0:00:02 > 0:00:05This is St Pancras, undoubtedly London's most spectacular
0:00:05 > 0:00:08and romantic railway station. It's a Gothic masterpiece
0:00:08 > 0:00:12and a temple to the pioneering age of steam.
0:00:12 > 0:00:15'This is Climbing Great Buildings. Throughout this series,
0:00:15 > 0:00:20'I'll be scaling our most iconic and best-loved structures, from the Normans to the present day.'
0:00:20 > 0:00:23- Whey!- 'I'll be revealing the buildings' secrets
0:00:23 > 0:00:27'and telling the story of how British architecture and construction developed
0:00:27 > 0:00:30'over 1,000 years.'
0:00:43 > 0:00:45The middle years of the 19th century
0:00:45 > 0:00:47was the pioneering age of the railways.
0:00:47 > 0:00:51Great networks spread from London to all parts of Britain,
0:00:51 > 0:00:57each owned by a company which wanted to show off its credentials with a grand terminus in the capital.
0:00:57 > 0:01:02In 1866, the Midland Railway Company built its station and hotel.
0:01:02 > 0:01:08This is St Pancras, the grandest station of its date in the world.
0:01:08 > 0:01:13'St Pancras International is Britain's most recognisable railway station.
0:01:13 > 0:01:17'It consists of two different parts, both on an epic scale.
0:01:21 > 0:01:26'At the front of St Pancras is the majestic Neo-Gothic Midland Grand Hotel.
0:01:27 > 0:01:31'And behind it stands the station, with its huge train shed,
0:01:31 > 0:01:33'a 19th-century engineering marvel.
0:01:35 > 0:01:40'In order to reveal the architectural and technological advances made in constructing St Pancras,
0:01:40 > 0:01:46'I've been given unprecedented access to get a perspective of the building never seen before.'
0:01:46 > 0:01:47What a view! Look at that!
0:01:47 > 0:01:54'I'll be scaling the stunning Midland Grand Hotel to get a unique view of this Neo-Gothic masterpiece.'
0:01:54 > 0:01:59- Lay back and look at that. - I know!- Lay back and think of medieval England!
0:01:59 > 0:02:02'I'll come face to face with the most famous railway clock in Britain.
0:02:03 > 0:02:06'And I'll get up close to the incredible train shed
0:02:06 > 0:02:09'to reveal the secrets behind its construction.'
0:02:09 > 0:02:11The next departure will be Jonathan,
0:02:11 > 0:02:14arriving at platform one in about 12 seconds.
0:02:14 > 0:02:19'But I won't be going it alone. One of Britain's top climbers, Lucy Creamer,
0:02:19 > 0:02:23'a team of riggers and intrepid cameraman Ian Burton
0:02:23 > 0:02:26'will be joining me on my Victorian voyage.
0:02:26 > 0:02:33'The man with overall responsibility for St Pancras was famous architect Sir George Gilbert Scott.
0:02:33 > 0:02:35'First, he constructed the train shed.
0:02:35 > 0:02:41'In 1868, he set about building the most spectacular and modern hotel to front it.
0:02:41 > 0:02:46'This was to be a grand advertisement to claim that the Midland Railway
0:02:46 > 0:02:49'was one of the finest in the world.
0:02:49 > 0:02:53'My journey begins on the 100-foot south face of this glorious hotel.
0:02:53 > 0:02:57'The perfect place to explore the Victorians' love for all things Gothic.'
0:02:58 > 0:03:01- It's a fine building, isn't it? - Absolutely!
0:03:01 > 0:03:05- A few decades ago, it was slated for demolition.- What?!
0:03:05 > 0:03:10- Can you believe that? - No. That's scandalous. They obviously saw sense.- Yeah.
0:03:10 > 0:03:14And now it's cleaned, we can go up and have a look at the sculpture
0:03:14 > 0:03:17and see the marvel of craftsmanship that it is, because it is!
0:03:17 > 0:03:20- Let's get up there and have a look! - Shall we?
