How the Fehmarnbelt Tunnel is being built [video] | Hacker News Reader

How the Fehmarnbelt Tunnel is being built [video]

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181 pointsblutack108 comments

There are some great questions in here. But what I'm most curious about is how the keep the individual segments from sinking into the seabed at different rates. I can't imagine that the interfaces would remain water tight if any segment sunk by, say, more than 30cm. Can we really be certain about the stability of sediment underwater at the loads that will be applied?

Looks like they’re over digging the trench, then partially backfilling with aggregate. So the sections aren’t sat on sediment, but rather a thick bed of gravel type material that will distribute the load over a larger space.

I would also be interested to know what the tunnels effective weight will be once it’s submersed. Given the sections are hollow, the road and train sections will create a buoyancy effect. Possibly enough to offset the total weight of the concrete, given they need to fill ballast tanks in-order to sink the sections. If that’s the case, they can probably adjust the ballast tanks to keep the sections near to neutrally buoyant, and thus apply little pressure to the sediment below.

This makes sense and, although I didn't include it in my comment, the buoyancy was part of my curiosity. While it's clever to take advantage of the buoyancy created by the air cavity, if they're nearly-buoyant that would also mean that the variability in traffic would create a significantly variable (as a percentage) load. I wonder how this is accounted for.

For the record, I don't think I'm "gotcha-ing" the engineers by thinking of these questions. I'm sure there have been answer to these questions since before the project began, it's just that I would like to know the answers.

They also must have a way to seal off segments in case of a water breach? Although, that seems awful given there will be human traffic in the tunnel

See the video for answers:

After putting in a segment, the trench is backfilled with rocky material (over the segment), so that any buoyancy is negated by the fact that it's held down by a large layer of rocks. This layer presumably also prevents most, if not all, leaks from generating instant floods in the tunnel.

Lastly, once completed the project will result in 5 parallel, but mostly independent tunnels (two train tunnels, two highway tunnels, and a service tunnel between the highway tunnels). I presume that the tunnels can be isolated and waterproofed seperately.

I'm not an engineer so I might be missing something, but according to Wikipedia[0]:

> The precast concrete tunnel sections will have a rectangular cross-section that is about 40 metres (130 ft) wide and 10 metres (33 ft) high

and (also mentioned in the video):

> The tunnel will consist of 79 standard elements with a length of 217 metres

If it's a perfect cuboid, this should result in a buoyancy corresponding to ~87,000 tonnes. According to the video, each segment weighs (over) 73,000 tonnes, though this presumably doesn't include other stuff that will be added into the tunnel like road surface material, rail tracks etc.

[0] https://en.wikipedia.org/wiki/Fehmarn_Belt_Fixed_Link#Tunnel...

Concrete is 2.4 times the density of water, according to Google, steel rebar is about 8. The video mentioned that they were plugged (and thus full of air) and were being given additional lift by the barges so they could float and be towed.

So it appears they will not be buoyant.

Here's some info about the seals between sections from https://www.trelleborg.com/en/media/products-and-solutions-n...

    Trelleborg’s Gina gaskets and Omega seals fit between the sectional elements of immersed tunnels to prevent water ingress due to external water pressure. 
    Designed to handle intense transfer of hydrostatic loads and movements between tunnel ends caused by environmental pressures such as seismic activity, soil settlement and temperature effects, Trelleborg’s sealing systems promise a product life expectancy of up to 120 years with little-to-no maintenance.

Not a civil engineer but have done some work in construction. What you're describing is referred to as differential settlement, and can be a problem for any structure (house, skyscraper, bridge, etc). I don't know enough to guess what they're doing here but usually there's some work with the underlying foundation (ie dig and fill back in with something uniform, put piers or piles to reach a more stable surface, etc).

The other things you might worry about is expansion and contraction due to temperature changes, and even just minor size differences in manufacturing (for instance when using moulds to manufacture concrete, those moulds themselves might not all be perfectly the same size or they might change over time). So often in concrete bridges (or even concrete/steel pipes) there will be "joints" designed to absorb changes within some tolerance (eg with pipes, there's typically a rubber gasket that keeps things air/water tight while also allowing some compression/expansion).

at least underwater and covered over by rocks, temperature variation are probably generally less than open air.

