Thread by @GarethDennis

Right! I am watching the second half of #BuildingTheChannelTunnel whilst I eat my tea... The first half was great, so I'm looking forward to it!

We're straight back into the thick of it... Though we've also jumped back in time again #BuildingTheChannelTunnel

We're barely five minutes in and there's some strong graphics action going on (the tunnel is getting soggy) #BuildingTheChannelTunnel

We've been joined by @christianwolmar again! #BuildingTheChannelTunnel

Now we're comparing the French and British lunch habits... I think the programme is trying to suggest that the French are lazy, but I'm going to give them a chance to, ahem, dig themselves out of this particular hole #BuildingTheChannelTunnel

It's okay, they've said that a bottle of wine per person at lunch probably didn't impact on the French rate of tunnelling... #BuildingTheChannelTunnel

On a more serious note, #BuildingTheChannelTunnel is doing a good job of highlighting the dangers of productivity-based remuneration... Safety and welfare takes a hit. 1500 workplace injuries a month is appalling, even by 1980s/90s standards 🚑

It is worth remembering the 11 workers who died #BuildingTheChannelTunnel... All of which were avoidable deaths. If someone bemoans "'elf and safety" culture within earshot, make sure you give them a verbal slap.

Now we're getting onto the most impressive tunnel engineering... The crossover caverns! #BuildingTheChannelTunnel

There are two of them, and (at the time - and perhaps still?) they were the largest undersea excavations undertaken in history. The challenge for engineers was immense #BuildingTheChannelTunnel

tl;dr - nae rings pal

Enter: shotcrete. The same technique used in the crossover caverns in @Crossrail, too (and much else besides)... #BuildingTheChannelTunnel

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You can see what the part-finished @Crossrail tunnels looked like if you head to my website here: garethdennis.co.uk/engineering/20…
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In any case, John Wildgoose is telling us about cracks. #BuildingTheChannelTunnel

And also about scary-looking yellow doors that would have trapped workers in the case of a flood... #BuildingTheChannelTunnel

We've reached September 1990 #NoContextDateDropping #BuildingTheChannelTunnel

Helen Nattrass is back, telling us how they kept the tunnels in line so that the British and French ends actually met-up #BuildingTheChannelTunnel

LASERS.

Woah - breakthrough time for the two halves of the service tunnel... #BuildingTheChannelTunnel

...and these two were the tunnellers who did it! #BuildingTheChannelTunnel

What an image for our times... Civil engineering rendering the seas as inconsequential, borders as unimportant, and nations as neighbours. #BuildingTheChannelTunnel

#vivelafrance ❤️

Everyone loves a tunnel breakthrough... #BuildingTheChannelTunnel

We're about to start talking about trains, innit... #TrainTwitter #BuildingTheChannelTunnel

Well, I'm not... "train enthusiast" @MrTimDunn is. #BuildingTheChannelTunnel

Though we've almost immediately segwayed into talking about track #winning

Prescott isn't happy (despite the grin) #BuildingTheChannelTunnel

"An example of the poor quality of the British rail network was..."
[programme uses stock footage of Class 91 in Swallow livery on the ECML]
...
[Gareth rage-quits]

[...]

Tim is telling us about Willesborough level crossing in Ashford. I'm back! #BuildingTheChannelTunnel

Tim's also got a challenge to his moquette game... #BuildingTheChannelTunnel

Whoever decided that the Queen wasn't supposed to get involved in politics? It's no wonder she wore that EU hat... #BuildingTheChannelTunnel

It's funny seeing the international platforms at @LondonWaterloo being used for their original purpose! #BuildingTheChannelTunnel

What a vehicle.

Uh oh... 🔥

Ouch.

Fast-forward to today, however, and the Chunnel transports millions of HGVs a year between the UK and the continent. Well, for the rest of this month, anyway.

Colin Saxby is talking about how tricky moving over 10000 vehicles per day in one direction is. Pre-Brexit, I'll add.

Tim's finished his journey! He's in Paris! #BuildingTheChannelTunnel

Tim is talking about baguettes in his @districtline moquette.
#BuildingTheChannelTunnel

That segment was my favourite in the whole two episodes.

#BrexitMeansBrexit

The Channel Tunnel is one of Europe's greatest engineering achievements.

Whilst wreckers above water are trying to undermine decades of collaboration, the Chunnel and all those who worked on it cemented our connection with Europe like nothing else could #BuildingTheChannelTunnel

And there we go! I thought that was terrific. Lots of superb library footage, and great interviews with the people who drove the tunnels under the sea. #BuildingTheChannelTunnel

Oh, and just in case you wanted an idea of scale... Here's a slice of Chunnel with a slice of Eurostar train in it that someone's kindly deposited in the @railwaymuseum! #BuildingTheChannelTunnel

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