0:03:22 > 0:03:25'I want to see up close how Gilbert Scott
0:03:25 > 0:03:29'used the Victorians' infatuation with all things romantic and medieval
0:03:29 > 0:03:31'to build a contemporary work of genius.'
0:03:31 > 0:03:38It's covered in stuff. Stuff that hopefully you'll explain to me.
0:03:38 > 0:03:41'Gothic architecture flourished in the medieval era
0:03:41 > 0:03:45'but fell out of favour as Classical building became the norm.
0:03:45 > 0:03:48'By the Victorian age, the Gothic style was back in fashion
0:03:48 > 0:03:53'and so Gilbert Scott used pointed arches, intricate stone carvings,
0:03:53 > 0:03:57'clusters of towers and pinnacles to make the St Pancras Midland Grand Hotel
0:03:57 > 0:04:00'a landmark of the Gothic revival.
0:04:00 > 0:04:04'While the building was an advert for the Midland Railway Company,
0:04:04 > 0:04:07'the vast array of materials Gilbert Scott used to construct it
0:04:07 > 0:04:10'was an advert for the Midlands as a whole.
0:04:10 > 0:04:13'And with the company's trains servicing all parts of that region,
0:04:13 > 0:04:17'it certainly wasn't a problem delivering those materials to London.'
0:04:17 > 0:04:20The Midland Railway Company took advantage of a great opportunity
0:04:20 > 0:04:26because the lines they owned that ran through the heart of England yielded the materials that built this hotel.
0:04:26 > 0:04:31They included the red clays of Nottinghamshire that gave such a nice, warm brick,
0:04:31 > 0:04:34the red sandstone from Mansfield in the same county,
0:04:34 > 0:04:39slates for the roof from Leicestershire and the golden limestone from Lincolnshire.
0:04:39 > 0:04:42All that could be loaded onto the company's trains,
0:04:42 > 0:04:45brought down their lines, right to the building site.
0:04:50 > 0:04:53'Gilbert Scott was a follower of the writer John Ruskin,
0:04:53 > 0:04:57'who proposed study of Gothic buildings not just in England but in Flanders and Italy.
0:04:57 > 0:05:02'What he ended up with was colourful Gothic arches and simple stone tracery
0:05:02 > 0:05:07'combined with a very un-medieval riot of wrought-iron balconies.
0:05:08 > 0:05:12'Gilbert Scott mixed red brick contrasted with lighter shades of stone
0:05:12 > 0:05:17'to create this striking facade. This technique is called structural polychromy.
0:05:17 > 0:05:21'As the design was influenced by both Gothic town halls and cathedrals,
0:05:21 > 0:05:23'it's adorned with intricate sculpture.'
0:05:26 > 0:05:29- Look at those. Amazing attention to detail, isn't it?- I know.
0:05:29 > 0:05:33- It doesn't seem to last the test of time, does it?- No.
0:05:33 > 0:05:37- She's unfortunately suffered a couple of losses.- She has, bless her.
0:05:37 > 0:05:40- Where would you place that character? - In terms of centuries?
0:05:40 > 0:05:47- Yeah, the dress.- Greek?- Look at you, you're on fire, woman! Yes!
0:05:47 > 0:05:51And the one in the foreground with the smooth and modest lines?
0:05:51 > 0:05:55- I don't know. Middle Ages? - Middle Ages!- Come on!
0:05:55 > 0:05:57- Two out of two. - Don't ask me any more.
0:05:57 > 0:06:01And look what the Grecian-looking lady's doing. She's got a victory wreath
0:06:01 > 0:06:04- and she's giving victory to the Middle Ages.- Oh, right.
0:06:04 > 0:06:08Look at the style of this building. It's so fabulously medieval.
0:06:08 > 0:06:14- For Gilbert Scott, the architect, his philosophy was to follow the Gothic style.- Right.
0:06:14 > 0:06:18And to bring back to Britain the spirit that was the Middle Ages.
0:06:18 > 0:06:22- Oh. Good for him.- Yep.
0:06:22 > 0:06:26- Lay back and look at that. - I know!- Lay back and think of medieval England.
