few niggly issues along the

way, we're looking pretty good.

The niggly issues were actually more serious than it sounds.

A few months earlier, on their first journey under the harbour, things didn't

always go to plan.

And TBM Kathleen and members of her crew, including Vincent, Andreas,

Red Dog and Griffo, had some serious challenges to overcome.

We then made the decision to immediately stop the tunnel boring machine and to

prepare for an intervention.

They had to enter the pressurised cutterhead when TBM Kathleen was deep

the harbour to replace a metal wedge.

A 400 -kilogram cutter wheel was threatening to come loose and severely

the TBM.

And the last thing you want to do is put a hole in Sydney Harbour. But just when

they thought their problems were over, a stream of bubbles started to appear on

the surface of Sydney Harbour, right above their TBM.

Bubbles are not good. It means that something is going wrong.

We had a little bit of air escape into the harbour at one stage.

The team were alerted to the issue by members of the public.

who are starting to get concerned, thinking it might even be a whale.

Probably quite dramatic to look at the outside, more of a panic, but on the

inside everything was fine.

With these troubles now behind them, the specialised flurry TBM is about halfway

through the second drive, and things seem to be going well.

Actually, we're bang on schedule.

Yeah, we're literally...

Monday early.

The crew have made a few changes, and it's allowing the TBM to work faster and

more efficiently.

Made a few modifications to the cutter head, which has improved it a lot to get

rid of the clay.

That was our biggest problem in the first drive.

Lessons learned on the first trip under the harbour means this TBM is flying

through the treacherous ground under the seafloor.

Working on her first TBM, site engineer Jamie Chirk takes the walk to TBM

Kathleen every day.

Before the launch, she was nervous about what to expect and has had a steep

learning curve, but now she's settled into the day -to -day routine of working

on the TBM.

So at the moment, we're excavating, and that means the tunnelhead is turning.

Once the excavation is done, we get into the ring -building process, and then

once the whole ring's installed, I just check that the ring's been built in a

good position and that there's no major gaps.

For Jamie, she can see herself being a tunneller into the future.

enjoyed the crew life actually. I think just being together as a crew, we spend

so much time together every day, day in day out, every week and I think it makes

all the difference when you work with the right group of people.

With every concrete ring installed, TBM Kathleen is inching towards the finish

line and into history under Sydney Harbour.

On Sydney's Lower North Shore, a brand new metro station is being constructed.

It's called Victoria Cross, and when completed, it will contain the largest

underground cavern ever built in Australia.

But this daunting task doesn't faze station engineer David Anse.

We're at the bottom of the hill here, so this one will only be 25 metres deep.

Up at the northern shaft.

It's at the top of the hill, so we need to be 45 metres deep to ensure that the

cavern is dead flat.

The major challenge here is the steep topography in the area.

So it's been decided there will be two entrances to this station.

The northern end will be dug 45 metres deep and the southern end about 25

to ensure the train platforms are level.

Surrounded on all sides by golden Sydney sandstone, Everything in this station

has mega proportions, and David and his team need a head for height.

And this is what 45 metres of cut sandstone looks like.

This station is a beast. There is nothing bigger on the Metro.

Further down below, the mega size of the cabin is astounding.

But with two TBMs on their way from Crow's Nest, they have just 18 days to

prepare for their arrival.

We've got a little bit to do before the TBM comes through.

So the TBM will come through on the left -hand side.

We've got just under three weeks to actually pour the invert up to the point

where the waterproofing is now.

So, yeah, we are under time pressure to get that done.

The TBMs are on schedule to break through.

traverse the huge cabin, then start the 1 ,500 -metre downhill run to their

final destination.

No, we're not going to slow them down.

They're just going to stay here, do some maintenance, and then head off to

Blue's Point.

And when the TBMs do arrive, David and the team are ready.

The walls fall, and TBM winch.

And later...

TBMA make their grand entrances.

They can now take a little time to regroup before the final push to Blues

Sydney's Central Station is the largest and busiest railway interchange in the

country, as it's expanded over the years.

