51–60 of 102 posts
> The Fehmarnbelt Tunnel will complete the high-speed rail connection between Stockholm and Hamburg. Not really, mostly cause Sweden don't want to build high speed rail, even when EU would have paid for a big share of it.
Very nice video explainer https://public.skyfish.com/p/sundogbaelt/2675422/70675433?pr...
> The Fehmarnbelt Tunnel will complete the high-speed rail connection between Stockholm and Hamburg. Not really, mostly cause Sweden don't want to build high speed rail, even when EU would have paid for a big share of it.
Most of the Malmö Stockholm line is 200km/h plus (see https://commons.wikimedia.org/wiki/File:Map_of_Swedish_railw... ) and that’s generally seen to be where “high-speed” starts. But yes, they could do a lot better.
Hmm, website owners can apparently mess with my settings and make their site "smooth scrolling". Ugh. It's like having a nightmare where I'm trying to scroll as hard as I can but I feel like I'm scrolling through mud. It actually feels like they have a speed limit to scrolling, I'm used to giving my MX Master 3S a big spin and being at the bottom of a page near instantly, here it takes time.
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A video posted in another thread says the segments are sealed with bulkheads, floated into position, submerged by allowing water into a ballast section, dropped into place , aligned with pins, drawn to the next segment with hydraulic jacks, and sealed to it with rubber gaskets. Then the bulkheads can be removed. The gaskets also allow for some thermal expansion. I'm curious what the lifetime of those gaskets might be…
They are GINA gaskets[0], they were supposed to last 120 years[1], but it has recently been shown that they may deteriorate faster than previously expected due to being under constant compression[2][3] [0] https://www.trelleborg.com/en/marine-and-infrastructure/medi... [1] https://www.trelleborg.com/marine-and-infrastructure/-/media... [2] https://www.sciencedirect.com/science/article/abs/pii/S08867... [3] https://da…
https://www.trelleborg.com/marine-and-infrastructure/-/media...
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Here's a similar video for BART's Transbay Tube, which was built in a similar way.[1] The major differences come from building in an earthquake zone. The Transbay Tube is mostly steel, rather than concrete, for flexibility. There are expansion joints. And the Transbay Tube sits on a gravel and sand base rather than hard rock, on purpose. The Transbay Tube sections were built in the Bethlehem Steel shipyards in San Fr…
It's not in an earthquake zone, but isn't the Scandinavian continent still rising at a surprisingly fast rate? I wonder if that could affect the engineering of the Fehmarnbelt tunnel, in an "in x years one end of the tunnel will have risen n centimeters compared to the other end" way. It's probably such a small amount it's well within levels where regular maintance will cover it anyway, but I'm still curious.
Not so much that far South in Denmark, but the wikipedia article mentions a lake in Sweden that has its shores rebounding (moving upwards) at about 2mm per year. The Northern side moves faster so it is effectively tilting.
I'm amazed that engineers can make submerged tunnels work and that leaks don't (literally) sink the whole plan.
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Do you have a source for how little maintenance this will need? I imagine there will be teams of people continually employed for regular maintenance and operations. Concrete does develop “bugs” in the form of cracks, chips, or other damage that needs to be repaired. While software engineering certainly deals with different constraints, I don’t think this is a fair comparison. When stakes are low (as they are for most…
> Do you have a source for how little maintenance this will need? In Germany, twice a year inspection is mandatory for infrastructure [1] but this is only a visual inspection. Once every 6 years you got a large inspection [2] that includes a full go over everything including functionality checks plus a review of documentation (if it is still up to code) and of accident documentation, as well as a "knock test" on ever…
I wonder what the relationship is between the word engineering in the sense used here and software engineering ? I am amazed how bad software engineering has become with constant updates of software because of “improvements” or because there has to be constant release cycle else the software is unmaintained or bad. While this kind of engineering is designed to be untouched for the next 15 to 30 years. Minimal mainten…
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I really hate how German environmental activists resort to hyperbole and alarmist language by default when voicing concerns. This only makes it harder for me to take them seriously. And then there is this tried and true tradition of commissioning studies with the sole intent to support a predefined viewpoint rather than taking an unbiased approach. This makes it so hard to trust any information when political argumen…
Agreed to that, but they are right with stating, that digging up so much ocean soil in a direct line might disrupt entire maritime ecosystems.
Didn't happen. The (fairly small) compensatory digging had the effect the engineers had calculated and the water flow actually increased slightly and the Baltic Sea ecosystem is fine -- or at least not harmed by this particular project.
I think we should trust the people who can (and do) make calculations over those who can't (and don't).