0:06:26 > 0:06:28SHE LAUGHS
0:06:36 > 0:06:38Hi, fellas.
0:06:38 > 0:06:40Yeah, that's a good climb, that one.
0:06:40 > 0:06:45- This would be your front door, wouldn't it? You'd jump out every morning.- Be like, "Whey!"
0:06:45 > 0:06:49- "See you later, dude!"- Yeah. "Oi, gargoyle girl!" they'd shout.
0:06:49 > 0:06:52- That's a bit harsh! - THEY LAUGH
0:06:52 > 0:06:56- Are you calling me a gargoyle? - No, I mean like one of those attractive middle-aged...
0:06:56 > 0:06:59No, not Middle Ages! No! That's not what I meant!
0:06:59 > 0:07:03- Doosh!- When in a hole, you've got to stop digging, haven't you?
0:07:03 > 0:07:05'Now I've removed my foot from my mouth,
0:07:05 > 0:07:08'I want to look at the interior of this magnificent building.
0:07:08 > 0:07:14'St Pancras is currently undergoing a massive restoration and refurbishment programme,
0:07:14 > 0:07:16'but when the hotel opened in 1873,
0:07:16 > 0:07:20'its facilities were at the forefront of innovation and design.
0:07:22 > 0:07:26'The hotel harnessed the technology of the railways to make it a world leader in comfort.
0:07:26 > 0:07:29'Steam was used to power many of the hotel's features,
0:07:29 > 0:07:32'including the ultra-modern central heating system,
0:07:32 > 0:07:37'the vast laundry, the appliances in what was Britain's most expensive kitchen
0:07:37 > 0:07:41'and even the electric bells in the rooms to call for room service.
0:07:41 > 0:07:47'The Midland Grand also had the first room in Europe where ladies where allowed to smoke in public.
0:07:47 > 0:07:52'However, despite its cutting-edge technology, the hotel had one major flaw.
0:07:52 > 0:07:58'By the turn of the 20th century, guests had come to expect certain standards regarding cleanliness.
0:07:58 > 0:08:04'But the Midland had only eight communal bathrooms to service over 400 guests
0:08:04 > 0:08:07'and that was never going to wash with this demanding clientele.
0:08:07 > 0:08:09'The bedrooms couldn't be converted to be en suite
0:08:09 > 0:08:13'because the fireproof floors were built so solidly.
0:08:13 > 0:08:17'So, ironically, the hotel's design proved to be its downfall.'
0:08:19 > 0:08:23The building ceased being a hotel in 1935
0:08:23 > 0:08:27and it was then turned over to offices for the London Midland Scottish Railway
0:08:27 > 0:08:30and then British Rail in turn.
0:08:30 > 0:08:34The glorious Victorian wall paintings were covered over in emulsion
0:08:34 > 0:08:36and there was even talk of demolition.
0:08:36 > 0:08:42But in 1967, English Heritage put a Grade I listing on it, which meant that it was protected,
0:08:42 > 0:08:48but renovation costs money and the cash wouldn't be found for another 30 years.
0:08:51 > 0:08:54'The renovation of the hotel has been a mammoth project
0:08:54 > 0:08:57'which has taken over a decade to realise.
0:08:57 > 0:09:00'The aim is to restore the hotel to its former glory,
0:09:00 > 0:09:05'including the hotel's most splendid original feature, the grand staircase.
0:09:05 > 0:09:10'The stairs were a showcase for Gilbert Scott's Gothic revivalist ideas.
0:09:10 > 0:09:14'It's currently in the process of being restored and is in a fragile state.
0:09:14 > 0:09:20'I'm climbing on ropes to see exactly how his ideas were put into practice inside the building.'
0:09:20 > 0:09:24In the early pioneering days of the great railway hotel,
0:09:24 > 0:09:26a big staircase was an essential feature.
0:09:26 > 0:09:30It had to be grand enough to give you a hint of the opulent rooms beyond,
0:09:30 > 0:09:32show you the height of the building
0:09:32 > 0:09:37and also be broad enough to allow ladies with bustles to pass each other comfortably.