The foundation stone of the original building was laid in 1903, and it slowly

took shape over the next few years.

In 1906, the station was opened to the public, complete with the Grand

Concourse, with a towering roof canopy over the main terminal.

This concourse is still in use today, and so is its centerpiece.

the clock that has been marking time for commuters for 120 years.

But with the construction of the new Metro and Central Walk, the new

pedestrian walkway, this historic station's layout is in desperate need of

upgrade.

Enter John Prentice and Neil Hill, lead architects charged with designing a

beautiful yet functional new space called the Northern Concourse.

Initially the 1906 building, which was a single -storey, beautiful kind of

station in the park, got built up with a clock tower.

Then the suburban lines came in and all of that congealed into quite a complex

organism. But then this project became the unlocking all of that complexity to

open it back up again.

The task was set.

But the puzzle of unlocking the complexity of Central's maze -like

had no easy solutions.

We have to create an identity for the stations that they know they arrive at

Central Station. We've got to free that up. We've got to get the view lines up

so that you can see the whole facade.

Well, if you were to release the facade, then you can see it and celebrate it.

What we've got to do then, the route sails past, opening up, releasing the

heritage building.

I think it's very important that these facades are released as well and that

what we introduce to this works with those facades.

Despite the complexity, when it came to winning the pitch, the purity of their

design only needed some lines drawn on a page.

The success of this project came down to one drawing, and it's this drawing

here. We wouldn't have had this project if that drawing wasn't produced and

presented to the client base. We wouldn't be standing here today.

With all of the complexities of this station and the site, I think we both

realised and the team realised to open up that space was going to be important.

The plan was to combine the walkways and passageways into one vast, light

-filled transit space and a single -span canopy with diamond -shaped skylights.

But was this idea too ambitious?

Only ambitious designs can really engage people. The public are the ones that

are going to be the beneficiaries of this ambition.

Great design is one thing, but how were they going to build it without

interrupting the never -ending stream of people using the station?

So working with some of the best engineers and builders in the world, a

for the modularity built off -site was critical for this to be successful.

The new Northern Concourse canopy will have a modular design.

and be fully assembled in a test run before being installed at Central.

There's this one drawing we made a promise and now we have to deliver.

When the city line is complete, the new driverless trains will terminate in the

south at an existing railway station called Sydney.

It's a main junction for the southwestern rail lines of Sydney, and

heritage platforms will need to be upgraded for the new metro.

But before trains can run, some critical work requiring major surgery to the

Sydney trains network needs to take place.

At Sydenham, we've got six rail lines that converge into four coming into the

city. So we've got the Illawarra Mains, Illawarra Locals and the Bankstown line

that comes through. They all converge at Sydenham Station.

So we actually have a natural bottleneck in the system. That bottleneck's been

there for a very long time.

As the new Metro will be a standalone railway, with no direct interface with

Sydney train's railway line, Nathan and his team must clear this bottleneck and

separate the tracks.

So the Metro will run parallel.

to the existing rail lines.

We've got a massive possession at the Sydney Junction to separate the future

metro network.

Huge amount of work in a very tight area. Everything's got to go like soft

We've got a very short, well -defined window to achieve this here. They don't

have much time.

But as this is a very busy section of the Sydney trains network, they can't

the whole site to themselves.

We also have a live set of tracks on the other side. We've got a separation set

out. We've got a single track in between with an isolation to separate our

workers from the live rail.

The track team get cracking.

They've got to get the job done and replace the tracks in time for the

peak. Just 48 hours away, the site has a maze of lines, power and

switchgears, all squeezed into a narrow corridor.

Ballast is dug out as new sections of rail and points are brought onto the

The crew are sharing the site with machines called regulators and tampers.

They're reshaping and levelling the ballast and straightening and

the existing tracks.

We've got dozens and dozens of machines, each doing their own specific task.

Line, signal and track crews all work on the site.

while the high -rail loaders position the rails and sleepers.

