Boris Johnson proposes a 22-mile bridge across the Channel | Hacker News Reader

Boris Johnson proposes a 22-mile bridge across the Channel

theguardian.com

23 pointsigravious72 comments

At least Boris is fixated on absurd bridges that will never be built, not walls.

A brief response from a structural engineer:

https://theconversation.com/boris-johnsons-english-channel-b...

Artificial islands, he likes those too. And why not, the UK used to do megascale engineering at the drop of a hat. Now we can't even do railways.

A response from the Telegraph. http://www.telegraph.co.uk/travel/lists/worlds-longest-bridg...

For comparison they show the following list.

  Where                                | Length in kilometres
  Danyang–Kunshan Grand Bridge, China    165
  Changhua-Kaohsiung Viaduct, Taiwan     157
  Tianjin Grand Bridge, China            114
  Hong Kong-Zhuhai-Macau Bridge, China   55
  Bang Na Expressway, Thailand           54
  Lake Pontchartrain Causeway, USA       38
  > 'Boris Bridge', UK-France            35

In light of all these other megastructures the proposed Boris Bridge doesn't sound too unreasonable? Considering the two economies it would link… Linking Ireland and the UK, that'd be another matter entirely.

The Danyang-Kunshan is mainly over land. It's an elevated railway line. It does cross the Yangcheng Lake, but that part is only 9km long. It's not a suspended bridge, there are piles every 80m. Not suitable for heavy maritime traffic. The lake has an average depth of 2m. https://www.lakepedia.com/lake/yangcheng.html It's not comparable as a channel crossing.

https://en.wikipedia.org/wiki/Danyang%E2%80%93Kunshan_Grand_...

Likewise the depth of Jiaozhou bay is 10 to 15m. The channel is 45m deep between Calais and Dover (the shortest and shallowest crossing). Moreover the strait of Dover (or Pas de Calais in french) is the busiest shipping lane in the world

http://i.dailymail.co.uk/i/pix/2014/05/22/article-2636152-1E...

The only bridge on that list even remotely comparable is the Hong Kong-Zhuhai-Macau Bridge. The rest are essentially elevated highways which are almost entirely over land.

I am not a civil engineer so this is just some uninformed speculation:

- The channel goes to about 45m deep between Dover and Calais, while the path of the HK bridge only goes to about 20m depth.

- The bay formed by the Pearl River is more enclosed and protected from weather than any part of the channel.

- The bridge would need sections elevated high enough for future mega container ships.

- The HK bridge cost $15.9b. I'd expect the channel bridge to cost much more. It might be cheaper to just build another tunnel.

Edit: and, of course, by the time I finish this comment there are 10 more saying basically the same thing.

The Hong Kong-Zhuhai-Macau includes a section of tunnel, so it doesn't need the height above the water that a pure bridge crossing would require.

The size of ships and number of ships going through the English channel are much larger than any of the bridges listed above apart from possibly the HK <-> Macau bridge.

Some of those can't admit any ships, never mind the biggest ships on the ocean.

For example, the Lake Pontchartrain Causeway impacts quite small boats:

https://en.wikipedia.org/wiki/Lake_Pontchartrain_Causeway#/m...

That's a completely different project than something that won't impact traffic that needs 50 or 70 meters of clearance.

The engineer's statements linked by the parent poster mentions Danyang-Kunshan:

"the longest bridge in the world is the Danyang–Kunshan Grand Bridge in China. It is mostly a conventional bridge made from columns sunk into the seabed, although it has a cable-stayed section. The bridge is 165km long (just over 100 miles) but the short distance between the columns would not do for the busy Channel."

the problem they say is that this would be on one of the world's most active shipping lane and that boats would need to be able to pass under the bridge, requiring it to be much higher than the other bridges of that list

Can someone explain to me why a wall can't be built?

I know people say it shouldn't be built - but I don't understand why people say we "can't" build it when they've been built before, and we've done endlessly more complex things - rockets, going to the moon, et (all while China is building artificial islands and the like).

In comparison to some of those feats, a wall seems trivial.

Cross-post: http://johnsalvatier.org/blog/2017/reality-has-a-surprising-...

Let’s consider some of these details. Something I think people don’t consider is that there are a non-trivial number of land animal species that migrate across the border. They have no concept of nation-states, and for some, our xenophobic electorate is basically passing a death sentence. The wall would devastate several important ecosystems, especially in the Rio Grande Valley.