While the surrounding seabed can be a nice thermal sink to stabilize temperatures, the aggregate around it could be fairly good insulator, there are tubes in London that have warmed the underground to such an extent that it would take months to cool down. Understandably, lots of the heat in the London tunnels is from braking which shouldn't be occurring in this tunnel.

Point is, I don't think one could model the Fehmarnbelt tunnel as open air or assume that the surrounding material is an infinite heat sink.

https://citymonitor.ai/transport/londons-tube-has-been-runni...

As the segments float when they are filled with air (this is how they're floated out for installation), the only reason they won't float back up when installed is that they're covered with a layer of rocks afterwards. Thus I don't think the load on the seabed will be as great as perhaps you fear - it could be very low if that's what they need to make it work.

This isn't correct. The rocks on top are not to prevent the tunnel segments from resurfacing.

The tunnel segments have ballast tanks which are empty during towing, then are filled with water to increase the density of the segment and sink it to the ocean floor.

You are probably correct - I assumed the ballast tanks were part of the end doors, which were later removed, but re-watching, I think I read too much into that part of the video.

I'm not familiar with the details of tgia project, but i know that for other submerged tunnels they pump grout (kind of liquid cement) under the segments, so both segments on a joint rest on the same chunk of grout. There are probably pipes embedded in the tunnel segments during construction xfor this purpose

Have rising sea levels and storm surges been taken into account for the planning of the entrances? Watching the video, wondering if it is an accurate depiction of size and placement, I couldn't help the bolt of consternation that shot through me, because those entrances look awfully close in elevation to sea level.

And regarding air management, in Japan and HK at least, driving through lengthy tunnels can already be a stinky affair, especially in summer, so ensure your vehicle's air conditioning system is set to cycle the air inside the car. The Tokyo Bay Aqua Line tunnel that connects Yokohama to Chiba is quite long and it uses large fans that vent at mid-way points, one doubling as a tourist stop. The Fehmarnbelt tunnel being the longest in the world is therefore longer, and I didn't see such venting points. Yes I noted the air movers in the video. But hey, I'm hopeful that such problems will attenuate with electrification.

It's only the longest immersed tunnel, nowhere near the longest overall. It's only 18km. Though the Tokyo Bay Aqua Line tunnel is only 10km long, the Channel Tunnel is 50km, but then again, that one doesn't have car traffic.

The idea of sealing each section and then floating it into position seems so elegant and simple. Is this a common technique for a project of this style, or a new innovation?

The immersed tube technique is used for the BART Transbay Tube, Chesapeake Bay Bridge Tunnel, and Øresund Bridge Tunnel between Denmark and Sweden. The Fehmarn Belt will be the longest when it opens. I think the technique is mainly used for shallow tunnels in flat areas.

It can't possibly be new. Multi-billion dollar construction projects are fairly common and that kind of capital investment makes people very clever.

Oil rigs definitely follow the prefabrication and then float-into-position approach, and have been doing that for a long time.

I'm sure there's a good reason why it's more cost effective or feasible to do this instead of drilling a tunnel under the seabed.

To your point of this technique not being new: the mulberry harbors the allies built following the d-day invasion of operation overlord made use of prefabricated sections code named phoenix, that were towed into place and then sunk to form the structure of the harbor. They were so named, I think, because after being built they were sunk off the coast of England before being refloated in preparation of the operation, i.e. like the phoenix the rose, or something poetic like that.

If you're ever in or around Normandy I highly recommend a visit to the beaches. They're much bigger than I had imagined, and it really hit home then what a massive operation it was.

Anyway – no, the technique is not new.

Not new - as mentioned above the BART trans-bay tube was built this way back in the '70s

The scale is different, but it’s far from a new idea. https://en.wikipedia.org/wiki/Immersed_tube#Examples:

The first tunnel constructed with this method was the Shirley Gut Siphon, a six-foot sewer main laid in Boston, Massachusetts in 1893. The first example built to carry traffic was the Michigan Central Railway Tunnel constructed in 1910 under the Detroit River, and the first to carry road traffic is the Posey Tube, linking the cities of Alameda and Oakland, California in 1928. The oldest immersed tube in Europe is the Maastunnel in Rotterdam, which opened in 1942.