Not only do we have big plant, big front -end loaders, big excavators,

everything they're moving around is large. We've got large lengths of rail.

rail comes in 110 -metre length.

We've got the sleepers. They're all large, heavy concrete sleepers. We've

poles to move. We've got overhead wiring structures, large steel elements.

Everything is large and everything is big on this build. The hundreds of

sleepers are connected to the rails with hundreds more clipped.

Locked in with a tool called a pan puller.

The 400 tonne trains doing up to 80 kilometres an hour put huge stress on

track and the clips keep the rails firmly in place.

Once the rails and sleepers are in, they can start dropping in the ballast.

One of the underrated components of a track system is ballast. Ballast is what

stabilises the track and what holds the track in place.

Railway track is flexible.

but able to withstand the forces placed on it by the train.

Joining the sections of track requires a special welding technique.

We've got large lengths of rail. They do need to be welded together.

There is a fine art in welding rail.

To join the track, they use a powerful chemical reaction called thermite.

Thermite is a mixture of powdered aluminium and iron oxide.

The mixture burns at 2 ,200 degrees Celsius.

liquefying the steel inside the mould and fusing the ends of the lines

It's one of the last activities we do, but it also controls the temperature and

movement and stability of the rail as well. It actually holds the rail and the

rail formation together.

It's been a massive effort, and the trains are back up and running in all

directions. We now not only have our new metro separated out, we have now

rebuilt and reinstated the entire Sydney trains junction, and that's now running

with passengers.

TBM's Nancy and Mum Cheryl are powering their way deep into downtown Sydney.

Leaving Waterloo, they dig deep below the excavation work at Central and pass

this new station location and push onto Pitt Street.

The tunnels they have left behind at Central will be broken into later to

complete the underground station box.

For TBM Nancy, The first daylight she will see in 12 weeks will be right in

centre of Sydney at Pitt Street.

And her destination is coming up fast.

At the business end of the TBM, Timo and the control room crew have the machine

at its slowest pace in months. Just about to fire the conveyor belts up,

Start having a bit of a scratch away and work our way into Pitt Street,

hopefully within a couple of hours.

This is the first big breakthrough in downtown Sydney.

The entire team is on edge.

These are our cylinders that push out the cutter head.

This is our thrust force that we'll be pushing against the rock.

It's all wound right back.

So we can just come in nice and slow and still grind up the rock as we're going

in.

They've been pushing against hard rock for months, but the closer they get to a

breakthrough, the more delicate the operation.

On the Pitt Street side, a crowd of VIPs and Metro workers have gathered to see

one of the most important breakthroughs on the whole project.

Preserving the integrity of the exit point is critical to keep the cabin wall

stable and avoid any delays.

Pitt Street construction manager Bobby Sahin wants to see a breakthrough with

collateral damage.

We've put mitigation measures in place, such as coring holes around the future

perimeter of where it comes through. We've done saw cuts on the place to help

control the breakthrough in some previous breakthroughs. There has been

excessive overbreak, which comes down as well.

Yeah, copy, copy for Timo. The call comes in.

Copy that, mate. Starting up the machine now.

Then Timo wakes up.

That's 1 ,300 tonne beef.

Let's give her a go.

But this is more than just a spectacle.

Getting this wrong could mean weeks of extra work for station crews to repair

the damaged wall.

We've got just over a metre to go for breakthrough.

Yeah, it's pretty slow going.

Keeping it slow keeps it safe.

Because we don't have that pressure of the hard rock, we can't put the pressure

on there, just so we don't drop that whole last bit of stone down and just

away at it.

Cracks are starting to form on the rock face.

We're nearly there, 700 mil, and it's just started to get a bit of cracking on

the other side there.

It's one of the rare occasions when cracks are good.

As Timo and the crew inch into history, a hush falls.

Cameras roll.

as TBM Nancy creeps forward.

There she comes.

From here on, they're in a grey zone between tunnel and station excavation.

Then TBM Nancy gets a whiff of fresh air.

That'll be rumbling over there now, yep. And the barrier between Waterloo and

the CBD is smashed forever.