0:09:37 > 0:09:40But it wouldn't be long before the elevator was invented,
0:09:40 > 0:09:43and that took the impetus off building a staircase.
0:09:43 > 0:09:48You still get grand hotel staircases into the 1930s, the Art Deco era,
0:09:48 > 0:09:54but today, when we walk into a new hotel, we hardly expect to see one. More like a bank of elevators.
0:09:54 > 0:09:59Seems a shame, really, to miss out on exercise for the body and the eye.
0:10:06 > 0:10:10'Climbing the staircase on ropes enables me to closely observe
0:10:10 > 0:10:14'the structural honesty of this Victorian Gothic architecture.'
0:10:14 > 0:10:19Those Gothic revivalists, they argued that truth to materials is what they're about
0:10:19 > 0:10:24- and so, remember, on the outside, they show the colour of the stone. - Yeah.
0:10:24 > 0:10:28And inside they show the raw construction.
0:10:28 > 0:10:32If you're going to criticise Classical builders for hiding everything under stucco,
0:10:32 > 0:10:37why don't you reveal all of your structure? If this is a railway hotel, why not use cast iron?
0:10:37 > 0:10:39This is actually quite pioneering.
0:10:39 > 0:10:47- It's the first time that exposed iron construction was shown in a polite interior like this.- Oh, right!
0:10:47 > 0:10:53'To complete Gilbert Scott's design, the staircase is topped off with a cathedral-like vaulted ceiling.
0:10:53 > 0:10:56'St Pancras is not a cathedral to worship God,
0:10:56 > 0:11:00'but rather to praise the Victorian age of industry and commerce.'
0:11:00 > 0:11:04- Look at that ceiling up there. - I know.- Incredible, isn't it? - It's beautiful.
0:11:04 > 0:11:09When you look straight up at that blue with the gold stars in the ceiling,
0:11:09 > 0:11:15it looks like the Victorian appreciation for medieval cathedrals and churches.
0:11:15 > 0:11:20They so often painted them blue to make the vaults look like heaven with the stars twinkling down on them.
0:11:20 > 0:11:26- There's this whole medieval universe up there.- And those windows, they look very church-like.- Yeah.
0:11:26 > 0:11:30Right, Jonathan, we can't go up any more, unfortunately.
0:11:30 > 0:11:33- We've got to... - Too fragile, is it?- Yep.
0:11:33 > 0:11:35- Shall we head on down? - Shall we?
0:11:40 > 0:11:41Descender.
0:11:42 > 0:11:45# I wish I could fly... #
0:11:46 > 0:11:50Ooh. Watch your camera.
0:11:51 > 0:11:54'The refurbishment of St Pancras Midland Grand Hotel
0:11:54 > 0:11:58'is costing over £200 million
0:11:58 > 0:12:01'and more than 6,000 people have worked on the project so far.
0:12:01 > 0:12:08'Wherever possible, the building's original opulence is being restored, returning it to its former glory.'
0:12:09 > 0:12:13This is going to be the lounge bar for the new hotel. So the public
0:12:13 > 0:12:16will come into this space from the Euston Road,
0:12:16 > 0:12:20straight into this interior and hopefully get that "wow" factor.
0:12:20 > 0:12:23It's a very exotic-feeling space, isn't it, because of the gold?
0:12:23 > 0:12:28I love the way that the materials, the marble, is actually complemented by the paint
0:12:28 > 0:12:31and you get a sense of Victorian interiors.
0:12:31 > 0:12:35The painting and gilding to the ceiling is completely new.
0:12:35 > 0:12:39It's based on the paint research, the understanding and analysis of the building
0:12:39 > 0:12:41as well as taking tracings of the original
0:12:41 > 0:12:47so what we have is an accurate representation of the 1892 design.
0:12:47 > 0:12:51- And that's real gold leaf you've got.- Yeah, this is 23 and a half carat gold leaf
0:12:51 > 0:12:53This is a very traditional technique,
0:12:53 > 0:12:56the same as they used in the 19th century.