Walls also need to be maintained, like any other piece of infrastructure. Have you ever visited the great state of Michigan? We can’t even handle roads. How will the federal government, which doesn’t have the best track record with maintaining infrastructure, deal with a 2,000+ mile-long wall?

Another issue is surveillance. Who will watch the entire thing? Who will make sure someone isn’t chipping away at the other side with a spoon or trying to dig under it? You can’t watch thousands of miles of wall very easily.

There are all kinds of issues with this (oh, funding is a big one too), and this just scratches the surface. If you Google “Trump border wall problems”, plenty of articles have already been written that go into much more detail.

>xenophobic

Yeah there's no way any friendly, rational person can look at Mexico and possibly come to the conclusion of "no thanks, I'd prefer not to have that here".

Mexico has no problem with extreme prejudice towards the rest of Latin America. Policies that people would decry x1000 if the US did them to poor Mexicans. But somehow the US applying some basic restriction to Mexico is "xenophobic" among other horrible phobias.

There are wall prototypes that allow for small/medium size animal passage, but not humans. Also, the entire southern border won be walled. If there is a natural border, mountainous terrain, etc, the wall won't be built there. While the area may be unsuitable for human crossing animals may not have a problem with it.

Roads have different material and structural requirements than walls. Maintenance will obviously cost money, but it serves a purpose. 450,000 people were caught in 2016 trying to illegally cross the southern border. Now imagine how many made it through. I assume you will not find this argument very convincing if you are the kind of person that believes that illegal immigrants make money for the state they illegally live in.

CBP border agents monitor the wall. And again, it isn't just 2000 miles of wall. It is "smart wall", where it will have the most impact to prevent crossings

So wait, we're going to have people just stare south for 8 hours a day? How is this not 'government waste'?

Well, hundreds of thousands of people try to cross the southern us border every year. It is only wasteful if they aren't accomplishing anything. And, these days we have video cameras, so one person can monitor multiple miles of the wall from an operations center

Then why do we need a wall if we're just going to use cameras anyway? It'll slow them down, yeah, but just by the amount of time that it takes to climb a ladder, cut some wire, whatever. Maybe 2 minutes max?

The cameras aren't going to be directly on the wall, and they won't be easily accessible.

I'm confused. Are there going to be cameras? If they aren't on the wall, where are they? Hidden in some cactus or in a drone? Still, why a giant wall then if all it ends up being is a concrete hurdle?

Yes, but the camera won't be easily accessible at all, let alone from the Mexican side.

The wall is so people can't just mosey across the border. Even if you had cameras there, sending out a team once you see someone crossing would be very difficult to find them. With the wall, it will be passable but will take work and a fair amount of material like ladders, ropes, etc which will all take time, and allow for security to arrive with a greater chance of catching people.

But that's like a 3 minute delay, max.

How do you know how much time it takes to get from the closest dispatch center to the furthest possible point before the next dispatch center?

Ok, so napkin math time:

Assume you need 3 people to drive out to apprehend illegal crossings for officer safety. You also then need 3 others to watch while others are out apprehending and then be able to respond for other illegal crossings.

Assume 3 minutes to cross over the barriers per person.

Assume it takes you no time to see the crossing happen, you can tell the second a ladder is put up.

Assume the roads are dirt, but in good and dry conditions. So you can travel about 40 mph on them on average, including the time to accelerate from 0mph at the remote watch tower station and then back down to 0 to apprehend people. 40mph is 2/3 miles per minute, btw.

So, the minimum distance at 3 minutes to cross would then be 2 miles. Meaning you'd need about 6 guys every 2 miles. So about 12,000 people for the 2,000 mile border.

Now you can play with the numbers, and talk about capturing people that scatter into the interior, but you're still at about 1 officer per 1 mile (ish), not 1 officer per 10 miles or 100 miles of border, with significant downtime per officer per day.

You can't build a wall on the border because 2/3 of the border is over the middle (more accurately, the thalweg[0]) of the Rio Grande and the Colorado River. So you'd have to build it on the American side, most of which is private property that would have to be taken by eminent domain, and its owners compensated, many of whom would sue to prevent that – notably, Cards Against Humanity[1].

[0] https://en.wikipedia.org/wiki/Thalweg [1] https://cardsagainsthumanitystopsthewall.com

Parent never claimed the wall can't be built. Depending on your interpretation, they claimed it will never be built, or merely claimed that Boris isn't obsessed with a wall.