Yeah, fellas, up to breakthrough into Pitt Street.

Congratulations lads and well done.

It feels amazing.

So incredibly proud of the team. Two years of hard work to get to today.

I feel so fortunate to be able to spend this time with everyone involved to

celebrate.

Beautiful. Nancy, she behaved nicely for us today.

a strange structure has appeared 180 kilometers north of sydney on the

of newcastle but blink and you'll miss it as it won't be there for long

the 2200 square meter northern concourse canopy destined

for central station has been painstakingly put together in a trial

to hugh griffith as the project leader for the northern concourse to get this

behemoth built twice.

The roof has been extremely challenging.

Trying to get access into the Grand Concourse with Sydney trains has pushed

down a road where we've basically built a kit of parts that we can then

reassemble.

This is no flat -packed coffee table.

The canopy has thousands of separate parts in all shapes, weighing many

So there's eight major steel beams, which you call the hockey stick.

They come in two pieces and weigh approximately 30 tons per hockey stick.

The cassettes, there's 58 of those and they're approximately 5 tons each.

All of the finishes are on them, all the services are contained within the

cassettes and that allows us to do multiple lifts.

Design leader John Prentice is also on site to follow its program.

Ultimately it was about the respect for the heritage building.

I mean, there's such bold architecture in the old, and we had to kind of match

that with something new and make it really identifiably new, but still

respectful in its form and shape.

And what has he been most impressed with about the design?

The complexity and the simplicity.

I think the two things coming together, this just highlights a well -coordinated

design from all aspects.

This trial run has been a success, but major challenges still remain.

How can we get this up and how can we get it built while we've got 270 ,000

people a day walking through Central Station?

It's taken over six months to assemble the canopy.

But the modular design means it comes apart very quickly.

Ready for the truck.

This afternoon, once everyone's had a look, we start taking it to be.

All right, man, winch it up.

You can imagine that the size of this roof as it is now, once it's broken down

into pieces on trucks and the logistics and driving everything through the city.

Coming down, man. You're looking good.

The trucks roll in and the pieces are lifted in a precise order, ready for

reassembly. She's all tied down. Next stop, central.

As night falls, the semi -trailers are ready to go.

These are the first of many trips for these trucks.

Tonight, the roads were cleared, and the convoy arrives safely in the city.

Rolling over the truck bridge to their final destination.

Hundreds of individual pieces of a giant puzzle.

They'll only know if they've done everything right when the time comes to

all back together.

At Victoria Cross, both TBM Wendy and

TBM Mabel have arrived.

They now need to get to the far end of the cabin to start digging again.

They do this by a maneuver known as a traverse.

Tunnel manager Kat Skevity has led the two northern TBMs in a race against time

and distance.

We're just going to traverse all the activities that are happening at the

time. So you can see here we're laying modules, we're grabbing, we've got a TBM

there, we've got a TBM there.

The brutal lifestyle the TBMs lead takes a huge toll.

And at every breakthrough, a major pit stop means more than just a grease and

oil change.

Teams of technicians service every inch of the battered metal monsters.

At 265 metres long, Victoria Cross is also the longest cavern on the Metro,

and it highlights a bizarre challenge that faces the TBM once they exit the

tunnel.

TBMs move through the ground by pushing off the rings they're installing in the

tunnel behind them.

But what to do when there's no tunnel and no ring?

A system of steel tracks called modules are laid along the floor of the cavern.

So the TBM pushes off its own module, so we've got module 1 down the bottom and

then module 2 is off the top.

As the TBM emerges into the cabin, the modules must be lined up perfectly to

guide the 130 metre machine from one end to the other.

And the TBM uses a dolly to push forward.

The dollies are massive sections of steel bolted to the track.

They replace the concrete tunnel rings, giving the TBM something to push

against.

So this bit here is the dolly, and that pushes against the module to push the

TBM forward.

As it digs, eight hydraulic rams push the cutterhead hard into the rock.

