With just 16km, this is not by any stretch going to be the world's second-longest tunnel, just the world's second-longest road tunnel. The longest tunnels are rail tunnels, which measure up to 57km (Gotthard base tunnel), and if you count subway tunnels the longest is Guangzhou metro line 3 with 60km. (https://en.wikipedia.org/wiki/List_of_long_tunnels_by_type#U...)
Wow, it's pretty fun to read a completely positively spun article about something that's been heavily criticized locally.
The highway in question has been a weird-ass pet project since the 60's. It's been routinely denied and shelved many times, but after Stockholm implemented congestion tolls in 2006, it had a resurgence.
Originally it was all aboveground and bridges, but the reason it's now morphed into the longest road tunnel project in Sweden, is because the response to every small NIMBY protest has been "fine, we'll dig it down, but it'll cost more". Note that it's still aboveground in some places, and in something that I'm sure is pure coincidence, those areas are among the least affluent residential areas of Stockholm. Note that everyone living above the tunnels will still get to enjoy years of underground rock blasting, I'm sure that'll be fun.
And since almost the entire highway is now in a tunnel, and since it's going to be the longest in Sweden, the budget has gone up dramatically. How to finance it? Oh, our glorious politicians decided to use money from the congestion tolls. Never fucking mind that the initial promise of those were that the funds were going to be used solely for public transportation projects and improvements - things that would actually solve congestion. But all of that is now put on hold for the next 10-20 years, because this one road eats all the budget.
Yet another criticism is that the highway doesn't really solve the problem, because there's actually very little existing traffic that goes between the points it will connect. Truck transports from the south of Sweden to north of Stockholm take different routes already, they don't go through Stockholm. So you won't get rid of all the heavy traffic that's currently congesting the E4, because most of that is actually going into or out of Stockholm. All the ports of Stockholm are over on the east side of the city. Yes, if you live in the far west suburbs of Stockholm, you now get an easy way of going to the southern suburbs, good for you, but that's going to increase total traffic, not decrease it.
But the most annoying thing about the project is that in this latest round where a ton of challenges forced it underground into tunnels, which resulted in significant increases in cost and time, noone has re-evaluated what the traffic situation in Stockholm is going to be like in 2026 when it's estimated to be completed. (Note: Of course it won't be completed in time or on budget, so 2026 is highly optimistic already). Here on Hacker News there's regularly articles about our glorious new electrically powered autonomous rideshare future of transportation, but this highway project doesn't take any of that into consideration. They're just assuming that traffic will increase like it has the past few decades, they're assuming it's going to be 100% ICE-powered human-driven cars. And yet you have articles like this which heaps praise on the environmental concerns and solutions of yet another ridiculously expensive highway that noone really needs or wants.
Yet another criticism is that the highway doesn't really solve the problem, because there's actually very little existing traffic that goes between the points it will connect.
The route between Kista and Huddinge is perhaps one of worst traffic route in entire Country. This is because there is HUGE traffic almost 8-9 hours a day on this route. I drive this route twice a month and its horrible. So I don't know who told you that there is very little existing traffic here.
I was thinking the same thing reading the article. The traffic situation in Stockholm is terribly inefficient, and seems to me marred with short sighted political decisions possibly stemming from these projects being vanity projects more than they are solutions to anything. (I'd like to add that I believe this applies to parties of all color.)
The congestion charge backtracking is an egregious example of politicians breaking their promises, definitely agree with this as well.
Anyone have insight into different tunnel-building technologies? In particular, when is a boring machine a more appropriate solution than drilling-and-blasting?
It's complicated and I'm not an expert, but I understand the main risk with TBMs is running into a type of rock it can't handle and suddenly having a multi-million dollar paperweight wedged in a very awkward location. They're also not well suited to really hard rock, which requires frequent cutter replacements.
In this case, the tunnel is very long and deep, magnifying the unknown territory risk. Also, the bedrock in most of Scandinavia (and, I presume, Stockholm) is both very shallow and mostly granite, which is extremely hard and thus not a good fit for a TBM.
Source: My childhood in Helsinki was punctuated by the periodic sound of blasting rock as they cut out what was supposed to be the new central station. Overall, Helsinki is basically granite Swiss cheese due to parking garages, pedestrian tunnels, basements, bomb shelters, military tunnels, the metro etc and AFAIK all of it has been drilled and blasted, not TBM'd.
The cross section of those Stockholm tunnels (I know, I actually worked on a few tenders for them) is very wide and flat.
Generically speaking for a TBM to be competitive you need to have a "minimal" length of tunnel, a TBM has huge - really huge - mounting/assembling (and later disassembling) costs and quite a lot of space at both ends of the tunnel.