0:12:56 > 0:12:59It makes this entrance space feel very special and quite exotic.
0:12:59 > 0:13:03It's wonderful to see it back in place. I'm going to stay and admire it a bit longer.
0:13:14 > 0:13:19'The room arrangements in Victorian hotels were the inverse of what we see today.
0:13:19 > 0:13:22'The very best suites were on the lower floors
0:13:22 > 0:13:26'and the further up the building you went, the lower the standard of accommodation.
0:13:26 > 0:13:30'In the days before lifts, the lower down the social scale you were thought to be,
0:13:30 > 0:13:33'the more stairs you had to climb.'
0:13:33 > 0:13:38Well, times change, and the upper floors have now been turned into swanky apartments
0:13:38 > 0:13:42and one of the best of them can be found on this, the fifth floor.
0:13:45 > 0:13:51'I'm on my way to see the penthouse apartment within St Pancras' iconic Neo-Gothic clock tower
0:13:51 > 0:13:55'which has helped to keep travellers on time for over a century.'
0:13:58 > 0:14:02- Jonathan.- Hi, Peter. - Welcome to the clock tower.
0:14:02 > 0:14:06- Thanks for letting me have a look. So...- Come on up.
0:14:08 > 0:14:12Here we are in the clock tower room itself,
0:14:12 > 0:14:15which is a huge space, ten metres high.
0:14:15 > 0:14:20It's a fantastic space. I mean, you can see the Victorian bare brick and the timber.
0:14:20 > 0:14:24It soars above you. But how different is it to the way it was?
0:14:24 > 0:14:28This was just a storeroom. There was virtually no light in this room
0:14:28 > 0:14:31because they had wooden louvres to make it look like a bell tower.
0:14:31 > 0:14:34The bell tower never held any bells, it wasn't a belfry.
0:14:34 > 0:14:38No, indeed, it was just a false idea that George Gilbert Scott had
0:14:38 > 0:14:42to make it look more like an Italian Florentine bell tower
0:14:42 > 0:14:45as he built his Gothic idea for the whole station hotel.
0:14:47 > 0:14:50This is the way the clock winder would come up to do his winding
0:14:50 > 0:14:56- and to maintain the clock. - I do like these treads. They're like little railway lines. Very simple.
0:14:56 > 0:15:02Yes, good quality cast-iron engineering. Yes, indeed, I like these stairs.
0:15:02 > 0:15:04And here is where the clock faces are.
0:15:04 > 0:15:07Four huge clock faces.
0:15:07 > 0:15:10So on a misty winter evening, it's still these clocks
0:15:10 > 0:15:14illuminated from this room which guide travellers to the station.
0:15:14 > 0:15:18The clock's not only a bright beacon, it's a very good timekeeper, as well,
0:15:18 > 0:15:22which is essential for a station, and that's what the railway company wanted
0:15:22 > 0:15:24when they put the hotel and clock tower up.
0:15:24 > 0:15:29'The top of the clock tower is 240 feet high
0:15:29 > 0:15:32'and is the tallest point at St Pancras.
0:15:32 > 0:15:35'I'm going to climb from Peter's apartment up the famous steeple
0:15:35 > 0:15:38'in order to get a unique view of the hotel and station
0:15:38 > 0:15:43'and see how the differing architectural styles of the two buildings actually work in unison.
0:15:45 > 0:15:49'This time, I'm not climbing with ropes. I'm going to use a good old-fashioned ladder.'
0:15:49 > 0:15:53I tell you what, this is not what I was expecting. It's quite spooky.
0:15:53 > 0:15:59- Isn't it? Yeah. Feels more ancient than something Victorian. - Yeah, definitely.- OK, we're off.
0:15:59 > 0:16:02Now, this is rickety.
0:16:02 > 0:16:05There's lots of missing rungs and it's very dusty,
0:16:05 > 0:16:09so I can't imagine that people came up here very often.
0:16:09 > 0:16:13But when they did, they'd have needed at least some light
0:16:13 > 0:16:15and not a little nerve.