And at the same time, the rams compress the concrete segments behind it tightly

together. In the cabin, they're tricked into sliding the machine along the

module.

Those rams down in the back of the TBM, they're extents, and then that all...

on these bottom rails.

They creep through the station box, hauling what the crew call trailers or

trailing gear, the articulated sections that make up the bulk of the TBM.

They move about two metres at a time and we aim for about 60 metres a day.

To keep that rate up and traverse the massive station box, the crews on the

rattle guns and modules are going hard.

because there's still one and a half kilometres to TBM Mabel and TBM Wendy's

final destination.

Two metres at a time, both TBM Mabel and TBM Wendy travel the 265

metres through Victoria Cross and begin their final push into Blues Point.

The closest station to the Sydney Harbour Bridge is Barangaroo.

Right on the harbour's edge, it's had more than its fair share of challenges

far.

Excavation was delayed for months after the discovery of the oldest Australian

-made colonial boat.

This wreck is the wreck of the earliest known Australian -built ship that we

have in Australia.

A major road was moved to enable the excavation of the massive station box,

a gigantic cabin was carved out.

So TVM Kathleen...

could launch under the harbour twice.

All this has meant that more than 3 million tonnes of excavated spoil has

converged at Barangaroo.

And trucking it all out is not an option.

At Barangaroo, that kind of challenge of 22 ,000 trucks potentially going on the

road, that's just not an outcome we want.

But fortunately, the site's unique location has provided a centuries -old

solution.

It's so obvious when you think about it. We're right on the harbour. We can use

barges. That's how people have done it for hundreds of years.

Hugh and the team have decided to barge the spoil up the Parramatta River to a

site called Clyde.

Barges are great for taking bulk materials out. The site is adjacent to

harbour. We can pretty much load it straight onto them, take them upriver

process the spill from there.

But while it solves logistics issues within the city limits...

This is no leisurely cruise.

The Parramatta River is a busy commercial waterway.

Getting the material away from the Brangaroo site on barges was great, but

got to get it up the river to Clyde, and that river is really challenging.

Twists and turns, narrow, you need really skilled pilots and operators.

The Parramatta River runs virtually due west.

The barge journey takes them under yet more road and rail bridges.

And after 20 kilometres...

It eases into the moorings at Clyde, where the covers are slid back and the

unloading can begin.

All this material is being recycled.

It's all going on to other construction jobs around Sydney. Nothing's going to

waste. One of the most significant construction jobs where this spoil is

recycled is the new international airport being built at Badgerys Creek,

kilometres away.

After years of indecision and debate, this major new 24 -7 airport has been

given the green light.

And the mountains of spoil from the metro site is being used for the

of the 3 ,700 metre runway.

And how are the estimated 10 million passengers a year landing at the airport

going to get around?

You guessed it, a brand new metro.

It's late at night, and the streets of downtown Sydney are quiet.

Except at Central Station, where the construction crews are about to

the northern concourse canopy.

500 square metres of steel and aluminium, and weighing in at 330

canopy will stretch across eight platforms.

It's Greg Cook's job as operations manager to get this megastructure.

rebuilt on a convoluted site about 500 square meters a new roof that's uh

back in again and it's all about 330 tons worth of steel so a fair bit of

coming all the way down from the hunter valley a fleet of trucks have been doing

the 180 kilometer run from newcastle in the dead of night now with the giant

hockey sticks bolted together and sitting in their special cradle the

cranes and rigging crews are ready to take on a massive lift deep into the

of Central.

The first half of the roof is already installed, located above the excavation

site. It didn't need a station shut down, but the western side of the canopy

a whole different animal.

Tonight what we're going to be doing is the western end, sort of close to the

station master's office over there. So the guys are going to have to be onto it

to make sure that we get there by the end of the possession.

Possession means that Sydney trains have handed over the site to the

construction crews.

The gates are locked.

Trains are stopped and the power is off.

It's site superintendent David Hudson's signature on the paperwork.

The trains

will run again first thing Monday morning, meaning the main structure

will need to be in and bolted down in just 48 hours.