To be fair to joelrunyon, he wasn't saying that i was claiming that - he was using my feeble witticism as a jumping-off point to ask a question about «why people say we "can't" build it» (emphasis mine).

FWIW, i did indeed mean to imply that Trump's wall is absurd and will never be built. I assume that, like the Channel bridge, the Hyperloop, the Freedom Ship, etc, it could be built, given enough time and money. I just don't think that there are enough people who think it's worth the cost to pay for it.

Thank you for the presumption of good will. Doesn't happen much online these days. Cheers.

Not the answer you’re looking for, but if you think about short-term and long-term political willpower, “shouldn’t” and “can’t” turn out to be the same thing.

I heard that a big portion of the border is over a mountain range, both making actual wall construction hard and almost fulfils the same role of a wall?

Saying 'walls can't be built' is just an ideological exaggeration.

Why do you think the wall isn't happening? They are building prototypes right now.

Is the wall absurd because people will find another way around? Or because you think it literally can't be built? Or it's absurd to protect the borders of a country? Or is it absurd simply because it is proposed by Trump and you just don't like him?

Also, I don't see why this bridge can't be similar to the Chesapeake Bay bridge. That has a 1km span for ships up to 60m to pass under.

I think borders between countries that keep people out are inhumane. Also building literal walls at great cost is to me the opposite of what we need - we need to connect people not separate them. I do not believe immigrants from South America and Central America are a threat to us.

Why just countries? Do you live your personal life like this? Is your private property, and private house with locks on it inhumane?

The United States isn’t your backyard.

Well, it's more my back yard than a non-citizen without a valid visa who illegally crossed the border.

The wall isn’t happening because it’s nothing more than a campaign lie and an extension of the electorate’s racism, which, like the wall, has no place in modern society and is unsustainable in the long-term.

So was the Iron Curtain. Arguments like that don't necessarily keep governments from embarking on foolish projects.

Sustainability in this case also is a question of scale and the particular design and purpose. Both Hadrian's Wall and the Limes lasted for quite some time.

Misguided and malevolent as the intent behind that wall may be if completed it quite likely will contribute to keeping people out of the US just as much as the Iron Curtain for some time was a mostly effective tool for keeping people inside certain countries.

So, is that wall desirable? No. Is it sustainable? That depends entirely on what resources the American people are willing to commit on its long-term upkeep.

Either way, building and maintaining such a wall is a colossal folly because the funds required to do so will of course be lacking for other, probably more beneficial projects.

Unfortunately, that doesn't necessarily mean it isn't happening.

So the wall isn't happening because it is a lie? That isn't a very strong argument.

The wall isn’t happening because, among other reasons, 2,000-mile long structures aren’t trivial to build, especially when subject to the whims of the political machine. Have you considered too just how long the thing would take? We’d probably be well into the next administration by the time it even got close.

No one ever argued for a 2000 mile long structure that completely disregards any natural wall that already exists

Immigration is a tough issue, and so are xenophobia and racism. But spending tens or hundreds of billions of dollars to build a wall that has countless logistical problems (say goodbye to several migratory species that cross the border; hope none of them are important for the food chain), is just so mind-bogglingly shortsighted and cruel. How many immigrants could we help for that much money?

Have Americans so quickly forgotten that, up until rather recently, there was no immigration policy? You could just come to the US to flee whatever terrible life you had before, and nobody asked any questions. I feel incredibly fortunate that my mom’s side came here from Germany well before WWII. I wouldn’t want to prevent anyone else from having a chance to be here.

Why help immigrants that illegally crossed the border? Why not help immigrants who come here legally, and US citizens? To do that you can't keep having the population of medium sized city sneaking into the country every year.

And Yes, there was immigration policy, going back hundreds of years. Remember the Chinese exclusion acts? Also, America highly favored not just white Europeans, but a specific type of white North/Western European from the beginning

Yes.

<sighs> the man practically defined the 'dead cat strategy': https://en.wikipedia.org/wiki/Dead_cat_strategy thats all this is, thats all he ever does.

    Johnson has previously promoted the idea of another Channel Tunnel but is now said to think a bridge could also be possible, telling aides that such feats of engineering have been achieved in Japan.

The 20 mile bridge he seems to be alluding to is in China, ladies and gentlemen. The longest bridge in Japan is 2.4 miles long.