0:16:23 > 0:16:25What a view, look at that!
0:16:27 > 0:16:32It's fantastic to see the top of the train shed. Really majestic vision.
0:16:32 > 0:16:36'I'm very excited to be at the top of Britain's most inspiring railway station.
0:16:36 > 0:16:40'From here, I can appreciate the sheer scale of that gigantic train shed.'
0:16:40 > 0:16:45When St Pancras was built, the train shed looked enormous,
0:16:45 > 0:16:50but it wasn't the widest train shed in London. There were two which were broader.
0:16:50 > 0:16:55Kings Cross just next door and Euston a little way along the Euston Road.
0:16:55 > 0:17:01But both of those had pillars dividing up the individual glazed vaults.
0:17:01 > 0:17:08Whereas this one was an entire span, and for 25 years it was the broadest single span in the world.
0:17:11 > 0:17:14'But, in order to have a closer look at how it was built,
0:17:14 > 0:17:17'I need to abseil down.'
0:17:19 > 0:17:22Good. Well done.
0:17:22 > 0:17:24- He's doing it, he's doing it. - Let's do it.
0:17:24 > 0:17:28Let's go. Watch those slates.
0:17:28 > 0:17:32- The slate crawl.- I'm making it up but it seems to be working.
0:17:49 > 0:17:53'In the Victorian age, time in Britain wasn't standardised
0:17:53 > 0:17:57'and railway stations in the big cities held independent time.'
0:17:57 > 0:18:02It's curious to think that in those early pioneering days of the Victorian railways,
0:18:02 > 0:18:06every city used to keep their own railway time according to when the sun went down,
0:18:06 > 0:18:10so Bristol might be 20 minutes later than London.
0:18:11 > 0:18:17But when the railways all joined up, you had to know what time your train was going to depart and arrive
0:18:17 > 0:18:21on a standardised system, so in November 1840,
0:18:21 > 0:18:25the Great Western Railway created standardisation
0:18:25 > 0:18:28and clocks had to be synchronised across Britain.
0:18:30 > 0:18:33Tell me when to use feet. SHE LAUGHS
0:18:33 > 0:18:35- Now! - THEY LAUGH
0:18:36 > 0:18:38Whoa. Watch that window.
0:18:38 > 0:18:40HE LAUGHS
0:18:40 > 0:18:43That went badly.
0:18:43 > 0:18:46- That wasn't a good move.- No.
0:18:51 > 0:18:54- Right, sorted?- Yep. Let's go.
0:18:57 > 0:18:59Wow!
0:18:59 > 0:19:05Now this, St Pancras train shed, was the work of William Barlow.
0:19:05 > 0:19:08He's an under-sung hero of British architecture.
0:19:08 > 0:19:12But it's still a world-beating building in my view.
0:19:12 > 0:19:15A spectacular piece of railway architecture.
0:19:15 > 0:19:19'I now need to get across to the train shed so I can have a look at this engineering marvel.
0:19:19 > 0:19:22'But between it and me is a gap of 30 feet.'
0:19:23 > 0:19:25Oh, crikey.
0:19:25 > 0:19:29'So my next challenge is to walk across something called a Burma bridge
0:19:29 > 0:19:32'with nothing below me but a 100-foot sheer drop.
0:19:32 > 0:19:34'This is not a time for nerves.'
0:19:36 > 0:19:40So step on the...rungs themselves.
0:19:40 > 0:19:43Not on the wires. Step straight in the centre.
0:19:45 > 0:19:48HE LAUGHS
0:19:52 > 0:19:55- Like that?- No. - Your hands in front of the straps.
0:19:55 > 0:20:01- Yeah.- And just pull your hands over the top, over the side, and then hold the ropes in front of you.
0:20:05 > 0:20:08How are you balanced today?
0:20:29 > 0:20:35'Well, I'm glad that's over, but now at least I'm able to finally see St Pancras Station up close.
0:20:38 > 0:20:43'I'm going inside to see how Barlow's ingenious engineering made it the envy of the world.