The biggest challenge...

is with the first lift of the hockey stick.

Oh, look, the complexity of the hockey sticks, it's unusual shape.

You can see there that a lot of the steel mass is sort of down in the base.

Guys are going to have to rig it up so that it has this even balance because if

they rig it too much one way, then they go to try and put it in, just won't fit.

So that's going to cost them precious time. So they're going to have to make

sure when they lift it up, it's all level, ready to go and drops into place.

the pre -fabricated structure has already had a test assembly up at

but now the riggers and crane operators are under huge pressure to get the

balance exactly right there's only one or two millimeters of clearance between

the bolt holes on the pylons and the 33 ton beams every piece of kit from change

to shackles will play a role in making this job a success or failure chris is

the dogman

He will be the conduit between the operator of the crane and what is

on the ground.

That's your position as a dogman.

You've got to be on your game, especially with power and trains and

that around. So everyone's just got to be on the ball and communication's the

key. Is that lift at the front, Charlie?

No, not yet, mate.

It's been built once, fully disassembled, then transported 180

freeway. Will the mega Meccano step that is the northern concourse canopy

cooperate?

Deep under the surface of Sydney's central business district two tunnel

machines are racing to the next stop on their journey Martin Place Despite

ongoing challenges on this site Will Freelander and his team have managed to

the cabins ready in time for TBM Nancy's arrival Getting the site ready for the

TBM to get here is always a little bit of a question. Are we going to make it?

Brian Marshall has seen a few cabins in his time, but this one is special.

You know, this is one of the biggest cabins I've ever built as far as a metro

station is concerned, you know. I've done jobs in London and Singapore.

This is a really big cabin. It's an impressive sight.

With the breakthrough imminent, a big crowd has come to see the event

with a video and light show we're lucky to have got to this stage in this job

where our full concrete lining and everything is complete and we're able to

know really show it off on her journey to martin place tbm nancy has dodged

underground road tunnels and foundations of iconic buildings and after years of

planning problem solving and hard work it come down to this moment Pretty

confident that everything's going to go well, so should have the big show in a

couple of minutes.

With TBM breakthroughs, even the best laid plans can come undone very quickly.

Hopefully it comes out in a nice, even face.

The time for talking is over.

Time for action.

Good to hear the rock, the cracking and popping with the force of the machine.

We had some pretty big blocks come out, which just makes for a bit more drama,

makes it a bit more exciting. But everything went to plan, and I think we

a pretty good show for the people today.

With this breakthrough at Martin Place, it's now a race to the finish line for

all the TVM.

Over the next few weeks...

Blues Point will be the finish line for three of these gigantic TBMs.

And on her way down to the harbour foreshore from Victoria Cross, TBM Wendy

takes line on her.

Smashing her way in at the bottom of the shaft.

Just two weeks later, TBM Nancy beats the minefield of subterranean obstacles

in downtown Sydney.

And just three days later, TBM Mabel pokes her cutterhead out at Blue's Coin.

Then TBM Mum shows.

A 1300 ton machine that has been navigating underground by this tiny beam

light from the laser theodolite makes her run straight into Barangaroo.

Where the perfectly shaped wall falls with precision.

Of the five tunnel boring machine.

TBM Kathleen has faced the biggest technical challenges as she tunnelled

the bottom of Sydney Harbour.

Now she's on the brink of a historic moment for the Metro build, and everyone

nervous, but also excited for what comes next.

This is the final breakthrough for all tunnelling on this great project.

achievement. I've been on this project for two and a half years now, and to get

to where we are on this day, it's goosebumps.

This is the end of the line for TBM Kathleen, where she will be dismantled

lifted from the shaft.

Today the breakthrough is at the base of what we call a blues point receiver

shaft and we'll be ready to punch through not long from now.

The shaft is so narrow, all non -essential gear is lifted out.

So we don't have much space down there, so just by precaution taking that out.

And a four -person team, including Vincent and Michele, will be lowered in.

The tension is mounting.

Not long now.