Specifically, both (they are two tenders, E302 and E308) tunnels have not a "direct access", there are two "service tunnels" (of a much smaller cross section, rather "steep" and non-linear) that allow access to the main tunnels from the outside, and the outside area available is anyway small, so a TBM could not have been used anyway, even if the cross section wasn't so "flat".
Back to generically speaking, the rules of thumb (approximate, only to give you an idea) for choosing NOT a TBM are:
1) anything shorter than 5-7 Km
2) anything larger than diameter 12 m or not round or simil-round
3) anything in terrains that are too "hard" or too "soft" [1]
To give you a rough approximation, a (single bore) tunnel made with traditional excavation can have a production of 100-120 m/month, a TBM can usually dig around 400 m/month, so it is much faster.
There are also "mixed mode" approaches, where you (quickly) bore a smaller "pilot hole" in the center of the tunnel by means of a small TBM, usually 3.8 or 4 meters in diameter, so you have a 1:1 representations of the terrains and can (from the small bore) perform any kind of consolidation/impermeabilization etc., then you enlarge the hole by traditional blast and drill.
The much reduced amount of explosives needed for enlarging the hole and a great semplification in the ventilation plant , besides the possibility to always work on "known" terrain make this a very good approach in my experience, and the blast and drill enlargement of the pilot hole is much faster than "full face" excavation, the same rough estimate is around 150-180 m/month.
[1] or more generally where large variations in the nature of terrain is expected, a TBM for "soft" is different from one for "hard" and viceversa
Mining guy here. It 95% cost. TBM is great if you have money and are going through residential type areas, can get through most rock, not as nimble though.
Drill and blast are the most common by far, especially in mining industry where they are lots of twists and turns, and no-one cares about noise etc.
On the topic of Swedish tunnels there's the one through Hallandsås, where three (?) different construction companies tried. Several tunnel boring machines got stuck in the soft rock, cows died from water poisoning, and the whole thing was delayed more than 100% of the estimated project time. Fascinating story.
> Additionally, the original drill, which was said to drill 100 meters per week, broke down after drilling only 18 m (59 ft). The rock was too soft, so the machine could not use it to pull itself forward. The contractor tried to drill traditionally, but had to spend a lot of effort on sealing the water leaks. The contractor went bankrupt and a new contractor, Skanska, was contracted. The new contractor had similar trouble but a better contract that gave compensation for troublesome rock conditions.
TBMs are way more expensive up-front but allow little to no disturbance of the surroundings, and can produce smooth walls & line it as they go.
TBMs can also bore in soil or sand.
Aside from disturbance and raw feasibility (not sure you can D&B underseas) the main split point is going to be the length of the tunnel. TBMs mean large up-front fixed cost but have a lower price per distance and higher time efficiency, so D&B is more suitable for shorter tunnels (how short will also depend on the diameter you need).
That aside, TBMs are awesome, I got to visit one as a kid (the operator gave tours of the TBM during the few weeks of work prep' before digging actually started in earnest) and it was a great experience, they're impressive bits of machinery & technology.
> "The harder and stronger the rock is, the quicker we advance."...
I like how counter-intuitive is this statement.
I used to live in a place where the soil was part of a river delta. It was really easy to drill but impossible to keep the tunnel in place and free of water. And it sometimes just sinks the above-ground facilities: https://www.20minutos.es/fotos/actualidad/24-horas-en-fotos-...
> ..."Drilling and blasting isn't so time-consuming, but sealing the rock from water leakage is. If the rock is very fractured, we need a lot of concrete sealant or reinforcement columns to ensure integrity," said Brantmark, describing the work of the three Atlas Copco Drill machines in use.
Yeah, this is why there is constant talk of a tunnel connecting Helsinki and Tallinn and/or Stockholm and Turku.
The distance is much more than the channel tunnel, and the population that would use it is much less, but it might still be feasible simply because it could be routed almost entirely through hard granite. In Helsinki a lot of the kind of infrastructure that is placed above ground basically everywhere else is being dug underground simply because the cost of digging is less than the cost of land, and so everything that doesn't need windows gets sunk in the rock. And when you dig, you actually get to recoup some of your expenses by selling the stone you quarry...
That's by the way the reason there are so many tunnels in Stockholm but very few in Göteborg. It is very easy (relatively speaking) to dig tunnels through granite but very hard through muddy sediment. Some tunnels are still being dug in Göteborg but they are much more expensive than in Stockholm.
Nowadays, one of the main problems of digging in Stockholm is that there are already so much stuff dug out that it is hard to find room for new tunnels!