(That Japanese bridge has the longest suspension span, but I don’t see how he would call that solved)

'Building a huge concrete structure in the middle of the world’s busiest shipping lane might come with some challenges.' https://twitter.com/ukshipping/status/954132391127339008

I'm not against major infrastructure projects but there must be 100 more suitable ideas for improving links within the UK, never mind Europe.

There are tall bridges designed to allow large ships to pass underneath. I'm not sure how that affects the cost, though.

There's one in Saint-Nazaire, France (which has a large ship building industry) which crosses the Loire river. It looks pretty cool. https://hu.wikipedia.org/wiki/F%C3%A1jl:Pont-Mindin.jpg

you don't need the entire bridge to be tall either, the San Mateo Bridge is eight and a half miles long and only raises up high enough for ships to pass for a short portion on the western side where I believe the water is deepest.

> the San Mateo Bridge is eight and a half miles long and only raises up high enough for ships to pass for a short portion

> (the channel is) the world’s busiest shipping lane

> the biggest ships on the ocean.

Spot the problem with the "short portion" idea.

I’m a little surprised that a road link didn’t get at least slightly more serious consideration when the existing tunnel was planned.

Certainly, in light of recent politics, I can’t help thinking that a road link would make “middle England” feel connected to Europe in a way no amount of rail traffic can.

The trains are much faster than cars (160km/h or 100mph in the tunnel), and it’s a lot easier to ensure fire safety. It’s a 50km tunnel! That requires a lot of precautions. There haven’t been any fatalities, and one of two fires was caused by vandalism: http://news.bbc.co.uk/2/hi/europe/67950.stm

Oh and the capacity of a rail tunnel is higher, too. The Gotthard Street tunnel has around 17.5k vehicles per day, whereas the Eurotunnel averages “50,000 passengers, 6,000 cars, 180 coaches and 54,000 tonnes of freight” (http://www.telegraph.co.uk/travel/destinations/europe/france...)

Lastly, as other have mentioned, driving 50km in a tunnel would not be pleasant. The passenger train is much nicer, and the car shuttle is very low-stress, too.

@edf13 recently posted this 2007 BBC article: http://news.bbc.co.uk/2/hi/uk_news/6517611.stm

“ Cross-Channel bridge bid revealed

Plans for the Anglo-French bridge have been preserved

People could have driven between England and France across a huge suspension bridge if plans had been approved, records show.

A submission for a £3bn three-lane motorway link was made to transport officials in April 1981, files released by the National Archives show.

Engineering group LinktoEurope estimated motorists would pay a £5.60 toll charge and lorries £8 to cross.

The records did not show how seriously the government considered the plans.

Margaret Thatcher's government was discussing the Channel Tunnel project when the bridge plan was submitted for consideration.

[…] ”

Consider the original project was politically debated in the early ‘70s. It was another era. A lot of the marvellous bridges we now have around Scandinavia and so on, did not exist; and people were skeptical a bridge could survive the Channel weather (which can be pretty bad) - plus, of course, nobody wanted to disrupt one of the busiest shipping lanes in the world. In the end, anyway, even through the tunnel a road was ditched, mostly because people in charge simply didn’t trust private drivers to be good enough. An accident down there would be a nightmare, the security issues were huge. Rail can be controlled fairly effectively.

Plans for a long bridge were considered, eg:

https://youtu.be/r_HN26VVXAk?t=9m15s

I also remember at the time a (pretty crazy) plan for a partial road bridge going out for a few miles from each side that then turned into a tunnel by way of a long corkscrew-style descent under the sea. I can't imagine that would have been practical ...

Edit: Wikipedia has the details. Apparently the bridge plan was called "Eurobridge", and I wasn't imagining the bridge/tunnel hybrid either, it was called "Euroroute". https://en.wikipedia.org/wiki/Channel_Tunnel#Initiation_of_p...

Edit #2: Euroroute video: https://amisduvieuxcalais.com/index.php/calais-video/calais-...

Apparently the combination of bridge and tunnel to cross a body of water has been used quite successfully in several places:

https://en.wikipedia.org/wiki/Bridge%E2%80%93tunnel

I don't know if it would have been helpful in this case, though.

The issue with road traffic in such a tunnel (or also on such a bridge) is the emergency procedure. If there's an accident on the end cars turn around wild and block the passage etc. The trains are operated with an engine and driver on each end. In case of emergency the rear can take over immediately and return to the other end of the tunnel.