All tunnels in the Netherlands are built this way. You can't drill through mud.

I think OP is referring to using the interior space of the segment for buoyancy rather than hauling it on a barge, not prefabrication in general.

The caisson technique is not new.

It’s not caisson either. How about understanding the conversation and questions being asked before jumping in with dismissive (incorrect) answers?

? This is not caisson construction.

It's what the construction consortium writes they are doing [1]. Looks like it too?

[1] https://www.betoningenieure.de/dateien/FT2018/Seiten/fehmarn...

What that shows is the mold that is used to make the tunnel segments.

A Caisson is like an upside down boat turned into a diving bell that is used to get access to the seafloor.

https://en.wikipedia.org/wiki/Caisson_(engineering)

Famously used in the construction of the Brooklyn Bridge

https://fromthepublicdomain.com/2020/08/26/the-brooklyn-brid...

10 minute documentary on Brooklyn Bride https://www.youtube.com/watch?v=Ct_-0GC_QfM

The Ken Burns' documentary is really worth a watch, https://en.wikipedia.org/wiki/Brooklyn_Bridge_(film)

https://www.pbs.org/kenburns/brooklyn-bridge/

I think this might be a translation issue - the German Senkkasten is literally "sinking-box," so maybe it does apply to structures like these segments too? But the English caisson only means the diving-bell things.

Yes it must be lost in translation somehow, in Italian also "cassone" is both the "diving bell" thingy and the "sinking box".

The Mose in Venice (though it is a sort of foldable dam) has inside a tunnel for maintenance and it was built in a similar way:

https://www.mosevenezia.eu/cassoni/

> But the English caisson only means the diving-bell things.

https://en.wikipedia.org/wiki/Caisson_(engineering) disagrees. It distinguishes between box caissons and open caissons.

That's still not what's being used here.

I think it's the only way to do it: https://en.wikipedia.org/wiki/Immersed_tube#Construction

looking at videos YT is suggesting, which are mostly about construction of underwater tunnels, it seems it's common

How do they join the tunnel segments to each other? How do they properly seal it? The video glosses over that part.

Grout. Inject grout between the units from a pontoon, ROV or diver to guide.

When dry, inside can detach a bulkhead, remove surplus grout from new unit, and remove it's bulkhead in turn. It's shallow water so doesn't need high pressure resisting caulk seals to be mostly watertight.

They say 15mm tolerance. You could butt fit rubber or polystyrene foam to keep things mostly OK and.. grout.

They must not be in an earthquake zone. The BART transbay tunnel has giant rubber flexible joints between segments.

> They must not be in an earthquake zone

It's between Denmark and Germany. You can look it up. No, it isn't in an earthquake zone.

Earthquakes are overrated. See https://en.wikipedia.org/wiki/Seikan_Tunnel#Maintenance

They probably do have these too. Given time everything moves.

I'm curious about the seals between sections. How they do that?

It seems that they have rubber gaskets on the ends. Once the sections are in place, friction (from the foundations and overburden of that segment and the rest of the tunnel) would hold it in place. There do also seem to be systems that have cables to keep the segments in tension.

https://www.penta-ocean.co.jp/english/business/civil/crawnci...

and how is the bulkhead removed?

Especially s bulkhead that's between two segments that are both underwater.

I'm assuming the bulkhead is secured inside the tube. Once complete you enter at the end of the tube (on landside) and sequentially go through removing each bulkhead from the inside of the tube.

How exciting this would be to cycle through the tunnel once the tunnel is completed but not yet released to public (car) traffic? Near Hamburg people enjoy riding their bikes on a nearly completed section of a new motorway although it's strictly forbidden.

My number one question is how they plan to dredge the seabed and keep that surface flat enough for the tunnels to sit on. connecting with millimeter precision would require a flat surface, no? Fascinating.

2 million+ tons of emitted CO2 mostly from the Portland concrete elements.[0] We really need to find some low-carbon alternatives that are structurally and economically feasible.

Hope it's worth it.

[0]: [pdf] https://vvmdokumentation.femern.dk/39.%20E6TR02217843.pdf?fi...