I lived in Solna for half a year, then Tyreso and Lappis for my studies. Do you know if the blue line stations also used this kind of sealing, or is that something new they're doing?
This brings up the question of whether or not there's a good list of long road tunnels you can drive through? I'd love to cruise through one of these bouncing off the rev limiter, just for the fun of it :)
[+] [-] nstom|8 years ago|reply
[+] [-] ttkari|8 years ago|reply
[+] [-] maljx|8 years ago|reply
[+] [-] sctb|8 years ago|reply
[+] [-] germainelol|8 years ago|reply
[+] [-] speps|8 years ago|reply
[+] [-] Gustomaximus|8 years ago|reply
[+] [-] chha|8 years ago|reply
[+] [-] henrikschroder|8 years ago|reply
The highway in question has been a weird-ass pet project since the 60's. It's been routinely denied and shelved many times, but after Stockholm implemented congestion tolls in 2006, it had a resurgence.
Originally it was all aboveground and bridges, but the reason it's now morphed into the longest road tunnel project in Sweden, is because the response to every small NIMBY protest has been "fine, we'll dig it down, but it'll cost more". Note that it's still aboveground in some places, and in something that I'm sure is pure coincidence, those areas are among the least affluent residential areas of Stockholm. Note that everyone living above the tunnels will still get to enjoy years of underground rock blasting, I'm sure that'll be fun.
And since almost the entire highway is now in a tunnel, and since it's going to be the longest in Sweden, the budget has gone up dramatically. How to finance it? Oh, our glorious politicians decided to use money from the congestion tolls. Never fucking mind that the initial promise of those were that the funds were going to be used solely for public transportation projects and improvements - things that would actually solve congestion. But all of that is now put on hold for the next 10-20 years, because this one road eats all the budget.
Yet another criticism is that the highway doesn't really solve the problem, because there's actually very little existing traffic that goes between the points it will connect. Truck transports from the south of Sweden to north of Stockholm take different routes already, they don't go through Stockholm. So you won't get rid of all the heavy traffic that's currently congesting the E4, because most of that is actually going into or out of Stockholm. All the ports of Stockholm are over on the east side of the city. Yes, if you live in the far west suburbs of Stockholm, you now get an easy way of going to the southern suburbs, good for you, but that's going to increase total traffic, not decrease it.
But the most annoying thing about the project is that in this latest round where a ton of challenges forced it underground into tunnels, which resulted in significant increases in cost and time, noone has re-evaluated what the traffic situation in Stockholm is going to be like in 2026 when it's estimated to be completed. (Note: Of course it won't be completed in time or on budget, so 2026 is highly optimistic already). Here on Hacker News there's regularly articles about our glorious new electrically powered autonomous rideshare future of transportation, but this highway project doesn't take any of that into consideration. They're just assuming that traffic will increase like it has the past few decades, they're assuming it's going to be 100% ICE-powered human-driven cars. And yet you have articles like this which heaps praise on the environmental concerns and solutions of yet another ridiculously expensive highway that noone really needs or wants.
[+] [-] tegeek|8 years ago|reply
The route between Kista and Huddinge is perhaps one of worst traffic route in entire Country. This is because there is HUGE traffic almost 8-9 hours a day on this route. I drive this route twice a month and its horrible. So I don't know who told you that there is very little existing traffic here.
[+] [-] mstade|8 years ago|reply
The congestion charge backtracking is an egregious example of politicians breaking their promises, definitely agree with this as well.
[+] [-] jamesblonde|8 years ago|reply
[+] [-] Sharlin|8 years ago|reply
[+] [-] jpatokal|8 years ago|reply
In this case, the tunnel is very long and deep, magnifying the unknown territory risk. Also, the bedrock in most of Scandinavia (and, I presume, Stockholm) is both very shallow and mostly granite, which is extremely hard and thus not a good fit for a TBM.
Source: My childhood in Helsinki was punctuated by the periodic sound of blasting rock as they cut out what was supposed to be the new central station. Overall, Helsinki is basically granite Swiss cheese due to parking garages, pedestrian tunnels, basements, bomb shelters, military tunnels, the metro etc and AFAIK all of it has been drilled and blasted, not TBM'd.
[+] [-] jaclaz|8 years ago|reply
There is also a "form factor".
TBM's dig "round" holes.
The cross section of those Stockholm tunnels (I know, I actually worked on a few tenders for them) is very wide and flat.
Generically speaking for a TBM to be competitive you need to have a "minimal" length of tunnel, a TBM has huge - really huge - mounting/assembling (and later disassembling) costs and quite a lot of space at both ends of the tunnel.