0:20:58 > 0:21:02'140 years after the station first opened
0:21:02 > 0:21:05'and following an £800 million redevelopment,
0:21:05 > 0:21:10'the station is now called St Pancras International and is Britain's hub for the Eurostar.
0:21:12 > 0:21:16'The train shed roof, which had been bombed during World War II, was completely reglazed
0:21:16 > 0:21:19'but the original structure remains intact.'
0:21:20 > 0:21:24This building deserves some statistics. It's 105 feet tall,
0:21:24 > 0:21:30over 245 feet wide and it's that free span which makes it so majestic
0:21:30 > 0:21:34and which gives it an awe-inspiring power to this day.
0:21:35 > 0:21:38The train shed structure may look simple enough from above
0:21:38 > 0:21:41but the giant single-span roof needed to be supported
0:21:41 > 0:21:46and Barlow's solution was both innovative and ingenious in its design.
0:21:48 > 0:21:52Barlow figured that if he built this broad span with a pointed arch,
0:21:52 > 0:21:57it would be all the better for bracing the effect of the wind against its sides.
0:21:57 > 0:22:00Now, a card model is always going to wobble around a little bit,
0:22:00 > 0:22:06but what you see is that where it comes down to meet the walls, it doesn't really move a great deal.
0:22:06 > 0:22:11But there is always a big danger of large structures which might spread.
0:22:11 > 0:22:13The more you press down, the more it settles,
0:22:13 > 0:22:16then the likelier it is to push out at the base.
0:22:16 > 0:22:21And so what he decided to do was put in a whole series of iron tie rods
0:22:21 > 0:22:24which span underneath the train platforms
0:22:24 > 0:22:27and tie the bottom of this great arch together.
0:22:27 > 0:22:31Now, this little model's just got three of them, represented by string,
0:22:31 > 0:22:33but if you cut through the string...
0:22:37 > 0:22:39..it falls straight to the floor.
0:22:39 > 0:22:42Now, obviously, this structure is slightly different
0:22:42 > 0:22:45in that it's a frame rather than a single sheet,
0:22:45 > 0:22:48but nonetheless, the same basic principles apply.
0:22:48 > 0:22:51This lattice-work structure is so strong
0:22:51 > 0:22:56that modern engineers have figured that even the tie beams may not have been necessary.
0:22:56 > 0:22:59Typical of a Victorian belts and braces approach to building.
0:23:00 > 0:23:03'Building the roof was a mammoth task.
0:23:03 > 0:23:10'At the height of construction, there were over 1,000 men, 100 horses and 22 steam engines on site.
0:23:12 > 0:23:15'I'm going to climb 100 feet up the massive roof
0:23:15 > 0:23:18'to see up close exactly how Barlow constructed it.
0:23:18 > 0:23:21'But it's not going to be easy.'
0:23:21 > 0:23:24This, I think, is 105 to the apex.
0:23:24 > 0:23:27And we're over trains and railway lines and...
0:23:27 > 0:23:32- It's a big space, this. - Yeah. I'm really excited about this.
0:23:39 > 0:23:42It's quite dusty up here, though. Bring some dusters up with you.
0:23:42 > 0:23:45What's your grip like on dusty metal?
0:23:45 > 0:23:47It's a bit, er, slippy.
0:23:47 > 0:23:51Slippery. That's my favourite climber's word.
0:23:51 > 0:23:52Good to go.
0:24:01 > 0:24:03Lovely.
0:24:08 > 0:24:11This is awesome! I'm loving it!
0:24:14 > 0:24:19I'm standing in the roof of St Pancras. It's just so cool!
0:24:19 > 0:24:23'Seeing the scale of the station roof from this height is staggering,
0:24:23 > 0:24:27'but amazingly it had to be extended for its modern-day use.'
0:24:27 > 0:24:33Now, Barlow's task was to design a building 105 feet high
0:24:33 > 0:24:37so that all of the smoke of the railway could be absorbed into its rafters,
0:24:37 > 0:24:42but also to allow the arch sufficient height against its width to stand properly.