At $200/tonne (a reasonable minimum price that we should be paying for CO2 emissions), you'd be looking at $400 million budget increase on a project with a budget roughly 8.5 billion USD 7 years ago [1]. It wouldn't make or break the project.

If we want people to start taking CO2 into consideration when designing projects, it needs to have a cost associated with it. Ideally that cost should be used to offset the CO2 emitted. It wouldn't solve any issue but it will incentivize solutions that use less CO2.

[1] https://femern.com/finance/

When it's the government doing the building, where is the money going to actually go? Are there readily available carbon capture facilities operating right now at commercial scale?

400 million would fund a lot of emissions reductions (obvious ones like improving residential/commercial efficiency with insulation, adding more renewable energy, and less obvious ones like improved grid interties, etc). CCS is not real yet (though if there was $200/t on the table, it would be more likely to come around).

The real positive impact it would have though is incentivizing lower carbon development: if traditional concrete has unpriced carbon emissions, there's no incentive for a design to specify using a low carbon alternative that might cost slightly more.

$200/tonne is far above "reasonable minimum price" for CO2 emissions. Average estimate is closer to $50/tonne. At $200/tonne, you're entering "viable air capture of CO2" territory.

> At $200/tonne, you're entering "viable air capture of CO2" territory.

Yes. Since the issue is we've emitted too much CO2, the solutions are either to not emit it, or to remove it after emission. You set the price to whatever the actual cost is to remove it, and that lets the person do the emitting decide if it is worth it to emit, or if it would be cheaper to use an alternative. I view that as the reasonable minimum price.

If we were looking to go carbon-negative to start to undo decades of harm, you would want the carbon price to be higher than the removal cost.

> Average estimate is closer to $50/tonne.

Where did this number come from? I've never heard it. It doesn't line up with the goals of Canada ($50 this year, targeting $170/t in 2030), and the spot price in the EU was 85 euro in December.

> Since the issue is we've emitted too much CO2, the solutions are either to not emit it, or to remove it after emission.

There are more than just these two options. For example, you can capture CO2 at the emission site, which is much cheaper than doing the same after it dissipates to low concentration in the atmosphere.

> If we were looking to go carbon-negative to start to undo decades of harm, you would want the carbon price to be higher than the removal cost.

While preventing future bigger changes to climate might be worthwhile, I for one believe that imposing enormous burden on entire world just so that we revert to CO2 levels from, say, 1950, is simply not worth it. Say what you want about future climate “catastrophe”, but as of today, we are just fine.

> Where did this number come from? I've never heard it. It doesn't line up with the goals of Canada ($50 this year, targeting $170/t in 2030)

See eg.

https://www.edf.org/true-cost-carbon-pollution

https://www.irena.org/-/media/Files/IRENA/REmap/Methodology/...

Etc. The figures you are quoting are just politicians trying to get more tax money through climatewashing, these have nothing to do with actual externalities of GHG emissions or with mitigations.

> For example, you can capture CO2 at the emission site, which is much cheaper than doing the same after it dissipates to low concentration in the atmosphere.

If this project captured the emissions at the site, then they wouldn't have to pay the hypothetical carbon fee. That would be a reasonable option for the designer to consider (along with low carbon concrete or just building it and paying whatever fee it would entail)

> While preventing future bigger changes to climate might be worthwhile, I for one believe that imposing enormous burden on entire world just so that we revert to CO2 levels from, say, 1950, is simply not worth it. Say what you want about future climate “catastrophe”, but as of today, we are just fine.

The climate is an inherently unstable system - we're still dealing with the effects of carbon emissions from decades ago. If we stopped all carbon emissions now, the climate wouldn't stabilize for centuries or millennia.

> https://www.edf.org/true-cost-carbon-pollution

From your source, "The current central estimate of the social cost of carbon is over $50 per ton in today's dollars. While this is the most robust and credible figure available, it does not yet include all of the widely recognized and accepted scientific and economic impacts of climate change. For that reason, many experts agree [PDF] this is far lower than the true costs of carbon pollution."

> https://www.irena.org/-/media/Files/IRENA/REmap/Methodology/...