Very true. However, a train on fire usually can’t turn around, but there are several emergency stations in the tunnel with emergency evacuation for people (via the service tunnel) and automated high-pressure water droplet extinguishing systems. This was installed in response to a fire in 2008 iirc. It facilitated rescue and fire fighting (because the exact position of the fire is known) and the automated system also helps minimise damage to the tunnel infrastructure.

There are difficulties with combustion engines in enclosed areas - namely a lack of oxygen. The ventilation would be a challenge. I see that the longest road tunnel in the world is Lærdal Tunnel which is 15 miles instead of the 20ish for the Channel. It also appears to not be under water and hence ventilation is probably easier.

The tunnel is over 30 miles long, 31.4 miles or 50.5 km. The tunnel must first go deep enough to go under the sea on either side, adding to its length.

Sitting on a rail car sounds a lot more pleasant than driving through a tunnel for 30-60 minutes. Do you think there is enough demand to justify a road link in addition to the vehicle transport trains?

There is certainly demand for more freight capacity; the ferries seem to be the biggest problem with regular delays.

When these delays occur it's not unusual for the serving motorway to double as make-shift lorry park. https://en.wikipedia.org/wiki/Operation_Stack

For regular passenger cars, I'm not so sure as it's mostly holiday traffic. Most people travelling for business would use the Eurostar (a regular passenger express) and I don't see much complaints about the capacity of this?

The channel tunnel trains are apparently at 54% capacity, so clearly no, at current prices there is no more demand for transport of that mode.

https://twitter.com/Ben_e_lux/status/954467087975673857

Dropping that price in the near future a bit seems like a much better use of funds than a prolonged and vastly expensive engineering project. But, there's no glory for Boris in that plan. He picks attention-grabbing, simplistic and iconic over quietly getting on with it, sound management and details every time.

Attention grabbing fool

Yes, although I wouldn't completely dismiss the idea just because it came from him.

But you can dismiss the idea because you can already take your car across the channel. OK, it goes into a train that goes in a tunnel under the channel, but this scheme has the virtue of being real and usable today.

It I am told that it's running at around 54% percent capacity. It's approximately half-empty. There's competition from ferries too.

And that's before Brexit lowers demand.

There is no economic case for another highly expensive crossing. Funding the channel tunnel more would be easier and produce faster results.

https://twitter.com/Ben_e_lux/status/954467087975673857

And that's before Brexit lowers demand.

We don't really know that, Eurotunnel have stated they don't think it will have an effect.

There is no economic case for another highly expensive crossing.

We don't really know that either, there is a time cost to using the tunnel, perhaps demand would go up if it was easier.

> Eurotunnel have stated they don't think it will have an effect.

> Eurostar: "should the UK leave the customs union... these new customs obligations would be very difficult to put in place in the restricted space available in stations, and would make our current cargo business (Eurodespatch) economically unviable. ... Divergence between UK and EU rules... would lead to significant cost and complexity for our business. Depending on the nature of any differences between systems, it may not be possible to operate either from an economic or practical standpoint."

Honestly, "we don't think it will have an effect" is not the message that I take home from that.

https://mobile.twitter.com/mattholehouse/status/954286948520...

> there is a time cost to using the tunnel, perhaps demand would go up if it was easier.

There's a time cost to everything. The trains in the tunnel travel up to "160 kilometres per hour (99 mph)" https://en.wikipedia.org/wiki/Channel_Tunnel

Is there a reasonable suggestion that other options would be faster between equivalent points?

Have you travelled on it, because you can't just drive up and get straight on.

> Have you travelled on it,

Yes, more times than I can count on fingers. As a seated passenger and on a vehicle.

As a seated passenger: if you find Kings Cross easy to get to, it's very convenient, and much faster and more relaxing than all the attendant faff of a short flight from an airport.

In a vehicle: I get that there are onloading / offloading delays, which is why I'd like to see numbers before I form an opinion on which would be faster, the existing tunnel or hypothetical bridge.

Boris Johnson has a knack for ideas that sound good and distract from bad news.

He would like to be inspiring, but he falls short with these pie-in-the-sky projects. This one will be forgotten in a few weeks, along with the bad news that would otherwise have been on the front pages.

Im not a Boris fan but this was one of the options proposed when the channel tunnel was built, so I don't know why people think it's absurd

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