
Boris Johnson proposes a 22-mile bridge across the Channel - igravious
https://www.theguardian.com/politics/2018/jan/19/boris-johnson-proposes-22-mile-bridge-across-the-channel
======
twic
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...](https://theconversation.com/boris-johnsons-english-channel-
bridge-an-engineering-experts-view-90409)

~~~
joelrunyon
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.

~~~
failwall
Cross-post: [http://johnsalvatier.org/blog/2017/reality-has-a-
surprising-...](http://johnsalvatier.org/blog/2017/reality-has-a-surprising-
amount-of-detail)

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.

~~~
oh_sigh
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

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

~~~
oh_sigh
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

~~~
Balgair
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?

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

~~~
Balgair
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?

~~~
oh_sigh
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.

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

~~~
oh_sigh
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?

~~~
Balgair
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.

------
ysr23
<sighs> the man practically defined the 'dead cat strategy':
[https://en.wikipedia.org/wiki/Dead_cat_strategy](https://en.wikipedia.org/wiki/Dead_cat_strategy)
thats all this is, thats all he ever does.

------
hinkley

        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)

------
dazc
'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](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.

~~~
swimfar
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](https://hu.wikipedia.org/wiki/F%C3%A1jl:Pont-Mindin.jpg)

~~~
scrumbledober
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.

~~~
SideburnsOfDoom
> 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.

------
dasmoth
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.

~~~
rwmj
Plans for a long bridge were considered, eg:

[https://youtu.be/r_HN26VVXAk?t=9m15s](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...](https://en.wikipedia.org/wiki/Channel_Tunnel#Initiation_of_project)

Edit #2: Euroroute video: [https://amisduvieuxcalais.com/index.php/calais-
video/calais-...](https://amisduvieuxcalais.com/index.php/calais-video/calais-
en-video)

~~~
schoen
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](https://en.wikipedia.org/wiki/Bridge%E2%80%93tunnel)

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

------
tomgp
Attention grabbing fool

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

~~~
SideburnsOfDoom
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](https://twitter.com/Ben_e_lux/status/954467087975673857)

~~~
tonyedgecombe
_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.

~~~
SideburnsOfDoom
> 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](https://en.wikipedia.org/wiki/Channel_Tunnel)

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

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

~~~
SideburnsOfDoom
> 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.

------
amriksohata
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