Dated literature review, relying largely on a US government document from 2013, which was itself updated in 2016 for being inaccurate

The IPCC was estimating 135-5500/t in 2018, though criticism was fairly levelled that current economic models can only estimate impact of implementing moderate carbon costs. https://www.resources.org/archives/latest-ipcc-report-sounds...

> The figures you are quoting are just politicians trying to get more tax money through climatewashing, these have nothing to do with actual externalities of GHG emissions or with mitigations.

Disagree strongly. Also, the carbon market in the EU and the climate costing in Canada - neither of them goes into general tax coffers.

Looking at https://ember-climate.org/data/carbon-price-viewer/, in the EU, it’s about €80 per ton at the moment. At current exchange rates, that’s about $90.

It's worth considering the difference in CO2 emissions from the longer transit routes that would have previously been taken. Over the life of this tunnel, the net CO2 emissions are likely negative.

Very cool, In Norway they are considering creating a floating tunnel that is held up with giant floating bois tederet to the ground because some places the sea is just to deep and steep. Anyway here is a video, dunno about current status: https://youtu.be/Gt1MDQHLjF8?t=26

This would almost certainly require some advanced sea traffic mitigation. See the Sunshine Skyway Bridge Tragedy [1]. Even with openings for vessels, there's a real threat by large vessels.

[1] https://en.m.wikipedia.org/wiki/Sunshine_Skyway_Bridge

> there's a real threat by large vessels.

Which is a bit weird: Why have those pontoons on the surface in the first place? They could provide just as much buoyancy if they were tethered just above the tunnel itself, at a depth of some tens of meters. Or below it, pushing upwards in stead of pulling. (This would also avoid any potential problems with ice dragging them sideways in the winter.)

I was just thinking, when was the last time we did something like this in the US? The California rail project has been going on for years, no one dares to even suggest building something like this. All great bridges were built over 50 years ago. If you suggest to do something major in the Bay Area, you would be booo'ed into oblivion for a mere suggestion.

In the NYC area off the top of my head there's been the Tappan Zee bridge, the East Side Access project bringing the Long Island Rail Road into Grand Central Terminal, and 2nd Ave Subway Phase 2. Penn Station Access is being discussed, as is the Triboro RX line.

ETA: If you're curious NYC has a dashboard of capital projects >$25 million here: https://www1.nyc.gov/site/capitalprojects/dashboard/dashboar.... I think the complaint that we don't build anything in this country anymore is sometimes overstated.

ESA and 2nd Ave Subway Phase 2 are kind of the poster children of what's wrong with American infrastructure projects.

ESA was started in 2006 and planned to be finished in 2009 at the cost of $4.3B. It is now projected to be finished in 2023, at a cost of $12B.

Phase 2 of SAS costs $6B despite the fact that most of the tunnel actually already exists, and won't open until possibly 2029.

It's not even really about saving money to save money, but the high costs of these projects suck money away from other projects and needs. It's basically unfathomable at these prices for NYC to do something like Paris and build out 200 km (124 mi) of metro in the next decade.

The East Side Access is also a project that would never be built in Europe. What they should've done is built a through-tunnel through Manhattan connecting Long Island Railroad and New Jersey Transit, with two or three smaller stations across midtown.

Basically, instead of ESA and (ultimately cancelled) Gateway projects, calling for new tunnels connecting to giant carvern terminuses in the city, u connect these projects into one long tunnel without terminuses.

A terminus requires a lot of platforms and tracks because trains need to get completely emptied and turned around. If you stop at multiple stops and terminate at the other end of the city, you can do that a that a place where's plenty of space (or multiple different points). You also spread the passenger loads across multiple stations, meaning less passenger flow per station, less dwell time for trains (=higher frequency), and people will be closer to where they need to go (i.e. you can connect to all subway lines in Manhattan).

The eastern span of the SF-Oakland Bay Bridge was rebuilt (checks notes) a decade ago.

Not only is that far more recent than 50 years ago, it's also in the Bay Area.

I'm not sure they are doing that much better than the US. The completion date for this bridge is (currently) estimated at 2029. Fun sequence of sentences from its wiki page...