0:24:42 > 0:24:48The length of this building is 680 feet, that's longer than Canterbury Cathedral in entirety.
0:24:48 > 0:24:52But even so, it's not long enough for Eurostar trains today.
0:24:52 > 0:24:56So the far end of the station is a brand new shed to take their length
0:24:56 > 0:24:58and you'll just see one leaving now.
0:25:02 > 0:25:06- I felt a bit of a rumble then. - Did you?- Yeah, I did.
0:25:06 > 0:25:10- It sort of felt like everything was shifting a bit.- Ah.
0:25:10 > 0:25:12It was bizarre. Must have been a train.
0:25:12 > 0:25:17I guess something that has to be taken into consideration when you build iron structures like this
0:25:17 > 0:25:21is that metal inevitably expands when it's hot and contracts when it's cold,
0:25:21 > 0:25:26it moves in the wind, so you have to build in a certain flexibility,
0:25:26 > 0:25:29and Barlow had to figure that into his equations.
0:25:29 > 0:25:32This is like a living thing that has to breath
0:25:32 > 0:25:35- like a great ribcage. - And you can feel it.- Yeah, you can.
0:25:35 > 0:25:39- Yeah, a ribcage.- Gives it life, doesn't it?- Yeah. Definitely.
0:25:48 > 0:25:52It's from perspectives like this you get a sense of the sheer numbers involved
0:25:52 > 0:25:56in the construction of this amazing thing. For every one of these 25 trusses,
0:25:56 > 0:26:00there are countless big rivets just bolting every little component in place.
0:26:00 > 0:26:05Of course, all this had to be worked out on drawings before they were ordered and brought to site.
0:26:05 > 0:26:11But the energy invested in melting and hitting rivets countless thousands of times,
0:26:11 > 0:26:16all of that human endeavour and effort, it's all embodied in this amazing structure.
0:26:26 > 0:26:30We've reached Stew, which means we can't go any further, which is a shame.
0:26:30 > 0:26:35- Otherwise we're over the electric cables of the trains. - And that means 25,000 volts.
0:26:35 > 0:26:38Yeah. We'll be turned into bacon.
0:26:38 > 0:26:43I just cannot get over the scale of it. It just must have been phenomenal to see at the time.
0:26:43 > 0:26:49- Even now it's phenomenal, isn't it? - It's the confidence, isn't it?- Yeah.
0:26:49 > 0:26:51Shall we?
0:27:03 > 0:27:08Right, the next departure will be Jonathan, arriving at platform one
0:27:08 > 0:27:10in about 12 seconds.
0:27:10 > 0:27:14'It seems hard to believe that this magnificent Victorian icon
0:27:14 > 0:27:19'was almost demolished. Thankfully, one man campaigned tirelessly to ensure
0:27:19 > 0:27:24'this testament to Victorian architectural brilliance remained standing.'
0:27:24 > 0:27:27- Don't smash your camera. - HE LAUGHS
0:27:30 > 0:27:33At the bottom of the abseil is this character, Sir John Betjeman.
0:27:33 > 0:27:35When I was a teenager, I read Betjeman,
0:27:35 > 0:27:39and he's one of the people who got me really enthused about architecture.
0:27:39 > 0:27:42He was a lover of the steam age and all things Victorian
0:27:42 > 0:27:45when many others simply couldn't see their beauty,
0:27:45 > 0:27:50and it was his campaigning that made St Pancras listed Grade I in 1967.
0:27:50 > 0:27:54And that put it on a par with the greatest country houses and even cathedrals.
0:27:54 > 0:27:58So it's thanks to Sir John that this place not only survives
0:27:58 > 0:28:01but was reborn into a new railway age.
0:28:24 > 0:28:28'Next time, how the florid imagination of one visionary artist
0:28:28 > 0:28:32'created a building which inspired a century of modern architecture.'
0:28:36 > 0:28:40Subtitles by Red Bee Media Ltd
0:28:40 > 0:28:43E-mail subtitling@bbc.co.uk