We build the last ring, and so we have another meter to go.

This will be the first and only breakthrough for the crew rostered to

TVM Kathleen.

Oh, if you go full speed, it's like punching through a wall. It just blows

It looks spectacular, but we want it to be nice and controlled.

It's time to go.

The crew in the basket descend slowly into the abyss.

Four blokes down in the man basket there, they're our spotters and they're

keeping an eye on the base itself and making sure that the breakthrough is

uniform and nothing out of the ordinary is happening. They're also keeping

contact with the guys in the TBM and making sure that everything's right on

other side.

From inside the cabin, the TBM crew can see a live video feed of the rock face

on their phones as they advance ever closer to a place in the history book.

We're about 200 off. You should be able to see the cutters soon.

So breakthrough is imminent.

A few bits of rock are breaking off the face now and we're seconds away from

breakthrough. Then the last wall on the city section of the Sydney Metro crashes

into the Blues Point shaft.

After all challenges and setbacks, they've finally made it.

Yeah, the feeling is one of relief to know that, you know.

Two and a half years of hard work, we finally got here and got here safely.

Really good. Oh, there we go.

I'm done.

To finally get here after all this time and all this effort is an amazing

achievement for everybody.

Kelly?

And wherever we are around the world, we will come back to take the train.

Light rain is falling at Central Station.

And it's the only light thing on site.

They're asking if we can get this first one in.

As the mega steel structures for the northern concourse canopy are ready for

reassembly.

resting in special cradles.

The 40 -metre hockey stick girders will be lifted over the rails and into

position on the western side of the central site.

Operations Manager Greg Cook is confident everything will go to plan.

So lots of planning and effort and energy that go into it, lots of trial

and lots of experience from the crew who've been there and done it before.

Yeah, mate, can't come on your righty. A specialist crew will use the 200 -tonne

tower crane to align the 25 millimetre bolt holes in 30 metre chunks of steel

weighing 33 tonnes each.

Materials and equipment are being lifted in.

The roof is 16 metres above the ground.

So Dogman Chris hooks up an elevated work platform to crane it onto the site.

We're just hooking up an EWP here.

The EWP is dwarfed by the roof beams as it flies into position.

Shane, just give us a kick on your left, mate. The riggers attach any struts and

braces to the beams before they're lifted.

Everything has been carefully planned and rehearsed to deal with a crushing

deadline and convoluted site.

Getting the jib right up, mate.

We're just going to walk this pop out so we can stand it.

Then the lifting chains are attached to the first hockey stick.

Do you want me to see if they can change that for you, bud? With the extensions

attached to the beams.

The crew will need to work out a new center of gravity.

Not easy when they're 16 meters above the ground.

The crane gently takes up the slack.

For this lift, it's all about balance.

The beam must fly perfectly straight.

But even using the pre -aligned lifting points, the beam isn't sitting perfectly

level.

Remember there was a gap.

Chris and the riggers shorten the chains at one end to try to get the beam

level.

Shorten again, mate.

And they try again.

This time, the hockey stick plays ball.

As we know, plans never survive the first shot of battle, but...

Guys have adjusted, they've readjusted the rigging, made sure that it was all

balanced and you can see at the moment I think it's looking like it's probably

going to fit.

The giant beam swings out over the site past some of Sydney's most treasured

historic buildings where all the prep work will now come into play as the beam

lines up with the pylons and footings.

The guys are going to have to drop them down onto the supports when they get

them in place. Hopefully all the holes line up. If they don't line up, there'll

be a few minor adjustments to try and get the few first bolts in. The centre

gravity in the beam is right at the very top.

If it doesn't land squarely on the footing, the holes won't line up, the

will be unstable, and the crew will need to start over.

You see the guys up there at the moment just doing the last adjustments to the

steel, trying to get the holes lined up, and what they'll be doing is...

Trying to put the podger in, get one of the holes lined up, get a couple of

bolts in there and it'll be able to be secured at that end.

16 metres above the ground, with 33 tonnes of steel hanging in the breeze,

crew battle to get the first critical bolts into the beam.