"and the tunnel idea received support from a large majority of the Danish parliament in January 2011. By 2012, therefore, the completion date had been pushed back to 2021, and in 2014 was estimated to be 2024, and then in 2015 delayed further to 2028. In 2020 it was delayed to 2029."

https://en.wikipedia.org/wiki/Fehmarn_Belt_Fixed_Link

Well, the 2nd Ave subway was first proposed in 1920. It only took them a hundred years to build the first section.

https://en.wikipedia.org/wiki/Second_Avenue_Subway

I absolutely love to complain about the 2nd Ave Subway, but it's worth noting that the "100 year" figure includes ~50 years of NYC mostly just promising to build the line.

Actual construction began in the 70s, and was subsequently suspended for another 20 years because of the city's poor finances. So that gets us closer to a merely ludicrous 30-50 year construction timescale instead of an egregious 100 year one.

NYC Water Tunnel No. 3[1] is somewhat comparable in scale, although not in geologic considerations (NYC is situated on top of solid bedrock, and they're boring directly through it well below ground level).

[1]: https://en.wikipedia.org/wiki/New_York_City_Water_Tunnel_No....

You only have to go back 19 years for the Zakim bridge in Boston.

https://en.wikipedia.org/wiki/Leonard_P._Zakim_Bunker_Hill_M...

The Sunshine Skyway was completed in 1987, under 40 years ago. https://en.m.wikipedia.org/wiki/Sunshine_Skyway_Bridge

Not quite the same scale, but still impressive: https://en.wikipedia.org/wiki/Evergreen_Point_Floating_Bridg...

How much time does this actually save? Just looking at the crude map it doesn't like like a huge amount? Like slightly more than cutting a rectangle into a hypotenuse (idk the term, like cut into triangle, the new long edge, still shorter than the other two combined)

VERY cool though

The new train line is going to be 160km shorter while also allowing higher speeds. Trains between Hamburg and Copenhagen are projected to take less than 2:30h, down from 4:40h today.

That's pretty good. Especially if it saves energy on trains. but the cost is HUGE for 2 hours.

It's 2 hours times the number of passages through the tunnel. Hint: there will be more than a single passage.

Jokes aside, there are sometimes rail projects where millions are spent to save 2 minutes. Or even just tens of seconds. Over the lifetime of the infrastructure it is still worth it, especially when combining multiple projects.

2 hours savings is huge. You won't find many infra projects with those kind of time savings.

It is a cost that will probably amortize itself easily over the decades it will be in service.

Train from Copenhagen to Hamburg goes from 4.5 to 2.5 hours. As a Swede, this makes vacations to the continent via car or train much more attractive.

That sounds really nice! I wish we had train network in the US. Though I get the country is huge but so is Europe from tip to tip.

You do. It's just not used for PAX, besides a few exceptions. Look for Class 1 Railroad on Wikipedia, and compare freight to passenger trackage.

> Like slightly more than cutting a rectangle into a hypotenuse (idk the term, like cut into triangle, the new long edge, still shorter than the other two combined)

Diagonal. The word you were looking for is diagonal. :-)

There is a Rødby-Puttgarten ferry route. The ferry takes 45 minutes. In the daytime there are two departures/hour in each direction. On busy days you need a reservation.

The ferry cost about three times as much as the fee for the Great Belt bridge to Fyn, so people use the ferry because they still save a couple of hours, depending on traffic.

So the bridge will make a huge difference.

Could probably turn that production facility into a lucrative business if those tunnel segments could be transported down the coast / into the Mediterranean.

Concrete is ALWAYS produced locally, unless there is a very good reason not to. Shipping it is not cheap.

Conversely so many buildings are made out of blockwork, and I don’t know if those concrete blocks are manufactured particularly locally.

They almost always come from a foundry within 200-500 miles, yes.

That's shipped via road though isn't it? Barging would be immensely cheaper for long distances

precast and otherwise pre-fabricated concrete has been in use for about as long as there's been concrete.

Sure - and it's generally sourced from the closest concrete foundry possible, unless there is something exceptional about the design of the units which make that impossible. When I researched this in undergrad ~2006 90+ % of all concrete was sourced within 300 or 400 miles, iirc.

Ah I think I misunderstood what you meant by 'local'.

I remember this project being controversial back in the day. I wonder what the locals think of that today. Definitely impressive technology.