Specifically, both (they are two tenders, E302 and E308) tunnels have not a "direct access", there are two "service tunnels" (of a much smaller cross section, rather "steep" and non-linear) that allow access to the main tunnels from the outside, and the outside area available is anyway small, so a TBM could not have been used anyway, even if the cross section wasn't so "flat".
Back to generically speaking, the rules of thumb (approximate, only to give you an idea) for choosing NOT a TBM are:
1) anything shorter than 5-7 Km
2) anything larger than diameter 12 m or not round or simil-round
3) anything in terrains that are too "hard" or too "soft" [1]
To give you a rough approximation, a (single bore) tunnel made with traditional excavation can have a production of 100-120 m/month, a TBM can usually dig around 400 m/month, so it is much faster.
There are also "mixed mode" approaches, where you (quickly) bore a smaller "pilot hole" in the center of the tunnel by means of a small TBM, usually 3.8 or 4 meters in diameter, so you have a 1:1 representations of the terrains and can (from the small bore) perform any kind of consolidation/impermeabilization etc., then you enlarge the hole by traditional blast and drill.
The much reduced amount of explosives needed for enlarging the hole and a great semplification in the ventilation plant , besides the possibility to always work on "known" terrain make this a very good approach in my experience, and the blast and drill enlargement of the pilot hole is much faster than "full face" excavation, the same rough estimate is around 150-180 m/month.
[1] or more generally where large variations in the nature of terrain is expected, a TBM for "soft" is different from one for "hard" and viceversa
[+] [-] rmm|8 years ago|reply
Drill and blast are the most common by far, especially in mining industry where they are lots of twists and turns, and no-one cares about noise etc.
[+] [-] mrmanner|8 years ago|reply
> Additionally, the original drill, which was said to drill 100 meters per week, broke down after drilling only 18 m (59 ft). The rock was too soft, so the machine could not use it to pull itself forward. The contractor tried to drill traditionally, but had to spend a lot of effort on sealing the water leaks. The contractor went bankrupt and a new contractor, Skanska, was contracted. The new contractor had similar trouble but a better contract that gave compensation for troublesome rock conditions.
https://en.m.wikipedia.org/wiki/Hallands%C3%A5s_Tunnel
[+] [-] masklinn|8 years ago|reply
TBMs can also bore in soil or sand.
Aside from disturbance and raw feasibility (not sure you can D&B underseas) the main split point is going to be the length of the tunnel. TBMs mean large up-front fixed cost but have a lower price per distance and higher time efficiency, so D&B is more suitable for shorter tunnels (how short will also depend on the diameter you need).
That aside, TBMs are awesome, I got to visit one as a kid (the operator gave tours of the TBM during the few weeks of work prep' before digging actually started in earnest) and it was a great experience, they're impressive bits of machinery & technology.
[+] [-] kartan|8 years ago|reply
I like how counter-intuitive is this statement.
I used to live in a place where the soil was part of a river delta. It was really easy to drill but impossible to keep the tunnel in place and free of water. And it sometimes just sinks the above-ground facilities: https://www.20minutos.es/fotos/actualidad/24-horas-en-fotos-...
> ..."Drilling and blasting isn't so time-consuming, but sealing the rock from water leakage is. If the rock is very fractured, we need a lot of concrete sealant or reinforcement columns to ensure integrity," said Brantmark, describing the work of the three Atlas Copco Drill machines in use.
Now I live in Stockholm and it's pure rock. These are pictures from the subway: https://www.boredpanda.com/stockholm-metro-art-solna-centrum...
[+] [-] Tuna-Fish|8 years ago|reply
The distance is much more than the channel tunnel, and the population that would use it is much less, but it might still be feasible simply because it could be routed almost entirely through hard granite. In Helsinki a lot of the kind of infrastructure that is placed above ground basically everywhere else is being dug underground simply because the cost of digging is less than the cost of land, and so everything that doesn't need windows gets sunk in the rock. And when you dig, you actually get to recoup some of your expenses by selling the stone you quarry...
[+] [-] bjourne|8 years ago|reply
Nowadays, one of the main problems of digging in Stockholm is that there are already so much stuff dug out that it is hard to find room for new tunnels!
[+] [-] black_puppydog|8 years ago|reply
[+] [-] ajeet_dhaliwal|8 years ago|reply
[+] [-] Sharlin|8 years ago|reply
[+] [-] henrikschroder|8 years ago|reply
[+] [-] zeristor|8 years ago|reply
https://en.wikipedia.org/wiki/Stad_Ship_Tunnel
[+] [-] tristor|8 years ago|reply