An error here and they'll be back to square one.

But the two giant pieces are united at last and the bolts are tightened down.

the very first steel beam is in place and everyone can breathe a sigh of

Over the next few weeks the remaining hockey sticks are installed and the

prefabricated cassettes are hooked up one by one and craned into place.

The northern concourse canopy is rapidly taking shape.

But there's still a long way to go.

At Central Station, operations manager Greg Cook and his excavation team have

spent months digging the massive station box for the new Metro.

And very soon, they'll see the light at the end of a tunnel.

This is the moment we've been waiting for. We're three -quarters of the way

into a 27 -metre deck, and we're about to start to punch through the tunnel.

Two TBMs have already passed through under Central, and now the team need to

break into the tunnels they've left behind to complete the underground

box. Greg knows you only get one crack at cracking the shell on a TBM tunnel.

The engineering, geotech...

structural checks that we had to do on the tunnels to make sure when we're

breaking through that the stability of the whole tunnel is never ever

compromised. At the moment this small 15 centimetre thick section of concrete

stands in the way of connecting Central to the metro tunnels under it and it's

got to go.

And it's come down to this moment right now where we're going to put the

jackhammer on it ready to pierce straight through.

And if all goes according to plan, we'll be able to break it apart piece by

piece.

As the tunnels come apart, Greg heads topside to check on the finishing

to the northern concourse canopy.

We've only got a few little bits and pieces to do and be all zipped up and

open to the public.

It's hard to put into words the amount of effort and energy that the team has

put into this project, all the way from the start to the finish.

We've had everybody that's been part of this has really put their heart and soul

into it.

But at the end of the day, the product that we've produced is just fantastic.

And to sit back, look at it, and to know that you've been a part of it with a

great group of people has been a fantastic experience.

But just as the team were ready to move on to the next stage of construction, an

unforeseen event...

on an international scale changes everything

we

were in full swing building at every site deputy chief executive of sydney

rebecca mcfee and then covered

and project director Hugh Lawson... So let's just stop.

..were on the ground when the ground fell out from under the entire world.

We had to really rapidly work with our contractors to find safe ways of keeping

those sites moving and our workers turning up each day so that we could get

bill done but so that they could also continue to be paid.

Lockdowns have come at a moment when the project was at a crossroad.

The tunnels and stations are transitioning.

out of excavation and into construction.

When we'd finished with the station excavations, for example, and we're in

process of handing over, there's a bit of time there where you're doing all the

paperwork, we're making sure all those arrangements are in place, and visiting

the sites then, it was kind of eerie.

Even though the metro construction has resumed, with COVID safe practices in

place, many of the immense station voids and metro tunnels are still strangely

free of any of the usual activity.

as the contractors wrap up and move on.

I remember going to Crow's Nest.

You're 25 metres below ground, and this huge space surrounds you looking up.

There's just this shaft of light coming in, just cutting across this whole

cavern. You think, this is huge.

In the lead -up to this moment, the work had been progressing well.

The Sydney Metro City Line is now a system of more than 30 kilometres of

and eight... station where once there was four million tons of rock in another

few weeks the station contractor is going to be in they're going to be

installing platforms they're going to be building structure you're never going

to see it like this again these immense rock and concrete voids are visible for

just a short time as the metro construction retools to fight covid and

construction it's just a moment in time between these two parts of the project

And the next thing you know, there's a station in there. You never see the size

of the excavation again. And when passengers catch the Metro, they only

about a third of the space we built below ground.

So, yeah, really unique experience, but surreal.

Really quite eerie to be in that space and feel so small.

Next time, it's an historic moment when a new Metro train travels under the

harbour for the first time.

What have we...

Just done.

A 180 -year -old mystery is finally put to rest.

And here is an account of the discovery of a grave, which I know immediately is

the grave of my great -great -great -grandfather.

And a major disaster threatened to destroy years of painstaking work.

Get a call, come out of the meeting here and told there's a fire at Central

Station.

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