Local here. We were told to enjoy about 60 additional freight trains per day. The promised noise protection barriers were saved on due to budget after public voting went through.

Interestingly the ferry which is currently used to transport trucks is only at roughly half capacity.

It is a prestige project and I will have to move to some other place as I live next to the train tracks. These are used very sparingly today and are mostly not even electrified and one-tracked. Many wildlife refuges are on the way to move for the sake of the new tunnel.

I think it has to be looked at from a greater picture. I previously lived in Skåne in Sweden, from there I could get to Gothenburg in little over 2 hours and Stockhholm in like 4 and a half, with the slow high speed trains in Sweden running at a maximum of 200 km/h.

By distance from Malmö to Hamburg is a bit farther than to Gothenburg and Berlin is a bit closer than Stockholm, with the forced dogleg of going through the Fehmarn Belt. By air it would be like Leipzig. That is how far into Germany you get.

It is simply ridiculous that the only way I could think of to get to the larger cities in northern Germany would be to fly. Take the train to Copenhagen airport and likely Ryanair or something similarly awful costing less than the ticket to the airport.

Sure I could look up some train travel with a multitude of changes through Denmark, likely taking the train on the ferry. Or an over night sleeper style, if they even run. I know there's been talk of them starting again.

It's 2022, there should be high speed links.

It would be one change of train, in Copenhagen, to get from Malmö to Hamburg. The faster train used to go on the ferry, but it's diverted through Jutland while they're upgrading the tracks for this tunnel.

The new-ish night train runs direct from Malmö, but only in some months of the year. (A seats-only overnight train runs all year from Copenhagen. But that was not fun the one time I used it.)

flixbus

Subjecting myself to 10 hours on a cramped bus isn't what I would call an option.

> Interestingly the ferry which is currently used to transport trucks is only at roughly half capacity.

Sometimes the existing solution doesn't need to be bursting at the seams to justify building something better. A better solution can induce its own demand.

Yes I imagine most of the traffic goes through the bridge in Denmark. What is more, that bridge is a single point of failure, which is a problem in case of an accident or maintenance.

You might find the electric freight trains are quieter than you expect. I did, in a place I lived in England.

There's a rail noise map for some lines in Denmark. Activate Temavælger - Jernbanerstøj - Større Jernbaner 1,5m, and start at Copenhagen Airport, the Øresund line might be similar.

https://miljoegis.mim.dk/modules/mobile/?profile=noise

That is too bad, maybe they can still add in the sound proofing.

I think that ferry was the first one I'd been on with train tracks. One of the times I crossed it we had to get out, walk onto the ferry, then get on the train.

The better article on this would be "Why the Fehmarnbelt tunnel was not built". Because in Germany you cannot build big public projects in time and within budget. First you have politicians in the way, interfering in the project, with often absurd goals. But even worse, you have competing companies, which litigate contracts after the deadline, so you have to wait 10 years until the courts decided if the contract is valid or not. Costs are 10x higher then of course.

In Denmark this project would have been built in a year, in time and in budget. But unfortunately this involved Germany, so now they have another huge stinking overcost project. Denmark is angry

Is Denmark really angry?

About construction delays and politicians getting in the way etc., I can only think of BER as a catastrophic project. Do you have more in mind?

Stuttgart21 is also extremely late, over budget, and controversial enough that it's considered a reason why the Greens won city council in Stuttgart, marking their first ever majority council in a major German city.

In Cologne a tunnel collapsed during construction, killing two people: https://en.wikipedia.org/wiki/Cologne_Stadtbahn#Tunnel_colla...

Sure they are. They approved it 2011. Germany just now, halfways.

https://www.tunnel-online.info/en/artikel/tunnel__3596417.ht...

But apparently it's again stopped: https://www.dredgingtoday.com/2022/01/19/leipzig-court-tempo...

Overview: https://en.wikipedia.org/wiki/Fehmarn_Belt_Fixed_Link

There should be better articles about the cost overruns.

There was news recently that the environmental survey was not done as thoroughly as it should have been and that they were building (or planning to build) through areas where actually so far undiscovered reefs are. A court awarded an injunction to hold work there for now if I recall correctly. I can't image that it is that popular.

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